Hybrid Sensorless Control of IPMSM Combining High Frequency Injection Method and Back EMF Method

This paper introduces a new hybrid sensorless control of interior permanent magnet synchronous machines (IPMSM) combining high frequency injection and back EMF based method. The proposed control system realizes position, speed, and torque control in the entire speed range. Owing to the reliability and the space-saving feature, the sensorless control is applied to direct drive applications with great expectations. As successful applications, an injection molding machine and a compressor are introduced in this paper. Experimental results show the effectiveness to the required specification of the control modes.