Power Battery Real-time Online Monitoring System And SOC Estimation For Electric Vehicle

With the rapid development of the global economy, demand for vehicle energy is growing in the dual pressure of energy shortage and environment pollution, electric vehicles as a kind of new energy vehicles, with its low pollution, wide application and low maintenance costs, will become the focus of development of automobile industry and energy industry in the future. Power battery is the energy source of electric vehicles, and it is also a major factor influencing the performance and production costs of electric vehicle. Battery management system is the link between power battery and vehicle, provides basis for the rational management and optimal control of power battery. State of charge (SOC) as an important parameter to characterize the remaining capacity of battery is the key to the research of battery management system.A power battery real-time online monitoring system for electric vehicle is studied in this paper. The system consists of two parts, one is the power battery online monitoring terminal installed on electric vehicle to collect the battery information. The other part is the software of power battery real-time online monitoring system for electric vehicle, which is installed in the upper computer in monitoring center. This paper has completed the design of software of power battery real-time online monitoring system for electric vehicle, and can realize SOC estimation function of the software monitoring system by using the BP neural network algorithm. The main work is described as follows:(1) Deep understanding of the working principle, characteristics and influence factors of lithium iron batteries SOC through the related literature at home and abroad, and several common SOC estimation methods are analyzed comprehensively, and then SOC algorithm based on neural networks are studied deeply, and power battery SOC is estimated by using the BP neural network algorithm.(2) The software of power battery real-time online monitoring system for electric vehicle is designed and implemented in this paper. Microsoft Visual Studio2010as development environment of the system software, SQL Server2008as the database management system, using C#development language to develop PC monitoring software in accordance with the MVC (Model-View-Controller) model. Design and implementation of software based on a hierarchical structure are introduced in detail.(3) The experimental platform of system hardware and software is constructed, so the experiments for the system have been carried out. The system software designed in this paper realizes the communication with the power battery online monitoring terminal, real-time online monitoring of power battery status, fault diagnosis, SOC estimation, report forms and data storage functions. The experimental results verify the reliability and feasibility of the system, and show that the power battery SOC estimation with high accuracy could be obtained by using BP neural network algorithm.