High Performance and Reliable Torque Control of Permanent Magnet Synchronous Motors in Electric Vehicle Applications

This paper presents a novel, high performance maximum torque per ampere control (MTPAC) of an interior permanent magnet synchronous motor (IPMSM) that is chosen for a vehicular application. In vehicular applications IPMSMs are usually controlled with MTPAC method due to fully utilization of reluctance torque, usually with this method maximum torque per ampere trajectories are obtained by look up tables because of nonlinear relation between torque and current; however, utilization of look up tables decreases the real time performance and reliability of the system. Some studies have been used MTPAC with nonlinear equations between d-q axes currents and torque; however, controller calculation burden can be reduced with proposed method. In this study relationship between torque and stator current magnitude is obtained as a first order linear equation with curve fitting. Thereby it has been possible to work with only one linear torque equation instead of nonlinear equations, therefore controller performance and reliability is increased. Control of the motor is simulated under different load conditions, and results are given and analysed.