Four-quadrant sensorless control in switched reluctance machine drive using pulse injection based on special flux linkage curves

This study presents four-quadrant sensorless control in switched reluctance machine (SRM) drive for startup and low speed. The proposed control method is based on two special flux linkage-current characteristic curves which can be obtained expediently and quickly without the need of external mechanical fixtures. The narrow voltage pulse is injected into the idle phases by the power converter and the rotor position zone within an electrical cycle is determined by comparing the measured flux linkage with the two flux linkage-current curves. The judgment rules and flow-chart of rotor positions estimation are proposed to implement the four-quadrant operation in SRM drive. The effectiveness of the proposed sensorless technique is investigated through a series of experiments on a three-phase 12/8 pole SRM drive platform. The experimental results show that the four-quadrant sensorless control of SRM is implemented without the requirements of additional hardware circuit and complicated computation.