Estimation of on-fly phase resistance of on 8/6 switched reluctance motor for sensorless control

Abstract

Given that most sensorless methods use the “flux linkage” algorithm for their control, this paper deals with possibilities to improve this sensorless method. When using the sensorless “flux linkage” method it is necessary to know not only the values of phase voltages and currents, but also the correct value of the phase resistance. During the operation of the switched reluctance motor, the value of the phase resistance is significantly changing due to the temperature dependence. Such resistance error causes an inaccurate estimation of the flux linkage. For this reason, it was desirable to implement a sensorless control algorithm for estimating phase resistance. In this paper, the experimental results of the implemented algorithm for estimating the phase resistance under the sensorless operation of a switched reluctance motor are presented. The practical implementation of control of the switched reluctance motor is carried out using a control system with a 16-bit digital signal processor.