Correction Method of Reference Flux for Maximum Torque per Ampere Control in Direct-Torque-Controlled IPMSM Drives

Abstract

In this paper, a maximum torque per ampere (MTPA) control strategy for direct-torque-controlled interior permanent magnet synchronous motor (IPMSM) drives is proposed. For current-controlled IPMSM drives, many methods have been proposed, in which the periodic signals are injected into reference current vectors. On the other hand, the direct-torque-controlled IPMSM drives require the torque and stator flux linkage magnitude as their references. The proposed method injects signals into the reference flux in a manner similar to that used for the signal injections in current-controlled IPMSM drives. The main feature of the proposed method is the ability to search the optimal current directly and successively using a local search algorithm. Therefore, variations in the parameters can be considered. The simulation and experimental results validate the proposed method.

Design and control of variable field permanent magnet motors

“…Furthermore, a wider constant power speed range (CPSR) is also expected. In order to satisfy the requirements at various operating points under the electrical and mechanical restrictions, new control strategies typified by, for example, maximum torque per amperes and flux weakening (FW) control using d ‐axis current adjustment have been developed . Meanwhile, in order to respond to the diversified requirements of a wide range of motor application fields, such as electrification of automobiles, railways, aircrafts, ships, home appliances, and robotics including surgical robots, revolutionary motor technology is necessary, where it is essential to fundamentally change the magnetic circuit of a traditional synchronous motor to provide a variable field function like a direct current (DC) shunt motor on the premise of matured power electronics technology.…”