Battery Management System Temperature Change Rate Control

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Solution Overview

Problem

Existing rapid charging technologies for electric vehicle batteries face challenges in preventing battery cell deterioration due to heat generation during high-energy density charging, as they rely on temperature measurement delays and simple current control, which can lead to reduced charging speed and safety risks.

Innovation Solution

A battery management system (BMS) apparatus and control method that measures and estimates temperature and state of charge (SOC) to calculate temperature change rates, allowing for dynamic adjustment of charging currents to maintain optimal temperatures, thereby minimizing battery cell deterioration and ensuring rapid charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high current is applied during rapid charging to achieve high energy density, then charging speed is improved, but heat generation increases causing battery cell deterioration

Engineering Contradiction:
Improvecharging speedVSAvoidheat generation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by calculating the temperature change rate and predicting future temperature trends before the battery actually reaches dangerous temperatures. This allows the control system to proactively adjust charging current to prevent overheating while maintaining rapid charging capability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback by measuring actual temperature, calculating temperature change rates, comparing predicted temperature with reference values, and dynamically adjusting charging current based on this feedback loop to balance charging speed and temperature control

Inventive Principle:
Principle #23Feedback

2Reliability

If temperature reference value is lowered to prevent battery deterioration, then battery safety is improved, but charging speed decreases

Engineering Contradiction:
Improvebattery safetyVSAvoidcharging speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system applies dynamics by making the charging current adaptive rather than static. The charging current dynamically adjusts based on real-time temperature measurements and calculated temperature change rates, allowing the system to maintain high charging speeds when safe and reduce current only when necessary to prevent overheating

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes parameters by using temperature change rate as an additional control parameter beyond just absolute temperature. This allows for more nuanced control of charging current, enabling the system to maintain higher charging speeds by considering the rate of temperature change rather than solely relying on absolute temperature thresholds

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If simple temperature measurement and comparison control is used, then device complexity is reduced, but temperature control precision deteriorates due to time delay

Engineering Contradiction:
Improvecontrol system complexityVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

By calculating the temperature change rate and predicting future temperature, the system performs preliminary action to anticipate temperature trends before they materialize. This compensates for measurement delays without requiring complex predictive models or additional sensors

Inventive Principle:
Principle #10Preliminary action

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

The system effectively suppresses battery cell deterioration by accurately controlling charging currents based on real-time temperature and SOC data, maintaining optimal charging conditions and preventing overheating, thus enhancing battery life and safety.

Implementation Method 1

a temperature, a state of charge, a voltage, and a charging current of a battery may be measured

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

a temperature change amount and a temperature change rate may be calculated

Methodology Applied
Scientific EffectTemperature change rate calculation:

Implementation Method 3

heat generated at this time may have a great influence on the deterioration of battery cells

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

dynamic adjustment of charging currents to maintain optimal temperatures

Methodology Applied
Scientific EffectThermal management:

Data Source

PatentEP3739719B1Apparatus and control method for battery management system
Publication Date: 2022.08.17 SK ON CO LTD
  • EP3739719B1 patent drawingFigure 1
  • EP3739719B1 patent drawingFigure 2(a)~2(b)
  • EP3739719B1 patent drawingFigure 3

AI summary

An embodiment of the present invention is directed to providing an apparatus and a control method for a battery management system (BMS) that may operate in an optimal charging temperature range to suppress deterioration of battery cells during rapid charging of a secondary battery that requires a high charging current.