| 摘要 |
PURPOSE:To maximize energy saving effect over the entire load region of induction motor by providing power factor command means, load variation parameter converting means, and the like, thereby controlling the induction motor at an optimal power factor which varies automatically depending on the variation of load. CONSTITUTION:The induction motor controller comprises means 18 for detecting power factor of an induction motor 12 being driven with an AC variable voltage power supply 10, means 36 for outputting an optimal power factor depending on the variation of load on the motor 12, and means 14 for comparing power factor with an optimal power factor and controlling the output voltage of the AC power supply 10. The optimal power factor generating means 36 comprises an arbitrary power factor command means 37, converting means 38 for outputting a compensation value which varies depending on the load variation parameters of the motor 12, and means 39 for calculating an optimal power factor value based on an arbitrary power factor and a compensation value. This controller varies the optimal power factor automatically depending on the variation of load on the induction motor 12 and operates the induction motor 12 with an optimal power factor over the entire operating region. |
