SPACE VECTOR PWM TECHNIQUE WITH MINIMUM SWITCHING LOSSES AND A VARIABLE PULSE-RATE

A novel randomized control strategy for three-phase voltage source inv erters, based on the voltage space vectors, is described. An implicit asymmetrical modulating function results in switching losses in the in verter being reduced by about half in comparison with those using the classic space vector pulsewidth modulation (PWM) method. The pulse rat e is varied within individual 60 degrees sectors of the vector plane, so that the power spectra of the output voltage are spread over a wide frequency range and acquire a continuous part. The relevant theoretic al analysis, computer simulations, and experimental results are presen ted.