Research And Design On Electric Vehicle Battery Safety Management System

In recent years, with the increased pressure of energy and environment, pure electric vehicles has been gradually moving towards the world stage. Power battery is not only a major energy carrier and power source of pure electric vehicle, but a core part of the pure electric vehicle technology, and has a direct impact on the use of pure electric vehicle performance and manufacturing cost. As a kind of tool, battery management system has a function for real-time monitoring and management of power battery working status,ensuring safe and reliable work, extending the cycle life. It has important significance on reducing the cost of electric vehicle and improving the electric vehicle safety. The distributed management system is designed in this paper in combination with electric vehicle high voltage system safety standard and management system features. The content is as follows:1. Third-order RC dynamic model of power battery is established, the parameters is estimated, and Taylor formula is used to optimize the model. SOC of battery is estimated based on the RC dynamic model, SOH prediction model and estimation method is proposed.2. The various kinds of potential faults of pure electric vehicle high voltage system are analyzed in detail. Control strategies are studied on all kinds of fault system and on high voltage system at starting, running, stopping course.3. The causes and effects of the differences of the battery group are analyzed and the balance management hardware circuit is designed, then cell equilibrium control strategies are put forwarded.4. Minimal peripheral control system is designed by using the Infineon 16-bit microcontroller XC2338 N based on the system parameters detection and regulatory requirements. System is designed modularize,and composed of temperature detectionmodule, voltage detection module, current detection module, high voltage loop interlock module, insulation detection module, pre-charge module and CAN communication network module. Not only the basis for the system of real-time monitoring and estimating SOC is provided, and a platform for the system to further expand is provided.5. The simulation platform is builded based on Matlab/Simulink, the cell model and balance management hardware circuit is debugged and validated. Simulation results show that the battery model and the hardware circuit performance is good, can achieve predetermined security management strategies.