Battery Cell Balancing Groups for Faster Passive Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The passive balancing scheme in battery management systems is slow due to small cell balancing currents, and simultaneously turning on multiple balancing switches can damage switches and resistors due to large currents forming a short path.
Innovation Solution
A battery management apparatus and method that groups adjacent cells and simultaneously turns on balancing switches for these groups, using a cell balancing resistor to increase current magnitude and improve balancing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple balancing switches are simultaneously turned on to improve cell balancing speed, then cell balancing speed is improved, but large current flows through the switches and resistors causing potential damage
Solution Approach 1:
The patent divides the battery cells into multiple groups (odd-group and even-group) and controls balancing switches in each group separately. By alternating between groups rather than activating all switches simultaneously, the system achieves parallel processing of multiple cells while avoiding excessive current concentration in any single switch or resistor, thus resolving the contradiction between speed improvement and component durability.
2Ease of manufacture
If a fixed-size cell balancing resistor is used in passive balancing scheme, then cost is rationalized, but cell balancing current is small when cell voltage decreases resulting in slow balancing speed
Solution Approach 1:
The patent implements dynamic control of balancing switches based on real-time cell voltage detection. When cell voltage decreases, the system activates additional balancing switches in alternating groups to increase the balancing current magnitude. This dynamic adjustment allows the system to maintain cost-effectiveness with fixed resistors while adapting the current path to preserve balancing speed across varying voltage conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances cell balancing speed while minimizing switch and resistor damage by strategically grouping cells and controlling balancing switches, maintaining system integrity and efficiency.
Implementation Method 1
The passive balancing scheme is a resistance discharge scheme
Data Source
AI summary
A battery management apparatus for perform cell balancing of a battery and a cell balancing method thereof are provided. The battery management apparatus includes a detection circuit that detects pieces of state information of battery cells, a cell balancing circuit that controls whether to discharge each of the battery cells, and a control unit connected to the detection circuit and the cell balancing circuit. The control unit determines whether there is a need to perform cell balancing based on the pieces of state information of the battery cells; groups the battery cells into at least two groups, when it is determined that there is the need to perform the cell balancing; determines whether to apply a group control strategy based on the pieces of state information of the battery cells; and simultaneously controls balancing switches in the cell balancing circuit to perform the cell balancing.