Battery Equalization Circuit With Separate Power Branches
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Solution Overview
Problem
Existing battery equalization systems have low efficiency and long equalization times, which affects the consistency of battery cells in electric vehicle packs, leading to reduced capacity and shorter battery life.
Innovation Solution
A battery equalization system with a power supply circuit that includes a collection circuit, an equalization circuit, and a controller to manage charging and power supply, allowing for continuous equalization processing by disconnecting the charging branch circuit when the battery is full and maintaining power to the equalization circuit through a separate power supply branch, thereby extending equalization time and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the charging branch circuit is disconnected when the battery is fully charged, then the battery can be protected from overcharging, but the equalization circuit cannot receive power to continue equalization processing
Solution Approach 1:
The power supply system is segmented into two independent branches: a charging branch circuit connected to the high-voltage direct current output terminal for battery charging, and a first power supply branch circuit connected to the low-voltage direct current output terminal for equalization processing. This segmentation allows the charging circuit to be disconnected when the battery is fully charged while the power supply branch remains connected to provide continuous power to the equalization circuit, thereby maintaining equalization efficiency without compromising battery protection.
Solution Approach 2:
The first power supply branch circuit acts as an intermediary between the charging device and the equalization circuit. It receives low-voltage direct current power from the charging device and supplies it to the equalization circuit independently of the charging branch circuit's connection state. This intermediary role enables the equalization circuit to receive continuous power even when the charging branch circuit is disconnected after full charging, resolving the contradiction between battery protection and equalization efficiency.
2Device complexity
If equalization processing is performed only during charging, then the system structure is simple, but the equalization time is long and efficiency is low
Solution Approach 1:
The equalization circuit is designed to receive power from the first power supply branch circuit connected to the low-voltage direct current output terminal of the charging device. This configuration enables the equalization circuit to operate continuously both during the charging process and after the charging is completed. The controller maintains the connection of the power supply branch circuit even after the battery is fully charged, allowing the equalization circuit to continue processing without interruption, thereby significantly reducing equalization time and improving efficiency without substantially increasing system complexity.
3Device complexity
If the equalization circuit shares the same power supply as the charging circuit, then the system is simple, but the equalization process must stop when charging is complete
Solution Approach 1:
The power supply structure is segmented into two independent circuits: the charging branch circuit connected to the high-voltage direct current output terminal for battery charging, and the first power supply branch circuit connected to the low-voltage direct current output terminal for equalization processing. This segmentation allows the equalization circuit to receive power independently from the charging circuit, enabling equalization to continue even after charging is complete, thereby extending the equalization duration without significantly increasing overall system complexity.
Solution Approach 2:
The first power supply branch circuit serves as an intermediary power supply path that bridges the charging device and the equalization circuit. It receives low-voltage direct current from the charging device and provides continuous power to the equalization circuit regardless of the charging branch circuit's state. This intermediary structure enables the equalization process to extend beyond the charging duration, resolving the contradiction between system simplicity and equalization duration.
Data Source
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AI summary
The present application discloses a battery equalization system, a vehicle, a battery equalization method, and a storage medium. The battery equalization system includes: a collection circuit; an equalization circuit; a controller; a charging branch circuit, connected to a charging device and a battery pack; and a first power supply branch circuit, connected to the charging device and the battery equalization system, and configured to supply power to the battery equalization system. When a state-of-charge of the battery pack is full and a cell in the battery pack needs enabling of equalization, the controller controls the charging branch circuit to disconnect, and controls the first power supply branch circuit to keep connected, so that an equalization module performs equalization processing on the cell that needs enabling of equalization. By improving the electrical connection structure of the battery equalization system, the present application extends the battery equalization time, improves the battery equalization effect, and resolves the technical problem of low equalization efficiency of the battery equalization system in the related art.