| Limited fossil fuel resources and environmental issues are pushing industry toward energy efficient and environmentally friendly solutions.People in the auto industry are producing more and more hybrid and all-electric cars.Therefore,as a component of electric vehicle,electric drive system has been widely concerned by both industry and academia.Many commercially successful electric vehicles are the Permanent Magnet Synchronous Motor,which is efficient due to its high torque and power density.In recent years,however,the uncertainty of rare earth pricing has led to extensive research on rareearth-free motors.Among them,switched reluctance motor is an important competitor of electric vehicle application because of its simple structure,firm structure,low cost and high reliability.This paper takes switched reluctance motor as the research object,and studies a driving charging integrated device based on electric vehicle platform.The advantage of the device is that the winding of SRM is reused as the large inductance of charging buck-Boost circuit,and the function of power factor modulation is realized.Specific research work is reflected in the following aspects:Firstly,the article introduces the basic physical structure of the switched reluctance motor,as well as its working principle.It also briefly describes the types of power drivers for such clicks and their working principles.Then according to the characteristics of the motor,its equivalent circuit,linear,quasi-linear and nonlinear mathematical models are analyzed and deduced in detail.The basic control method of switched reluctance motor is introduced,and the performance advantages of various control algorithms are analyzed and discussed.Secondly,this paper introduces zero torque control of switched reluctance motor drive-charge integrated system.An SRM converter topology with integrated drive,regeneration and charging functions is proposed for the drive system of switched reluctance motor of plug-in electric vehicle.The multifunctional drive system can reduce the size,weight,and ease of carrying of electric vehicles.It has three modes,drive mode,regeneration mode and charging mode.The proposed SRM converter is asymmetric in driving and regenerative modes.In charging mode,all phase windings act as inductors,and the converter runs as a Buck-Boost converter to meet charging characteristics and power quality requirements.Finally,a zero-torque control method for battery charging is proposed.In this method,the rotor can remain stationary,increasing efficiency.Since the sine wave current exists in the phase windings,we use the finite element method to analyze the magnetic field and torque.The performance of the converter is verified by simulation results.This highly integrated technology will play an important role in the miniaturization and efficiency of electric vehicles. |
