IPMSM torque control method considering DC-link voltage variation and friction torque for EV/HEV applications

This paper proposes a PMSM torque control method considering DC-link voltage variations and friction torque. For EV/HEV applications, a two-dimensional look-up table (2D-LUT) is used for a current reference generation due to its stable and robust torque control performance. Conventionally, this 2D-LUT is established by a flux-torque table to overcome DC-link voltage variations. However, the flux table establishment is more complex than the speed table establishment. Moreover, one flux data reflects several speed conditions in variable DC-link voltage, friction torque cannot be considered by using the flux table. In this paper, a speed-torque 2D-LUT is used for a current reference generation. With this table, PMSM torque control is well achieved regardless of DC-link voltage variations by the proposed control method. Also, friction torque is compensated by a novel compensation block described on this paper.