Gas-Insulated Disconnector Heat Conduction for High-Current Contacts

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Solution Overview

Problem

Existing gas-insulated medium-voltage power switchgear faces challenges in efficiently dissipating heat from high-current contact points while maintaining cost-effectiveness and avoiding additional moving parts that can reduce reliability.

Innovation Solution

A disconnector design with a heat-conducting device using copper stranded conductors and a second spring mechanism to enhance heat dissipation through conduction, combined with a non-magnetic holding device for insulation, allowing efficient heat transfer to the housing without increasing installation space or requiring external cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If high currents are switched through contact fingers, then power transmission capability is improved, but contact temperature increases due to high power loss

Engineering Contradiction:
Improvepower transmission capabilityVSAvoidcontact temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

A heat-conducting device made of thermally conductive material (such as metal) is introduced as an intermediary between the contact fingers and the housing. This mediator transfers heat away from the contact fingers to the housing, which has a larger surface area for heat dissipation, thereby reducing contact temperature while maintaining high current transmission capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The solution transitions from one-dimensional heat dissipation (through the contact fingers themselves) to three-dimensional heat management by introducing a dedicated heat-conducting device that extends into the housing structure. This allows heat to be distributed across a larger volume and surface area, improving thermal management efficiency

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If additional heat sinks are added to increase cooling surface area, then heat dissipation is improved, but device complexity and installation space increase

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidstructural complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The heat-conducting device serves multiple functions simultaneously: it acts as a thermal conductor to transfer heat from contact fingers, provides structural support for the contacts, and can serve as part of the housing structure itself. This multi-functionality reduces the need for separate dedicated heat sink components, thereby limiting the increase in device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The heat-conducting device is integrated with the housing structure, merging the cooling function with the existing structural framework. By combining thermal management functionality with the housing, the solution avoids adding separate complex cooling systems while still achieving improved heat dissipation

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If external cooling mechanisms are added, then heat dissipation is improved, but reliability decreases due to additional moving parts

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidsystem reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The heat-conducting device operates passively through thermal conduction without requiring external power sources, control systems, or moving parts. The housing's natural surface area and the inherent thermal properties of the heat-conducting material enable automatic heat dissipation, eliminating the need for active cooling mechanisms and maintaining high system reliability

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The solution replaces potential mechanical cooling systems (such as fans or pumps) with a passive thermal conduction system. By using the fundamental physical principle of heat conduction through the heat-conducting device and housing, the invention eliminates mechanical moving parts that would reduce reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Loss of energy

If contact finger cross-section is increased to reduce resistance, then power loss is reduced, but installation space requirements increase

Engineering Contradiction:
Improvepower lossVSAvoidinstallation space
Core Design Contradiction:
Loss of energyVSVolume of moving object

Solution Approach 1:

The heat-conducting device acts as a mediator that addresses the power loss issue without requiring larger contact fingers. By efficiently conducting heat away from the contact interface, it reduces the thermal effects of resistance, allowing the contact fingers to maintain their original small cross-section while still managing the heat generated by current flow

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances heat dissipation capabilities, reduces contact temperatures, and maintains reliability by avoiding additional components in the dielectric field, thus ensuring safe operation within temperature limits without the need for external cooling mechanisms.

Implementation Method 1

A heat-conducting device with a second spring mechanism is proposed to improve heat dissipation by conduction

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

This is achieved primarily by transferring the lost heat into the protective gas, i.e., by convection

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4094281B1Disconnecting device and protective-gas-insulated medium-voltage power switchgear
Publication Date: 2025.08.27 SIEMENS AG
  • EP4094281B1 patent drawingFigure 1~2
  • EP4094281B1 patent drawingFigure 3
  • EP4094281B1 patent drawingFigure 4

AI summary

The present invention relates to a disconnecting device, comprising: at least one contact (6), which has a first spring apparatus (13, 16) in order to form a pressing force against a counter contact (7); and a holding device (11, 12) for the contact (6), characterized in that a thermal conduction device (22, 23, 24, 25, 31, 32, 35) is designed to press the holding device (11, 12) and the contact (6) against each other. The present invention further relates to protective-gas-insulated medium-voltage power switchgear having the disconnecting device according to the invention.