Active Operating Region Adjustment Control of a Permanent Magnet Synchronous Motor Drive by Reflecting Permanent Magnet Flux Linkage Variations in Real Time

A permanent magnet synchronous motor (PMSM) drive has been widely used for various industrial applications such as electric vehicles (EVs) and home appliances due to its attractive features such as high power/torque density and high efficiency. While a PMSM has various attractive features, it also includes some drawbacks such as parameter sensitivity with respect to operating conditions of PMSMs. For example, permanent magnet (PM) flux linkage of an IPMSM is decreased as magnet temperature of in a rotor of PMSM increases. As known, a characteristic current of a PMSM is determined by its PM flux linkage and an operating region and operating characteristic are affected by the characteristic current. In this paper, a control algorithm is proposed for a PMSM drive to adjust its operating region actively by reflecting PM variations in real time. PM flux linkage of a PMSM is estimated through a stator flux linkage observer in real time and the estimated PM flux linkage is applied to the active operating region adjustment (AORA) algorithm for more effective utilization of an IPMSM drive operation. The proposed AORA algorithm for a PMSM drive is implemented and verified experimentally in this paper.