Implementation of an Initial Rotor Position Estimation for PMSM Drives Based on High Frequency Voltage Signal Injection

In this paper, the analysis and implementation of an initial position estimation method based on high frequency sinusoidal voltage signal injection is presented for an interior permanent magnet synchronous in-wheel motor used for skateboards. The importance of a proper initial position estimation is to control precisely the torque in electric vehicles from the motor start-up. Initially, the high frequency sinusoidal voltage injection method is modeled and analyzed. Secondly, the transfer function of the estimator is analyzed and its gains are calculated. Finally, implementation details and experimental results are shown to verify the effectiveness of the estimation method. It can be seen that the initial position estimation converges correctly, and the transition between using the low and high speed estimation methods occurs smoothly.