4719

4438

كارشناسي ارشد

قدرت

اصفهان: دانشگاه صنعتي اصفهان،دانشكده برق و كامپيوتر

1388

ده،94،[II]ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد مدني

محمد اسماعيل همداني گلشن

11/8/88

مهدي معلم، اكبر ابراهيمي

1396/09/20

كتابنامه

مهندسي برق و كامپيوتر

ID4438

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

The Impact of Static Voltage Sourced Compensators on the Performance of Distance Relays Azin Shojaei azin shojaei@ec iut ac ir Date of Submission 2009 6 2 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan Iran 84156 83111 Degree M Sc Language FarsiSupervisor Seyed Mohammad Madani madani@cc iut ac irAbstract Today s interconnected transmission networks with long distance between generation and load centersnecessitate exploiting permissible capability of the power transmission line As a result power system hasbecome increasingly complicated and therefore the reliability of such a system is reduced Flexible ACTransmission Systems FACTS are considered to be a partial solution for these problems Static voltage sourced compensators are the most important part of FACTS controllers If such a compensator is connectedin parallel with a system voltage of the connection point is regulated by the injected or absorbed reactivepower of the compensator On the other hand series compensators which inject capacitive or inductive seriesvoltage into a transmission line can control the line current and thereby the transmitted power StaticSynchronous Compensator STATCOM and Static Synchronous Series Compensator SSSC are examplesof series and shunt compensators respectively The third one is Unified Power Flow Controller UPFC which is based on two back to back voltage source converters is a multi functional FACTS controller TheUPFC compensator is a combination of series and shunt static voltage sourced compensators which arecoupled via a common DC link This compensator by means of angularly unconstrained series voltageinjection is able to control concurrently or selectively the transmission line voltage impedance and loadangle or alternatively the reactive and real power flow in the line The UPFC may also provide anindependently controllable shunt reactive compensation On the other hand Protection of transmission lines is a very important concern in power systems Distance relays are frequently used to protect transmission lines due to their simple and precise operation The protection design of a transmission line equipped with FACTS controllers involves selection of theproper settings and characteristic of its protective relays In such a line during fault the relay s voltage andcurrent signals will be affected by the FACTS intervene Therefore studying the impact of these controllerson the performance of distance relays is important This thesis introduces accurate models for positive negative and zero sequence networks ofSTATCOM SSSC and UPFC during fault Based on these models the apparent impedance seen by distancerelay can be easily calculated for different fault types For verification of the presented models thesecompensators with control loops details are simulated Simulation results confirm the accuracy of thepresented model The transient apparent impedance is also demonstrated in the presence of these controllersin the transmission line Then the influences of fault type fault location fault resistance system sourcecapacity and compensator settings on the performance of distance relays are investigated For simulation a500 kV transmission line with sources at each ends is proposed Simulations are executed inMatlab simulink Key Words FACTS Voltage Converter STATCOM SSSC UPFC Distance Relay Over reach Under reach

محمد مدني

محمد اسماعيل همداني گلشن

مهدي معلم، اكبر ابراهيمي