Research On The Hybrid Electric Vehicles Energy Storage System Features And Management Technology

Energy-saving and environmental protections have been targeted on the development of the automobile industry. As a new type of transport adding a source of energy diversification, the hybrid electric vehicles arouse widespread concern and have been greatly developed with its benefits of low emission and low noise. Battery Management System is one of the key technologies strengthening practical and commercial utilization of electric vehicles. In the hybrid electric vehicle energy storage system one of the main problems is the accurate estimate of battery SOC. Therefore the research of Battery Management Technology and System was of great significance.Various experiments on Ni-MH battery are carried out. The performances of voltage, available capacity, internal resistance and temperature are analyzed and appraised respectively. The research shows that the Ni-MH battery is applicable to hybrid electric vehicles.Based on the study of the existing battery SOC estimation method, Ah-dynamic hysteresis SOC Estimation is proposed. The method combines Ah-SOC and dynamic hysteresis SOC. Dynamic hysteresis SOC is based on Ni-MH battery open circuit voltage of the dynamic hysteresis model.Using the energy balance test, the energy consumption test, NEDC cycle test and Real Cut driving cycle test to verify the accuracy of SOC estimation algorithm. The bench test results show that this method is with high accuracy and reliability of estimation.Battery management system directly controls and manages the whole process of running battery. As to hardware circuit design we used the 16-bit embedded microcontroller MC9S12DG128B of freescale as a cpu and expanded the associated external circuit with its related modules. Thus implementation is made on precise detection of battery performance parameters, including the module voltage, the pack voltage, current, temperature and so on. A large number of experimental data proved the feasibility and effectiveness of the designed BMS.This dissertation mainly introduces the system design and implementation of the measuring instruments of internal battery ohmic, and elaborates on the structure. In this design, phase lock loop used can improve the precision and simplify the test circuit.The stady of internal resistance of battery lays the foundation for the SOH of battery.