Sensorless Control of Synchronous Reluctance Motor Based on High Frequency Signal Injection

Aiming at the nonlinear characteristics of synchronous reluctance motor (SynRM) caused by electromagnetic saturation and cross coupling of stator inductance, a sensorless control method combining recursive least square method and pulsating high frequency current injection was proposed. The principle is to inject high frequency sinusoidal current signals with fixed amplitude into the direct axis of synchronous reluctance motor observation coordinate system, and extract voltage signals containing rotor position information from the quadrature axis. The recursive least square method with forgetting factor is used to realize the online identification of the motor resistance and inductance parameters. The sensorless control of motor is realized by proper signal processing method. In this paper, theoretical analysis, software simulation and prototype experiments are carried out to verify the accuracy and practicability of the proposed method.