Analysis And Research On Electric Vehicle Safety In Use

Safety in use of the electric vehicle is always the key factor affecting the process of the market.This paper analyzes and studies the problem from two aspects respectively: traction battery fire and high voltage electric shock,which have an effect on the safety of the electric vehicle.The model of battery thermal runaway and the law of thermal diffusion are established,and the advices of battery optimization and electric shock protection are put forward.Also,the simulation and real vehicle verification are carried out.The main contents in this paper include the following aspects: This paper combs the development policies of electric vehicle in major automobile countries,and discusses the practical significance of the research,summarizes the research status of the electric vehicle safety in use.Through comparing the difference of the energy system and the traction system between the electric vehicle and the traditional automobile,this paper analyzes the influence of the structural difference on the safety of the electric vehicle.Lithium-ion battery can cause fire in extreme cases,and the failure of the high voltage circuit system will do harm to people.This paper also establishes the model of thermal runaway and the law of thermal diffusion through battery short circuit test,and analyzes the deep cause of electric shock and set the threshold of human body current and energy,provides theoretical basis for the next step of security design.Based on the cause of the battery fire and the characteristics of the lithium-ion battery,some improvement suggestions from the aspects of cell,module,system and the application of the whole vehicle are put forward.According to the characteristics of high voltage circuit and single-point failure of electric vehicle,the paper researches the key points of the high voltage electric shock protection from two stages: avoiding the occurrence of electric shock accident and reducing the harm from the accident.Basic protection can effectively prevent personnel from touching high voltage live parts,and single-point failure protection can reduce the harm of the electric shock to human body.In order to confirm the optimal combination of protective measures,theoretical analysis and Multisim simulation are used to compare the protective performance of different combinations.At last,this paper will carry out the real vehicle safety design and high voltage electrical test to verify the safety performance of the electric vehicle.Upon inspection,the vehicle safety design ideas and advices in this paper can effectively improve the electric vehicle safety in use,and is conducive to the development of electric vehicle safety technology and can promote the market process to a certain extent.