A MULTILEVEL VOLTAGE-SOURCE INVERTER WITH SEPARATE DC SOURCES FOR STATIC VAR GENERATION

A new multilevel voltage-source inverter with separate de sources is p roposed for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS) including static var generation (SVG), p ower-line conditioning, series compensation, phase shifting, voltage b alancing, fuel cell, and photovoltaic utility systems interfacing, etc . The new M-level inverter consists of (M - 1)/2 single-phase full bri dges in which each bridge has its own separate de source. This inverte r can generate almost sinusoidal waveform voltage with only one time s witching per cycle as the number of levels increases. It can solve the size-and-weight problems of conventional transformer-based multipulse inverters and the component-counts problems of multilevel diode-clamp and flying-capacitor inverters. To demonstrate the superiority of the new inverter, an SVG system using the new inverter topology is discus sed through analysis, simulation, and experiment.