HF injection-based sensorless technique for fault-tolerant IPMSM drives

High Frequency (HF) injection sensorless techniques potentially cover an important segment of the sensorless drives market, allowing rotor flux position estimation at low and zero speeds where standard sensorless methods fails. This paper proposes an innovative HF injection-based sensorless technique able to increase the robustness to open-phase faults, simply changing the HF signals processing method after fault detection and with no modifications on the additional signals generation at the inverter level. Experimental results performed on an IPMSM drive confirm the consistence of the proposed approach.