A Sensorless Position Estimation Method For Primary Winding Segmented Permanent Magnet Synchronous Arc Motor Based on Improved DOB

The electromagnetic parameters of the primary-winding-segmented permanent magnet synchronous arc motor undergo significant variations in the winding-segment region, general position estimation methods cannot eliminate the dc bias caused by the sensor. This article introduces a frequency adaptive position estimation method that swiftly tracks the back electromotive force (BEMF) during medium-speed operations, which is based on the disturbance observer. It operates without any phase lag within the winding-segment region. Subsequently, it fuses the BEMF of adjacent segments to achieve a position estimation with essentially no phase lag, and obtains speed estimation information through a phase locked loop. By judiciously selecting parameters, the proposed method serves to attenuate potential dc components of the BEMF in the winding-segment region. Finally, experimental results validate the effectiveness of the proposed method.