A low loss matrix converter for AC variable-speed drives

This paper reports the construction and testing of a matrix power convertor in which novel switching methods are employed to minimise the losses in the switching devices. A mixture of hard and soft commutation is used during each cycle of the output waveform. This permits losses to be reduced to a minimum while waveform quality is enhanced. It is demonstrated that at elevated switching frequencies the efficiency of a matrix power converter can be comparable to that of traditional inverter drives. IGBTs are used as the switching devices and a microcontroller is used to generate the switching waveforms and provide control. Reactive components have been minimised so that the matrix converter is now approaching an all-silicon solution to AC-AC power conversion. Practical results are presented