| The development and utilization of new energy vehicles is an important measure of energy-saving and emission-reduction in the field of transportation, which has been approved by governments and large transnational automobile enterprises in the world. Using lithium-ion power battery as the power source of new energy vehicles has become an irreversible trend and direction. Due to the physical and chemical characteristics of lithium-ion power battery, battery management system has become an important tool and necessary configuration of battery state management, energy management and safety management in the battery system. At present, research on key technology of battery management system are mainly concentrated on: establish a system model with accurate description of the battery characteristics, estimate the battery remaining power state accurately, assessment the battery efficiency condition effective, predict the battery state of health reasonably, build an efficient battery balancing control system and solve the problem of battery thermal equilibrium system management and so on. Several key problems of the lithium-ion power battery management system have discussed, and have achieved the following results:Firstly, equivalent circuit model of lithium-ion power battery which accommodates the estimation of state of charge(SOC) and the evaluation of state of function(SOF) had established, base on the research on lithium-ion power battery characteristics and summarized the existing model of lithium-ion power battery. The model used the improved second-order RC network equivalent circuit model of lithium-ion power battery, had considered the model accuracy and computational complexity, and achieved the identification of the parameters by using the classical least squares method. The results of the experiment and simulation show that the model is validity and has theoretical and practical value.Secondly, on the basis of summarizing the extended Kalman filter and suboptimal multiple fading Kalman algorithm, a strong tracking Sigma point Kalman filtering algorithm(STSPKF) is proposed. The three algorithms had analyzed and compared through simulation and experimental tests. The results show that the STSPKF algorithm has a higher accuracy.Thirdly, the definition of SOF is proposed in summing up the basis work of domestic and foreign researchers. Further more, this paper preposed a SOF controller design method which based on fuzzy logic algorithm, and then modified the parameters which used the fuzzy logic algorithm meet the application requirements. The fuzzy logic toolbox of Matlab software had used to simulate the experimental analysis. By selecting several representative performance statuses, the significance and importance of SOF research are demonstrated.Fourthly, battery management system and a battery pack are designed. Hardware platform of battery management system is built base on the core of embedded microprocessor ARM. The hardware platform sampling the monomer battery state by adopting the battery monitoring chip, equipped with a variety of data communication bus interface in order to adapt to different systems and demands; equipped with large capacity memory pieces in order to preserve the system running data and fault information. Design and development a battery management system software platform which based on embedded operating system UCOS-II. The software platform encapsulates the hardware interface layer and the underlying driver layer, design battery model calculation; power state estimation algorithm, and the effectiveness of the evaluation algorithm, multiple battery management system application on the basis of the software platform. In order to satisfy the stringent requirements of application environment, battery pack is designed base on the former battery management system, which includes the structure, the balancing system, the safety protection and the heat balancing system etc.Fifthly, the main scheme and algorithm is tested and verified which present by this paper through simulation experiment, laboratory experiment and real vehicle test. The experimental results show that the methods and algorithms which dicussed in this paper can realize the combination of theory and practice. The battery management system products base on this theory has good practical value and can satisfy the needs of practical applications. |
PDF Full Text Request