Study of rapid speed-changing methods in ac. motor drives

Previous studies of speed changing in induction motor drives have been concerned either with varying the frequency of a sine-wave supply, or have considered steady-state or quasi-steady-state operation with inverters. The present contribution discusses various techniques for controlling the start-up performance of an induction motor system with sine-wave, 180° inverter and 120° inverter waveforms. Computed results are presented using a well tried and tested digital computer program.