Multifrequency space vector pulse width modulation for asymmetrical six-phase drives

Pulse width modulation (PWM) strategies for the control of asymmetrical six-phase drives have been widely studied since the beginning of this century. Carrier-based and different space vector PWM algorithms have been developed and evaluated. Nevertheless, there are still some challenges that require research work in this field. This paper deals with this topic, and introduces three space vector techniques. The methods are based in a recently developed scheme that combines the nearest two medium and two large size voltage vectors to synthesise the reference vector. The schemes enable either sinusoidal or multifrequency output voltage operation modes. Theoretical derivation supported by closed-loop tests demonstrate the viability and potential of the proposal.