Zero-Sequence High-Frequency Voltage Injection-Based Sensorless Method for Open-Winding-PMSM Drives With Common DC Bus

This article proposes a sensorless method for open-winding (OW)-permanent magnet synchronous machine (PMSM) drives with common dc bus utilizing zero-sequence (ZS) high-frequency (HF) voltage injection. The injection pattern is implemented with the ZS steerable space vector pulsewidth modulation. The three phase HF currents are amplitude-modulated by the rotor saliency. The rotor position can be extracted via a position observer with concise demodulation process. Different from other HF injection-based sensorless methods relating to the ZS, the proposed method no longer needs to build the ZS path deliberately. When compared with the classical HF voltage injection-based methods, owing to the separation of the injection voltage and the field-oriented control output voltage, the proposed method exhibits lower loss, vibration, and acoustic noise. Finally, the effectiveness of the proposed sensorless method is verified by experiments on a 12-slot/10-pole OW-PMSM drive platform.