Rotor-Flux Vector Based Observer of Interior Permanent Synchronous Machine

In this article, the sensorless control system of the interior permanent magnet synchronous motor (IPMSM) is considered. The control system is based on classical linear controllers. In IPMSM, there occurs nonsinusoidal distribution of rotor flux together with the slot harmonics, these are treated as control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting in disturbances. This negative effect can be minimized by using the observer structure, which is based on the rotor flux vector in (α-β) stationary frame together with the classical rotor speed and position law of estimation. The performance of the observer structure is validated by simulation and experimental results in the sensorless control system with field-oriented control.