Robustness analyses and improvement for position sensorless control of IPMSMs to inductance variation due to magnetic saturation

This paper proposes a new robust position sensorless control of Interior Permanent Magnet Synchronous Motors(IPMSMs) to inductance variation using the un-known input observer. In position sensorless control of IPMSMs, accurate motor parameters are required for position estimation. However, inductance variation due to magnetic saturation is known to heavily deteriorate performance of sensorless control. The authors has already proposed un-known input observer for position sensorless control of IPMSMs. This paper shows that the proposed observer possesses high robustness to magnetic saturation by analyses and experiments.