Research On Integrated Drive Power Converter Topology And Control Of Switched Reluctance Motor For Electric Vehicle

One of the core technologies of electric vehicles,electric vehicle control systems have become the main research object,Switched reluctance motor(SRM)is a new type of double salient structure motor.It has large torque at start-up,strong fault tolerance,single-phase operation,high control flexibility and cost control.It is very suitable for electric vehicles.In this paper,a new type of integrated drive charging topology of SRM is proposed.In the driving part,Buck-Boost converter is cascaded with asymmetrical half-bridge power converter to construct the SRM high-voltage freewheeling,voltage regulation and speed regulation control of SRM is studied,the topology feasibility and stability of SRM integrated drive power converter for electric vehicles are verified by experiments;Buck-Boost converter and asymmetric half-bridge power topology cascade are used to realize high-voltage freewheeling of switched reluctance motor and the voltage and speed regulation control of SRM.The charging control part uses SRM two-phase winding as the charging boost inductor to construct a bridge-less Boost rectifier charging power converter topology,and realizes AC charging power factor correction(PFC)under the average current control strategy.The work done are as follows:(1)According to the characteristics of integrated drive charging topology for electric vehicles,a bidirectional DC-DC converter is proposed to construct the drive power converter topology.The working principle of the bidirectional DC-DC converter and the double closed-loop PI control strategy are studied.The feasibility of the bidirectional DC-DC converter is verified by experiments.(2)Aiming at the problem of starting the SRM drive freewheeling of electric vehicles,the SRM integrated drive power converter topology of electric vehicles is proposed,and the SRM high-voltage freewheeling is constructed.Under the high-voltage freewheeling state,the negative torque of the motor is reduced or the opening interval is increased,which can increase the output of the motor and effectively improve the performance of the motor.Under the constant voltage and speed regulation control strategy or the voltage and speed regulation control strategy,the motor can run stably.The feasibility of the SRM integrated drive power converter topology of electric vehicles is verified by experiments.(3)In order to solve the problem of integrated charging of electric vehicles,a new idea of integrating charging topology into driving topology is proposed.On the premise of not adding devices,the two-phase winding in SRM is used as the charging Boost inductor to construct the bridgeless Boost rectifier charging topology.Under the average current control strategy,the bridgeless boost rectifier charging topology realizes the consistency of the frequency and phase of inductor current and input voltage,reduces the pollution of charging to the power grid,and the feasibility of the topology of integrated charging power converter for electric vehicles SRM is verified by experiments.