| As generally recognized,electric vehicles(EVs)possess many advantages,such as motor-regenerative braking capability,little exhaust emissions.EV contribute to the remission of air pollution problem.The switched reluctance motor(SRM)is gaining increasing attention as a candidate for EV and PHEV electric propulsion for its simple and rugged construction,rare-earth-free feature,ability of extremely high-speed operation,and hazard-free operation.The performance of SRM is closely related to the source power.For example,output torque of SRM can increase with high demagnetization voltage,especially at high speeds,which enables faster reduction of phase current to zero after the aligned position.However,while the motor supplied from higher voltage at low rotational speed,the switching frequency increases.It leads to rise of switching losses.One good solution for the operation in range of low rotational speed is to feed the motor with low voltage and to increase this voltage proportionally as the speed increases.Therefore,the multilevel converter is very useful.However,the excitation and demagnetization voltage are limited by the source voltage in conventional SR drives.This paper introduces the new power converter with switch capacitor.The added capacitor and original dc-link capacitor could be connected both in series and in parallel.In addition,the paper introduces a new topology that drive the SRM by three level inverter.The increase of control freedom contributes to decrease the torque ripple and extend the constant torque area.In addition,this paper produces an integrated topology.That can work in battery-alone drive mode,generator-alone drive mode,hybrid drive mode,battery charge mode and so on.To verify the performance of the proposed converter topology,related experiments is employed.The results of which demonstrate the validity of the proposed topology. |
