Patent ID: 8558500
Filing Date: 2013-10-15
Classification: B60L,H02P,Y02T

Abstract:
1. A control system for an AC motor, comprising: an inverter that converts DC voltage into AC voltage for driving and rotating the AC motor; and a rectangular wave voltage controller that controls a voltage phase of a rectangular wave voltage applied to the AC motor so as to perform torque control, wherein the rectangular wave voltage controller includes: a linear approximation unit that calculates a first slope as a ratio of a change in torque to a change in the voltage phase at a first operating point, based on the voltage phase and an operating state of the AC motor, said first operating point corresponding to the current operating state and voltage phase; and a phase change amount calculation unit that calculates a torque compensation amount based on a command value of the torque control, and calculates an amount of change of the voltage phase according to a first phase change amount obtained by dividing the torque compensation amount by the first slope.