Font Size: a A A

Research On Vibration Of The Driving And Steering System Of The Electric Vehicle And Reliability Of The Drive Motor

Posted on:2008-08-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y C XueFull Text:PDF
GTID:1102360212997783Subject:Solid mechanics
Abstract/Summary:PDF Full Text Request
With the deterioration of global energy crisis, as well as the strengthening of environmental protection consciousness, development and research of hybrid vehicle, as transitional vehicle to pure electric vehicle, have got attention from the countries around the world.There are many types of electric vehicle, including pure electric vehicle, hybrid electric vehicles and full cell electric vehicle. No matter what type it is, the motor driving system is an important part of the electric vehicle and a main vibration source of a vehicle, so the motor driving system and its vibration is the research focus. Then it is very important to develop a motor driving system with high performance and operates steadily. How to solve the vibration caused by excitation of driving motors and road roughness is a key problem for us too.This paper summarized the domestic and foreign vehicle vibration theory, the fundamental structures and key technologies of electric vehicles, the present condition and the development of drive system of the electric vehicle. From the view of electric machinery application and structural dynamics, we analyzed the excitation of SR motor on electric vehicle, the vibration of multiple degree of freedom, the coupled vibration of steering system and the reliability of electric vehicle drive-motor. The vibration of Hybrid electric vehicle is also analyzed in this paper, so the vibration theory of environmental-friendly electric vehicle is established.This paper consists of seven chapters, its research contents mainly dear with:Chapter one: IntroductionIn this part, background information and research motives is discussed, the present condition and the development of domestic and foreign environmental-friendly electric vehicle is introduced, including pure electric vehicle, hybrid electric vehicles and full cell electric vehicle. Review and prospect of vehicle vibration and motor reliability are also summarized in this part.Chapter two: Basic TheoryThe basic analysis method in vehicle vibration is synthesized in this part, including the simplified of automobile vibration system and the vibration of vehicle body and wheel double mass system. The basic structural of electric vehicle and its key technology are analyzed in details here.Chapter three: Research on Excitation of SR Motor on Electric VehicleNew type of switched reluctance motor was applied to electric vehicle. Considered electromotor as vibration source, stimulation of electromotor was analyzed in particular orientation. Expressions of radial force and torque variance were obtained by analytical method. During the course of system analysis of electric vehicle and SR electromotor, both radial force of SR electromotor and torque variance were considered. It was concluded that there are direct relationships between amplitude and initial phase in vertical orientation by numerical analysis. There are maximum and minimum of amplitude, and the way to make sure them is proposed. New reliable foundation was proposed to solve vibration problems of design and control of SR electromotor.For the research of the vibration excited by switched reluctance motor, if the vibration source is electric motor the impact of radial force and torque fluctuation should be considered. To improve the design of electric motor, develop its control theory and spread its application the vibration should be considered according to the application environment in the research of the structure design and control of SR electric motor.Chapter four: Vibration Research on Electric Vehicle Based on Switched Reluctance Motor and Driving SystemIt is considered that only excitation is brought by new switched reluctance motor (SRM). The model of five-freedom-degree vehicle vibration system with switched reluctance motor and its driving system is established according as whole vehicle system. Vibration responses of whole vehicle system of electric vehicle are analyzed. The key and perfect results are obtained.According to the significant excitation characteristic of SRM for the research of the electric vehicle based SRM drive system and its vibration, emphasis is placed on the impact of full vehicle vibration caused by drive motor but neglect the vibration caused by road roughness. The drive motor should be view as the excitation source to analyze the steady state response of vehicle body and man-seat. This is important in whole vehicle design. So to improve the reliability and stabilization of electric vehicle, the vibration of electric vehicle motor must be suppressed and its impact to full vehicle excitation should be considered too.Chapter five: Research on vibration of the driving and steering system of the electric vehicle and reliability of the drive motorCoupling vibration of steering system and drive system of electric vehicle (structure of driving motor and drive-axle) is researched. The model of four-freedom-degree pendulum vibration is established. The influence of gyroscopic effect and road surface roughness on electromotor is analyzed. Numerical solution for system vibration response of practical vehicle model is simulated, and good results of numerical analysis are obtained. The presented method provided the theoretic basis for development of electric vehicle.Because of the gyroscopic effect and the excitation of road roughness and electric motor, the coupled vibration among steering wheel, electric motor and anterior driving axle is very complex and significant in typical electric motor and anterior driving axle electric vehicle。It shows strong effect to the rub-impact of rotors and stator in motor. So how to solve it is the necessary technical basis in the design of electric vehicle. Only, analyze the invalidation and reliability based on the structure of electric vehicle can solve the related problems and promote the development and research of electric vehicle.Chapter six: Vibration Research on hybrid electric vehiclesAccording to the structure of the double power sources in HEV, a vehicle model of five-dof excited by engine and electric motor is established. An excitation expression of double excitation source was obtained by analytical method. By analyzing the vibration response for the excitation of full vehicle and man-seat, the perfect simulation of vehicle vibration was obtained. This also supplies reliable basis of theory for researching in HEV.Based on the excitation characteristics of engine and SR electric motor, the research of HEV and its vibration should be focus on impact of the dual excitation of drive motor drive engine on the vibration of full vehicle and man-seat, road roughness can be neglected. The drive motor and engine should be view as the excitation source respectively to analyze the steady state response of vehicle body and man-seat. This is important in whole vehicle design. To improve the stability of electric vehicle, the impact on vibration system of the different excitation should be distinguished and solved.Chapter seven: conclusions and prospectsThis part makes summaries conclusion of the article and prospects the correlative problem of electric vehicle and its vibration.
Keywords/Search Tags:Electric Vehicle, Vibration, drive system, steering system, SR motor drive, Reliability, stimulation and response
PDF Full Text Request
Related items