| 摘要 |
PURPOSE:To generate the three-phase current command having an accurate sine wave form with the small distortion in the high frequency also for the subject induction motor by a method wherein a digital processing is performed using a speed command and an actual speed, and a digital current waveform generating circuit which outputs a slip frequency, and a processing device which outputs a phase difference and an amplitude. CONSTITUTION:A microcomputer 15 performs a digital processing using the speed command nc and the actual speed n, and output the slip frequency omegas, the phase angle theta and the amplitude I. Also, the digital current waveform generating circuit, consisting of counter circuits 16 and 17, a composite circuit 18, an up-down counter 19, decoders 20-22, D-A converters 23-26 and the like, outputs three-phase current commands iu, iv and iw. These current commands iu, iv and iw are give to are given to an induction motor driving circuit 27, and the three-phase induction motor is driven. |
