SVG using open-winding transformer and two inverters

The static Var compensator (SVG) is a practically used method for supplying reactive power to a power system. In a typical SVG system, a multiple inverter or a PWM (pulse width modulation) inverter with high carrier frequency is usually used. Certain drawbacks are associated with these methods, such as complex configuration of transformer or high switching losses. To overcome these problems, we propose a new high efficiency SVG system using an open-winding transformer and two space vector modulated inverters. This configuration consists of a 3-level inverter with switching at once every cycle and a 2-level inverter of about 1 kHz switching frequency, connected respectively to the opposite terminals of the open-winding transformer. With the proposed configuration, good current waveforms, high efficiency and low acoustic noise can be obtained.