Multi-module-cascade high-voltage composite switch

Application of low-voltage insulated gate bipolar transistors (IGBTs) in high voltage power electronics system is attractive for low cost, high operating frequency, low weight and low volume. The paper presents a multi-module-cascade High-Voltage Switch based on modular multilevel converter (MMC). With the cascade of low-voltage modules, it is realized high-voltage composite switches with working voltages of several kilovolts. The switch proposed can absorb voltage spikes caused by parasitic parameters and back energy stored in parasitic parameters to power supply. The voltage balancing is automatic during conduction mode. The voltage-balancing scheme during static and dynamic transient state is explained and analyzed in detail. The simulation results are presented to verify the validity of the scheme.