Power System’s Voltage Stability Improvement Using StaticudVar Compensator

摘要

In alternating current systems, voltageudfluctuation is a common phenomenon. Most of the voltageudfluctuation problems result from the changes in the system’sudreactive power resulting from excessive supply orudconsumption of reactive power by the elements of the systemudand the variation in the consumers’ loads. In this paper, theudeffect of Static Var Compensator (SVC) in stabilizing powerudsystem’s voltage through effective reactive powerudcompensation was investigated. Power flow equationsudinvolving voltage drop with/without SVC were developed.udSVC modeling equations were also developed and used touddetermine its parameters. Based on the SVC parameters,udSIMULINK blocks were used to implement the phaseudcontrolled Thyristor–Controlled-Reactor Fixed-Capacitorud(TCR-FC) SVC. The Nigerian 28-bus power system used forudthe study was also modeled using SIMULINK/MATLAB. Theud28-bus system was first simulated without SVC and then withudtwo SVCs located at different buses to obtain the bus voltagesudin both cases. From the bus voltages the total voltage dropsudfor the system with and without SVC were estimated andudcompared. The compared results clearly showed that, theudsystem’s voltage drop was reduced by 33.78% indicating audsignificant improvement in the system’s voltage stability whenudSVCs were applied.