Secondary battery pack charging and discharging management system

Abstract

The invention provides a secondary battery pack charging and discharging management system. The secondary battery pack charging and discharging management system comprises a battery pack, a step-up and step-down module and a main control module, wherein the battery pack is formed by a plurality of individual battery modules through serial connection; a self-control part of each individual battery module is used for controlling a serial-in switch and a bypass switch to be turned off or turned on; the main control module is used for generating a signal for controlling a battery pack step-up and step-down circuit short-circuiting switch and a signal for selecting a single battery to be serially connected into the battery pack according to the working state of the battery pack, and controlling a step-up and step-down circuit to adjust charging and discharging voltage and current. By adopting the secondary battery pack charging and discharging management system provided by the invention, under the situation that the capacity and the internal resistance of each single battery are different, the utilization ratio, the service life and the safety of the entire battery pack are improved; by calculating balance use battery quantity, under the situation that any step-up circuit is not used, different voltage can be obtained; the operating costs of electricity-consuming equipment such as electric vehicles which use the secondary battery pack charging and discharging management system can be reduced and the overall working efficiency of the equipment is improved.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a charge and discharge management system for a secondary battery pack. Background technique [0002] Battery packs, especially power battery packs, are used more and more, such as electric tools, various electric vehicles, etc. The individual differences of batteries and the differences in the environment in which they are used cause differences in the capacity and internal resistance of individual batteries, and in Over time, the changes will be even greater. If it is not controlled and managed, it will have a huge impact on the safety of charging and discharging, the overall use capacity and life. [0003] In the prior art, the charging and discharging management of the battery pack focuses on balancing each battery during charging and discharging, so as to advance and retreat together, and adopts passive equalization (shunting or energy-consuming equalization) and activ...

AI Technical Summary

Problems solved by technology

Among them, the passive equalization circuit is simple and low in cost, but the effect is poor, the heat generation is high, and the energy utilization rate is low, and it can only play a role in charging, and cannot balance in discharging.

[0004] Active equalization can work both in charge and discharge, but it is only in the concept or laboratory research at present, and the market application value is not great. The main reasons are as follows: 1. The equalization current is too small to meet the actual requirements; 2. In electric vehicles, etc. In the application, the working current is large, and the equalization current is also large, so the equalization equipment is large in size, high in cost, and poor in vibration and weather resistance when installed on the car, so the overall reliability is poor; 3. Although the efficiency is much higher than that of the passive type, it is still not enough and causes cooling problem

[0005] In addition, whether it is passive balancing or active balancing, when a single battery in the battery pack has serious problems (such as open circuit, short circuit, large internal resistance and cannot be safely discharged, etc.), the entire battery pack has to go on strike, and the problem battery cannot be avoided. Instead choose to use a normal battery

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