Position estimation method which is suitable for highly magnetic saturation of IPMSM

This paper describes position estimation method for interior permanent magnet synchronous motor (IPMSM) using idea of pattern matching technique. The IPMSM possess a unique relationship between a set of phase inductances and rotor position, that make it possible to estimate rotor position in standstill and very low speed region, where EMF become no enough for position estimation. Up to the present, many sensorless control methods for IPMSM based on magnetic saliency have been proposed. However, recently IPMSM, which possess higher torque density, the sensorless control performance to be degrade. To overcome this problem, we have proposed a new approach for position sensorless control, which utilize pattern matching. This paper reports of measurement of inductance spatial distributions in various load conditions and discuss feasibility of our proposed approach.