A nonsinusoidal reference wave for PWM AC drives

The authors propose a suitable reference wave for pulse width modulation (PWM) AC Drives. Staircase reference waves whose levels are calculated to eliminate certain harmonics, are studied. A certain staircase reference waveform with L levels is constructed; when L is made very large, in limit, this staircase waveform approaches a continuous one which is called Quasine (Quasi+Sine). This approach compared to the classical harmonic elimination method has the advantage that the magnitude of nontriplen harmonics is reduced. The authors developed a computer program by TURBO PASCAL 6 to have a comparison between the harmonic contents of output voltage for various reference waveforms.