A variable frequency space vector modulator for VSI fed induction motor drives

A space vector modulator with variable clock frequency is presented in the paper. It is based on the selection of the appropriate modulator clock frequency according to the minimum value of the switching states duration. The purpose is to reduce at the same time the dead time effect on the voltage inverter output waveform, the harmonic content and switching losses. The proposed techniques has been implemented by means of a digital modulator realized by using programmable logic devices. Several tests have been performed and the results compared with the fixed frequency modulation techniques.