Fast Discharging (N+1) Switch Converter With Regenerative Flyback Operation for N-Phase SRM Drives

This article proposes a converter topology that can provide fast discharging for any N-phase switched reluctance motor (SRM) drive. The proposed converter achieves fast discharging with only (N+1) switches for an N-phase SRM drive. The discharging can also be varied and made faster as per requirement. The proposed converter achieves fast discharging by dumping the winding energy to a capacitor and feeding it back to the source through a flyback transformer. The proposed converter uses fewer switches, is easy to control, and has variable discharging voltage which can be made much greater than the supply voltage. The proposed converter has been implemented with a four-phase SRM drive using MATLAB/Simulink software and the results are presented. A hardware prototype of the proposed converter is developed in the laboratory and tested on a four-phase SRM. The corresponding experimental results are presented at different operating conditions. The proposed converter is also compared with other existing SRM converters with respect to different performance metrics and a detailed comparison table is presented. Using the proposed converter, a minimum discharge time of 0.32 ms has been achieved at 3 A reference current.