Position Sensorless Control of SRMs Based on Improved Sliding Mode Speed Controller and Position Observer

This article presents a sensorless control strategy based on an improved sliding mode speed controller (SMSC) and sliding mode position observer (SMPO) for switched reluctance motor (SRM). The proposed method could reduce the motor speed response time and improve the estimation accuracy of rotor position information. First, an improved SMSC based on time-varying function (TVSMSC) is proposed to reduce the influence of internal parameter disturbance and external load disturbance so that the SRM’s actual speed can accurately track the reference speed. In order to reduce the initial harmful peak generated by the SRM during initial startup, a time-varying function is introduced into the new approach rate. Then, to obtain more accurate rotor position information, an SMPO based on the inductance model is used to estimate the rotational speed and rotor position in real time. Finally, the experimental validation is performed. The results show that the proposed strategy can effectively reduce the overshoot and speed transient response time while maintaining high robustness and high estimation precision of rotor position.