Sensorless control of interior permanent magnet synchronous motor: An overview and design study

This paper provides an overview of the progress in sensorless permanent magnet synchronous machine (PMSM) control techniques in Japan. In the first stage, the techniques extracted rotor position information by back-EMF zero-crossing detection techniques. Since around 2000, model-based position-sensorless control techniques have been evolved and are widely used in home appliances as well as general industrial applications. Simultaneously, sensorless control based on the magnetic saliency has been developed and commercialized. However, owing to the considerable flux saturation in the rotors, the accuracy of saliency-based position detection depends on the design and structure of the motor. In future motor drives, motor design optimization for saliency-based sensorless control is expected to be the foremost issue for machines. In this paper, an example of design optimizations of application-specific IPMSM for saliency-based sensorless control is introduced.