A method and system for controlling battery charge and discharge

Abstract

The present application discloses a battery charge and discharge control method and its system, wherein the battery charge and discharge control method specifically includes the following steps: detecting the state of each battery unit; selecting a number of specified battery units according to the state of all battery units Combine into a series circuit for charging / discharging; after charging / discharging for a period of time, according to the current state of all battery cells, recombine to obtain a new series circuit, and charge / discharge the battery cells in the new series circuit. The application can carry out dynamic equalization control of charging and discharging of the battery pack, realize full charge and discharge of the battery pack on the basis of ensuring stable input / output of the series battery pack, make full use of all capacities of the battery pack, and avoid redundant configuration.

Description

technical field [0001] The present application relates to the field of batteries, and in particular, to a method and system for controlling charging and discharging of batteries. Background technique [0002] In the prior art, due to problems such as the production process, the capacity of the battery cells is small, and it is difficult to meet the load's demand for energy storage capacity, so it is inevitable to use batteries in groups. In order to meet the required current, voltage or power requirements, a large number of single batteries need to be connected in series and in parallel to form a large-scale battery system. In terms of battery grouping technology, grouping or networking of small-capacity single batteries has great advantages over large-capacity single batteries in terms of energy storage system safety, reliability, and control performance. This has been confirmed by many practical applications. For example, the Tesla Model S electric car uses 8127 18650 sma...

AI Technical Summary

Problems solved by technology

Passive equalization discharges high-voltage batteries by adding bypass resistors to each battery, so that the voltage of each battery in the series battery pack is balanced, mainly to solve the balance problem during the charging process, and it is powerless to discharge equalization. At the same time, the equalization circuit It will cause a certain energy loss and reduce the energy efficiency of the battery system; active equalization realizes energy transfer between adjacent batteries by adding energy storage or conversion devices such as capacitors and transformers. The equalization loss is low, but there are many components and complex structures , high cost, low equalization efficiency, and it is difficult to fully utilize all the capacity of the battery pack

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