Analysis, Simulation and Experimental Investigations on ac Chopper Fed Series Motor

Abstract

AC voltage controllers employing phase controlled Triac or back to back connected SCRs are widely employed for the speed control of ac series motors in a number of applications. They are found to create some problems such as introduction of harmonics, poor supply power factor, interference to communication equipments and heating of the motor. Chopping technique employing PWM control strategy is found to overcome some of the problems associated with phase control. Hence, in this paper, an attempt is made to introduce ac chopper for the speed control of ac series motor. The switching angles of the ac chopper are controlled to get a smoother output waveform. AC chopper fed series motor is extensively analysed and its performance compared with that of the conventional controller. The drive system is simulated in SIMULINK and the performance observed. Experimental investigations are also carried out on a power MOSFET based ac chopper fed series motor to confirm the theoretical results.

Indexing terms:

• AC chopper
• Series motor