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

This paper proposes a sensorless method for open winding permanent magnet synchronous machine drives with common DC bus utilizing zero-sequence high frequency (HF) voltage injection. The injection pattern is implemented with the zero-sequence steerable space vector pulse width 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 zero-sequence, the proposed method no longer needs to build the zero-sequence 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 open winding permanent magnet synchronous machine drive platform.