Dual Busbar Contact Assembly With Copper Interfaces for Low EMI

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Solution Overview

Problem

Existing contact systems for double busbars are complex and inefficient in maintaining low contact resistance and preventing electromagnetic field radiation, especially in high-voltage applications like electric vehicles.

Innovation Solution

A contact system featuring stacked, individually insulated aluminum busbars with copper contact elements and a contact device that applies a normal force using a tie rod and spring elements to ensure reliable electrical connection and minimize electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a contact system uses a simple clamp contact design, then the device complexity is reduced, but the contact resistance may increase and reliability decreases

Engineering Contradiction:
Improvecontact system structureVSAvoidelectrical connection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The contact system is segmented into distinct functional components: clamp contacts for mechanical attachment, copper contact elements for electrical conduction, and insulation for electrical isolation. This segmentation allows each component to be optimized independently, maintaining simplicity while ensuring reliable electrical connection through specialized copper contact elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact system employs composite material structure by combining aluminum busbars with copper contact elements. The copper material provides superior electrical conductivity at the contact points, while the aluminum busbar provides mechanical strength and low weight. This composite approach reduces contact resistance without requiring complex overall system design.

Inventive Principle:
Principle #40Composite materials

2Reliability

If copper contact elements are used in the contact area, then contact resistance is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvecontact resistanceVSAvoidcontact element integration
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The copper contact elements are merged with the aluminum busbar structure to form an integrated double busbar assembly. The contact elements are positioned and secured within the busbar structure, combining mechanical support and electrical conduction functions in a single manufacturable component that reduces assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact elements are designed to be self-positioning within the busbar structure, utilizing the inherent geometry of the double busbar arrangement to automatically align copper contact elements with corresponding clamp contacts, eliminating the need for complex alignment procedures during manufacturing.

Inventive Principle:
Principle #25Self-service

3Object-generated harmful factors

If the double busbar arrangement is used, then electromagnetic field radiation is reduced, but the contact system complexity increases

Engineering Contradiction:
Improveelectromagnetic field radiationVSAvoidbusbar configuration
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The double busbar arrangement positions positive and negative conductors in close proximity, creating opposing electromagnetic fields that cancel each other out. This equipotential arrangement minimizes external electromagnetic radiation without requiring additional shielding components, maintaining system simplicity while reducing harmful electromagnetic emissions.

Inventive Principle:
Principle #12Equipotentiality

4Weight of moving object

If aluminum busbars are used, then weight is reduced, but contact resistance increases compared to copper

Engineering Contradiction:
Improvebusbar weightVSAvoidelectrical conductivity
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The busbar system applies local quality by using copper material specifically at the contact elements where electrical conduction is critical, while the main busbar body remains aluminum for weight reduction. This localized application of superior conductive material optimizes the weight-conductivity tradeoff by concentrating expensive, heavy copper only where it provides maximum benefit.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The contact system uses composite materials by combining aluminum busbars with copper contact elements. The aluminum provides lightweight structural support while the copper provides superior electrical conductivity at contact points, achieving both weight reduction and maintained electrical performance through material composition rather than uniform material selection.

Inventive Principle:
Principle #40Composite materials

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 system effectively reduces contact resistance and electromagnetic field radiation by using copper contact elements and a robust contact mechanism, ensuring reliable high-voltage connections while being structurally simple and efficient.

Implementation Method 1

at least one spring element (128) arranged between the contact device (104) and one of the contacts (114)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

both busbars (108) each have an electrically conductive contact element (106) made of a copper material in a contact area (112)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

the positive and negative conductors can be arranged as parallel and close together as possible, since the electromagnetic fields caused by the opposing current flows cancel each other out

Methodology Applied
Scientific EffectElectromagnetic field cancellation: Electromagnetic Induction

Data Source

PatentEP4089856B1Contact system for electrically contacting a dual busbar
Publication Date: 2024.02.14 LISA DRAXLMAIER GMBH
  • EP4089856B1 patent drawingFigure 1~2

AI summary

The present invention relates to a contact system (100) for electrically contacting a double busbar (102), wherein the double busbar (102) has two busbars (108) made of an aluminum material, each of which is enclosed by insulation (110) and stacked on top of the other, wherein both busbars (108) each have a contact element (106) made of a copper material in a contact area (112) which is electrically connected to the busbar (108), wherein the contact elements (106) are arranged opposite each other on outer surfaces of the double busbar (102), wherein the contact elements (106) are electrically contacted by two contacts (114) of a contact device (104) which are spaced apart from each other by a jaw opening (116).