Simultaneous recovery commutation current source inverter for AC motors drives

Abstract

A simultaneous recovery commutation current source inverter is provided by connecting three AC output terminals of a main inverter and an auxiliary inverter in parallel with each other and to three terminals of an induction motor, providing a high AC impedance DC current source through inductors connected in series to a variable DC electric source so that DC electric power is supplied to both sides of a main DC bus of the main inverter, providing a low AC impedance DC voltage source by supplying DC electric power to both sides of an auxiliary DC bus of the auxiliary inverter through a rectifying circuit from the respective connecting points of the main inverter, auxiliary inverter and the three motor terminals. Snubber circuits may be added to the respective semiconductor elements for safe switching operation.