Use HF Signal Injection for Simultaneous Rotor Angle, Torque and Temperature Estimation in PMSMs

Use of high frequency (HF) signal injection-based methods with PMSMs has been widely investigated for several purposes including rotor angle/speed estimation, permanent magnet (PM) temperature estimation and torque estimation. This paper analyses the opportunities of multi-estimation. The physics behind these methods are analyzed, from which the number and characteristics of the HF signals to be injected can be deduced. Based on this, injection of a pulsating HF current 45° shifted from the d- axis and a rotating HF current in the stationary reference frame is found to be a suitable solution for simultaneous rotor angle, torque and magnet temperature estimation.
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This work was supported in part by the Research, Technological Development and Innovation Programs of the Spanish Ministry of Science and Innovation, under grant PID2019-106057RB-I00.