Suppression of current ripple in a single current sensor sampling scheme for switched reluctance motor

In order to make further efforts to reduce the cost of switched reluctance drive which is designed for electric bicycle, a sampling scheme for single current sensor is proposed. Under the single current sensor sampling scheme, principle of unobservable area within the current ripple are analyzed. By establishing equivalent circuit model, the relationship between the maximum value of pulse current, the rise time of excitation current and the drop time of freewheeling current and other parameters are analyzed. Effect of motor winding resistance to pulse current amplitude, the rise time of excitation current and the fall time of freewheeling current is analyzed. The relationship between the winding resistance and average torque, torque ripple, system efficiency is researched. The optimization method is proposed to suppress the current ripple, by choosing appropriate winding resistance to adjust the excitation voltage and current voltage for changing the current rate to achieve the suppression of pulse phase currents. Finally, the sampling scheme and control algorithm of the switched reluctance motor are verified by experiments which show that this method is feasible and valuable.