Full-Bridge Reactive Power Compensator With Minimized-Equipped Capacitor and Its Application to Static Var Compensator

This paper discusses reactive power compensators from the point of stored energy in the capacitor, and proposes a single-phase full-bridge configuration of semiconductor switches to be used with reduced equipped capacitance for reactive power compensation. By applying this concept to shunt-type static var compensator, a static synchronous compensator can be achieved with reduced-sized capacitor. Additionally, the switching loss can be reduced due to its distinctive capacitor voltage waveform, which swings at the double of the line frequency. Modulation technique and capacitor voltage control method based on the reduced capacitance and high-voltage ripple in the capacitor are proposed. The concept and control method were confirmed with small-scale experiments.