Design And Implementation Of Master-slave Lithium Battery Management System For Photovoltaic Energy Storage

With the development of society,a series of problems such as the energy crisis,the contradiction between human development and the ecological environment have emerged endlessly due to the uncontrolled exploitation and plunder of the earth's energy resources such as oil and coal.Photovoltaic energy storage technology came into being under this background.Therefore,it is very important for the development of photovoltaic energy storage technology to develop the efficiency of battery management systems,to improve the performance of photovoltaic energy storage systems and solve the problems caused by the inconsistency of lithium batteries during the operation of the photovoltaic energy storage system.Until now,domestic and foreign-related enterprises and universities have made great achievements in the field of battery management system technology,but it's needed to be improved in terms of parameter collection,balanced circuit topology and balanced strategy.Especially in the field of photovoltaic energy storage,there are some common problems such as low accuracy of battery parameter collection,serious energy waste,and high cost.Based on these problems,starting with the two aspects of balanced topology circuit and balanced control strategy,this paper aims to reduce the battery cost through the study of active balancing technology of lithium battery,and further improve the energy utilization rate of the battery pack and extend the battery pack life cycle..First of all,this paper studies the current problems the photovoltaic energy storage technology is facing now,and explains the significance of balancing technology in improving the service life of battery packs.This paper then analyzes the work principle of lithium power battery pack from the aspects of working characteristic and circuit model,and determines the battery model and suitable equilibrium variables for this article;this article next designs a multi-channel active equalization topology structure based on a flyback converter after comparing and analyzing the advantages and disadvantages of the existing equalization circuit,and the circuit design,parameter determination and feasibility simulation verification of the flyback transformer are carried out;Then an active balanced control strategy based on model predictive control is designed according to the balanced topology circuit in this paper,and the effectiveness of the algorithm is verified by the Matlab/Simulink battery management system simulation platform;this paper designs the overall scheme of the battery management system,and details the hardware and software architectures,functions and design goals of the system.Then the hardware circuit of the system is specifically designed and the corresponding schematic diagram is given.The main hardware modules include: controller module circuit design,balance module circuit design,circuit design of single voltage acquisition module,circuit design of temperature acquisition module,communication module circuit design and system power module circuit design.Finally,the software design of the system lower computer and upper computer is carried out.In the end,this paper designs a set of battery management system experimental prototypes based on the balanced topology circuit and equalization strategy.Based on this experimental prototype,the single cell voltage acquisition accuracy,temperature acquisition accuracy,and equilibrium strategy are tested.Finally the effectiveness of the equilibrium strategy designed in this paper is verified after contrast analysis.