Analysis of Hysteresis in Resonance-Based Position Estimation of Switched Reluctance Drives.

In switched reluctance motors, rotor position information can be extracted from the measurement of position-dependent phase voltage resonances. Due to hysteresis in the magnetic core of the machine, subsequently triggered resonances can exhibit different resonance waveforms, even when the rotor is held at a constant angular position. In order to analyze the influence of hysteresis, a finite-difference model of a magnetic lamination is coupled with a scalar Preisach model and with an electric circuit comprising an air gap and an equivalent capacitance associated with the converter, power cable and phase winding. A good correspondence is obtained between simulated and measured time-domain resonance waveforms. The model is used to predict the impact of hysteresis on the initial position estimation at start-up of the drive. [ABSTRACT FROM PUBLISHER]