Optimal Location Of Series-Shunt Facts Devices In Transmission Line And Impact Of SSSC Compensated On Performance Of Distance Relay

The research works says that the impacts of facts devices changes with the change of their location on transmission line. Basically in power system we have two types of compensation devices. First is series facts devices, second is shunt facts devices by using these devices controlling of transmission line voltage and power flow is possible. Facts devices are also very useful to control the reactance power of transmission line and damping of power system oscillation for high power is possible. Series facts devices are connected in series of transmission line and works as a controllable voltage source. Shunt facts devices are connected in shunt with power system line.it works as a controllable current source. During the SLG fault, shunt capacitance of SSSC-compensated line affects the performance of distance relay. Research also shows the impact of ignoring the shunt capacitance of the line on the distance relay over and under reach conditions. By using MATLAB we can study the effects of series and shunt compensation according to the variation of location of these in transmission line. We can find the most suitable and optimal location of series, shunt or the combination of both compensation

Modified discrete Fourier transform algorithm for protection of shunt compensated distribution line

Introduction. The response time of the relay plays vital role when fault occurs on the line. Various algorithms are adopted to increase the sampling rate of the relay which, in turn, improves the response time. Methods. Discrete Fourier transform and modified discrete Fourier transform are the two algorithms used to calculate the fundamental frequency phasor of the signal required by the relay to initiate trip command. It is known that discrete Fourier transform takes four to five cycles to produce the fundamental frequency phasor but it fails to deal with the decaying DC component. On the other hand, modified discrete Fourier transform improves the response time by removing the decaying DC component along with the other harmonics in just one cycle and a few samples. The aim of this paper is to cover discrete Fourier transform and modified discrete Fourier transform algorithms to analyze the performance of the three overcurrent and one earth fault relaying scheme for different types of faults occurring in the distribution system. Methodology. The concept of three overcurrent and one earth fault scheme is also explained in this paper for protection of shunt-compensated distribution system. The scheme is designed for variable power factor. MATLAB/Simulink is used as the software tool to validate the results obtained for various types of faults occurring in the system. The results are represented graphically to illustrate the time of response of the protection scheme when shunt compensators are connected at the receiving end of distribution network.Вступ. Час спрацювання реле відіграє життєво важливу роль при виникненні несправності на лінії. Для збільшення частоти дискретизації реле застосовуються різні алгоритми, що, своєю чергою, покращує час спрацювання. Методи. Дискретне перетворення Фур’є та модифіковане дискретне перетворення Фур’є – це два алгоритми, які використовуються для розрахунку вектора основної частоти сигналу, необхідного для реле подачі команди на відключення. Відомо, що для отримання вектора основної частоти дискретного перетворення Фур’є потрібно від чотирьох до п'яти циклів, але воно не справляється з постійною складовою струму, що згасає. З іншого боку, модифіковане дискретне перетворення Фур’є покращує час спрацювання, видаляючи постійну складову струму, що згасає, разом з іншими гармоніками всього за один цикл і кілька вибірок. Мета цієї статті полягає в тому, щоб охопити алгоритми дискретного перетворення Фур’є та модифікованого дискретного перетворення Фур’є для аналізу характеристик трьох схем реле максимального струму та однієї схеми захисту від замикань на землю для різних типів несправностей, що виникають у розподільчій системі. Методологія. У статті  пояснюється також концепція трьох схем перевантаження по струму і однієї схеми замикання на землю для захисту розподільчої системи з паралельною компенсацією. Схема розрахована на змінний коефіцієнт потужності. MATLAB/Simulink використовується як програмний інструмент для перевірки результатів, отриманих для різних типів відмов, що виникають у системі. Результати представлені графічно, щоб проілюструвати час спрацьовування схеми захисту, коли шунтуючі компенсатори підключені на приймальному кінці розподільної мережі

UPFC for Analysis of Relay Performance During Power Swing Condition

Distance relay plays important role in the transmission line as far as protection of the system is concerned. Now a days facts devices has been widely used in transmission line because of their numerous advantages, but its present in transmission line leads to some obstacle in operation of distance protection. Present of FACTS controller causes change in the measured impedance of the distance relay which in turn can cause undesirable tripping or improper operation of relay. So it is a challenge to correct the operation of distance relay in the presence of FACTS devices so that FACTS device can be used properly without any interruption. For this purpose, it is necessary to analyze the impact of these devices on relay under different circumstances so that new reach setting of distance relay can be made accordingly. This study presents effect of series and shunt compensator as well as UPFC on performance of distance relay with both analytic and simulation methods .In this study, its effects have been seen on the relay by comparing R-X characteristic and apparent impedance for different fault condition and location of the fault

Impact of Static Synchronous Compensatoron Performance of Distance Protection of Transmission Lines

The effect of static synchronous compensator (STATCOM) installed at transmission line on the performance of distance protection is investigated in this paper. The paper explores an apparent impedance calculation procedure for transmission line incorporating STATCOM based on the power frequency sequence circuits. A detailed model of 6 pulses STATCOM and its control and a mho relay model are proposed and integrated into the transmission system. The paper investigates distance protection operation of transmission lines with STATCOM connected at the midpoint during several operation conditions. Installation of STACTOM in the midpoint to control the reactive power flow affects the operation accuracy of distance relays. The simulation results of distance relays for the protection of transmission line incorporating STATCOM are presented. The analytical calculations show the impact of STATCOM on the distance protection relays during the different faults conditions. The study is carried-out using PSCAD/EMTC software

An Update on Power Quality

Power quality is an important measure of fitness of electricity networks. With increasing renewable energy generations and usage of power electronics converters, it is important to investigate how these developments will have an impact to existing and future electricity networks. This book hence provides readers with an update of power quality issues in all sections of the network, namely, generation, transmission, distribution and end user, and discusses some practical solutions

Errors Analysis in Distance Relay Readings with Presence of FACTS Devices

This  paper  presents studying the  performance of  distance impedance relay with the presence of  FACTS devices .Also  the measured  impedance  at   the  relaying  point  in  the  presence  of  series FACTS device SSSC , and  shunt FACTS device called STATCOM are obtained. A detailed  model of both SSSC and STATCOM  is  introduced  and  then  the  faulty  system is studied analytically , where  the  errors in the measured  impedance of distance impedance relay   are  introduced as a result of the presence of  series  and  shunt  FACTS  devices. The analysis results show the effect of impacting the FACTS devices location, the values of inserted SSSC and STATCOM voltages (operational conditions) and also the fault resistance values. Keywords: Distance Relay, FACTS, STATCOM, SSSC