This paper proposes a novel topology of power converter in switched reluctance motor drive for electric vehicles, which include a front-end DC/DC boost-buck inverter and a classical half-bridge power converter based on the splendid characteristics of the switched reluctance motor. The equivalent circuit modes and the control strategies in the driving state, braking state, and charging state are described. In the driving state, the front-end DC/DC converter works in boost mode, the dc-link voltage is reduced for the reduction of the phase current ripple at low rotor speed state, the dc-link voltage is increased for the reduction of the commutation time, enhancing the efficiency of the system and the rated output torque capacity at high rotor speed or heavy load. In the braking state, the front-end DC/DC converter works in buck mode, the mechanical energy can be converted into electrical energy through the asymmetric power converter and be fed back to charge the battery through the front-end DC/DC converter. In the charging state, the power factor correction circuit can be constituted, the buck mode of the front-end DC/DC converter is used for charging the battery, the harmonic proportion are reduced substantially, the phases of the voltage and current are close, the power factor is enhanced to 0.99. The simulated results and the experimental results have verified the effectiveness of the proposed novel topology.
 

Switched reluctance,electric vechicle,motor drives,power factor corretion,inverter