Sensorless Control for IPMSM in Entire Speed Range Based on HF Voltage Signal Injection and Virtual BEMF

In this paper, a sensorless control algorithm for an interior permanent-magnet synchronous motor (IPMSM) using high-frequency (HF) voltage signal injection with square wave reference and virtual back electromotive force (BEMF) is proposed. This paper modifies the voltage model of IPMSM using virtual BEMF. Based on the modified voltage model, the proposed algorithm estimates the rotor position using virtual BEMF of fundamental frequency and HF. Using the proposed method, sensorless control in full speed range is possible with no conventional transition methods between zero/low speed and medium/high speed. The proposed algorithm is verified by simulation and experimental results with 1.7 kW IPMSM. The proposed method shows identical stable operation performance with the conventional transition method with a much simpler implementation.