The Study Of Estimating The Remaining Power Of Battery In A PV-Grid Complementary System

With the development of society and the aggravation of environmental pollution,People's awareness of environmental protection is growing.So searching for and use new green energy has become the urgent task.As an inexhaustible green energy,How to use the solar energy effectively increasingly become the focus of scientific research.Solar PV power generation system can convert solar energy into electricity for people to use.The improvement of PV energy storage technology is the key to the efficient use of solar energy.And accurate estimation of the remaining power of storage battery is the key and difficult point in energy storage technology.This paper introduces a PV-grid complementary system and recommends the function of storage battery in the system.Moreover,the paper also analyses the performance requirements of the energy storage battery in PV-Grid complementary system.Due to the high energy efficiency,long life,safety and other characteristics,LiFePO4 battery will be the first choice for PV storage battery in the future.In this paper,the structure,working principle and main parameters of LiFePO4 battery are analyzed.We designed a experimental platform in order to solve the problem of aging influence in estimation of remaining power of battery.A large number of charge-discharge experiments were carried out to study the aging characteristics of LiFePO4 batteries.Based on the analysis of the change of the internal resistance and the voltage recovery rate,a method for estimating the remaining power of battery based on health factors is proposed.It is proved that the method has a high accuracy even in the age of battery through a large number of experimental data.