| Abstract |
The difficulties encountered when trying to get high performance control of ac motors at low speed are well known, owing to the difficulties to get accurate measurement of the motor flux in such conditions. This paper presents a solution to this problem by using a microcomputer model for the motor flux. Briefly, this model consists in a forecasting open loop algorithm taking into account current, speed and other parameters of the motor. At higher speed, flux measurement becomes more accurate and can be used by a correction algorithm in order to improve the forecasting of the flux vector. Illustrations of the method are given in various industrial and traction applications and specially for high power drives using asynchronous or synchronous motors. |
