Automatic calibration of a resolver offset of permanent magnet synchronous motors for hybrid electric vehicles

In this paper, we consider the automatic calibration of resolver offset in a hybrid electric vehicle. This offset between a permanent magnet synchronous motor (PMSM) and its resolver results from manufacturing tolerance such as nonuniform windings in the motor, assembly tolerance, and so on. The resolver offset needs to be compensated for precise torque control of the PMSM. The suggested calibration method consists of two stages: the cooperative control between the motor controller and other vehicle component controllers, and the current control of the PMSM designed based on Lyapunov stability. The cooperative control sets up the specific condition of HEV under which the current control is performed. Then the offset is measured and calibrated at the steady state under the current control. The designed algorithm is verified by simulations.