Virtual Cells for Battery Thermal Management

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Solution Overview

Problem

Conventional battery thermal management systems are inadequate in controlling heat generation from within the battery, especially during high current demands or faults, leading to potential overheating and thermal runaway, particularly in advanced high energy density batteries like lithium-type batteries.

Innovation Solution

The implementation of virtual cells, managed by a battery thermal management system (BTMS) controller, which senses temperature and current levels to activate virtual DC/DC or AC/DC converters to reduce current loads on overheating battery cells, thereby controlling heat generation and maintaining safe temperature limits without compromising normal load demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional external cooling systems are used to transport heat away from the battery, then the battery temperature can be reduced, but the system cannot control heat generation from within the battery during high current demands or faults

Engineering Contradiction:
Improvebattery temperature controlVSAvoidthermal management adequacy during faults
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent introduces virtual cells as intermediary components between the battery cells and the thermal management system. These virtual cells act as current redistributors that can divert current away from overheating battery cells, thereby controlling heat generation at its source rather than merely cooling the battery externally.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the electrical parameters (current distribution) of the battery system by activating virtual cells to redirect current flow. This parameter change approach allows the system to reduce heat generation in specific battery cells by modifying the electrical load distribution in real-time based on temperature conditions.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If virtual cells are activated to reduce current loads on overheating battery cells, then heat generation from within the battery is controlled, but the current load capacity of the battery pack may be compromised

Engineering Contradiction:
Improvebattery cell temperatureVSAvoidcurrent load capacity
Core Design Contradiction:
TemperatureVSPower

Solution Approach 1:

The virtual cell activation is a dynamic process that adjusts current distribution in real-time based on battery temperature conditions. The system can dynamically switch virtual cells on or off, and adjust their current handling capacity, allowing flexible adaptation between temperature control and power delivery needs without fixed compromises.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system applies partial current redistribution only to the extent necessary for thermal management. Virtual cells divert only the excess current causing overheating, while allowing normal current flow to continue for meeting load demands. This partial action approach ensures power capacity is maintained unless and until thermal limits are approached.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If high current is drawn from the battery to meet load demand, then the load demand is satisfied, but heat generation increases beyond the capability of external thermal management systems

Engineering Contradiction:
Improveload demand fulfillmentVSAvoidheat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The system performs preliminary thermal management by continuously monitoring battery cell temperatures and proactively activating virtual cells to redistribute current before dangerous heat accumulation occurs. This preliminary action prevents the need for aggressive cooling later and allows sustained high current operation within safe temperature limits.

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

This approach effectively prevents battery overheating and thermal runaway by directly managing heat generation from within the battery, ensuring stable temperatures and meeting load demands through the use of virtual cells that compensate for reduced current loads.

Implementation Method 1

activating, with the BTMS controller, at least one virtual cell to provide current or sink current for at least one of the battery cells

Methodology Applied
Scientific EffectElectrical energy transformation:

Implementation Method 2

sensing, with at least one temperature sensor, a temperature of at least one battery cell in a battery pack

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 3

sensing, with at least one current sensor, at least one current within the battery pack

Methodology Applied
Scientific EffectCurrent sensing:

Implementation Method 4

determining, with a battery thermal management system (BTMS) controller, if the temperature of any of the battery cells in the battery pack exceeds a temperature limit

Methodology Applied
Scientific EffectSignal processing and control:

Data Source

PatentEP2871703B1Method and system for battery thermal management
Publication Date: 2018.05.23 THE BOEING CO
  • EP2871703B1 patent drawingFigure 1
  • EP2871703B1 patent drawingFigure 2
  • EP2871703B1 patent drawingFigure 3

AI summary

A system, method, and apparatus for virtual cells for battery thermal management are disclosed. The disclosed method involves sensing, with at least one temperature sensor, a temperature of at least one battery cell in a battery pack. The method further involves sensing, with at least one current sensor, at least one current within the battery pack. Also, the method involves determining, with a battery thermal management system (BTMS) controller, if the temperature of any of the battery cells in the battery pack exceeds a temperature limit (TLimit). Further, the method involves activating, with the BTMS controller, at least one virtual cell to provide current or sink current for at least one of the battery cells in the battery pack that exceeds the temperature limit.