PC controlled transistorized pwm inverter for induction motor drive

Speed control of transistorized PW inverter fed induction motor with selective harmonic elimination and current controlled scheme using personal computer (PC) is described. The whole set of switching angles for eliminating the unwanted harmonies up to 550 Hz while controlling the fundamental corresponding to V/F graph of the machine for constant flux operation, and minimizing the immediate dominant voltage harmonic that will be present in output voltage of the inverter has been presented.The effect of lock-out time an the harmonic spectra,variation of switching frequency of the device, overall block diagram of the drive system with the necessary interfacing cards, their respective function and software realization of the above PWM -schemes have been presented.