Position Offset Injection Based Winding and Permanent Magnet Temperature Decoupled Estimation for PMSMs

This paper proposes a decoupled approach for winding and permanent magnet (PM) temperature estimation of SPMSMs based on high frequency (HF) position offset injection. The decoupled temperature estimation model in the position-offset frame is derived, which can achieve decoupled estimation of the winding and PM temperatures. To avoid the parameter dependence and fundamental components influences, HF position offset is injected into machine to induce HF response, from which temperature dependent parameters can be extracted. In the developed estimation model, the temperature dependent terms contain cosine operation of current angle, which can ensure the high signal to noise ratio, especially in low current angle conditions. Moreover, the winding temperature estimation is decoupled from the PM temperature estimation, which can improve the accuracy of temperature estimation. The proposed approach is validated on the simulations and experiments.