The Mathematical Model and Simulation of Static Var Compensator in Medium Transmission Line

Problem statement: The Static Var Compensator (SVC) have been widely investigated its effect on transient stability of Single Machine Infinite Bus (SMIB) system. The exact medium transmission line model in power system consists of the series resistance series reactance and shunt capacitance. It is not easy task to obtain the mathematical model of the SVC with the exact medium transmission line model for investigating transient stability performance. Approach: This study applied the concept of the two-port network to simplify the mathematical model of the power system. The full capacity of the SVC on transient stability improvement of the SMIB with the medium transmission line was then investigated. The proposed method was tested on sample system and compared on various cases. Results: The first swing of rotor angle curve of the faulted system without resistance was obviously higher than that of with resistance whereas the second swing of the faulted system without resistance was slightly less than that of with resistance. The system with a SVC could improve transient stability of power system. Conclusion: The SVC and resistance of the line can improve first swing of rotor angle. The resistance of the line provides negative effect on second swing of rotor angle. The simulation results indicate that for practical medium line, the resistance is very import parameters for evaluating transient stability of power system.