Battery Pack Parallel Charging Sequence to Minimize Loop Currents
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Solution Overview
Problem
The existing battery systems face challenges when connecting multiple battery packs in parallel, as voltage differences can lead to loop currents, potentially causing irreversible damage or safety accidents, especially at low temperatures.
Innovation Solution
A battery system and parallelization method that involves setting charging priorities for battery packs based on their voltages and using switching circuits to connect them in parallel, ensuring that voltage differences between packs in the same priority are within a preset value, thereby minimizing loop currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple battery packs are connected in parallel to increase power output, then the power supply capability is improved, but voltage differences between packs generate loop currents that can cause irreversible damage or safety accidents
Solution Approach 1:
The patent applies preliminary action by establishing charging priorities for battery packs based on their voltage levels before parallel connection. The control device sorts battery packs into different charging priority groups according to voltage differences, ensuring that packs with similar voltages are charged together. This pre-organization prevents large loop currents from forming when packs are connected in parallel, thereby resolving the contradiction between power output and battery safety.
2Ease of manufacture
If battery packs with different voltages are connected in parallel, then the parallelization process is simplified, but large loop currents are generated that can overheat batteries and connecting circuits
Solution Approach 1:
The patent applies local quality by treating battery packs with different voltage characteristics differently through the charging priority mechanism. Instead of uniformly connecting all packs in parallel, the system divides packs into distinct charging priority groups based on their voltage levels. Each group is charged separately with appropriate current control, preventing harmful loop currents while maintaining the ability to parallelize multiple packs. This localized approach resolves the contradiction between ease of parallelization and loop current reduction.
Data Source
AI summary
The present application relates to a battery system and a parallelization method and apparatus thereof. The parallelization method of the battery system includes: acquiring voltages of the battery packs respectively; setting a charging priority of each of the battery packs according to a preset rule and the voltages of the battery packs; and controlling the switching circuit corresponding to the battery pack in the highest charging priority to be turned on to connect a charging loop of the battery pack for charging, and if the voltage of the battery pack currently charged is increased to a value close to the voltage of the battery pack in a next charging priority, controlling the switching circuit corresponding to the battery pack in the next charging priority to be turned on.