Modular DC Link Capacitor Plug-In Busbar Interface

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing power electronics devices for electric vehicles face challenges with undesired voltage peaks and electromagnetic compatibility issues due to rapid switching of high currents in DC voltage intermediate circuits, and the cumbersome process of manufacturing intermediate circuit capacitors according to specific manufacturer specifications.

Innovation Solution

The solution involves an intermediate circuit capacitor module with connecting means on electrode plates for a plug-in connection to busbars, allowing for flexible configuration and assembly, reducing stray inductance, and enabling efficient production and assembly of capacitors with different capacitances, while maintaining a standardized geometry for busbars.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DC link capacitor is rigidly connected to busbar using traditional assembly methods, then electrical connection is stable, but manufacturing complexity and cost increase due to custom specifications

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The DC link capacitor assembly is segmented into modular components: the capacitor unit with integrated first connecting elements, and the busbar with second connecting elements. This segmentation allows independent manufacturing and standardization of each component, reducing overall manufacturing complexity while maintaining reliable electrical connection through the plug-in interface between components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first connecting elements are designed as universal plug-in interfaces that can be standardized across different capacitor models and applications. This universal design allows the same connecting element structure to serve multiple functions: providing electrical connection, mechanical support, and alignment guidance, while enabling capacitors with different capacitances to use the same mounting geometry on the busbar.

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

2Manufacturing precision

If DC link capacitor is custom-manufactured according to each manufacturer's specifications, then electrical connection meets specific requirements, but production time and cost increase

Engineering Contradiction:
Improveelectrical connection specification complianceVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The first connecting elements are pre-integrated into the electrode plates during capacitor manufacturing, and the second connecting elements are pre-mounted on the busbars. This preliminary integration ensures that when the capacitor is assembled to the power electronics module, the electrical connection requirements are already satisfied, eliminating the need for custom specification adjustments and accelerating the assembly process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention allows parameter changes in capacitor capacitance while maintaining constant connecting element geometry. The first connecting elements on the electrode plates and second connecting elements on the busbars maintain standardized dimensions and positions, enabling capacitors with different electrical parameters (capacitance values) to be produced using the same mechanical interface, thus improving productivity without sacrificing manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If busbar assembly is performed manually with precise positioning, then connection accuracy is high, but assembly time and labor cost increase

Engineering Contradiction:
Improvebusbar connection accuracyVSAvoidassembly time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The first connecting elements on the electrode plates and second connecting elements on the busbars are designed to perform self-alignment and self-positioning during assembly. The plug-in interface geometry ensures that when the capacitor is brought near the busbar, the connecting elements automatically guide the components into the correct relative position, eliminating the need for manual precise positioning while maintaining high connection accuracy, thus significantly reducing assembly time.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3707737B1Power electronics device
Publication Date: 2022.08.17 VALEO EAUTOMOTIVE GERMANY GMBH
  • EP3707737B1 patent drawingFigure 1
  • EP3707737B1 patent drawingFigure 2
  • EP3707737B1 patent drawingFigure 3a

AI summary

The invention relates to a DC link capacitor module (1, 1'), in which a coil (4, 5) is electrically conductively attached to two mutually opposite electrode plates (2a, 2b), wherein a plurality of first connecting means (6) are provided on each electrode plate (2a, 2b) to produce a detachable or non-detachable plug-in connection to second connecting means (9a, 9b), which correspond thereto and are attached to a bus bar (7a, 7b) of a power electronics module (8).