Battery Cell Voltage Balancing Control Device
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Solution Overview
Problem
Existing cell balance control methods for charging multiple cell blocks in series are inefficient, leading to prolonged charging times due to neglecting voltage equality between discharge and charge target cell blocks, and requiring individual control that prolongs the charging process.
Innovation Solution
A control device and method that includes a controller detecting voltages across multiple cell blocks, updating the maximum voltage, and discharging cell blocks within a defined discharge target voltage range to maintain a specified voltage range, thereby actively balancing cell voltages and reducing charging time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cell balance control is performed by independently controlling each cell block and continuing charging for a predetermined time when voltage becomes equal to or larger than a predetermined voltage, then cell voltage balancing is achieved, but charging time is prolonged because discharging and charging continue even when voltages become equal
Solution Approach 1:
The control device continuously monitors the voltages of all cell blocks and uses this feedback information to dynamically adjust the charging and discharging operations. When the voltage difference between cell blocks falls within a predetermined range, the system automatically terminates cell balance control, preventing unnecessary continued operation and reducing charging time while maintaining reliable voltage balancing.
2Reliability
If cell balance control stops charging of the entire system when a cell block voltage exceeds a predetermined voltage and starts discharging the relevant cell block, then voltage balancing is achieved, but this approach is less efficient compared to continuing system charging while discharging only the relevant block
Solution Approach 1:
The system segments the cell blocks into different operational groups: cell blocks that require discharging to balance voltage, cell blocks that continue charging, and cell blocks that are temporarily suspended. This segmentation allows the majority of the battery system to continue charging while only the specific imbalanced cell blocks undergo discharging, thereby maintaining high overall charging efficiency while achieving reliable voltage balancing.
3Reliability
If individual cell blocks are independently controlled during cell balance control, then voltage balancing can be achieved, but the complexity of control increases and charging time is prolonged
Solution Approach 1:
The control device automatically identifies which cell blocks require discharging by comparing their voltages against the predetermined range criterion, and autonomously manages the charging suspension and resumption for different cell blocks. This self-service capability eliminates the need for complex external control interventions, reduces operational complexity, and maintains reliable voltage balancing through automated decision-making based on real-time voltage measurements.
Data Source
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AI summary
A control device includes a controller causing a plurality of cell blocks each configured of one or plurality of secondary battery cells and connected in series to be charged with a cell balance, and the controller includes a detector detecting a voltage of each of the cell blocks, an updater sequentially updating a maximum voltage of the detected voltage of each of the cell blocks, and a discharger discharging a cell block among the plurality of cell blocks, the cell block with a voltage range between the detected voltage and the updated maximum voltage within a discharge target voltage range defined in advance.