A multi-module PWM switched-reactor-based static VAr compensator

This paper presents a variable reactance-type static VAr compensator (SVC) which employs force-commutated switches as well as thyristors. The proposed compensator employs thyristor switched capacitors (TSC) and a fixed capacitor bank to control, in steps, the amount of reactive power generated. Fine adjustment of the reactive power generated and also the reactive power absorbed by the SVC are obtained with N modules of a new four-switch (force-commutated) PWM controllable reactor. These are controlled with phase shifted carriers in order to achieve harmonic cancellation. The features of this multi-module PWM SVC are analyzed using switching functions and confirmed with simulation results.