Research And Implementation Of Lithium Iron Phosphate Battery Management Control System

Energy shortage and air pollution are serious problems nowadays. The impact of rapid growth of oil-fueled car parc on energy consumption and environment cannot be underestimated. Clean and energy-saving electric cars have become the inevitable developing trend of the auto industry. Battery is the power source of electric vehicles, and lithium iron phosphate battery has superior performance to other batteries. Against the background the thesis studies the management control system of lithium iron phosphate battery packs.Combined with the practical application of the system, the thesis analyzes the performance, structure, principles and operating environment of lithium iron phosphate battery, puts forward the research tasks of the battery pack management control system,builds an overall system design framework and researches on achieving the basic functions of the system.The module-design idea is adopted in hardware design. Measurement module,equalization module and control module are designed. The battery pack ASIC and Hall current sensors, etc., are used to achieve the monitor of voltage, temperature and current and the estimation of battery SOC, accomplishing the voltage balance of monomer batteries among battery packs, attaining 90% energy transfer efficiency. A digital zero drift compensation circuit based on tiny signals pulsating change is designed to ensure system measurement accuracy.Software design focuses on achieving the functions of each hardware module, the peripherals drive and the host computer PC terminal monitor. Flexible software technology is applied to achieve scalability and versatility of the system test management software. The host computer PC terminal monitor software achieves the functions of monitor and management and the lower computer software of data acquisition, analysis, processing and so on. The same single chip microcomputer is used in the MCU of measurement module and control module to achieve independence and sharing part of the code of each module.After testing, the system accurately records temperature, voltage, current, SOC and other data of working lithium iron phosphate battery packs. The active balancing effect is obvious, and all performance indicators meet the design requirements. The system is proved to be stable and reliable, and can be applied to electric cars.