Optimal Design Proposal for Capacitance in Operating Area Expandable SR Motor Drive Circuit

A novel drive circuit for switched reluctance (SR) motor expanding the operating area under limited source voltage has been proposed by adding external capacitor in series to extend supply voltage. However, the capacitance of the external capacitor has not been optimized to be sufficient to extend the driving range of the SR motor. Subsequently, the authors have previously proposed a conservative design method for capacitance by linearizing the winding current. However, there is a problem in that the difference between the conservative design and the simulated fluctuation of the capacitor voltage is large. In this paper, an optimal design method is proposed for the capacitance by using an LC equivalent circuit at the beginning of excitation and demagnetization.