PERFORMANCE ANALYSIS OF AN ASYMMETRICAL PHASE-CONVERTER-FED INDUCTION-MOTOR

Of the various types of single-phase-to-three-phase static converters used to interface a three-phase motor to single-phase supply, one simp le type uses an open delta connection of a sinusoidal supply and a pul sewidth modulated (PWM) waveform to feed the motor. This paper present s an analysis of the performance of the three-phase motor when fed fro m such an asymmetrical supply. The analysis is based on the steady-sta te approximate-equivalent circuit of the motor, using the method of sy mmetrical components. The analysis is directed toward prediction of mo tor phase and line currents, along with the nature of generated torque . The computer-simulated waveforms are presented and compared with res ults from tests on a laboratory setup.