Advanced control algorithms for electric machine drives

Modern motor control technology has recognized its new era in the late 1960s by the vector control (field-oriented control) for AC machine drives. Since then, numerous control techniques have been developed to improve the controlled system performance and to expand their applications. This article addresses several advanced control algorithms for electric machine drives. One of the most important waves of research activities resides in sensorless control, in which the “mechanical sensors” can be removed, since information on angular speed and/or position can be estimated from “electrical” data (such as voltage and current) by using various estimation methods. The insight on the sensorless control of induction motor (IM) drives in literature will be made. The model reference adaptive system (MRAS) will be next treated, using the instantaneous reactive power as tunning adaptation signal. The method is shown to be a very comprehensive and effective estimation technique for industry applications. In the class of permanent magnet (PM) synchronous machines (PMSM), the interior permanent magnet (IPM) machine type has gained the popularity in the last three decades thanks to their excellent features (high efficiency, high torque per volume). The maximal torque per ampere (MTPA) control and Flux-weakening (FW) strategies have been developed to exploit the advantage of reluctance torque, which is originated from the saliency characteristics of rotor. These two strategies (MTPA and FW) will be treated in detail in this article and their performance will be illustrated by simulation results using a motor for EVs.