Stability Improvement of Power System By Using SVC With PID Controller

Abstract— This paper presents the model of a static VAR compensator (SVC) which is controlled externally by a Proportional Integral Differential (PID) controller for the improvements of voltage stability and damping effect of an on line power system. The PID controller parameters has been selected by using Ziegler-Nichols tuning rule method. Both single phase and three phase faults have been considered in the research. Phasor simulation method has been used & Simulation result shows that the SVC with PID controller is more effective to enhance the voltage stability and increases power transmission capacity of a power system. It has been observed that the SVC ratings are only 40 MVA with PID and 200 MVA without PID. The damping was 0.01% with PID controller in compared to that of 0.5% without PID. For single line to ground fault, Using PID the system voltage, power(P,Q), speed deviation(dω) becomes stable in 1.5s and without PID controller 3.5s, 3s & 4.5s respectively. Similarly, For L-L faults, Using PID the system voltage, power(P,Q),speed deviation(dω) becomes stable in 1.4s, 0.7s & 2.2s and without PID controller system becomes stable in 5s respectively. So with PID controller the system performance is greatly enhanced.