Control strategies for a hybrid static reactive compensator

This paper presents a hybrid approach for the reactive power compensation. The proposed approach combines a current regulated power electronic converter in series with the conventional static VAr compensator (SVC) connected in shunt to the power line. The current through this power electronic converter is controlled to inject sinusoidal currents of desired compensation level into the power system. The firing angle of the thyristors in SVC is controlled such that the fundamental voltage developed across it is equal to the line voltage. Consequently, the voltage stress on the power converter is decreased. A controller for this compensation system along with the start up strategy is proposed in the paper. Performance of the proposed approach is evaluated using computer simulations.