Research On Optimal Control Of Switched Reluctance Motor Drive System

Since the 1980 s,switched reluctance motor has appeared in front of the world as a new type of motor.Due to the special double salient structure and good speed regulation performance,the application range of reluctance motor has covered many fields such as household appliances,electric vehicles and medical treatment.To enhance the market competitiveness of the switched reluctance motor and improve the output characteristics of the motor,this paper conducts an optimization study on the traditional switched reluctance motor drive system.For the control strategy of the motor drive system: Firstly,a predictive current chopping control method in the low-speed range is proposed,by discretizing the winding voltage equation,the sampled current value at the next moment is obtained,at the same time,the value is combined with the hysteresis control to complete motor speed regulation.This method reduces the problem of current overpulse caused by the hysteresis of the system.Then,a partitioned current chopping control method combined with the predicted current in the low-speed range is proposed.According to the control signals of the present phase and the previous phase,and combined with the current of the present phase,the control signals of each phase switch are reconstructed,this method not only reduces the current overpulse,but also avoids the current fluctuation at the output of battery.Finally,simulations and experiments are used to verify the effectiveness of the two new optimized control strategies.For the cost of the motor drive system: Firstly,a positionless control algorithm with no position sensor is proposed,which includes rotor static positioning and lowspeed operation,in static positioning,the traditional pulse injection method was used to determine the initial starting phase by comparing the response current at the same time.According to the pulse injection method,an arbitrary rotor angle estimation algorithm based on the proportional relationship of similar triangle is proposed;At low speed,the double-threshold chopper control is used to construct a full-period current,and the full-period inductance curve is obtained,subsequently,the rotor angle is estimated based on the characteristic intersection points of the three-phase inductance curve.Then,a phase current reconstruction algorithm omitting current sensor is proposed,by resetting the sensor placement mode and winding mode,the three-phase current can be sampled by using two sensors,moreover,this method is extended to multi-phase motors to improve its applicability.Finally,simulations and experiments are used to verify the feasibility of the sensorless control method and phase current reconstruction method.There are 60 figures,6 tables,and 100 references in this paper.