Speed Sensorless Control of Permanent Magnet Synchronous Motor Based on Improved Sliding Mode Adaptive Observer

Permanent magnet synchronous motor (PMSM) requires the speed and position information for motor speed and torque controls. However, applying the sensors has many problems such as sensor mounting space and additional cost, etc. Therefore, in this paper, sensorless control method based on model reference adaptive system (MRAS) is proposed to eliminate the sensors. The method is constructed in two models which are a reference block as standard model and an adaptive block as the state observer model. Finally, an improved Sliding Mode Adaptive Law (SMAL) is proposed to estimate and reflect the error variables of the two models. The proposed control scheme is verified by the simulation.