Characterizing the torque lookup table of an IPM machine for automotive application

Motor drive technologies are being incorporated into the EV and HEV automobiles with ever increasing speed. With the output torque to be the main control target, various control algorithms are developed that aim to achieve high torque accuracy while maximizing the machine energy efficiency. Most of such control algorithms entail procedures to characterize the machine under control. This paper documents a detailed, industrially practical procedure of characterizing the torque lookup table for interior permanent magnet (IPM) synchronous machines. The characterized lookup table can be utilized in open-loop torque control algorithms, and is verified to achieve high torque control accuracy and suitable for torque control of IPM in automotive applications.