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

Paper Abstracts - Session Wise

 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. 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. 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. 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.

 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. 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: Conventional passive islanding detection techniques based on the rate of change of voltage, phase angle and frequency perform well in case of large power mismatch at the distributed generation terminal after loss of utility power supply. 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 negative-sequence current to positive-sequence current are introduced which in combination with the conventional features detects islanding condition 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 results clearly show that using proposed method a fast and reliable islanding detection task 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.