Sensorless Control of PMSM Based on Sliding Mode Observer

Because the working environment of the motor is mostly in a complex and harsh environment, the mechanical sensor cannot work stably, so the speed sensorless control algorithm is needed for control. The sliding mode observer (SMO) is frequently utilized due to its strong robustness and rapid response, demonstrating exceptional performance when encountering external disturbances and changes in parameters. Due to the problems of buffeting and low precision in traditional SMO, an improved SMO method is proposed by applying the linear combination of absolute value and function to the exponential reaching rate. The system's stability is assessed through the Lyapunov theorem. By comparing the simulation and experimental data from the two methods, the feasibility of the improved SMO is confirmed. In comparison to the conventional method, it enhances observation accuracy and effectively suppresses the system's inherent vibrations.