A control strategy for a UPFC-based fast voltage compensator and its performance analysis

In this paper a control strategy for a UPFC-based voltage compensator is proposed which is capable of a fast compensation of short-duration voltage variations in a three-phase AC power supply line. The proposed voltage compensator produces three-phase compensating voltages injected into the line when the rms value of voltage at a specified point on the line becomes smaller (larger) than a specified lower (upper) limit. Simulation analysis of a voltage compensator based on the proposed control strategy is carried out to show the dynamic performance and effectiveness of the compensator. A method to simplify the circuit configuration of the proposed voltage compensator is then shown. Experimental investigations are carried out to justify the simulation analysis.