Permeable Element Cooling for Sealed Electrical Machine Bushings

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Solution Overview

Problem

Existing sealed electrical machines face challenges in efficient cooling of lead conductors and bushings due to complex assembly processes and limitations in dielectric strength, leading to inefficient heat removal in large power generators.

Innovation Solution

A sealed electrical machine design featuring a casing with a high pressure chamber and a low pressure chamber, utilizing a permeable element and a cooling fluid that circulates through the electrical connectors to efficiently cool both the lead conductors and bushings, while simplifying the assembly process and enhancing dielectric strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If Teflon pipes are directly connected to lead conductors and bushings for cooling, then cooling function is provided, but dielectric strength is insufficient requiring minimum pipe length

Engineering Contradiction:
Improvecooling efficiencyVSAvoiddielectric strength
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

A permeable element is introduced as an intermediary component between the cooling fluid supply and the electrical connection elements. This permeable element allows cooling fluid to pass through while providing sufficient dielectric strength, eliminating the need for long Teflon pipes and enabling direct connection without compromising electrical insulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If multiple Teflon pipes are connected to cool lead conductors and bushings, then cooling function is achieved, but assembly becomes complicated and time consuming

Engineering Contradiction:
Improvecooling capabilityVSAvoidassembly complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Multiple cooling functions for lead conductors and bushings are merged into a single integrated system. The permeable element provides a common cooling pathway that serves multiple electrical connection elements simultaneously, eliminating the need for separate Teflon pipes for each component and greatly simplifying assembly.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If cooling fluid is injected from injector away from bushing duct, then assembly is simplified, but cooling efficiency is reduced

Engineering Contradiction:
Improveassembly easeVSAvoidcooling efficiency
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The injector component is extracted and eliminated from the system. Instead of injecting cooling fluid from a separate injector located away from the bushing duct, the permeable element directly channels cooling fluid to the electrical connection elements, achieving both simplified assembly and efficient cooling.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution provides quick and easy assembly, improved dielectric strength, and efficient cooling of electrical components, addressing the inefficiencies and complexities of existing systems.

Implementation Method 1

the cooling fluid passing through the chamber and the permeable element cools the permeable element

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

cooling fluid passes through the chamber and the permeable element cooling the permeable element, wherein said cooling fluid comes from a heat exchanger

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2267870B1Electrical connection of a sealed electrical machine and method for cooling an electrical connection of a sealed electrical machine
Publication Date: 2020.06.03 GENERAL ELECTRIC TECH GMBH
  • EP2267870B1 patent drawingFigure 1
  • EP2267870B1 patent drawingFigure 2
  • EP2267870B1 patent drawingFigure 3

AI summary

The electrical connection (1) of a sealed electrical machine comprises a casing (2) containing lead conductors (3) each connected to a bushing (4) via an electrical connector (5). The casing (2) has at least an inlet (6) and an outlet (7) for a cooling fluid. The electrical connector (5) comprises at least a permeable element defining a chamber (10) such that during operation the cooling fluid, passing through the chamber (10) and the permeable element, cools the permeable element. The method also refers to a method for cooling an electrical connection.