Research On Braking Feedback Energy Control System For Switched Reluctance Motor On Electric Vehicles

Electric vehicles receive widespread with the advantages of low-emission and pollution-free.Increasing the mileage is one of the hot spots of researching electric vehicles.Switched Reluctance Motor(SRM)has been applied to electric vehicles with high efficiency,high reliability and easy realization of four-quadrant operation.It is an effective way to improve the mileage of electric vehicles by using the reversibility of SRM and efficient energy recovery in the case of electric vehicle brake or long distance downhill.There are three control methods analyzing SRM.Current chopping control:limiting the phase current amplitude to protect the motor;pulse width modulation control,changing the PWM control signal duty cycle and determining the motor slow braking or emergency braking;angle position control,optimizing the turn-on angle and turn-off angle to achieve efficiency optimization of SRM at different speeds of brake feed.For the optimization of the turn-on angle and the turn-off angle,the turn-on angle is fixed and the turn-off angle is adjusted.Through the comparative analysis of the net power and the penalty coefficient,the optimal turn-off angle is selected at different rotational speeds.The optimal turn-on and turn-off angles at different rotating speed in a similar way.In order to verify the SRM brake feed energy control method,the experimental platform is set up,the prototype test system hardware and software are designed.Hardware design mainly includes power conversion circuit,driving circuit,detection circuit and isolation circuit.Software design mainly complete the control system main program and the corresponding control subroutine design by using TI company TMS320F28335DSP as the core control system.The experiment of SRM brake feed control system is carried out on the prototype platform.Finally,the experimental results are analyzed by combining the speed,current and PWM control signals collected by the experiment.The results show that the design of the control system can achieve SRM brake feed efficiency optimization.