Study on simulation model for reactive power compensator of a phase-control capacitor

Reactive power compensator of a phase-control capacitor and its characteristics are presented in this paper. Its operating principles and main circuit´s structure are described. When simulated by Matlab, the conduction angle of Gate Turn-Off Thyristor is adjusted, the voltage and current of the capacitor are changed, and the persistent current is derived in a period which can lead the equivalent electric capacity to change periodically. The voltage waveform is analyzed from the mathematic perspective. When the conduction angle of Gate Turn-Off Thyristor β changes from 90° to 180°, the equivalent capacitance is continuously changed from c/2 to c , then it can realize the purpose of dynamic reactive power compensation. By programming in Matlab, the study shows that system current only has odd harmonics, which can be filtered by the power filter.