H? Observer Based Sensor-less Control Strategy for Interior Permanent Magnet Synchronous Motor

Abstract

Nowadays a sensor-less vector control system for a motor drive becomes promising to avoid a position sensor. A back electro-motive-force or flux observer is used for sensor-less drive of permanent magnet synchronous motors from middle to high speed range. Thus, the estimation accuracy of the observer influences sensor-less drive performance. This paper proposes a sensor-less vector control system using the H? flux observer in which the observer gain is designed based on the H? control theory. This observer is insensitive to high frequency disturbances such as voltage disturbance due to non-linearity of PWM voltage source inverter, measurement noise of current sensors, and modeling errors. So, the total performance of a sensor-less control system is enhanced. The detailed configuration of the H? flux observer is described in this paper. Simulation results are compared with the conventional full-order flux observer-based sensor-less system.