A Modeling Method for Parallel Battery System Based on SOC Compensator

Abstract

The invention discloses a modeling method for a parallel battery system based on an SOC compensator. The parallel battery system is formed by parallel connection of N battery cells. The method is as follows: according to the known performance parameters of lithium-ion battery cells, using the operating characteristics of the parallel circuit and the current characteristics of each branch battery cell, a battery system mean value model is established, and then the actual value of each branch battery current and The average model branch current is compared to design a SOC compensator, so as to determine the mathematical relationship between the performance parameters of each battery cell and the performance parameters of the battery system, and establish a parallel battery system model. The parallel battery system model established by the invention can effectively simulate the charging and discharging characteristics of the parallel battery system, and the invented modeling method is applicable to both the parallel connection of battery cells and the parallel connection of battery modules.

Description

technical field [0001] The invention belongs to the technical field of design and control of a MW-level battery energy storage system in a smart grid, and relates to a modeling method for a parallel battery system based on an SOC compensator. Background technique [0002] Due to the advantages of high specific energy, no memory effect, long cycle life, and low self-discharge, battery systems based on lithium-ion batteries have been widely used in electric power, energy, military and other fields. At the same time, due to the constraints of the rated capacity and voltage of the battery cells themselves, it is usually necessary to connect multiple battery cells in parallel to form a battery system with a larger capacity, that is, a parallel battery system. For the parallel battery system, because of the inconsistency of the internal battery cells, the charging and discharging current of each branch will not be the same during charging and discharging; at the same time, the bat...

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Problems solved by technology

[0004] The problem to be solved by the present invention is to provide a parallel battery system modeling method based on SOC compensator to solve the problem that the battery performance parameters (such as voltage, current, etc.) And the problem that the charging and discharging characteristics are difficult to be accurately measured and estimated, to achieve the purpose of accurately predicting the charging and discharging characteristics of the parallel battery system

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