Battery Control Device Dynamic Parameter Correction

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Solution Overview

Problem

Existing battery control devices inaccurately determine allowable current and power during charge/discharge due to changes in battery voltage and internal resistance caused by temperature, charge time, and charge current, leading to potential overcharge or overdischarge states that can reduce safety and battery lifespan.

Innovation Solution

A battery control device that calculates allowable current and power by correcting the no-load voltage and internal resistance based on charge/discharge situations, including temperature, time, and current, using intercept voltage and internal resistance maps to accurately reflect dynamic changes during charging and discharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the maximum current during charge is calculated from the battery voltage during no-load and the internal resistance, then the calculation is simple, but the accuracy of the allowable current and power determination deteriorates due to changes in voltage and resistance according to charge situations

Engineering Contradiction:
Improvecalculation complexityVSAvoidaccuracy of allowable current and power determination
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the no-load voltage and internal resistance values adjustable based on charge/discharge situations. Instead of using fixed values, the system dynamically corrects these parameters according to temperature, charge time, and charge current conditions, allowing the calculation model to adapt to changing battery states and maintain accuracy throughout the charge/discharge cycle

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of no-load voltage and internal resistance based on charge situations. By introducing correction mechanisms that modify these parameters according to temperature, charge time, and current levels, the system maintains accurate determination of allowable current and power across varying operating conditions without requiring completely complex alternative calculation methods

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the no-load voltage and internal resistance are corrected according to charge/discharge situations, then the accuracy of allowable current and power determination is improved, but the device complexity increases

Engineering Contradiction:
Improveaccuracy of allowable current and power determinationVSAvoidcontrol device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-establishing correction mechanisms and relationships between charge situations and parameter adjustments. The control device is configured with predetermined correction logic that automatically applies the appropriate corrections based on monitored conditions, eliminating the need for complex real-time calculations while maintaining high accuracy in determining allowable current and power

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If fixed no-load voltage and internal resistance values are used, then the control device is simple, but the battery safety deteriorates due to potential overcharge or overdischarge states

Engineering Contradiction:
Improvecontrol device simplicityVSAvoidbattery safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies feedback by continuously monitoring charge/discharge situations including temperature, charge time, and current levels, and using this information to dynamically correct the no-load voltage and internal resistance values. This feedback mechanism ensures that the control device maintains accurate determination of allowable current and power throughout operation, preventing overcharge or overdischarge states while keeping the device relatively simple

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2857854B1Cell control device
Publication Date: 2019.05.08 HITACHI AUTOMOTIVE SYST LTD
  • EP2857854B1 patent drawingFigure 1
  • EP2857854B1 patent drawingFigure 2
  • EP2857854B1 patent drawingFigure 3(a)~3(b)

AI summary

A battery control device calculates at least one of an allowable current and an allowable power during charge/discharge of a battery from a no-load voltage and an internal resistance of the battery and corrects at least one of the no-load voltage and the internal resistance according to the situations of charge/discharge of the battery.