Saliency-Based Sensorless IPMSM Drives Using Derivatives of Phase Currents With Single DC-Link Current Sensor

In order to enhance the saliency-based position sensorless drives with a single current sensor (SD-SCS), this paper proposes a current derivative-based sensorless control using a tri-active vector pulse width modulation (TAVPWM). In the SD-SCS, the performance of the position estimation is deteriorated due to the injected voltage at the current reconstruction dead zone (CRDZ) and the unaligned sampling with a single current sensor. To improve the performance of the SD-SCS, the TAVPWM scheme is adopted to eliminate the CRDZ in the low-modulation region. Furthermore, the phase current derivatives, which are accurately reconstructed at each active vector of the TAVPWM, are utilized to minimize the position estimation error resulting from the unaligned current sampling. Owing to the proposed method, the switching frequency has been increased up to 16 kHz, which eliminates the audible noise virtually in the SD-SCS. Lastly, the enhanced dynamic performance of the SD-SCS is verified by various experiments.