Parameter Independent Position Sensorless Control of Permanent Magnet Synchronous Motors

This paper proposes a position sensorless control strategy for permanent magnet synchronous motors, which does not need any machine parameter. A novel back EMF-based method is introduced that utilizes the phase current derivatives during a brief short-circuit of the motor windings to estimate the current rotor position. Combining this approach with the saliency-based INFORM method enables highly dynamic operation in the whole speed range. This control strategy does not require any knowledge about the machine parameters and is therefore robust against parameter fluctuations. The model is described and experimental results are presented to demonstrate the reliability of the proposed approach.