The Magnet Operating Point Estimation Using Thermal Component Ratio Observer in PMSM

This paper proposes a method to estimate both the temperature and the magnetic flux density of the magnet using the thermal equivalent circuit and the magnetic equivalent circuit in PMSM. As a feature of this method, to ensure the robustness of the estimation, the measured temperature of the stator winding is used to compensate for the thermal capacitance in the transient state and the convective heat transfer coefficient in the steady state. The proposed thermal component ratio observer could be an effective method for the initial or constant condition optimization process of the temperature estimation. The advantage of this method is no anxiety affecting the original control system and this method can estimate the magnet operating point in real-time. The simulation and experimental verification have been provided to demonstrate the effectiveness of the proposed method.