Sensorless control of SynRM based on PWM inverter carrier frequency component

A sensorless control scheme of synchronous reluctance motor (SynRM) drives is presented using the balanced 3-phase carrier frequency component of a PWM inverter. SynRM has inherent rotor saliency and its position is estimated from alpha and beta carrier current component and the appropriate signal demodulation. The improved method of restraining d-axis current is proposed to reduce estimation error caused by magnetic saturation. This scheme gives dynamic estimation of the rotor position independent of the operating conditions including standstill, light and heavy loading. To confirm the effectiveness of the proposed strategy, an experimental system consists of a SynRM, DSP control board and inverters has been set up, and some experimental results are given to verify the proposed scheme.