The Research And Design Of Lithium-ion Power Batterys Management System

At present, with the worsening of environmental pollution and the gradually exhausted non-renewable energy resources, the international community should strengthen cooperation and seek new development direction to save conventional fossil energy and protect the environment. In the field of transport, the step of new energy vehicles getting faster and faster, especially pure electric vehicles. However, the problem of energy storing device becomes the bottle neck in the development of it. Lithium battery with high performance, low-pollution or non-pollution got more and more attention of the automobile industry, and was known as the first choice of new energy vehicles.Lithium-Ion Power Batteries were usually formed by a large number of battery cells, they need battery management system to carry out effective monitoring and management, so that it could ensure the stable, high efficient and safe running of the batteries system. The battery management system, which includes battery state detection, equalizing charge-discharge management, temperature management and State of Charge(SOC) estimation, by detect the voltage, current and temperature of Lithium-Ion Power Batteries. This paper will give a deep research on battery management system and its core function-SOC estimation.At first, this paper analyzes the domestic and international development of the battery management system, and introduces the characteristics of Lithium batterys. For battery model, this paper analyze the influence of some other parameters on the battery capacity, such as current and temperature, Consider these factors, a new model is proposed, which take advantage of self-adaptation adjustment of parameters based on equivalent circuit model, besides, the least squares method for curve fitting is used to estimate the unknown parameters. The simulation results show the validity and accuracy of the model. Secondly, after analysis and reserches of the mainstream algorithm of SOC,a novel method to estimate the state of charge of lithium batteries based on extended kalman filter(EKF) is introduced, which contains many factors, including estimation accuracy,error accumulation, algorithm complexity, and so on. Case studies show that the EKF algorithm has high estimation accuracy.Findly, this paper develops a prototype of the battery management system, including software and hardware design, and carries out a large number of experiments. Simultaneously, the PC control software is designed based on LABVIEW. At last, implement of the whole system is finished. Validation and test proved that the designs presented above are validate, and the batterys mangement system is up to the standard of estimation accuracy as well as management function.