Experimental Investigation on Stator Impedance Affected by Magnetic Saturation and Rotor Slot used for Sensor-less IM Vector Control System with High-frequency Voltage Signal Injection

Abstract

This paper investigates the influences of magnetic saturations of main and leakage fluxes for sensor-less vector control systems of an induction machine (IM) on static impedance characteristics using high-frequency voltage signal injection techniques. Furthermore, the amplitude characteristics of rotor slots are investigated by measuring the impedances of high-frequency components with respect to the rotor angle of the IM. The IM is vector-controlled with an ideal voltage source, and the stator impedances of the IM are evaluated from the amplitude ratios of high-frequency voltage to the current, extracted using fast Fourier transform analysis. As a result, the leakage flux saturation saliencies are obtained under the conditions of high-frequency and low-voltage levels, and it is confirmed that the impedance deviations for rotor slots increase under the same conditions as those for leakage flux saturations.