Research On Functional Safety Of Blade Electric Vehicles(BEV) Drive System Based On Fault Tree Analysis(FTA)

The functional safety stability of electric vehicles is important to ensure its normal operation.With the development and growth of Auto Industry,the way people travel has changed and the type of cars also shows the tendency of diversification.Electric vehicles get great public recognition for its advantages of energy conservation and environmental protection,so further study of electric vehicles has become a hot topic for each car company to compete and cooperate.The function of the car safety problems not only can effectively prevent the car parts damage,but also can effectively protect the life and property safety of driving staff.The failure probability of the drive control system is higher due to its complex working condition,therefore,it has been closely paid much more attention,so the research on the drive control system has guiding significance in reality.The research object of this article is Blade Electric Vehicles Drive System.This paper puts forward with Fault Tree Analysis which is concise and clear as the main research method.Firstly it expounds the basic definition of Fault Tree Analysis,mathematical basis and modeling steps.Then it mainly introduces the structure,working principle and main characteristics of various modules.Different modules classify according to the different fault standards.It explains in detail fault types,forms,causes and processing methods of different modules according to the selected failure criteria.It can be improved and optimized from the perspective of the designer.The purpose is convenient for users and maintenance personnel to deal with failure well-regulated and well-founded.We can list all possible failures for motor ontology and need to have a fully understand and grasp for the motor structure to prognosis according to practical situation.The equipment should timely alarm to prompt when the motor is abnormal.The fault tree of motor ontology is established according to the Fault Tree Analysis modeling step.It can be perfected in the software part of the motor controller and it can also realize to use MATLAB simulation.We come up with two common faults especially: the stator windings fault and the bearing fault.This paper draws two fault trees respectively,confirms the diagnosis method and provides reliability calculation for quantitative analysis.It sketches composition module and working principle of 3KW motor controller researched and developed by Laboratory and applies its topology to establish the fault tree.This paper should build fault experiment simulation platform of motor controller to observe the experiment phenomenon of current waveform or the change of the motor parameters which can feedback failure and the way which can keep motor controller to achieve the effect of the stable operation or security for emergency treatment.This chapter highlights the three-phase bridge open circuit fault simulation modeling and results analysis.It comes up with two aspects of hardware and software protection design module error protection circuit and algorithm for the controller researched and developed by laboratory.According to the different types of power battery material and structure,failure analysis can be used to effectively analyze the performance and reason of the power battery failure.The system security link and the weak link can be showed clearly to do further improvement for designers and provide powerful basis for maintainer to maintain.