Position sensorless starting method for IPMSMS by all-pass filters

This paper proposes the starting method for position sensorless controlled interior permanent magnet synchronous motors (IPMSMs) by using all-pass filters. The starting of IPMSM position sensorless control is well known to be extremely difficult due to the lack of electromotive information. Therefore, IPMSM is often started and accelerated with the high-frequency signal injection in general, and then the control algorithm is switched to position sensorless control without high-frequency injection in middle speed region. However, the acoustic noise due to high-frequency signal injection would occur, and the switching of control methods would cause some bumps. For this reason, IPMSM is desirable to be driven from the start to the steady state without high-frequency signal injection. This paper realizes to start the position sensorless controlled IPMSM without high-frequency signal injection by all-pass filter with the assistance of the appropriate initial vector setting of each controller, under the assumption that the high-frequency signal injection is used only at standstill. Finally, this paper experimentally demonstrates the feasibility and the effectiveness of the proposed method. © 2021 The Institute of Electrical Engineers of Japan.