ICPS 2017 |"pathways for grids of The future"

7th International Conference on Power Systems, 2017 | December 21-23rd, Pune, India

Paper Abstracts - Session Wise

20 Secured Relay Operations during Power Swing
Pratim Kundu and Ashok Pradhan
Abstract: Power swing occurs due to imbalance in load and generation. Voltage and current fluctuations during power swing may result in malfunction of distance relays in the network. A system integrity protection scheme (SIPS) based approach is proposed for predicting power swing behavior and initiating preventive measures for secure relay operations in the network. Synchronized data are utilized to calculate equivalent source behind buses in the network. The calculated parameters are used in the power swing equation to predict its effect on the distance relays in the network. Depending on the type of power swing, preventive measures such as blocking/unblocking of relays, change in load/generation and tripping of lines are initiated to avoid distance relay maloperations. The proposed method is tested for New England 39 bus system using simulation data from PSCAD/EMTDC and the results show the effectiveness of the method in avoiding relay maloperations.
153 An Energy Function Approach Utilizing Synchrophasor Measurements for Online Transient Stability Assessment
Saurabh Kesherwani, S. C. Srivastava and Abheejeet Mohapatra
Abstract: At present, the growing interconnected power system networks incorporating renewable energy sources, make the system operation more challenging. Most of the time the system operates near to its security limits. Hence, even a small disturbance may drag the system into unstable operating condition. For the stable and secure operation of the system, online assessment of its stability is very much required. In this paper, an energy function based approach is proposed for online assessment of the system transient stability. The Rate Of Change Of Energy (ROCOE) value is utilized to identify the stability of the system. The time-synchronized phasor measurements, obtained from the Phasor Measurement Units (PMU), are utilized to find the ROCOE. The convergent and divergent nature of the post-fault trajectories of the ROCOE is used to assess the stability condition of the power system. The proposed technique has been validated and tested on WSCC 9 bus system on Real Time Digital Simulator (RTDS).
287 Frontiers of Synchrophasor Solutions Deployment
Vahid Madani, M. Parashar, Anil Jampala and Jay Giri
Abstract: The utility industry at large has made significant investments in deployment of production grade Wide Area Monitoring Systems (WAMS) and synchrophasor technology in recent years, with now well over 4,000 Phasor Measurement Units (PMUs) globally. Some of early real-time PMU applications and visualization being deployed at utility and ISO control rooms include angular separation, oscillatory stability monitoring, islanding, disturbance detection and or voltage stability monitoring applications. While the industry-at-large, foresees the promise that synchrophasors and WAMS hold in modernizing the power grid, and shaping the generation Energy Management Systems, there are some common take-always from these early WAMS installations. This paper summarizes ongoing efforts at Pacific Gas & Electric (PG&E) including a state-of-art Proof of Concept (POC) facility that has been engineered for validating and maturing innovative applications such as PMU-based Real-Time Voltage Instability Indicator (RVII) and Linear State Estimation (LSE) before the applications can be rolled out into the control room. Some of the applications that have been introduced through the POC facility at PG&E are all now available for System Planners, Operational Engineering, and real-time operation use. The paper also describes some of the advances made in overcoming hurdles that had been identified and roadmap to addressing them.
290 Active Distribution Network and Microgrid Integration Strategy
Vahid Madani, Ratan Das and A.P. Meliopoulos
Abstract: Power system dynamics is changing partly due to the large scale deployment of renewable energy sources into the
electric grid. Integration of distributed energy resources (DERs), energy storage, and microgrid have introduced new challenges and opportunities for managing power system operation. Source and load control at the distribution level is quickly becoming a key requirement of this evolving system. Voltage regulation, frequency response baselining, anti-islanding, voltage ride through, and reactive margin support are amongst the technical challenges in the Smart Grid era. Microgrids can be used in conjunction with large scale DER deployment using asynchronous interconnection to the main ac grid. This approach helps to create frequency islands facilitating distributed frequency control and can be helpful in a grid with large scale renewable resources. Centralized protection and control (CPC) within a microgrid can provide significant benefits in achieving this objective. These industry initiatives require a renewed attention to protection, automation and control strategies. This paper discusses the benefit of CPC for more DER integration using microgrid as a component of the solution.
294 Application of Synchrophasor For Protection Co Ordination In An Interconnected Grid
Alok Pratap Singh, Saugato Mondal, Surajit Banerjee and Pritwish Mukhopadhyay
Abstract: Historically Real time vis-a-vis Post facto Analysis of Grid Events had always been carried out across control centers of Indian ISO, POSOCO through array of non-chronologically arranged relays from site complemented with control room available analogue/digital data and Sequence of Events (SoE) from SCADA/EMS and time stamped Disturbance Records (DR) / Event Logger Records (EL). However holistic post-dispatch forensic were limited with issues of data latency, gradualness of updation and skewedness of SCADA data and time drift among the digital recorders due to paucity of absolute time synchronization . Advent of Synchrophasor technology with beaming of time synchronized voltage or current phasors brought a paradigm shift in post-dispatch analysis. Any tripping or switching action or oscillation in a large interconnected complex grid like India have their global foot print not only on local but distant PMUs situated thousands of kilometers away from the loci of event. So each type of fault and resultant response of relaying and protective gear to isolate the fault generate unique signature on voltage, current, frequency or bus angle plots of local and neighboring PMUs. Analysis of signature can reveal instantly any discrepancy in Zone co-ordination of Distance protection or settings of Overflux relay or failures in Auto reclosing. This paper through case studies of PMU signatures envisages ways to detect on real time basis any mal functioning of relaying and protection including wrong settings and coordination.
357 Considerations on Measurement Locations for WAMS Based Linear State Estimation of Power Systems
Gopal Gajjar, Prashant Navalkar and Shreevardhan Soman
Abstract: Wide area monitoring of power systems through synchrophasors is now established technology. There are several ongoing projects throughout the world that utilize WAMS technology for performing state estimation for high voltage
transmission network. This paper highlights some of the aspects that need to be considered while planning and implementing the WAMS for successful execution of state estimation. This paper mainly focuses on the requirements of measurements locations, that would influence the satisfactory operation of state estimation. Each aspect discussed in the paper is illustrated by an example.
Rahul Shukla, Abhishek Gautam, N Nallarasan, S R Narasimhan, U K Verma and K V S Baba
Abstract: The Indian power system operation consists of integrated operation of AC and DC transmission system. HVDC back to back stations were used to transfer power between regional grids when various regions in Indian grid were not synchronised. EHVAC and HVDC based high power corridors helped regions deficit in power to obtain power availability from surplus regions. The skewed distribution of natural resources like coal, natural gas pushed for better connectivity across the grid. Now Indian Power System also has international power transfer with Bhutan, Bangladesh, Nepal & Myanmar in a step forward towards SAARC grid. The interconnection of the grids is an amalgamation of HVDC links (500 kV & 800 kV) and EHVAC (400 kV & 765 kV) lines for both inter regional/national as well as intra-regional power transfer. Synchrophasors at transmission level were first introduced in India in the year 2012 when a total of 14 PMUs were commissioned in Northern, Western & Southern Region however the usage for real-time visualization led to higher role of synchrophasor technology across control centres. However by the year 2017, the number of PMUs installed went up to 77 and with the better visualization tools, the usage of Synchrophasors for real-time operation by the system operator has increased. The enhanced visibility in grid operation with the use of synchrophasors has helped operator in identifying various aspects of integrated operation and take actions in real time. The paper discusses the utilization of synchrophasors in control room application for both real-time despatch and post-despatch analysis.

55 Impact of redox flow battery and capacitive energy storage devices in performance enhancement of restructured AGC of a CCGT incorporated hydro-thermal system
Debdeep Saha, Lalit Chandra Saikia, More Raju and Rumi Rajbongshi
Abstract: This article presents the effect of redox flow battery (RFB) and capacitive energy storage (CES) devices in enhancing the automatic generation control of a combined cycle gas turbine (CCGT) incorporated hydro-thermal power system under realistic restructured scenario. Stochastic fractal search optimized integral minus proportional-derivative with first-order-filter (I-PDF) controller is employed as secondary control for both control areas along with unique control action of CCGT consisting of air-flow and temperature control. Performance comparison of integral, proportional-integral, proportional-integral-derivative and I-PDF controller in absence of RFB and CES establishes the superiority of later. Simulations are carried out for bilateral transactions to investigate the extent of damping oscillations considering the presence of four combinations of RFB and CES namely RFB and CES at both areas simultaneously, RFB/CES at area1/area2 with CES/RFB at area2/area1. Results infer that RFB located at both control areas damps out the oscillations better than the other three combinations.
75 Three Phase Off-board Bi-directional Charger for EV with V2G Functionality
Anjeet Verma and Bhim Singh
Abstract: In this paper, a three phase off-board bi-directional charger is proposed for an electric vehicle (EV). The proposed charger exchanges the active power with utility and provides the reactive power compensation. The operating modes of bi-directional charger are: (i) an active power flow (charging and discharging), (ii) reactive power compensation (inductive and capacitive), (iii) simultaneous charging of EV and reactive power compensation, and (iv) discharging and reactive power compensation. The charger is also capable of operating under unbalance and distorted grid condition. The control of the charger uses the unit templates of point of common interconnection (PCI) voltages for generating the reference grid currents in synchronism with the PCI phase voltages. The harmonic distortion (THD) of the grid current remains within the limits of an IEEE 519 standard for all operating modes. The charger is designed for a 230V (rms) line-to-line (L2L), 50 Hz, three phase supply. The rating of the charger is selected of the order of 6.6 kVA. The performance of the charger is validated under various operating modes and at different dynamic conditions.
186 Application of Self Tuning Filter for Power Quality Improvement in Three-Phase-Three-Wire Distorted Grid System
Prakash Chittora, Alka Singh and Madhusudan Singh
Abstract: In this paper an application of Self Tuning Filter (STF) for power quality (PQ) improvement using shunt active power filter (SAPF) is discussed. In weak distribution system, due to presence of non-linear loads in the vicinity, the supply voltage also gets distorted. So mitigating PQ issues in such systems is a challenging task. The simulation model of STF technique is developed in MATLAB/SIMULINK environment. Extensive simulation results are presented to show the effectiveness of the proposed technique. The control algorithm results in supply currents THD maintained under the limit as specified by IEEE 519. Moreover STF is is discussed in the paper to extract all the harmonics from the load current and fundamental component of grid voltages for proper synchronization of SAPF.
266 A Choice Based Sizing of Storage in Isolated Renewable Energy Systems
Pawan Ghogare and Mangesh Thakare
Abstract: Indian government emphasizes on the use of renewable energy sources to meet energy demands. To meet the gap between energy supply and demand, efficient size of storage is important. This paper analyzes the methodology for sizing of storage in isolated renewable energy systems. It determines the size of components in standalone renewable energy system and storage size. A choice based approach based on the concept of loss of power supply probability is then presented to determine sizing of renewable energy source and its storage for particular load requirement. The solution clearly identifies feasible option in which user has choice to select system size and storage to meet the demand all the time. Two illustrative examples are presented to implement choice based approach.
300 Optimal Day Ahead Strategy Based on Capacity Loss for Battery Energy Storage System
Deshdeepak Sharma
Abstract: In this paper, a day-ahead optimal control scheme is suggested for battery energy storage system (BESS) for its charging/discharing operations. This control scheme keeps the BESS at its mid of maximum and minimum energy storing capability and incorporates capacity loss as an another feature. The cost-to-go function is designed considering battery's constraints and constraint of peak shaving in the power distribution system. A solution considering recursive approach based on dynamic programming is proposed.
332 Assessment of Harmonic Distortion on DistributionFeeders with Electric Vehicles and Residential PVs
Oguzhan Ceylan, Sumit Paudyal, Sudarshan Dahal and Nava Raj Karki
Abstract: Power-electronic interfacing based devices such as photovoltaic (PV) panels and electric vehicles (EVs) cause voltage/current harmonic distortions on the power grid. The harmonic current profiles from EVs and PVs depend on the design of the controllers integrated to the PV inverters and EV chargers. Similarly, the voltage and current harmonic distortions on a grid change throughout the day as the PV output power, number of grid connected EVs, and the other load pattern change. In this context, we present harmonic assessment to demonstrate cumulative effect of large number of EVs and PVs on a medium voltage distribution grid. We will demonstrate the case studies on the IEEE 123-node distribution feeder with 20%, 50%, and 100% PV and EV penetrations, based on time series simulations carried out for an entire day.
367 Comprehensive Review of Control Schemes for Battery and Super-Capacitor Energy Storage System
Rahul Mishra and Rakesh Saxena
Abstract: The energy storage unit of More Electric Aircraft (MEA) comprises of the combination of battery and super-capacitor to handle power imbalances. This energy storage unit charges when there is excessive power is available and can be utilized during power deficiency at the node. Generally, the batteries are used to regulate the DC bus voltage. The preferred batteries i.e. lithium-ion, lead acid etc. have low power density and limited no. of charging discharging cycles. The quick burst of power imposes a stress on battery and reduces its life. The super capacitor has high energy density and therefore it can rapidly supply the quick bursts of demanded power. The power quality of distribution system with ultra-capacitor is improved even in the presence of quick power bursts. This paper review major control schemes to utilize the combination of battery and super capacitor. This paper particularly focuses on the control schemes and the corresponding responses. The paper also summarizes the situations and scenarios in which the reviewed control strategies are incorporated. The meaningful simulation results are shown and comparisons are made to verify the effectiveness of reviewed control schemes.
382 Estimation of State of Charge for Li-ion Battery Using Model Adaptive Extended Kalman Filter
Venu Sangwan, Venkata R Vakacharla, Rajesh Kumar and Akshay Kumar Rathore
Abstract: An meticulous estimation of the state of charge (SOC) is of great significance in a battery management system (BMS) due to the requirement of ensuring safe and reliable operations for a Li-ion battery in battery electric vehicles (BEVs). Firstly, an equivalent circuit using one resistance-capacitor for describing transient behavior of the battery has been developed. The parameters of this equivalent model of battery, depends on temperature, that have been determined using Ageist Spider Monkey Optimization (ASMO). The objective of using optimization is to produce voltage curve using developed model that optimally fits the voltage curve obtained from experimental results for Driving Stress Test (DST) profile. Then, a model-based online iterative estimation, Extended Kalman Filter (EKF) has been implemented for battery SOC estimation. The estimation has an absolute root-mean-square error (RMSE) of less than 2% and an absolute maximum error of 6% in case of 0 ◦ C. In the other case ( 25 ◦ C and 50 ◦ C) it is less than 2%

138 Impact of System Parameters and Controller Gain on the Stability of a Multi-terminal DC Grid
Lokesh Dewangan and Himanshu Bahirat
Abstract: The impact of the system parameters and controller gain on the dynamic and steady state behavior of the multi-terminal direct current (MTDC) system is discussed using small signal model. The small signal model (SSM) of VSC is derived including controllers and measurement filters and it is also validated with non-linear detailed switched model in PSCAD simulator. The SSM of DC grid and VSCs are augmented into single SSM to study the stability of the MTDC system. The limitation of the PLL gain caused by the strength of AC grid (short circuit ratio) is illustrated using eigenvalues analysis. The effect of the controller gain on the AC resonance is also discussed in this paper. As the VSC terminals are increased, the DC resonance appears and its impact on the bandwidth of the direct voltage controller is also discussed.
209 Estimation of Switching Surge Flashover Rate for a 1200 kV UHVAC Transmission Line
Ramchandra Reddy Annadi and Chandrasekhar Patsa
Abstract: The rapid increase in transmission voltages to fulfil higher demand of the transmitted power yields to put the switching surges as the governing factor in the insulation design process for EHV and UHV systems. Contemporary methods of insulation coordination utilise probabilistic approach and statistical methods particularly in the case of ultra-high voltage systems. This paper proposes the statistical distributions of energization, fault initiation and fault clearing overvoltages of the 1200kV system modelled in PSCAD. Decisive figures like mean value, standard deviation and 2% statistical overvoltage values of switching overvoltage are estimated using randomness of the instants of closing with 200 operations for line energization and randomness of faulted phase, fault location and fault times with 3 faulted phases, 8 fault locations and 21 fault timings, 504 simulations for fault initiation and fault clearing. Ascertaining the investigations from the above simulations the stress on the towers is estimated. From the stress and strength of the tower a systematic approach to calculate the switching surge flashover rate (SSFOR) is presented.
221 Localization of Partial Discharge Source in Power Transformer Using Bat Algorithm
Kalyanchakravarthi Meka, Giridhar A V and Siva Sarma D V S S
Abstract: Partial discharge (PD) source location in power transformer by measured acoustic signals using bat algorithm is presented. The available literature data considered for this case study is five sensors but for identification of PD source location needs not more than four sensors. Thus, five combinations results are analyzed using bat algorithm. This algorithm is tested on the measured acoustic TDOA signals which were reported in the literature. The results shows that bat algorithm enhances the search operation and there by PD location accuracy is better with other population based methods existing in the literature.
245 Parameter Estimation of Multi-Transient Signal Using Band-Pass Matrix Pencil Method
Meghabriti Pramanik and Pabitra Mitra
Abstract: In this paper an application of band-pass matrix pencil (BPMP) method for accurate estimation of controlling parameters (amplitude, frequency, phase and damping factor) of the multi-transient signal has been shown. In case of low signal-to-noise ratio (SNR), matrix pencil (MP) method fails to estimate the values of four parameters of the considered signal. So, BPMP method is applied for estimation purpose. In BPMP method the signal-to-noise ratio (SNR) can be improved by utilizing the mechanism of pre-filtering using IIR filter. Pre-filtering is not trivial one, so backward process for the IIR filter is applied. To validate the proposed method, multi-transient signal is taken as test signal for simulation purpose and the obtained parameter values are compared with the true values.
262 An Ensemble Learning for Anomaly Identification in SCADA System
Irfan Siddavatam, Satish S, Mahesh W and Faruk Kazi
Abstract: As automation being on the surge, SCADA (Supervisory Control and Data Acquisition) substations are driven towards unmanned operations. Security of such substations is a major point of concerned in power system environment. Communication at substations can be inferred from packet level for different purposes like establishing performance pattern of peripheral devices, anomaly detection, and threat identification. The major contributions of this paper, we have implemented ensemble learning methods to identify the anomaly in SCADA traffic on an in-house developed industrial compliant test bench. Anomalies are detected by using deep packet inspection of SCADA network traffic.A mathematical model is defined for stream based anomaly detection for SCADA traffic,and the results shows the performance evaluation Decision tree and Random forest algorithm for anomaly detection.
333 Development of a Low Cost Portable Frequency Domain Spectroscopy Data Measurement Module for Oil-paper Insulation
Meenal Malviya, Hari Charan Verma, Arijit Baral and Sivaji Chakravorti
Abstract: The present paper discusses a hardware setup capable of carrying out Frequency Domain Spectroscopy (FDS) measurements. The hardware uses NI USB 6009 14 bit, 48 kS/s Data Acquisition (DAQ) system as the measurement module. The low-cost hardware is capable of generating various non-sinusoidal excitation voltage waveforms with the flexibility of connecting any standard function generator for extending operating range. The fundamental frequencies of the generated excitation waveform can be varied from 10 mHz to 1 kHz. In the present paper, the developed hardware is used to obtain the value of dissipation factor for a laboratory sample. Related analysis presented in the paper show that the developed hardware is capable of estimating tanδ for different excitation frequencies with satisfactory accuracy.
443 Evaluation of Arc Conductance for High Current Fault Arcs
Pranav Katare, Rajaramamohanarao Chennu, Dr. Ramachandra B, S Sudhakar Reddy and Anupam Awasthi
Abstract: Generally, standard electric arc models are of very much importance in order to study the arc behaviour and its performance in the circuit. Considering the dynamic nature of arc, it is necessary to precisely simulate the electric arc models to perform correct arc flash calculations in order to use those arc for the applications like short circuit tests and power system fault studies. This paper discusses the several arc models used to calculate arc conductance for various fault arc currents, which will be used for calculating the short circuit test parameters for real-time short circuit testing of surge arrester in High Power Laboratory, CPRI Bangalore.

103 Improvisation of Smart Home Automation Using Hybrid Sources
Siddhai Naik, Shubham Sharma, Seepij Umarwal, Katta Sri Harsha and Soumitra Das
Abstract: The evolution of technology and lifestyle in the past few decades has led to an immense change in technological as well as social front. Digitalization has taken over the world due to an easy control and accessibility to smartphones. It has led to a technology dependent automatic world ready to adapt to a precision and accuracy based labor-free system. Automation along with widely used smartphones plays an important role in the commencement of Smart Home Automation. On the other hand, exponential increase in demand for electricity due to urbanization has led to drastic decrease in the non- renewable resources and increase in greenhouse gases. This coerced the scientists to opt for easily available and cost efficient renewable resources. Smart home Automation when merged with renewable resource as co-generating system, will not only reduce human labour but will also contribute towards betterment of the environment. This paper focuses on a reliable, low cost and efficient Hybrid Smart Home Automation (HSHA) system for controlling as well as monitoring the loads. Wireless controlling and monitoring of loads is done using a smartphone via an android application. The android application has features such as password protection, availability of different modes of operation, real-time power monitoring and controlling the loads using switch or voice control. An android based controller circuit is built which serves as an intermediate platform between the user and the relay system. For wireless communication, Bluetooth module is used due to its flexibility and relays are for quick and methodical control of loads. A real-time prototype of the proposed system is designed for 1 kilo-watt household system and the experimental results are presented for different loads and modes of operation.
132 Multi-objective Optimization for Demand Side Management in A Smart Grid Environment
Lokeshgupta B, Arindam Sadhukhan and Sivasubramani S
Abstract: Demand Side Management (DSM) is an essential tool for the future smart grid environment. This helps the utilities to reduce their system peak load demand, energy bill and improve the system load demand profile. DSM implementation under the smart grid environment gives not only an advantage to the utilities but also profit to the consumers who are part of this technique. DSM which involves consumers as the crucial participants is usually modelled as optimization problems. DSM technique with single objective optimization alone may not satisfy the other objectives if the participation level is more. To overcome the above problem, this paper proposes a day-ahead based load shifting multi objective DSM technique to minimize utility energy bill and load profile deviation simultaneously. In order to test the proposed method, a test system with three different smart grid areas was considered. For comparison of results, the two objectives were also minimized individually. From the results it is clear that the proposed multi objective DSM technique is able to satisfy both the objectives with the best compromise solution.
190 Energy Scheduling of Residential Community Equipped with Smart Appliances and Rooftop Solar
Sandeep Kakran and Saurabh Chanana
Abstract: Demand side management (DSM) has been always a topic of interest among researcher. Residential energy management is also a part of DSM. In this paper, we have modelled the appliances used at home and designed an energy model for residential area. This energy model has been used for energy scheduling at the home. A common energy scheduler has been used for scheduling purpose. Time of Use (TOU) tariff has been used during the solution of the problem. A renewable energy source has been also included in form of rooftop PV panels. Finally formulated energy model has been solved using mixed integer linear programming (MILP) technique with the help of CPLEX solver of GAMS software.
249 PCA based Electricity Theft Detection in Advanced Metering Infrastructure
Sandeep Kumar Singh, Ranjan Bose and Anupam Joshi
Abstract: Advanced metering infrastructure is one of the important components of smart grid and offers an essential link between consumers and their loads, grid, and generation and storage resources. Electricity theft, one of the key concern in AMI, causes million dollar revenue loss every year in developing and developed countries. In this paper, Principal component analysis based electricity theft detection scheme is proposed. PCA is used to transform a high dimensional dataset into a low dimensional dataset. Using principal components, anomaly score is calculated and compared with a predefined threshold value. The proposed scheme is tested for different attack scenario using real dataset. The results show that the proposed scheme detects electricity theft attacks with high detection rate.
359 Smart Meter Design with Incorporated Dynamic Control of Grid Connected Three Phase Inverter
Navonita Sharma, Ajoy Kumar Chakraborty and Abanishwar Chakraborti
Abstract: In this paper, we proposed a smart energy meter prototype with the feature of three-phase inverter control that is supplied by a solar PV system and is connected to a grid. The inverter is controlled according to grid requirement and hence promotes the optimized penetrations of renewable to the grid. The smart meter designed has been incorporated with the feature of active and reactive power control. The controller is placed in the design of smart meter to eliminate the need of excess control system for controlling grid-connected inverters. This approach has been taken into account considering the need of inverter control for renewable integration in smart grid and hence including the control design in the smart energy meter can eliminate the use of excess equipment and also reduces the cost involved. This paper also describes the various literatures involved for control of grid connected inverter for non-ideal grid connections and also shows how the present system can be more efficient and cost effective for renewable integration with the grid system.
423 Smart Grid Development
Reena Ambekar and Harivittal Mangalvedekar
Abstract: This paper has briefly discussed the development of the erstwhile power network into smart grid with modern communication systems. These communication system networks (ICT) are susceptible to cyber attacks. These attacks are generally carried out by the attacker with the intention to create an emergency in the power system network. The power network may also have emergency situations. This paper has simulated the contingency attack and compared with the actual contingency occurrence at a generator bus. The paper discusses the need for reliability analysis of the power system in near future.
433 Resilience of Electrical Power Delivery System in Response to Natural Disasters
Naresh Malla, Shiva Poudel, Nava Raj Karki and Netra Gyawali
Abstract: The electric power transmission and distribution system is a complex and critical part of the national infrastructure. The transmission lines may span hundreds of miles, may include multiple generators and substations, and many key facilities are unguarded. They may be located in vulnerable geographic location and have been attacked by natural disasters. Because of complex nature of todays power system, fault in any link may propagate to cause cascading failure and ultimately blackout. Thus it is necessary to study impact of natural disaster on electrical power systems for understanding the causes of the blackouts, explore ways to prepare and harden the grid, and increase the resilience of the power grid under such events. This study is conducted in order to assess the resilience of Electrical Power Delivery System (EPDS) of IEEE 14 bus system. The resilience is accessed through different techniques like cascading failure analysis for accessing the hazard, risk quantification and ranking for measuring the hazard, and islanding operation and
detection for managing the hazard at the post disaster stage. Cascading failure analysis is performed for standard IEEE 14 bus system to determine the optimum value of system tolerance. Similarly, risk quantification criterion is applied to IEEE 14 bus system to determine the line which is most critical to natural disasters taking probability and severity into account. Finally, islanding operation and detection technique is employed to ensure survivability of IEEE 14 bus system even with limited operation.
442 Review of Web based Information Security Threats in Smart Grid
Vasudev Dehalwar, Akhtar Kalam, Mohan Lal Kolhe and Aladin Zayegh
Abstract: The penetration of digital devices in Smart Grid has created a big security issue. OWASP is an online community of security professionals that identifies the most critical web application security risk in IT domain. Smart Grid also uses client-server based web-applications to collect and disseminate information. Therefore, Smart Grid network is analogous to IT network and similar kind of risk exists in the Smart Grid. This paper review the security risk in Smart Grid domain with reference to OWASP study. The Smart Grid security is more biased towards vulnerabilities associated with a machine to machine communication. Methodology to minimise the risk of attack is also discussed in this research.

12 Modelling Local Electricity Market over Distribution Network
Falti Teotia, Parul Mathuria, Rohit Bhakar, Vivek Prakash and Sandeep Chawda
Abstract: To encourage transaction of electricity within distribution network for satisfying the demand locally under intermittency of distributed energy resources, Local Electricity Market (LEM) can be considered as a solution which encourage direct participation of end users in trading by incentivizing prosumers locally. The consumers also get benefited by low-cost power available from neighbor-hood prosumers. The paper proposes a LEM model and trading framework using system constraints. The outcomes of financial market clearing are used for assessing power flows in a MV level network. The analysis is done to highlight the mutual impact of network constraints on market clearing, and LEM on power flows and congestion. The simulation results highlight the need to couple both network operation and market operations for successful implementation of LEM into the existing system
14 An Enhanced 2-D Locational Marginal Pricing with FACTS Devices under Variable Bus Voltage Profile
Shri Ram Vaishya and Vaskar Sarkar
Abstract: The objective of this paper is to propose an AC optimal power flow (OPF) framework to perform locational marginal pricing (LMP) in the presence of voltage-dependent active and reactive power loads, and FACTS devices. The classical 2-D LMP assumes the load power factors to be independent of voltage magnitudes. This assumption is applicable only for the constant power load. The voltage dependency of the loads can affect the OPF result as well as the LMP. Therefore, in this paper, generalized voltage dependent load modeling is used which can consider any type of load. There can be multiple load bid requests of multiple load types from the same location. The reactive power compensators are also modeled as voltage dependent entities. Different active and reactive power LMPs are obtained for different types of loads and compensators. The proposed methodology is illustrated through a suitable case study.
151 Forecasting Global Horizontal Solar Irradiance: A case study based on Indian geography
Sagun Pai and S. A. Soman
Abstract: Solar generation technologies have undergone a significant growth in energy market for the past decade or so, due to higher penetration of renewable energy in electrical grid systems. Solar resource is extremely variable primarily due to climatic factors and hence, causes multiple grid and plant level problems. As a result, it is imperative to have forecast systems with high accuracy for varying time horizons. Here, we analyse some forecasting techniques and apply them for day-ahead solar forecasting. The techniques are evaluated by predicting global horizontal irradiance across five major solar power plant sites in the Indian subcontinent. The present findings and conclusions can be used to utilize solar energy resource in an efficient manner and help in power system management.
216 Copula Based Self Scheduling Model for Risk Averse GenCo in Restructured Electricity Market
Debasmita Panda, S N Singh and Vimal Kumar
Abstract: One of the important task of risk management process is the scenario consideration by knowing the dependence structure between market uncertainties. The paper presents a new copula based self scheduling (CB-SS) model for generation companies (GenCos) in day-ahead Indian electricity market (EM). Energy prices and unscheduled interchange (UI) charges are taken as market uncertainties. The proposed model also takes into account the forced outages of GenCo units as operational uncertainty. The uncorrelated uncertainty sources are modeled using copula to capture the dependence structure. Conditional value at risk (CVaR) is used as a risk measuring technique. The proposed model is tested on a GenCo situated in northern region of Indian EM.
234 Decentralized Interchange Scheduling in India
Vivek Pandey, Usha S and Vinay Kumar Shrivastava
Abstract: The paper discusses the decentralized interchange scheduling and despatch mechanism for Inter-State transactions in electricity as implemented in India. It elaborates the indigenous method of addressing the fundamental power system problems of Unit commitment, Economic Dispatch and Generation Control within the federal governance structure in India. It discusses the emerging challenges in Interchange Scheduling with the increasing number and volume of short-term open access transactions, envisaged integration of large scale Renewable Energy Sources and growing aspiration of market players as well as consumers in India. The authors derive learning from the experience at the interstate level and recommend implementation of the similar mechanism within the intra-State system for realizing the objective of economic and efficient operation of the electricity market in India.
329 Reference Bus Independent Components of LMP through a Non-Marginal Choice of its Energy Component
Deep Kiran, Abhijit Abhyankar and Bijaya Ketan Panigrahi
Abstract: In the loss compensated direct current optimal power flow (LCDCOPF) markets, the reference bus plays a crucial role in the decomposition of locational marginal price (LMP) components. For the correct valuation and settlement of financial instruments in these markets, it is important to rationally decompose the LMP into its components. Therefore, this paper proposes a simple non-marginal method for calculating reference bus independent components of LMP. The efficacy of the proposed method is supported by numerical results.
400 Cross-Terms Allocation of Line Losses using Game Theory
Satish Sharma, Deep Kiran and Abhijit Abhyankar
Abstract: The power loss on a branch are the function of power flows which are caused by various participants present in the network and it varies nearly quadratic with respect to these power flows. There are several methods present in literature to
unbundle or allocate the branch power losses based on different assumptions. In this paper, three game theoretic models are presented and compared, namely, Nash equilibrium, Shapley value and nucleolus, so as to allocate the cross-terms in branch power flow to each participant of the network. Additionally, these game theoretic models are compared with the some of the classical methods present in the literature. Further, it is observed that all these game theoretic models give the same solution for the allocation of the branch losses. It satisfies all the axioms of fairness and provide unbiased solution for loss allocation. The results are discussed and illustrated using an example.
434 Electricity Load Forecasting using fuzzy logic - Short Term Load forecasting factoring weather parameter
P Mukhopadhyay, G. Mitra, S. Banerjee and G. Mukherjee
Abstract: Electrical energy demand of an area depends on many factors like population, regional development, weather, electricity price, industrialization etc. Weather plays an important role in estimating the total demand met to a greater degree of accuracy. Accuracy in the forecast helps the system operator to optimize the generation and to keep suitable reserves in view of any contingency. The control area load has only a part of it that is susceptible to the weather, mostly the load for household purposes, while others are independent of the weather. Short term load forecast will not assume the contribution of agricultural load which is season dependent and thus is assumed to be constant in the span of few days. This paper aims at developing a model using fuzzy logic to have the weather and temperature to forecast the future load on a short term basis.

16 Impact of Distributed Generation Penetration Level on Relay Coordination
Adhishree Srivastava and Dr. Sanjoy Kumar Parida
Abstract: In today’s electrical grid, micro grid concept employing Distributed Generation is being implemented rigorously. With change in penetration level of DG, distribution system experiences variation in the short circuit level of the system. Therefore the relay settings should be revised at every level. This paper discusses the application of Gravitational Search Algorithm to find optimal relay settings in order to attain coordination of overcurrent relays. Relay settings required for an adaptive numerical relay is obtained for practical cases like system with different DG penetration level and fault types. A four bus radial system with DG and overcurrent protection is simulated in SIMULINK platform and programming is done using MATLAB software.
204 A New SVM based Islanding Detection Scheme in the Presence of Distributed Generation
Shashi Kumari, Bhavesh Bhalja and R.P Maheshwari
Abstract: The injection from small or medium sized distributed generation units operating in parallel with the utility grid supply presents several technical issues for the control and protection of the system. Amongst these need is there to protect the system from islanding, caused by the loss of the utility grid supply. Failure to trip islanded generator can lead to problems such as out of phase reclosing, threats to personnel safety, damage of network instruments and degradation of power quality. In this paper a new scheme for islanding detection of distribution network with Distributed Generation (DG) is proposed, using a Support Vector Machine (SVM) classifier. After generating test data (Voltage and Current) using PSCAD/ EMTDC simulation package, a decision of islanding or non islanding condition is carried out using SVM classifier. The proposed scheme is tested on islanding and various non islanding conditions such as faults on the adjacent feeder, sudden change of load, capacitor switching, normal condition etc. and found to be highly effective in islanding detection.
222 An On-line Fault Location Technique for DC Microgrid Using Transient Measurements
Anju Meghwani, Saikat Chakrabarti and S.C. Srivastava
Abstract: Locating faults in meshed dc microgrids poses challenges due to low impedance offered by the dc network. In this paper, an on-line fault location scheme which can be implemented as an additional feature in a relay is proposed. The algorithm is developed to determine fault location based on voltage and current transients. Both line to line and monopole ground faults are analysed separately and algorithms are developed based on the rate of change of current. Direct short circuit faults are located using transient measurements captured locally, while communication based technique is utilized to locate the impedance faults. The developed fault location technique is also capable of estimating the fault resistance accurately. The algorithm is validated on a $\pm 600$ V meshed dc grid, for both the types of faults under wide range of fault impedance at different fault locations.
386 A Passive Islanding Detection Technique for Distributed Generations
Bhatraj Anudeep and Paresh Kumar Nayak
Abstract: Passive islanding detection techniques based on the rate of change of voltage, phase angle and frequency perform well in case of large mismatch of power at the distributed generation terminals during islanding. However, such methods find limitation in detecting islanding conditions when power mismatch is very low. In this paper, two new features, the ratio of zero-sequence current to positive-sequence current and negativesequence current to positive-sequence current are introduced which in combination with the conventional features detects islanding even at zero power mismatch. The performance of the proposed method is tested for a wide variety of operating conditions using data simulated through PSCAD/EMTDC in the IEEE standard 399-1997 model. The result clearly shows that using proposed method a fast and reliable islanding detection can be accomplished.
418 A Hybrid GA - Interval Linear Programming Approach for Optimal Relay Coordination in Microgrids
Srinivas Stp and Shanti Swarup K
Abstract: This paper proposes hybrid Genetic Algorithm (GA) - Interval Linear Programming (ILP) approach to optimal relay coordination problem for microgrid scenario. Relay coordination in microgrids is complex because of varied fault current magnitude and direction due to existence of Distributed Generation (DG). Overcurrent relays are feasible and economic choice of protection for distribution systems connected with DG. The coordinated relay settings must account to all possible fault scenarios in both grid connected and isolated microgrid modes of operation. Inadequate fault current levels from grid connected to isolated mode is the major cause of miscoordination in the microgrid network. This paper systematically formulates the relay coordination problem for microgrid scenario as linear interval optimization problem and introduces a new method of solution to microgrid relay coordination using hybrid GA - ILP
method. The disadvantage of GA in finding global optimum and the feasibility of ILP method in including all the fault scenarios as “uncertain but bounded” intervals are combined to find the optimal overcurrent relay settings. The results show the effectiveness of proposed method. The programming is done using optimization tool box available in Matlab.
437 A Passive Islanding Detection Technique with Reduced Complexity for Distributed Generations
Prajna P. Mishra and C. N. Bhende
Abstract: Modern power electronic devices offer a reliable and economical solution for better management and control of electric power in the distribution system. However, the nonlinear operational characteristics of these devices may contaminate the voltage and current waveforms at the point of common coupling (PCC). Moreover, unbalanced load is a common phenomenon in the distribution network. Under such scenarios, the conventional islanding detection schemes may not give proper detection accuracy or may take long time to detect the islanding event. In this paper, sequence component based passive islanding detection scheme is developed for inverter based distributed generation under unbalanced and nonlinear loading conditions. The objective behind the detection technique is that the anti-islanding relay should not trip for non-severe and normally occurring disturbances such as power quality problems, variation of grid frequency. The proposed detection algorithm is tested on 13-bus standard distribution system as well as on balanced and linear load condition. It is found that the proposed scheme works effectively and enables fast islanding detection irrespective of the loading scenario. The proposed technique has reduced complexity and hence it is simpler to implement in the power system for anti-islanding protection.
439 Power System Asset Management using Advanced Protection Relays
Balakrishna P, Mital Kanabar and Vijaysarathi Muthukrishnan
Abstract: The evolution and deployment of smart grid asset management technologies since last decade has transformed the power system monitoring capabilities. Smart grid offers hardware, software, communication systems and data storage capabilities for asset management in the form of Intelligent Electronic Devices (IED’s). These IEDs for a typical asset can include protection devices and monitoring devices. Protection devices offer functionalities such as protecting the asset from events (faults) through breaker control, compute metering data, record transient & disturbance data during events and communicating the event summary to upstream systems. On the other hand, monitoring devices offer functionalities such as asset failure monitoring, diagnostics, incipient fault detection and helps in doing condition based maintenance scheduling. Due to the recent advancements in protection relay hardware and technologies, it is possible to utilize relays in performing asset management apart from as protection & control devices. In this paper, we discuss on what are the merits and advantages in doing asset management with protection relays with a detailed case study on motor monitoring & diagnostics using motor protection relay.

Tefera T Yetayew, T. R. Jyothsna and G. Kusuma
Abstract: Partial shade and mismatching among PV modules in a PV system are common phenomenon caused by trees, passing clouds, manufacturing tolerances, etc. Due to mismatching/partial shading, the P-V characteristic curve usually comprises of multiple local and a global peak. To extract the maximum energy, usually three techniques are proposed. The first one and widely used is to use central MPPT technique (use of by-pass diodes) to track the global peak, the second is use of distributed per module/ sub-module MPPT (DMPPT) and the third is reconfiguration of modules in an array. The second and third options can increase the extracted PV power. However, the increase in cost and implementation complexity and control are some of the challenges of the techniques. In this paper, performance evaluation of by-pass diode and DMPPT per module technique for PV system under partial shade has been done.
21 Solar PV Fed SIDO Modified Buck-Boost Converter for SRM Driven Irrigation Pump
Anjanee Mishra and Bhim Singh
Abstract: This paper provides a reliable solution for photovoltaic (PV) array fed irrigation pump system using switched reluctance motor (SRM). A PV fed single input dual output (SIDO) modified buck-boost converter is utilizes as a DC-DC power transformation stage between PV array and SRM-pump in proposed system. The power optimization of PV array and to provide soft-starting to SRM drive are the two major objectives of this converter. The continuous current through inductors of SIDO modified buck-boost converter helps to minimize the strain on its components and to enhance the conversion performance. The fundamental frequency switching of converter of SRM at line frequency minimizes the losses of the system and provides an opportunity to eliminate the sensors from the drive side. A self-start control algorithm is also introduced in the proposed system. The satisfactory steady-state and dynamic performances of the proposed system under variable environmental conditions show the superiority over the existing methods.
130 Single-Phase Grid Interactive Solar PV System Having Active Shunt Capabilities
Aakanksha Rajput, Neha Beniwal, Subarni Pradhan, Bhim Singh and Sukumar Mishra
Abstract: In this paper, a least mean switched error (LMSE) based control algorithm is developed for the control of a single- phase double- stage grid integrated solar photovoltaic (PV) system. The proposed control is robust and has a fast convergence rate. In the double stage topology, first stage contemplates with the boost converter which helps in tracking the maximum power point, whereas the second stage is a voltage source converter (VSC) which not only converts the DC power to AC power, however, it also helps in mitigating the power quality issues. A drift free MPPT (Maximum Power Point Tracking) method is used here for fast and accurate tracking of the maximum power point. A prototype of the system is developed in order to substantiate test results and to demonstrate the system efficiency under diverse non-ideal conditions.
147 Vienna Converter Fed Two Stage Grid Connected Photovoltaic Pumping System
Utkarsh Sharma, Bhim Singh and Chinmay Jain
Abstract: A topology of Vienna converter fed two stage solar water pumping system interfaced with three phase grid supply is proposed. The system uses a Vienna converter, a boost converter and a voltage source inverter to drive an induction motor (IM) coupled centrifugal pump. The proposed system helps in eliminating the loss of water discharge due to varying solar insolation in standalone solar water pumping systems. The IM is controlled using simple scalar control while the maximum power point tracking is achieved using the incremental conductance technique. The input power quality is improved by the constant frequency switching of the Vienna converter. Various modes of operation on the availability of active power sources are identified and the photovoltaic pumping system (PVP) is modelled and its performance is simulated in detail. The system indices at starting, steady state and with varying solar insolations are analysed. The simulated results show the feasibility of the proposed system in grid connected locations.
167 Integrated Control Strategy for a Power Converter Used for Photovoltaic Lighting Applications and its Transition Analysis
Ranjini B. R, I. Omsekhar and Gurunayk Nayak
Abstract: Utilization of solar energy for residential lighting applications in the off-grid areas plays a beneficial role in the present life. It is necessary to have a suitable dc-dc converter to make best utilization of solar power. This paper proposes a new topology for power converter with suitable control strategy implemented to drive LED lighting from a PV module. The working of power converter can be analysed under four different states of operation which can be categorized based on the availability of solar insolation, State of charging (SOC) of a battery and load requirements. Suitable integrated controller which is a combination of several control actions such as MPPT control, battery charge control, outer voltage and inner current loop control has been implemented. The analysis during the transition between different states of operation has been done based on the simulation results obtained from the Matlab/Simulink model.
192 Design and parametric study of active-type resonance HVDC circuit breaker
Prajakta Joshi, Himanshu Bahirat and Anupa Sabnis
Abstract: The important requirement of High-Voltage Direct Current (HVDC) multi-terminal system is the mature Circuit Breaker (CB). In this paper, the systematic mathematical modeling is implemented to design resonance circuit parameters of Active type resonance HVDC CB. The designed model of CB is tested on three cases, namely, fault current interruption, load current interruption and fault current interruption with variation of DC system inductance. Three cases are compared based on total time required to reduce fault current to residual current and to de-energize breaker system. The simulation results for these conditions validate the performance of designed HVDC CB.
317 Simpson's Rule Based SHE Pulse-Amplitude Modulation for Cascaded Multilevel Inverters
Piyush Kamani and Mahmadasraf Mulla
Abstract: In this paper, Simpson's rule based selective harmonic elimination pulse-amplitude modulation (SSHE-PAM) method is proposed for cascaded multilevel inverters. The SSHE-PAM method is free from the requirement of a solution of conventional nonlinear transcendental trigonometric SHE equations and hence can be implemented in real-time. Switching angles are calculated using univariate linear equations and remain constant throughout the whole range of modulation index. The voltage of dc sources are considered as a variable which varies linearly with variation in output voltage. The nearest harmonic present in the output voltage of L-level inverter is L-2. Voltage THD remains constant for a fixed number of inverter levels. A simulation study has been carried out using MATLAB/SIMULINK to validate the theoretical aspects of the proposed method. Comparative study shows that the proposed method eliminates a large number of harmonics as compared to the conventional SHE-PWM and SHE-PAM methods.
402 Tertiary Load Voltage control in An Interconnected DC Microgrid with Energy Hub
Shivraman Mudaliyar, Sukumar Mishra and Rishi Kant Sharma
Abstract: This paper presents a hierarchical control of an interconnected DC microgrid system. In an interconnected DC micrgrid, power injections and absorptions at different buses can cause significant voltage deviations at load terminals. Even though droop control at the primary level aids in sharing of load among the converters, it introduces load dependent voltage drop in the system. To overcome this, voltage restoration can be provided at the voltage controlled buses. However, secondary voltage control at different buses cannot ensure voltage quality at critical load buses. This paper proposes a tertiary load voltage control utilizing the coordination among different voltage controlled buses to set their references such that the load voltage deviation is minimized. Based on the present state of the network, the tertiary level runs an optimization algorithm and reroutes the power distribution in the network. This redistribution of power in turn mitigates the load voltage deviations. The proposed control topology is verified using simulation results for a four-bus interconnected DC microgrid system.

29 Energy Loss Minimization with Open Unified Power Quality Conditioner Placement in Radial Distribution Networks Using Particle Swarm Optimization
Shubh Lakshmi and Sanjib Ganguly
Abstract: This paper presents a planning approach for the integration of open unified power quality conditioner (UPQC-O) in a distribution network to improve its power loss and power quality (PQ). In UPQC-O model, the series and shunt inverters are not connected to common DC link. The shunt inverter is used to eliminate the harmonics created by load and to provide reactive power compensation. The series inverter is used for dual-purpose, i.e., for the protection of all its downstream loads from voltage sag, and to provide reactive power compensation during healthy condition. The objective function is formulated as the minimization of energy loss under the voltage, thermal overloading, and the desirable PQ constraints so as to determine the location(s) and size(s) of these two inverters. The particle swarm optimization (PSO) is used as the solution strategy. The UPQC-O model is suitably incorporated to the forwardbackward sweep load flow algorithm, which is used as the support subroutine for the PSO-based planning algorithm. The
results show that the optimal placement of the UPQC-O provides significant power loss reduction, bus voltage improvement, and
better PQ.
50 Power Quality Monitoring and Mitigation
Nikhil Gujar and Shefali Talati
Abstract: The use of induction furnaces for steel making has grown dramatically in the last decade throughout the world. The steel melting process involves the use of large quantities of energy in a short time and in some instances the process causes large decrease in the quality of electric power for electricity users on the same network. In this paper, harmonic measurement at point of common coupling of two industries having induction furnaces is discussed, in terms of current and voltage harmonics (when there is no load and when load increases and reaches maximum). The measurements were carried out for entire load cycle to identify current demand distortion and voltage harmonic distortion. To mitigate the harmonics, passive filter is designed and simulated using ETAP software. The simulation result shows the values of harmonics before and after implementation of the filter.
141 Study of Control Strategies for Shunt Active Power Filter for Harmonics Suppression
Sambasivaiah Puchalapalli and Naran Pindoriya
Abstract: Excessive use of nonlinear and time varying devices results in harmonic currents in the secondary distribution system. The suppression of harmonics is a dominant issue and one of the practical ways to compensate harmonics is shunt active power filter (SAPF). The core part of the SAPF is control techniques used for reference current generation. This paper presents a comprehensive study of three control strategies namely instantaneous reactive power (p – q) theory, synchronous reference frame (SRF) theory and instantaneous active and reactive current (id - iq) component method for SAPF in a three phase three wire distribution system. These three control methods aims to compensate harmonics, reactive power and load unbalance under sinusoidal balanced supply voltage conditions. Simulation results present a relative investigation of three control techniques based on current THD and load unbalance.
174 Power Quality Improvement in Single Phase Grid Tied Solar PV-APF Based System using Improved LTI-EPLL Based Control Algorithm
Yashi Singh, Ikhlaq Hussain, Bhim Singh and Sukumar Mishra
Abstract: This paper deals with an improved LTI-EPLL (Linear Time Invariant-Improved Enhanced Phase Lock Loop) based control algorithm for a single-stage solar PV (Photovoltaic) power generating system (PVGS) with the power quality improvement. The proposed PVGS comprises of a PV array, a single phase voltage source converter (VSC), a nonlinear load and the grid. The VSC is used as a link between the PV array and the grid. The VSC provides the multi-functional capabilities in PVGS. An improved LTI-EPLL based algorithm is used for harmonics mitigation, power factor correction and load compensation in proposed PVGS. The PVGS preserves its capabilities of compensating harmonics on cloudy days (i.e. PV power, PPVis present). It also provides this facility in the night time (PPV=0) with utilization of available power sources. Test results have been analyzed and the response of PVGS with an improved LTI-EPLL based algorithm under varying environmental conditions, load changes and different mode changes conditions.
Pranay Kumar Alladi, Siva Kumar G and Sreenivasarao D
Abstract: In this paper, a conductance factor based reference current extraction method is presented to control Distribution static compensator (DSTATCOM). The proposed control algorithm extracts fundamental in-phase and quadrature components of load currents using conductance factor and voltage unit vectors at the Point of Common Coupling (PCC) to compute the reference source currents during normal and distorted supply conditions. The compensator with this control technique will make the system to operate in either Unity Power Factor (UPF) mode or Zero Voltage Regulation (ZVR) mode. The performance of the proposed control algorithm under various conditions is demonstrated with simulation studies in MATLAB/SIMULINK environment.
211 Power Quality Enhancement at PCC for PMSM based Adjustable Speed Drive Load
Archana Sharma, Anshul Kumar Mishra, Bharat Singh Rajpurohit and Kailash Srivastava
Abstract: This paper presents the power quality improvement at the terminal of a permanent magnet synchronous motor (PMSM) based adjustable speed drive (ASD). An adjustable speed drive consists of a 3-phase rectifier, a dc link followed by an inverter. In order to operate the drive satisfactorily, the DC link voltage is needed to be maintained constant. DC link voltage depends on the supply voltage and on the size of the capacitor filter. Due to the capacitor filter the 3 phase supply current is highly non-sinusoidal in nature. At the input a typical ASD the current harmonics distortion has been found to be 288% due to the less conduction period of rectifier diodes. This high value of harmonic distortion is not acceptable for the utility as per IEEE 519 standard. A shunt active power filter (SAPF) has been used to mitigate the current harmonics at input of the ASD. Shunt active power filter has been controlled using the Anti-Hebbian control algorithm. Performance of Anti-Hebbian algorithm has been verified by comparing its performance with Synchronous Reference Frame (SRF) based control algorithm. Total harmonic distortion (THD) in source current has been reduced upto 4.98% using Anti-Hebbian control algorithm as compared to 12.86% in case of SRF based control algorithm.
355 DSP Implementation of the Empirical Wavelet Transform for Measurement of Power Quality Indices
Karthik Thirumala, Amod Umarikar and Trapti Jain
Abstract: The hardware implementation of empirical wavelet transform (EWT) for the estimation of the IEEE Standard 1459 - 2000 definitions is presented in this paper. The estimation of single-phase power quality indices (PQIs) using the EWT technique is implemented on a floating point digital signal processor TMS320F28377S. The EWT decomposes the signal into its frequency components adaptively; however, the estimation of PQIs require only the fundamental and non-fundamental components. Therefore, the algorithm aims to extract only the fundamental frequency component accurately by designing an adaptive wavelet filter. The accuracy and practicality of the EWT-based PQIs measurement have been verified by testing on practical signals acquired in the laboratory. Experimental results of the DSP-based PQIs are compared with the results obtained from MATLAB in terms of computational time as well as accuracy.

46 Frequency Excursions in Complex Power Systems - A Modular Approach
Suresh Varwandkar and M. V. Hariharan
Abstract: We report a new – modular - approach for modeling frequency excursions in complex power systems having generators with widely differing inertia. The approach is based on the concept of module - a subsystem - consisting of one generator and the rest of the power network without other generators. The modules are inherently decoupled by virtue of independence of prime mover turbines and it is conjectured that the dynamics of modules can be superposed. Ideas from quantum mechanics are used to define a new quantum derivative for modeling frequency dynamics of the modules. Superposition follows. Power-frequency relationships and ROCOF-equations are derived for single and multi-generator systems. It is shown that power-drags and frequency-drags exist among generators in multi-generator systems. These drags can cause concern especially in grids with wind generators. To the best of authors’ knowledge, theoretical contributions made in this paper have not been reported in power system literature earlier.
53 Parallel Operation Of Virtual Synchronous Machines With Frequency Droop Control
Prabin Adhikari, Suresh Prajapati, Indraman Tamrakar, Ujjwol Tamrakar and Reinaldo Tonkoski
Abstract: Studies had shown that the transient stability of a PV-Hydro micro-grid could be improved using a virtual synchronous machine(VSM), by injecting virtual inertia into the system. In the case of an interconnected system with multiple numbers of PV-Hydro micro-grid, a number of VSMs need to be operated in parallel. The parallel operated VSMs shall share the transient load in proportion to their respective capacities. Otherwise, the storage battery of one VSM will discharge more and other storage battery will less. This paper presents a control logic for parallel operated VSMs so that they share the transient load in proportion to the capacity of respective VSMs. Frequency droop control approach is used in the control logic to ensure proper load sharing. The control logic is simulated in MATLAB\ Simulink and results show that the frequency droop control approach is good enough for parallel operation of VSMs.
177 Comparative performance analysis of classical controllers for automatic voltage regulator
Shamik Chatterjee and Vivekananda Mukherjee
Abstract: This paper proposes a four term proportional- integral- derivative plus second order derivative (PIDD2) controller for automatic voltage regulator (AVR) system. The four parameters of the proposed controller are optimized using linear quadratic regulator (LQR) method. A juxtaposition of voltage responses of the AVR system with PID controller, tuned by different optimization techniques, and the voltage response obtained from the AVR system controlled by proposed controller is accomplished. Robustness analysis of the proposed PIDD2 controller is performed for controlling the AVR system while changing the studied system parameters. Simulation results manifest a stupendous response of the proposed PIDD2 controller in collation to the other optimizing techniques based PID controller for controlling the studied AVR system. Moreover, it is entrenched that the proposed PIDD2 controller is robust enough to control the studied system with variation in system parameters within a substantial range.
228 A Comparison of Power System Signal Detrending Algorithms
Krishna Rao and Shubhanga K N
Abstract: Wide Area Measurement Systems (WAMS) have facilitated tracking of oscillations in power system response signals. This has provided an impetus for application of signal measurement-based modal detection methods such as matrix pencil and Prony analysis. Detrending, which means removal of trend in a signal, is a pre-requisite for effective functioning of these modal detection methods. In this work, performance of three methods of detrending viz., Center-of-Inertia (COI)-based detrending, MATLAB function-based detrending and 'Zhou' detrending are compared with particular reference to power system signals. It is indicated that COI-based detrending is better suited to detection of modes from slip signals of generators.
307 Network Impedance Based Loss Allocation Technique Invarient of load fluctuation
Kamakshi Prashadini Swain and Mala De
Abstract: This paper presents a framework for allocating the power loss and branch flow in a deregulated power system. The developed technique is based on the concept of Relative electrical distance. An algorithm has been developed to recognize the contribution of the generator on the line flow and line loss. The developed method considers impedance of the network, which is a fixed quantity unless there is a modification in the network topology. The proposed technique is independent of continuous load changes in the network. This attribute excludes the need of repeated load flow analysis, which is used by most of the existing method to identify the contribution of generator on line flow and loss. Hence, the contribution of generator using proposed technique will be valid for longer time period unlike other generally used power flow based techniques. Proposed method also finds its application for deciding the cost associated with loss to the market players for a time period until new facilities are built up. Numerical demonstration on IEEE 69 bus system demonstrates the efficiency and robustness of the proposed method with specified parameters.
374 Adaptable operation of TSC-TCR for reactive power and harmonic injections
Snehal Kulkarni, Dipak Kulkarni and Sadashiv Halbhavi
Abstract: Electrical distribution system faces various problems like reactive power burden, unbalanced loading, poor voltage profile and harmonic distortion. Dynamic power factor correcting apparatus is required to get uniform voltage for fast changing loads. The old installations at the distribution level are still operating with TSC-TCR systems.The TSC-TCR system, while correcting power factor, inject harmonics into the lines causing higher THD of the distribution line supplies at PCC. This paper proposes to optimize both the harmonics and reactive power injection into the system by the operation of TSC-TCR type SVC used in conjunction with fast changing
loads at LV distribution level. Further it is proposed to provide user friendly approach to optimize either harmonic injection or reactive power or both together. This being a nonlinear problem Fuzzy logic system and ANN is used to get the solution. It is giving optimum triggering delay angles used to trigger switches in TCR. The various configurations discussed in the paper are attractive and can be used flexibly at distribution level.
428 Techniques for Practical Qualitative Approach Using Commercial Power System Simulation Software for Industrial Applications
Yara Rajashekar, P. Nandakumar, Jacob Philip and Anirudh Seshadri
Abstract: The differences between power system simulation commercial software designed for utility or large power system applications and industrial applications are obvious considering their capabilities and applications itself. The software for utility application have more transparent layers while offering the capabilities of different applications of the software, whereas the software for industrial applications allow only few layers to be accessed by the user as it aims for minimal set of solutions by hard-coding few functionalities. This however does not reduce the accuracy and performance of software but often restrict the user to quantitative results like time domain response which are good enough for most cases. Under some conditions, the user of the software may be required to do the qualitative analysis of the system like frequency domain analysis. The user either chooses to ignore it or purchase another software (or add-on in the same software if present) to perform required studies. An attempt is made to utilize the software to its maximum capabilities so as to allow the user to apply few practical techniques and obtain the desired qualitative results without going for another software or add-on module. This can be done using analytical as well as measurement based techniques like frequency scanning. As a case study, ETAP software is considered and the procedure to tune the power system stabilizer of a synchronous machine connected to infinite bus using a simple frequency scan is presented.

17 Internal Model Based Current Control for Grid Integrated Solar Photovoltaic
Rahul Jha and Gaurav Pandey
Abstract: In this paper, a single stage conversion method is used for the integration of the Solar PhotoVoltaic (SPV) with the utility grid. The three phase Voltage Source Converter (VSC) is used to extract the maximum power from the SPV. The power produced by the SPV changes with change in solar irradiance, hence a Maximum Power Point Tracking (MPPT) scheme is necessary to obtain the maximum power at a particular irradiance. In earlier works the conventional dq current control method is used. In this work the Internal Model Control (IMC) based current control is implemented. The IMC based controller has a simple design procedure and can be implemented using PI controllers. The Power produced by the SPV is used to supply the local load demand and the extra power, if any, is fed to the utility grid. If the load demand is more than the power produced by the SPV, the deficit power can be supplied by the grid. The SPV with IMC control will be validated under different irradiance level. The validation of the scheme is done using Matlab/Simulink under different irradiance values.
38 A New and Simple SRF based Power Angle Control for UPQCDG to Integrate Solar PV into Grid
Ashish Patel, Hitesh Datt Mathur and Surekha Bhanot
Abstract: In this paper, a new Power Angle Control (PAC) method for Unified Power Quality Conditioner with Distributed Generation (UPQCDG ) is proposed for effective grid integration of solar PV. In UPQCDG shunt Active Power Filter (APF) feeds power from solar PV to load apart from supplying reactive power demand, leading to increased rating of shunt APF. PAC method aims at effective utilization of series and shunt APFs of UPQCDG to reduce their ratings. In this work a new power angle estimation method based on instantaneous power calculation is proposed. Proposed estimation technique is simple, robust and utilizes already available measurements of UPQCDG. Performance of proposed system is tested in the presence of non-linear and reactive loads with detailed model of solar PV generation system. Dynamic performance of system is studied during grid disturbances such as voltage sag and swell, solar irradiation variation, and change in load. Simulation carried out in MATLAB/Simulink validate effectiveness of proposed method.
193 Technical Design of a Grid-Connected Photovoltaic System and Its Challenges in Nepalese Power Scenario
Ashutosh Timilsina and Binay Paudyal
Abstract: Solar Photovoltaic Technology has become a widely adopted electricity production alternative because of its huge potential in harnessing the solar energy as a renewable, reliable and sustainable source of electricity generation. Since Nepal receives around 300 days of sunshine in a year, its deployment could be beneficial in contributing to the national grid of the country. Nepal could benefit significantly via Grid-Scale Solar PV (GCPV) Projects, in conjunction with the hydropower projects. This paper presents the technical details of proposed GCPV Project based in Upper Mustang Region of Nepal and discusses about the challenges and possible mitigating measures of such system in Nepalese Context. This paper also analyses buffer storage type GCPV design to address the challenges for grid-integration of such system.
314 Control of Solar Energy Integrated Active Power Filter in Weak Grid System
Sachin Devassy and Bhim Singh
Abstract: In this work, a novel control of unified active power filter integrated with solar photovoltaic array (UAPF-PV) based on a modified symmetrical sinusoidal integrator (MSSI) is proposed. It is a three-phase four-wire single stage UAPF-PV system where the solar photovoltaic (PV) array is directly integrated with the DC-bus of UAPF-PV system. Two positive sequence extractors based on MSSI are used to extract fundamental positive sequence signals of distorted load currents and point of common coupling (PCC) voltages which are then used for generation of the reference signals for the shunt active filter and series active filter respectively. The shunt active filter maintains the grid currents balanced and sinusoidal while also extracting maximum power from PV array. The series compensator maintains load voltage sinusoidal and in phase with PCC voltage irrespective of harmonic distortions and sag in PCC voltages. The system performance is extensively analysed through Matlab Simulation under conditions of unsymmetrical loading, harmonic distortion and sag in PCC voltage and change in irradiation of solar PV array.
350 Dynamic Grid Support System for Mitigation of Impact of High Penetration Solar PV into Grid
Ajit Kumar K, Dr. Selvan M. P and Rajapandiyan K
Abstract: The growing global energy needs and the immediate need for an environment friendly sustainable growth have made us to focus on renewable energy sources, especially wind and solar. These renewable energy resources when implemented in large scale without any specialized controls are found to impact the integrity, reliability, security and stability of the power grid. Solar PV has become the major portion among the utility level renewable energy power plants. Solar PV power penetration into the grid is on continuous rise and plants of order of hundreds of MW are coming up in India and at global level. In India, till now the utility scale solar PV installations do not follow any specialized controls for grid support and will just get disconnected when there is a grid disturbance. This will severely impact the grid when the size and scale of the solar PV plant is huge. In this paper, initially, the drawbacks of large penetration of solar PV into the network is discussed along with a brief summary of the PV penetration analysis done on IEEE 9-bus system using ETAP. Further, various techniques for mitigation of impact of large penetration of solar PV into the grid have been identified and discussed. Dynamic grid support system with Low Voltage Fault Ride Through (LVRT) and Reactive Power Control has been implemented for a grid connected solar PV system using MATLAB Simulink. This technique will greatly help in reducing the impact of large penetration of solar PV into the network.
390 Steady State Analysis of PV integration in hydro dominated INPS grid using ETAP
Bikram Shrestha, Binay Paudyal, Netra Prasad Gyawali and Nava Raj Karki
Abstract: Renewable Energy sources are being popular nowadays, but their unpredictable nature may result in unwanted system consequences. Prior to integration of renewable source in a grid, the capability of the grid to handle that source must be studied. This paper is focused on finding hosting capacity of photo-voltaic(PV) in Integrated Nepal Power System (INPS) grid . Time domain load flow has been performed to identify if the system has enough margin and ramping capability to accommodate given size of PV. This load flow has been performed for dry and wet season using ETAP, an electrical simulation software.
398 Performance Evaluation of PV Array Configurations To Extract Maximum Power Under Different Partial Shading Conditions
Suneel Raju Pendem and Suresh Mikkili
Abstract: Photovoltaic (PV) generation systems has reported many problems with the partial shading conditions (PSCs), that can impacts the maximum power generation capability. The key objective of this research article is to model Series (S), Serial-Parallel (SP) and Bridge-Linked (B-L) PV array configurations to extract maximum power by decreasing mismatch losses; to analyze the output characteristics and to evaluate the performance of these configurations under different PSCs. The performance evaluation of these configurations provides the choice to choose the best PV array configuration to the design of PV systems to generate maximum power and fill factor, and therefore lowest power losses. The parameters of the KC200GT PV module are used for modeling of 5x5 PV array configurations. The MATLAB/SIMULINK software is used for the simulation.

32 An Enhanced Travelling Wave-Based Fault Detection and Location Estimation Technique for Series Compensated Transmission Network
Biswajit Sahoo and Dr. Subhransu Ranjan Samantaray
Abstract: A robust technique to enhance the fault detection, and location estimation for series compensated transmission lines is presented in this paper based on travelling waves applying Fast Discrete S-transform (FDST). The FDST of the modal components of retrieved currents is obtained at each terminal to find the arrival time of the first transient wave generated by the fault. The proposed scheme comprises of identifying the terminal with fastest arrival time of transient to find the faulted section and determine the fault location by calculating proper distance index. The simulation results have shown good performance of the proposed technique for various fault types, fault locations, fault resistances, fault inception angles, faulted sections, change in TCSC parameters and varying wind speeds when connected to windfarm. The performance of the proposed protection scheme is validated on the real-time digital simulator (RTDS) platform enhancing its applicability for the series compensated multi-terminal line.
40 A Power and Voltage-Angle based Index for distinguishing Symmetrical fault from Stable Power Swing
Shalini, Subhransu Ranjan Samantaray and Ankush Sharma
Abstract: This paper presents a new method for distinguish-ing symmetrical fault from stable power swing condition. It proposes a method to identify symmetrical fault as well as a fault during power swing which is otherwise difficult due to symmetrical nature of power swing. The algorithm utilizes synchronized phasor measurement unit (PMU) information at different buses in the transmission systems. The power transferred through each line and voltage angle at each bus is measured using PMU information and is used for detecting the faulted conditions in a transmission network. The performance of the algorithm is tested on an RSCAD platform for a modified Western System Coordinating Council (WSCC) 9-bus, 3-machine system with different fault scenarios.
41 Wavelet based Fast Fault Detection in LVDC Micro-grid
Shreyasi Som and Subhransu Ranjan Samantaray
Abstract: Low Voltage DC (LVDC) distribution system is gaining momentum which includes distributed energy resources and dc sensitive electronic loads. However, due to lack of standards and mature experience in dc protection, LVDC application is still an elusive issue. In order to ameliorate these deficiencies, a wavelet based fast fault protection scheme using local measurements has been proposed for eliminating threat on voltage Source Converters during fault. The wavelet energy and change in energy are the
key indicators to identify the fault with wide variations in operating conditions including the impact of grid-connected and islanded mode of operation. Further, the robustness of the proposed fast fault detection scheme has been validated for high impedance ground fault. The proposed scheme validation using Real Time Digital Simulation indicates that the proposed fault detector for LVDC micro-grid has potential ability in performing the desired task.
45 Implementation and Performance Evaluation of Bi-Pole HVDC Protection System using a Real Time Digital Simulator (RTDS)
K Vishnuvardhan Reddy, N Dhanunjayudu, S V N Jithin Sundar and T Tirupathi Reddy
Abstract: This paper deals with the HVDC protection system philosophy briefly and presents the HVDC protections, which are exclusive for HVDC system. This paper also describes the typical point to point Bi-Pole HVDC link protections implementation on a Hybrid Hardware consisting of high speed processor & Field Programmable Gate Arrays (FPGA’s) based I/O cards. Finally, Testing & Evaluation of the real time performance of the implemented protections using a Real Time Digital Simulator (RTDS), has been explained.
The protections system developed has been benchmarked with a ±500kVdc, 2500 MW Line Commutated Converter (LCC) based Bi-pole-HVDC link project. The Hardware-In-Loop (HIL) test results of implemented critical HVDC Protections like Valve short circuit protection, DC line to ground fault protection, Commutation failure prediction & protection are presented. The performance of the developed system has been found to be in agreement with that of the benchmarked Bi-pole HVDC protection system.
84 Detection and classification of Open Conductor faults in six-phase transmission system using k-nearest neighbour algorithm
Sunil Kumar Shukla and Ebha Koley
Abstract: The considerable rise in the demand of electrical energy in the existing power framework call for alternative solution. In this regard, six-phase transmission system seems to be the possible alternative which enables 73% more power handling capacity with existing transmission network. However, inspite of the associated advantages, protection of six-phase transmission line is still persisting as a great challenge. In this paper, a K-nearest neighbour (kNN) based protection scheme have been presented for detection and classification of all open conductor faults for a 138 KV six phase, 68 km long line simulated in MATLAB/Simulink environment. The fundamental components of current signals retrieved at the relaying point are used as input attributes to be fed to train the KNN. The effectiveness of the proposed scheme has been examined by variation in fault parameters such as inception angle and fault location. The observed results clearly reveal the performance of proposed technique in undertaking the intended task of detection/classification of open conductor faults in less than one cycle time. This validates the appropriateness and adaptability of the scheme under widely varying operating conditions.
144 Impact of UPFC on Alpha Plane line current differential protection
Bhupendra Kumar and Anamika Yadav
Abstract: This paper presents an impact on alpha plane characteristics of line current differential protection in presence of unified power flow controller (UPFC). UPFC is a versatile device with the ability to regulate bus voltage and control power flow of the transmission line independently and simultaneously; hence, it has an impact on the current signals received at the relay location. With the advancement in synchrophasor technology and wide area measurement system for transmission line protection, the differential protection scheme is a most suited scheme over the over-current, distance and directional protection. To investigate the impact of UPFC on alpha plane line current differential protection, detailed model of UPFC has been simulated in MATLAB and dynamic behaviour of the UPFC is considered. Moreover, an impact of different operation modes of UPFC and different compensation level on alpha plane characteristics are evaluated.
227 Instantaneous Symmetrical Components Based Microgrid Interface Protection Relay
Anoop V Eluvathingal and Shanti Swarup
Abstract: In this paper a new protection relay for interfacing microgrids with inverter based sources to an active distribution network is proposed. The proposed relay algorithm is based on instantaneous symmetrical components. The proposed scheme can address the protection issues in active distribution networks, caused by variable fault current contribution from inverter based sources. The effectiveness of proposed method is analyzed by conducting simulation studies in the PSCAD/EMTDC software environment.
325 Protection of DC and Hybrid AC-DC Microgrids with Ring Configuration
Rabindra Mohanty and Ashok Kumar Pradhan
Abstract: This paper presents protection techniques for DC and hybrid AC-DC microgrids. The DC microgrid protection is proposed based on difference of transient energy at both ends of the line to be protected using voltage and current measurements. Method can identify the fault is either internal or external. An index is calculated using discrete Fourier transform (DFT) of oscillating current in DC side for a fault in AC part of a hybrid AC-DC microgrid. The main goal of the protection scheme is to detect and isolate the faulted part without de-energizing the entire microgrid. These techniques are tested for high resistance faults, and radial and looped topologies and found to be accurate.

44 Performance Assessment of Different Droop Control Techniques in an AC Microgrid
Manjunath Kallamadi and Vaskar Sarkar
Abstract: The objective of this paper is to evaluate the performances of different droop control technologies that are proposed in literature for the real-time power balancing in a microgrid. Mainly, the decentralized droop control techniques are studied. The different attributes of the droop control are identified. Droop controllers are synthesized by considering all possible cases of an attribute. The generalized control architectures are presented based upon the broad classification of droop controllers. Extensive case studies are performed to verify the pros and cons of the selection of a particular feature in the droop controller. Both the transient and steady-state performances are evaluated.
169 Defining the boundaries of Microgrids in a large distribution system ensuring supply security
Kavitha S, Jayashree R, Mohamed Rafeequdin I and Karthikeyan Danasagaran
Abstract: A systematic procedure for defining the boundaries of microgrids, in a smart distribution system, becomes an essential part of building smart grids. A novel approach is proposed in this paper to build self sufficient microgrids, by splitting a large distribution system into a required number of microgrids. These microgrids will be capable of utilizing maximum output from the distributed renewable energy units, at any point of time. It will be ensured that the critical power requirements in the distribution system are always met, during the grid-connected and the islanded modes. This procedure can be carried out at the time of generation expansion planning, considering the probabilistic nature of distributed generator (DG) units. The uncertainties associated with real and reactive
power injection of various DG units and the loads are taken into account. The well-known PG&E 69-bus distribution system is
chosen, to check the effectiveness of the proposed approach.
170 Coordinated Control and Operation of a Multi-microgrid system
Saroja Kanti Sahoo and N. K. Kishore
Abstract: The concept of a microgrid is evolving due to the rapid growth of renewable energy resources and advancement in power electronics technology. The multi-microgrid operation is a way of improving the reliability of the overall system especially when the utility is absent. In this paper, a multi-microgrid system consisting of two microgrid structures with DFIG-based wind energy and solar energy based generation along with battery energy storage system is proposed. A coordinated control and operation of the multi-microgrid system are achieved in the gridconnected and isolated mode under various operating conditions.
274 Dispatchable Wind Power Generation Planning for Distribution Systems
Nand Kishor Meena, Anil Swarnkar, Nikhil Gupta and K. R. Niazi
Abstract: In this paper, a set of new planning strategies are proposed to optimally accommodate aggregated capacity of wind farms with special switching arrangements to make these dispatchable. The goal is to mitigate the issues of intense renewable power penetration on distribution systems such as wind power curtailment, reverse power flow problem, high voltage problem etc. The proposed model is investigated on a standard 33-bus radial distribution system and genetic algorithm is used to solve it. The simulation results of proposed model are compared with the same obtained by conventional planning models, which shows that the proposed approach is promising.
282 Reduced Communication based Local Averaging Method for Low Voltage DC Microgrid
Soumya Thomas, Soumya Ranjan Sahoo and Sandeep Anand
Abstract: DC microgrid consists of distributed sources, energy storages and loads interfaced through power electronic converters. In dc microgrid, maintaining low voltage regulation and proportional load sharing in various load conditions are the main objectives. Various communication based distributed control schemes are proposed in the literature, which have proven to be effective in realizing the aforementioned objectives. However, the existing schemes rely on an all-to-all/full communication topology. This results in a vast and unreliable communication architecture. A reduced communication-based cooperative control strategy is proposed in this paper to attain low voltage regulation and proportional load sharing. The communication topology is fixed and directed such that each converter receives information from at least one other converter. The source converters exchange their current measurements only with their neighbors. Each source converter uses this information to compute the local average current. This local average current is used to adjust the droop gain and voltage shift in the droop characteristic of the source. A small signal model with proposed control strategy for the microgrid is presented. Simulation results illustrate the performance of the microgrid with the proposed control scheme.
295 Optimal Positioning and Sizing of Distributed Generations in Radial Distribution System with Consideration of Real Power Loss and Short Circuit Currents
Snigdha Rani Behera, Soumya Prakash Dash and Bijaya Ketan Panigrahi
Abstract: Integration of DGs is beneficial to power system and society with respect to environmental, economical and electrical aspects. Therefore the optimal positioning along with sizing of distributed generations (DGs) for the radial distribution system (RDS) has been obtained in this presented work. Here the objective is concerned with different operational benefits to RDS along with the effect on short circuit current during symmetrical faults after insertion of DGs. Two indices, short circuit Index (SCI) and line current index (LCI) during short circuit are defined in this work to reflect the effect of DGs. The primary aim is to reduce the real power loss of the system along with reduction of adverse effect of DGs without degradation of system performance. The IEEE 69 bus balanced RDS with constant power load has been considered as test system. The weight based multi objective optimization technique is carried out using Differential Evolution Algorithm (DE).
360 Harmonics Detection Based Control of Solar-BESS Microgrid with Grid Synchronization
Shailendra Kumar and Bhim Singh
Abstract: This paper proposes a solar-battery energy storage system (BESS) based microgrid with the harmonics detection based control. Besides, the seamless transition capabilities, the proposed microgrid mitigates the power quality disturbances because of highly nonlinear load connected at point of interconnection (PIC). In this context, the voltage source converter (VSC) is controlled in grid connected and islanded mode depending on the availability of utility. The voltage control and current control are utilized together with synchronization control to synchronize a three phase microgrid to the utility. The harmonics detection current control forces the extracted fundamental current to be sinusoidal at highly nonlinear loads. Moreover, a PV (Photovoltaic) feed forward term (PVFFT) is also included in harmonics detection control for injection of extracted solar PV power to the distribution system under grid connected mode and to improve the dynamic behaviour under climate changes. Simulation and experimental results of solar-BESS based microgrid are presented under numerous operating states.
372 Optimal Allocation of Electronic Load Controller in Microgrid
Ankit Uniyal and Saumendra Sarangi
Abstract: The variation of voltage profile and active power loss in an isolated autonomous micro-grid system is a significant issue especially during the off peak loading condition. Voltage and frequency deviation for such a condition can be minimized consuming the excess power in a dump load. The optimal allocation of such load in the system can sort out violation of limits of voltage and frequency. The main objective of this paper is: (i) Finding out the optimal location and size of dump loads considering single and multiple objectives at off-peak hour. (ii) Assessing the voltage and loss profiles of the micro-grid with and without dump loads (ii) comparison of both the methods. The analysis has been carried out for an IEEE 33 radial bus test system modified as an autonomous isolated micro-grid. Results show the performance of the micro grid can be improved using such an approach.

13 A Comparitive Study Based On Objective Functions for Optimum Coordination of Overcurrent Relays
Nirmal Khristi, Jay Shah, V. N. Rajput and K. S. Pandya
Abstract: In the optimum coordination of Directional Overcurrent Relays (DOCRs), operational time of relays is minimized with maintaining coordination criteria between Primary and Backup (P/B) relay pairs. In the literature, a range of Objective Functions (OFs) including constraints with various weightings are developed to obtain the optimum coordination of relays. In this paper, the performance of different OFs is evaluated on IEEE 30-bus system. The comparative analysis is executed to find the best OF for the coordination problem of DOCRs.
201 A Coordinated control strategy using Rotor current limiter and switchable type stator passive resistive fault current limiter for enhanced fault ride-through
Vikas Sihag, Subhendu Sekhar Sahoo, P.M. Tripathi and Kalyan Chatterjee
Abstract: Doubly fed induction generator (DFIG) is widely used wind generator in recent years. However DFIG most prone to the fault. The consequences of the fault are rotor current, stator current and dc link over-voltage. These are the predominant causes of destruction of the generator and converter, which forces the disconnection of generator from the grid. However modern grid code does not allow the disconnection. So protection system is most predominant requirement for effective continuity operation. This paper proposed an enhanced strategy for handling the fault consequences. For revealing the effectiveness the results obtained using proposed scheme are compared with the rotor current limiter. The simulation is carried out in MATLAB\SIMULINK environment.
259 Optimal Selection of Significance Level for g-Means Algorithm Based Load Profiling
Mudassir A Maniar and Abhijit R Abhyankar
Abstract: Clustering Algorithms like k-Means, Fuzzy C Means (FCM), Self-Organizing Maps (SOM), Gaussian Mixture Model (GMM), Expectation Minimization (EM), etc. are adopted for load profiling. For all such clustering algorithms, number of clusters to be formed should be known a priori. But initial guess about a number of clusters is not always available for most of the applications. So, Cluster Validity Indices (CVI) are evaluated to quantitatively assess and judge the outcome and the number of clusters. Recently, g-Means clustering was proposed for load profiling where a number of clusters are evaluated by an algorithm based on specified significance level. Selection of is crucial for extracting optimal number of profiles or groups. This paper demonstrates the effect of on load profiling outcome and proposes a methodology to select appropriate value of the. Real Life data of 176 feeders of Central Indian state discom has been used to validate the proposal.
270 A Hybrid Approach to Solve OPP Problem Using Graph Theory and AHP
Pronob K. Ghosh, Soumesh Chatterjee and Biman Kumar Saha Roy
Abstract: This paper proposes a hybrid method for optimal PMU placement (OPP) using the graph theoretic approach and Analytical Hierarchy Process (AHP). Three effective criteria have been chosen from the network graph model to form a decision matrix for AHP. Then AHP does vertex ranking and edge ranking. The spanning tree has been formed from the parent graph according to the edge ranking. Some strategic locations have been identified from the spanning tree for PMU placement. The proposed method has been tested for IEEE 14-bus, 24-bus, 30-bus, 57-bus, 118-bus and New England 39-bus test systems. The proposed method successfully provide optimal PMU placement for complete observability of the systems studied. PMU placement obtained by the proposed method have been compared with the solution of the some other existing methods for the solution of OPP. The proposed method is found suitable and easy to implement.
312 Optimal Placement and Sizing of Multiple Active Power Filters for Radial Distribution System Using Grey Wolf Optimizer
Ashokkumar Lakum and Vasundhara Mahajan
Abstract: This paper presents, grey wolf optimizer (GWO) algorithm to solve a constrained nonlinear optimization problem of optimal placement and sizing of multiple active power filters (OPSMAPFs) for radial distribution system (RDS). It is a nature inspired stochastic algorithm. It has balanced exploration and exploitation characteristics. Minimization of the current of APF is taken as an object with three inequality constraints. To evaluate the performance of GWO algorithm, the simulation is performed on 33-bus RDS for twenty independent runs and compared with recently developed dragonfly algorithm (DA) and whale optimization algorithm (WOA). Simulation results demonstrate the effectiveness and stability of GWO algorithm.
315 Contingency Constrained Optimal Placement of PMUs For Wide Area Low Frequency Oscillation Monitoring
Abhilash Kumar Gupta, Kusum Verma and Khaleequr Rehman Niazi
Abstract: Power system low frequency oscillations' monitoring is a vital issue in operation of modern interconnected power system. The main reason behind it is that the poorly damped low frequency oscillations can occur under stressed conditions and can lead to system break-up or blackout. The modern utilities employ real-time wide area based monitoring using Phasor Measurement Units (PMU). So the optimal PMU placement is the most pertinent aspect to be taken care of keeping an eye on purpose of deployment and system characteristics. This paper addresses this problem keeping in mind both the system’s topological aspects and its behaviour. A multi-criteria contingency constrained approach is proposed for optimal PMU placement for real-time wide area low frequency oscillation monitoring. The buses critical to oscillation point of view are obtained using different criteria and then included in an Integer Linear programming approach. The proposed approach takes care of complete system observability and also considers single line outage and PMU loss. The proposed method is applied on IEEE-39 bus system and findings are shown. The proposed scheme, however, is not limited to present application and any number of practical criteria can be used in this generalized approach to evaluate PMU locations for different applications.
320 Optimal Tie Line Placement of Distribution System Incorporating Performance Based rates
Aprajay Verma and Shanti Swarup
Abstract: In this paper optimal tie line placement problem is solved focusing on minimization of penalties incurred by Distribution System Operator(DSO) for not meeting reliability standards .A discrete function of penalty rate was taken which varies increasingly with interruption time. The risk profiles of each load was simulated by Monte Carlo simulation method considering failure outage data of the feeders and lateral transformers. A graph theory based distribution load flow has been conducted and optimal tie line location was found out by fundamental loop based algorithm.

54 Fault Diagnosis in Distribution Power Systems Using Stationary Wavelet Transform and Artificial Neural Network
Himadri Lala, Subrata Karmakar and Sanjib Ganguly
Abstract: Short-circuit faults are the most commonly occurred transient events in a distribution system. Therefore, it is necessary to analyze fault transients to detect and localize. Detection and localization of faults in a distribution power system are very difficult due to the complex structure of the system. This paper presents an efficient time-frequency based detection and localization algorithm for distribution system faults. The proposed algorithm suggests a feature extraction from the transient signal using Stationary Wavelet Transform and machine-learning using Artificial Neural Network to detect and localize fault transients. The result obtained in this study proves the reliability of the proposed algorithm by achieving better accuracy in fault detection and localization.
71 Energy Management of Photovoltaic and Battery Energy Storage Based Grid Tied Three Level Inverter System
Archita Saxena, Hiralal Suryawanshi, Amardeep Shitole, Girish Talapur and Abhishek Chanekar
Abstract: With the increase in energy crisis and pollution, the solar energy terms out to be an alternative solution. This paper proposes a system comprising of PV array and a Li-ion battery connected to the grid through a three phase, three level diode clamped inverter. A power flow algorithm is proposed which determines the modes of operation of the system during climatic variations. The inverter is controlled by using synchronous reference frame technique that controls the active power injection into the grid and also regulates the dc-link voltage to a constant value. PLL (Phase locked loop) technique is used to detect the phase angle of the grid voltage. The inverter injects current into the grid in phase with the voltage to get desired unity power factor operation. The system is studied under different scenarios and verified by the result of the simulation.
225 Modeling and Simulation of Virtual Power Plant in Energy Management System Applications
Naina P. M, Haile-Selassie Rajamani and Shanti Swarup
Abstract: The high penetration of renewable resources in the existing grid, increases the complexities of the grid. Nowadays, the integration of renewable resources became a big issue. The participation of these resources in electricity markets is also a problem. The concept of virtual power plant (VPP) can enable the market participation of small generating units. The VPP can provide ancillary services like frequency support, reactive power support. This paper explains the VPP concept, the structure of VPP and also the market participation. An Energy Management algorithm for VPP is also explained. A small VPP model, consists of two distributed generation (DG) sources and two controllable loads, is demonstrated in MATLAB-SIMULINK. In addition, the current situation of the VPP, and identifies and proposes the future research lines.
269 Stochastic Distributed Energy Resource Management
Ye Ma, Satishkumar Ranade, Ankith Nadella, Nataraj Pragallapati, Jose Tabarez and Wenxin Liu
Abstract: This paper presents risk-based stochastic scheduling of distributed energy resources (DER) such as renewables, demand response and electric vehicles in an islanded system with limited conventional generation. The objective is to minimize the expected cost plus the risk of curtailing critical load. This risk is caused by uncertainty in renewable generation and demand. A stochastic batch sub-gradient approach is used to develop day ahead schedules under varying levels of DER penetration to demonstrate the importance of risk-based scheduling. The studies also bring out the synergies between modern DER technologies and underscore that, together, they permit high penetration with economic benefit and managed risk.
313 Reactive Power Management in Transmission Networks
Manohar singh, Vishnu vardhan T, J Pradhan and K S Meera
Abstract: Reactive power is an essential component for the smooth flow of the apparent power in the power networks. Generators are prime source for reactive power generation, to meet the network reactive power demand of network and load. This result in excessive flow of reactive power over the transmission corridors and may lead to voltage instability and uneconomical operation of network.
The control of reactive power in a small power system is straight forward, particularly when the load is reasonably stable/steady. However the control of reactive power is highly challenging for the power utilities operators in large power systems, where the power network consists of long distance power lines and highly variant load due to wide varying seasonal conditions. In this research article a simple reactive power management algorithm has been presented, so as to manage the reactive power flow in Northern Region of Indian grid which is experiencing wide variation in the daily and seasonal load curve. The finding of this work are in concurrence with the Indian grid code and are recommended to the northern region of Indian grid to manage their reactive power demand for next few years
339 A Novel Architecture to Achieve Power Balance by Responsive Demand
Anjali Jain, Ashish Mani and Anwar S. Siddiqui
Abstract: Electric power grid works well if power generation is always equal to power demand. However power demand is very dynamic in nature. Moreover, the inclusion of renewable energy sources in grid make the generation stochastic and intermittent. This makes generation dynamic as well. Usage of power by customers cannot be controlled by utility. Hence the solution is proposed to make the demand responsive in nature so that demand is always equal to generation. The power system can work really well if the parameters value at different location is known to the central utility centre where appropriate action can be taken depending on the conditions of the parameter values. Hereby, a novel architecture is proposed to maintain the power demand equal to power generation at all times wherein the control of power can be done centrally from the load dispatch unit. This paper addresses the discussion on communication technologies used for communicating generation with load and vice versa, and the system architecture to meet the power balance at generation and distribution level.
377 Reducing Distribution Losses using Distributed End-user Reactive Power Support
Charan Teja S, Jyothi Gajula and Pradeep Kumar Yemula
Abstract: Distribution losses are one of the major concern for India. According to central electricity authority(CEA) executive summary report May 2017 transmission and distribution losses accounts for about 22%. These losses can be reduced by improving power factor via local reactive power supply. In order to address the above issue this paper proposes a method for distributed reactive power support using end user equipment. The main contribution of this paper is to find the optimal bus location for reactive power injection considering the availability. A sensitivity matrix for power loss with reactive power injection is built for finding the optimal bus location subject to the availability of reactive power support at that location. In order to demonstrate the proposed solution approach, a IEEE 33 bus radial distribution system is taken. Results of the case study are obtained by using MATLAB programming and the same are presented. Obtained results show about 30% of reduction in losses and improvement in the voltage profile.
399 Isolated PV-Battery Management System to Power Home Appliances
Deepak Pullaguram, Shivraman Mudaliyar, Sukumar Mishra and N Senroy
Abstract: This paper presents an intelligent and cost effective approach for a photo-voltaic and battery based DC system. Typically a rooftop Photovoltaic (PV)-battery system employs an inverter to drive various home appliances. This conversion from low voltage DC to AC invariably causes an increase in both losses and cost. This paper proposes a novel back to back dc-dc converter topology for a PV-Battery standalone system that can cater to various daily home appliances eliminating the need for an inverter system. The proposed topology renders an additional degree of freedom where the load side converter regulates the load power by regulating the load voltage within limits without much effecting the load performance. Further, source side and load side power management schemes are developed which regulates the load voltage (within limits) and PV array output keeping battery’s state of charge into consideration. The proposed system is simulated in Matlab/Simulink environment. The results obtained under different loading conditions validate the proposed method.

81 Fault Detection Of Switches in Multilevel Inverter Using Wavelet and Neural Network
Ujjval B Vyas and Srivani S. G.
Abstract: A Multilevel Inverter (MLI) with an advantage of low Total Harmonic Distortion (THD) is appropriate for the grid integration of solar photovoltaic power plants but the high number of switches makes them prone to failures affecting their reliability. In this paper a comprehensive outlook of fault diagnosis method along with practical implementation of 5 level Cascaded H-Bridge Multilevel (CHBMLI) is done. An algorithm is developed based on the output of CHBMLI. The operating range of input voltage to CHBMLI for proper working of algorithm is determined and an attempt is made to determine the operating range for a neural network based fault detection.
233 An Overview of DC-DC Converter Topologies and Controls in DC Microgrid
Shweta Dahale, Aakriti Das, Naran Pindoriya and S Rajendran
Abstract: DC Microgrid has a promising future due to its better compatibility with distributed renewable energy resources, higher efficiency and higher system reliability. This paper presents a comprehensive literature review of DC-DC Converters topologies used in DC Microgrids. The advantages and limitations of classical and recent converter topologies are discussed. The Hierarchical Control Strategies-Primary and Secondary controls have been reviewed. Primary control relies only on local measurements used for proper load sharing among converters. Secondary control is a coordinated control with some form of communication for additional functionalities. A brief note on protection and the key challenges faced in DC Microgrid operation have also been discussed. This paper gives a brief idea about the recent developments and overall operation of DC Microgrid.
235 A Predictor-Corrector Based Rotor Slip-position Estimation Technique for a DFIG
Mridul Malakar, Praveen Tripathy and Srinivasan Krishnaswamy
Abstract: This paper presents a novel closed loop predictor-corrector based rotor slip-position estimation technique for a doubly fed induction generator (DFIG). The stability of the estimator has been analyzed and the range of gain for which the algorithm converges has been calculated. Finally, the working of the estimator has been simulated using PSCAD software and validated through hardware implementation using TMS320F28335 DSP kit along with the DFIG setup.
291 Knowledge Domain Inference Mechanism Linked Power Control Concept
Rajendra Kumar Pandey and Deepak Kumar Gupta
Abstract: This paper presents the development of knowledge domain inference concept with various well-known optimization techniques. The state variables of the system may deviate from the desired limits as operating conditions changes, so retuning of the controller is attained at almost the same time frame (with some controller switching delay) with inference rule linked with knowledge domain which brings all the states to acceptable limits in automation. The best optimization technique for the development of knowledge domain inference concept has been proposed for quick oscillation at varying perturbation. Particle Swarm Optimization (PSO), Gravitational Search Algorithm (GSA) and Firefly Algorithm (FA) have been used with Integral Time Multiplied by Absolute Error (ITAE) as an objective function. These techniques have been used to generate knowledge domain for Power System Stabilizer (PSS) control parameters offline at various operating conditions. This paper recommends the optimization techniques which performs best for the development of knowledge domain of PSS controller and related tuning.
348 Takagi-Sugeno-Kang Fuzzy Model-Based Self-Adaptive Maximum Power Harvesting Technique for PV Array: Tested on European Standard EN50530
Nishant Kumar, Bhim Singh and Bijaya Ketan Panigrahi
Abstract: This paper presents a self-adaptive maximum power harvesting technique for a PV array, which is executed by using Takagi-Sugeno-Kang fuzzy logic control (TSKFLC). Here a self-adaptive technique is based on an amount of power change, which is due to environmental changes (insolation and temperature). This approach enhances the dynamic response as well as reduces the steady state oscillations, which improves the efficiency and robustness of the system. The main purpose of development of self-adaptive based TSKFLC is maximum power harvesting from a PV array, in uncertain atmospheric conditions. The effectiveness of this self-adaptive based TSKFLC is evaluated on European standard-EN50530 test system. The testing in dynamic as well as in steady state conditions, is performed on MATLAB Simulink platform. After that, it is implemented on experimental setup, which satisfactory performance shows a fulfilment of the objective of the work.
425 PMSG Based Wind Power Generation for an Isolated Irrigation System with Inbuilt Frequency Regulation Capability
Ranjan K. Behera and S. K. Parida
Abstract: This paper proposes a robust wind and battery storage power system for remote induction motor as irrigation load under islanded operation. A direct torque control (DTC) of permanent magnet synchronous generator (PMSG) is used as wind energy conversion system and the battery is supported at the dc-link of back to back voltage source converter (VSC). The battery energy storage system (BESS) need to fulfill two objective, one is to support dc-link voltage and to remove the secondary frequency drop issue during the rotor speed restoration. A coordinated control technique is adopted in this work and which will ensure smooth operation of complete system. The battery storage system along with irrigation pump side converters are able to control and maintain the active power balance during over and under generation conditions as well as sudden load changes. A direct torque control method is used for controlling the induction motor drive. A suitable LC filter is used to avoid the effect of switching voltage on the irrigation load. Using simulation studies, it has been verified that the proposed PMSG and BESS systems are able to regulate the load side voltage and frequency within the acceptable limits even during the rotor speed restoration period. An experimental prototype of 2.5 kW rating is built in the laboratory to verify the proposed strategy and their associated control strategies have been developed using TMS320F240 processor.