Conductive Contact Element with Liquid Cavity for Heat Dissipation

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Solution Overview

Problem

Electrical contact systems face challenges in maintaining low resistance and efficient heat dissipation, especially in high-current applications like electric vehicle charging, where contact resistance leads to excessive temperature and potential fires, due to the trade-off between conductivity and wear resistance, and the limitations of conventional materials in managing high power losses.

Innovation Solution

An electrical contact element with a conductive body featuring a closed cavity filled with a liquid or gaseous material at a temperature below the melting point of the solid material, which enhances heat dissipation through convective circulation and thermal conductivity, allowing for improved heat transport away from the contact surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the contact surface is coated with wear-resistant materials, then the resilience of the contact surfaces is increased, but the electrical conductivity is reduced

Engineering Contradiction:
Improveresilience of contact surfacesVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The contact element uses a composite structure combining a solid conductive material body (first material) with a liquid/gaseous conductive material (second material) in a closed cavity. This composite design allows the solid material to provide mechanical strength and wear resistance, while the liquid/gaseous material provides high electrical conductivity and heat dissipation, resolving the contradiction between wear resistance and conductivity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention introduces a liquid or gaseous material into the contact element structure to serve dual purposes: maintaining electrical conductivity and enabling active heat dissipation through convective circulation. This pneumatic/hydraulic approach allows the system to achieve both wear resistance (through the solid structure) and high conductivity without the trade-off present in conventional coated contacts.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Power

If high currents flow through the contact, then the charging power is increased, but the temperature on the contact surface increases sharply

Engineering Contradiction:
Improvecharging powerVSAvoidcontact surface temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The liquid or gaseous material in the closed cavity acts as a heat transfer medium that actively removes heat from the contact surface through convective circulation. This allows high charging currents to flow without excessive temperature buildup, as the fluid continuously absorbs and transports heat away from the contact zone, enabling high power transmission with effective thermal management.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The liquid/gaseous material may utilize phase transitions (evaporation/condensation cycles) as part of its heat dissipation mechanism. During phase change, the material absorbs latent heat from the contact surface, providing intense cooling capacity that enables high current flow without temperature exceedance, thereby supporting high charging power levels.

Inventive Principle:
Principle #36Phase transitions

3Loss of energy

If the contact resistance is reduced, then the power loss is decreased, but the heat dissipation capability is not sufficiently improved

Engineering Contradiction:
Improvepower lossVSAvoidheat dissipation capability
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The liquid/gaseous material provides active heat dissipation through forced or natural convection currents within the closed cavity. This convective heat transfer mechanism continuously moves heat away from the contact surface, complementing the low contact resistance design. The system achieves both low energy loss (through minimized contact resistance) and superior heat dissipation (through fluid convection), resolving the limitation of conventional low-resistance contacts that still suffer from heat accumulation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 design achieves reduced contact resistance and enhanced heat dissipation, preventing overheating and potential fires, while maintaining conductivity, even at high currents, and allows for smaller contact dimensions without compromising performance, thus optimizing charging efficiency and safety.

Implementation Method 1

enhances heat dissipation through convective circulation and thermal conductivity

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

enhances heat dissipation through convective circulation and thermal conductivity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a body made of an electrically conductive first material... filled with a second, electrically conductive material

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3503304B1Electrical contact element of a plug system
Publication Date: 2020.08.26 NEXANS SA
  • EP3503304B1 patent drawingFigure 1

AI summary

An electrical contact element of a plug system for connecting an electrical device to a power supply comprises a body made of an electrically conductive first material, which has a first electrical contact surface at one end for establishing electrical contact with a second electrical contact element. The body has a closed cavity that extends from the first contact surface over at least part of the body's length. The cavity is at least partially filled with a second material that is liquid and/or gaseous at a temperature below the melting point of the first material.