CONTROL SYSTEM FOR AC MOTOR

摘要

A control system for an AC motor determines a slope KtI of a tangent TL at an operating point Pa corresponding to the current motor operating state and voltage phase (TO) on a torque characteristic curve (500) that is plotted according to a torque equation representing an output torque characteristic with respect to the motor operating state and the voltage phase of the rectangular wave voltage. The control system further calculates a voltage phase change amount ?ff for use in feed-forward control, according to ?Ttl/Ktl obtained by dividing a torque compensation amount ?Ttl for feed-forward control by the slope KtI.