Research And Design Of Lithium Batteries Management System Based On Micro-Grid

The energy storage of lithium battery is one of the important part of the power station of energy storage in micro-grid, for the effective management of the energy storage module of lithium battery in micro-grid and meeting the requirements of the micro-grid of lithium battery management system, then the SOC estimation algorithms of lithium battery will be detailed research in this topic, and the hardware and software of lithium battery management system based on micro-grid will be designed.Firstly, several common battery models were introduced by this article including the equivalent circuit model of lithium battery in this topic, then the advantages and disadvantages of the common battery SOC estimation methods and the influence factors of the battery SOC estimation were analyzed, furthermore the requirements of micro-grid to SOC estimation of the battery and SOC estimation algorithm used in this paper were expounded.Secondly, SOC estimation algorithm of lithium battery based on improved AUKF was proposed in this paper, on the basis of the equivalent circuit model, for simplifying the model and improving the accuracy of SOC estimation of the battery. The parameters and the impact factors were revised by the improved algorithm and the estimation accuracy also was improved. The simulation platform of estimation was built through MATLAB, the SOC estimation experiment of battery be carried out, and the experimental results were analyzed.Finally, the hardware and software of battery management system were designed by this paper for the work environment of the lithium battery management system and the need of micro-grid energy storage module. Hardware design included the minimum system of DSP controller and the power supply circuit of DC, the circuit of current sampling, the circuit design of voltage measurement, the circuit of battery temperature measurement, the module circuit of LCD display, the circuit of data communication, the module of protection and charge and discharge control, etc. Software design included the design of the main program, the program of the battery parameters acquisition and filtering, the procedure design of lithium battery SOC estimation, the subroutine design of balance control, the subroutine design of charging control, the procedure of protection and alarm, etc. Then the hardware circuit and software system had carried by the preliminary debugging, and the experiment of constant current charging, the experiment of pulse discharge, and battery SOC estimation were done and all of the experimental results were analyzed. The experimental results show that the designed system met the requirement of the energy storage in micro-grid for lithium battery management system, at the same time the SOC of battery can accurately be estimated by the SOC estimation algorithm of battery in running system, and the feasibility and advantage of this design was verified.