Considerations of harmonic and torque ripple in a large power doubly salient electro-magnet motor drive

The paper mainly discusses the problem of input current harmonics, output voltage harmonics and torque ripple in a large power doubly salient electro-magnet motor for air conditioner compressor. In order to select the proper input unit to reduce the input harmonics, the comparisons of multiphase rectifier and PWM rectifier are given. And in order to minimize the output harmonics and torque ripple, a novel dual stator doubly salient electro-magnet motor is presented, with suitable control algorithms. Also, the filters to optimize system performance are given. The overall strategy of motor drive is supposed to improve the electromagnetic compatibility. Finally, the strategy and control algorithms are utilized in a 200kW motor drive prototype.