Load distribution method for parallel application lithium battery packs in power supply system

Abstract

An embodiment of the invention discloses a load distribution method for parallel application lithium battery packs in a power supply system, and relates to the technical field of power electronics, and can lower the maintenance cost of the battery packs in the power supply system. According to the load distribution method, a lithium battery pack comprises two sub battery packs; each sub battery pack comprises a charging electrode, a discharging electrode and a common electrode, wherein a charging positive electrode is configured with a charging control switch with one-way conductive characteristic, and the current flows to the battery pack; a discharging positive electrode is configured with a discharging control switch with one-way conductive characteristic, and the current flows to an external load; each sub battery pack of the lithium battery pack is configured with a respective battery management system (BMS); and the BMSs are in mutual communication by adopting a CAN2.0B protocolfor exchanging the operation control information of each sub battery pack and realizing load distribution (sub battery pack "discharge" or "standby" state conversion control) of the sub battery packs.The load distribution method is applicable to parallel application battery packs in the power supply system.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a load distribution method among lithium battery packs used in parallel in a power supply system. Background technique [0002] At present, various DC power supply systems have been widely used. In order to improve the reliability of the DC power supply system, it is necessary to install a large-capacity battery pack in it. And in practical applications, it is usually necessary to configure two or more battery packs to operate in parallel to improve the reliability of the battery pack and increase the capacity of the battery pack. [0003] In order to ensure the stability of large-capacity battery packs connected in parallel, it is usually necessary to select the same model or even the same batch of batteries from the same manufacturer, and after the parallel circuit is set up, adjust the voltage and load of the two sets of batteries. When it is consistent with the loa...

AI Technical Summary

Problems solved by technology

[0004] However, due to the uncontrollable operating characteristics of the battery pack, in actual engineering applications, due to the quality control problems of the battery manufacturer and the influence of various complex environmental factors, the battery packs that have been erected in parallel often have unknown electrical characteristics. characteristics, and two groups of battery packs with unknown characteristics are often difficult to run stably after being directly connected in parallel, requiring technicians to make constant adjustments in subsequent maintenance, which undoubtedly increases maintenance costs

Images