Research On SOC Estimation Of Battery And Remote Monitoring Method For Extended Range Electric Vehicles

The increasing depletion of global oil resources and the serious environment problem caused by burning oil remind people the importance of new energy vehicles.Extended range electric vehicles(EREV or REEV),as a transitional type between traditional vehicles and pure electric vehicles,have the advantages of long mileage and low-emission.They have become development trend of new energy vehicle in recent yearsEREV are a kind of vehicles added with auxiliary power unit (APU) on the basis of pure electric vehicles, they are much more complicated than traditional vehicles and pure electric vehicles for thier structure and control method.This paper has taken battery management technology of EREV as the entry point, research work is carried out around the following three aspects as follows:Full investigation of lithium battery equivalent model has been taken to establish an Thevenin equivalent model of lithium battery. In order to suppress the strongly nonlinear characteristics of lithium battery itself and influences brought by external parameters variation, an intelligent algorithm, extended particle swarm optimization (EPSO), has been utilized in the stage of model parameters identification.The feasibility of the algorithm is verified by the experimental platform and the Matlab simulation model.Finally, Proportional-Integral Observer (PIO) is uesd to obtain lithium battery SOC in real time with the characteristic of high accuracy,strong robustness and high real-time.A battery management system based on Controller Area Network (CAN) is designed for EREV.It has distributed bus topology. The system includes a battery management unit(BMU) and battery control unit(BCU), This paper introduces the software and hardware implementation of BMU and BCU in detail, and verifies the feasibility of the battery management system.Finally, in order to ensure the security and stability of power battery operation, a battery remote monitoring system is established for monitoring battery woking status and vehicle operating states in real-time.The system includes vehicle monitoring terminals, server and users management platforms.The vehicle monitoring terminal access vehicle communication network via CAN bus, and the GPRS network is used to send the battery data to the server this paper details the hardware and software implementation of the vehicle monitoring terminal, communication mechanism and data structure, etc.