A high switching frequency IGBT PWM rectifier/inverter system for AC motor drives operating from single phase supply

A PWM (pulse width modulation) rectifier/inverter system using IGBTs (insulated-gate bipolar transistors), capable of switching at 20 kHz, is reported. The base drive circuit for the IGBT, incorporating short circuit protection, is presented. The inverter uses an Undeland snubber together with a simple energy recovery circuit, which ensures reliable and efficient operation even for 20 kHz switching. The front end for the system is a regenerative single-phase full-bridge IGBT inverter along with an AC reactor. The steady-state design considerations are explained, and control techniques for unity power factor operation and fast current control of the front end converter, in rotating as well as stationary reference frames, are discussed and compared. Results from computer simulations and experimental results for a 1.5 kW prototype system using GE type 6E20 IGBTs are presented.<>