Battery Module Discharge Balancing for Uneven Cell Aging
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Solution Overview
Problem
Existing battery module discharge balancing methods focus primarily on charging and fail to address unbalanced aging of battery cells, leading to reduced discharge capacity and service life due to temperature differences among cells.
Innovation Solution
A discharge balancing method that monitors and adjusts the discharge ratio of each battery block in a battery module by detecting cell voltages and calculating temporary adjustment parameters to balance aging and extend service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If charging balancing is performed to equalize open circuit voltage of battery cells, then charging uniformity is improved, but discharge capacity and service life are not extended due to unbalanced aging during discharge
Solution Approach 1:
The patent inverts the conventional charging-only balancing approach by implementing discharge balancing. Instead of only equalizing voltages during charging, the system monitors discharge processes and adjusts discharge ratios of different battery blocks to balance aging effects, thereby extending service life while maintaining voltage uniformity
Solution Approach 2:
The patent changes the balancing parameter from open circuit voltage (used in charging balancing) to discharge capacity and aging degree. By monitoring discharge voltage, current, and temperature to calculate aging degrees, and adjusting discharge ratios based on these parameters, the system achieves both voltage uniformity and extended service life
2Ease of operation
If all battery blocks discharge at the same rate, then discharge control is simplified, but total discharge capacity is reduced due to unbalanced aging of individual blocks
Solution Approach 1:
The patent segments the battery module into multiple battery blocks and assigns different discharge ratios to each block based on their individual aging degrees. The processor calculates and adjusts discharge ratios for each block separately, allowing optimized discharge capacity extraction while managing aging differences through segmented control
Solution Approach 2:
The patent implements dynamic adjustment of discharge ratios for different battery blocks based on real-time monitoring of discharge voltage, current, and temperature. The discharge ratios are continuously updated according to calculated aging degrees, enabling the system to adaptively maximize total discharge capacity while balancing aging effects
Data Source
AI summary
The invention provides a battery equipment discharge balancing method, wherein a battery module of the battery equipment includes a plurality of battery blocks connected in parallel, and each battery block includes a plurality of battery cells connected in series. During the discharging process, the voltage of each battery cell is measured to generate a plurality of battery cell voltages. When any one of battery cell voltages reaches a cut-off discharge voltage, it is determined that the battery module is fully discharged. Thereafter, a minimum battery cell voltage in each battery block is obtained respectively to generate a plurality of cut-off battery cell voltages. The discharge ratio of each battery block in the next discharge process is adjusted according to the cut-off battery cell voltages respectively, so as to increase the discharge capacity and service life of the battery module.