Enhanced Maximum Torque per Ampere Control With Predictable Core Loss for the Interior Permanent Magnet Synchronous Motor

Abstract

Due to the availability of extended applications for the reluctance torque, increasing incorporation of interior permanent magnet synchronous motors (IPMSMs) has been observed in the electric drive system, and to save energy and improve operation efficiency, the maximum torque per ampere (MTPA) control has attracted a lot of academic attention. However, in the traditional MTPA, the optimization objective of tracking the minimum armature current only applies to the situation where the energy consumption in the winding resistance is imposed as the sole constraint. The energy consumption in the core material, i.e., core loss, will grow as motor load and frequency increase, and hence the efficiency optimization control of the IPMSM should also consider the core loss. Firstly, this article proposes a novel mathematical model of the IPMSM which enables the establishment of control algorithms with predictable core loss. Then, a novel MTPA is proposed which can simultaneously optimize the copper loss and core loss to maximize the utilization of phase currents and minimize the electromagnetic losses of the IPMSM. To verify the superiority of the proposed MTPA, the analytical results are compared with the conventional MTPA and I_d = 0 control methods.