Sensorless vector control of permanent magnet synchronous motors based on the improved sliding mode observer

To improve the estimation accuracy of the sliding mode observer (SMO) of the permanent magnet synchronous motors (PMSM), an improved sliding mode observer is presented for sensorless vector control of the PMSM. A saturation function is used to the improved SMO for overcoming chattering and the observer of back electromotive force instead of the low-pass filter on conventional SMO. Simulation model of sensorless vector control of the PMSM is established based on MATLAB, and the corresponding experiment is performed based on TMS320F2808. Both simulation results and experimental results are obtained to verify the estimation accuracy and the control performance of the PMSM with the proposed improved SMO.