CONTROLLING AN AC MACHINE

摘要

A method of controlling an AC machine that includes a stator and a rotor, wherein the method includes, whilst operating the AC machine according to an overmodulation technique: determining a reference speed for controlling the operation of the AC machine; filtering the reference speed such that if the reference speed exceeds a speed limit of the AC machine, the reference speed is reduced towards that speed limit; and controlling the operation of the AC machine based on the filtered reference speed. It has been found that controlling the AC machine in this way helps to inhibit "windup" of a controller used to implement the method, even if the overmodulation technique sets a non-constant maximum voltage.