Flat Ribbon Conductor Connection in Wind Turbine Generators

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Solution Overview

Problem

Existing methods for connecting ribbon cables in wind turbine generators, such as cold pressure welding, require complex preparation, can be of poor quality, and are difficult to inspect or repair, while high-heat welding methods risk damaging surrounding components.

Innovation Solution

A method involving cutting and bending ribbon conductor ends to create overlapping partial end pieces, which are then connected using a single common area without additional materials, and utilizing a cutting-less tool to liquefy and bond the material, eliminating the need for heat and external rods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cold pressure welding is used to connect flat strip conductors, then no high temperatures are required and surrounding components are protected, but complex preparation is required and connection quality is difficult to ensure

Engineering Contradiction:
Improveconnection temperatureVSAvoidpreparation complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The contact surfaces of the flat strip conductors are pre-treated with abrasive paper or solvent before connection to remove oxidation and contaminants. This preliminary preparation simplifies the subsequent friction stir welding process by ensuring clean contact surfaces, reducing the need for complex preparation steps while maintaining connection quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The friction stir welding process generates its own heat through friction between the tool and the conductors, eliminating the need for external heating sources. The process is self-regulating, with the heat generated directly at the connection point, simplifying the overall manufacturing process while ensuring consistent connection quality

Inventive Principle:
Principle #25Self-service

2Temperature

If cold pressure welding is used to connect flat strip conductors, then no high temperatures are required, but the connection quality must be checked immediately and touch-up is difficult

Engineering Contradiction:
Improveconnection temperatureVSAvoidconnection reworkability
Core Design Contradiction:
TemperatureVSEase of repair

Solution Approach 1:

The connection quality is monitored in real-time during the friction stir welding process through parameters such as welding force, temperature, and displacement. This feedback mechanism allows for immediate detection of connection quality issues, enabling corrective actions to be taken during the process rather than requiring difficult post-manufacturing repairs

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The design of the friction stir welding process includes built-in quality assurance steps where connection parameters are controlled and monitored before the generator is completely assembled. This preliminary quality control prevents the need for difficult touch-up operations later in the manufacturing process

Inventive Principle:
Principle #10Preliminary action

3Strength

If welding with high heat is used to connect flat ribbon cables, then connection strength is improved, but heat development can destroy surrounding components

Engineering Contradiction:
Improveconnection strengthVSAvoidheat damage to surrounding components
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The friction stir welding process concentrates heat generation and melting only at the precise connection point between conductors, while the surrounding areas remain unaffected. The localized thermal zone is created by the rotating tool that generates friction heat only where contact is made, ensuring strong connections without damaging nearby components

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The friction heat that would normally be considered a harmful byproduct is converted into a beneficial heating source for the welding process. The friction between the rotating tool and conductors generates the exact amount of heat needed to create strong metallurgical bonds, turning potential heat damage into a useful heating mechanism for connection strength

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 method achieves high-quality connections with reduced preparatory work, minimal heat generation, and easy access for inspection, ensuring low resistance and avoiding damage to neighboring components.

Implementation Method 1

a rotating cutting-less tool is advanced through the workpieces to be connected in the axial direction during rotation, wherein the material of the partial end pieces is liquefied by the friction between the material of the partial end pieces and the tool

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the material of the partial end pieces is liquefied by the friction between the material of the partial end pieces and the tool

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

Solidification after removing the tool creates a material connection

Methodology Applied
Scientific EffectSolidification: Crystallisation

Data Source

PatentEP3469687B1Winding of a generator of a wind power installation, and method for connecting flat ribbon conductors
Publication Date: 2023.07.12 WOBBEN PROPERTIES GMBH
  • EP3469687B1 patent drawingFigure 1
  • EP3469687B1 patent drawingFigure 2
  • EP3469687B1 patent drawingFigure 3~4

AI summary

The invention relates to a winding of a generator (130) of a wind power installation (100), in particular of the rotor (134). The winding comprises a plurality of coils which are each wound with a flat ribbon conductor (12), wherein the flat ribbon conductors (12) each have two ends (10), and at least two flat ribbon conductors (12) are connected to one another. The flat ribbon conductors (12) are each cut or stamped, as seen from the respective end (10), at least up to a predefined length (23) of the flat ribbon conductor (12) in the longitudinal direction (20), so that at least two partial end pieces (18) of the flat ribbon conductor (12) are produced, said partial end pieces each having substantially the same width. In this case, the partial end pieces (18) are bent in such a way that the partial end pieces (18) overlap at least in a connecting region (28), wherein the connecting regions (28) of two ends (10) overlap in a common connecting region (31), and are connected there. The invention further relates to a method for producing a winding of this kind.