Battery Balancing Circuit Resuming Control From Stored State

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In electric storage cells used in PHEVs and EVs, SOC fluctuations lead to battery deterioration, and existing balancing methods fail to continuously and effectively manage balancing across suspensions, missing opportunities for capacity adjustment and worsening fluctuations due to state changes and bypass resistor errors.

Innovation Solution

An electric storage cell control circuit that stores and resumes balancing control information, selecting between old and new state information based on predetermined conditions, allowing for continuous balancing without starting anew each time, thereby ensuring accurate and efficient balancing control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If balancing control is always continued from suspended state, then balancing efficiency is improved, but fluctuation worsens due to battery state changes and bypass resistor errors

Engineering Contradiction:
Improvebalancing efficiencyVSAvoidbalancing accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control circuit determines whether to resume or restart balancing before actually executing the balancing operation. This preliminary determination step allows the system to assess battery state changes and bypass resistor conditions before committing to a balancing strategy, thereby preventing accuracy degradation while maintaining efficiency when conditions permit continuation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically switches between resuming balancing and restarting balancing based on real-time conditions. The balancing control strategy is not fixed but adapts to changing battery states and component conditions, allowing the system to optimize between efficiency and accuracy depending on current operational context.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If balancing is restarted anew each time, then balancing accuracy is improved, but balancing time increases

Engineering Contradiction:
Improvebalancing accuracyVSAvoidbalancing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs a partial assessment (checking battery state and bypass resistor conditions) rather than a complete restart of the balancing process. When conditions are favorable, the system continues from the suspended state with partial re-validation, avoiding the time cost of full restart while maintaining sufficient accuracy through targeted checks.

Inventive Principle:
Principle #16Partial or excessive action

3Duration of action of moving object

If balancing control information is stored, then balancing continuity is improved, but information accuracy deteriorates due to battery state changes

Engineering Contradiction:
Improvebalancing continuityVSAvoidinformation accuracy
Core Design Contradiction:
Duration of action of moving objectVSMeasurement precision

Solution Approach 1:

The control circuit incorporates feedback mechanisms that check battery state and bypass resistor conditions before and during balancing operations. This feedback loop allows the system to validate stored control information against current conditions, ensuring accuracy while maintaining continuity. The system only relies on stored information when feedback confirms conditions remain valid.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2717421B1Power storage unit control circuit
Publication Date: 2020.11.04 VEHICLE ENERGY JAPAN INC
  • EP2717421B1 patent drawingFigure 1
  • EP2717421B1 patent drawingFigure 2
  • EP2717421B1 patent drawingFigure 3

AI summary

To satisfactorily carry out balancing even when balancing control is suspended. It is selected according to a condition which of battery cell information (old state information) by the last balancing stored in a storage device and battery cell information (new state information) acquired during a start of this time is used, and the balancing control is performed.