Segmented Plate Electrical Connector for Railway Power Converters

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrical connectors in power converters on railway vehicles face challenges with skin and proximity effects at higher frequencies, leading to reduced performance and increased losses, especially when passing through watertight partitions, and are cumbersome and fragile during maintenance.

Innovation Solution

A robust electrical connector design featuring a pair of conductive plates with offset connection lugs and an insulating structure, allowing for easy assembly and disassembly, which reduces skin and proximity effects by minimizing inductance and electrical losses, and can accommodate various types of cables or connection bars.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional conductors are used in power converters operating at medium frequencies (10-150 kHz), then the electrical connector structure is simple, but skin effect and proximity effect increase, reducing effective cross-sectional area and generating heat

Engineering Contradiction:
Improveconnector structureVSAvoidelectrical losses
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent divides the conductor into multiple parallel conductive plates instead of using a single solid conductor. This segmentation increases the effective surface area for current flow, reducing skin effect and proximity effect losses while maintaining manageable structural complexity through modular plate assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from conventional wire-like conductors to plate-like conductors, adding a dimensional aspect to the conductor geometry. This dimensional change increases the surface area to cross-section ratio, effectively reducing skin effect and proximity effect while managing the complexity through standardized plate designs.

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

2Loss of energy

If Litz wires with multiple twisted small-gauge wires are used to limit skin effect, then electrical losses are reduced, but the connector becomes bulkier and more fragile

Engineering Contradiction:
Improveelectrical lossesVSAvoidmechanical robustness
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The patent uses multiple parallel conductive plates segmented and spaced apart, achieving the benefit of reduced skin effect without the bulk and fragility of twisted Litz wires. The plates are structurally supported by an insulating structure, providing mechanical robustness while maintaining electrical performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an insulating structure as an intermediary that supports and spaces the conductive plates. This intermediary provides mechanical strength and stability, replacing the fragile twisted wire structure of Litz wires while maintaining the electrical benefits of multiple conductors.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If ferrules with complex structure are used to ensure watertightness of bulkhead penetration, then sealing is improved, but assembly and disassembly become time-consuming and the components become more fragile

Engineering Contradiction:
ImprovewatertightnessVSAvoidassembly and disassembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent merges the sealing function with the connector body by integrating sealing elements directly into the connector housing. This integration eliminates the need for separate complex ferrules, simplifying assembly and disassembly while maintaining reliable watertight sealing through the unified design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The connector design incorporates multiple functions into a single integrated structure, including electrical conduction, mechanical support, and sealing. This multi-functionality eliminates the need for separate ferrules and simplifies the overall assembly process while maintaining reliability.

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

4Strength

If conductive rods embedded in rigid insulating blocks are used, then mechanical strength is improved, but skin effect and proximity effect are not adequately addressed at medium frequencies

Engineering Contradiction:
Improvemechanical strengthVSAvoidelectrical losses
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent replaces the single embedded conductive rod with multiple parallel conductive plates, segmenting the current path to reduce skin effect and proximity effect while maintaining mechanical strength through the distributed plate structure supported by the insulating housing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from rod-like conductors to plate-like conductors, adding a dimensional aspect that increases surface area for current flow. This dimensional change reduces electrical losses from skin and proximity effects while the plates are mechanically supported within the insulating structure.

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

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 connector effectively reduces electrical losses by minimizing skin and proximity effects, enhances ease of assembly and disassembly, and maintains mechanical robustness, suitable for high-frequency operations and harsh environmental conditions.

Implementation Method 1

In these so-called 'medium frequency' ranges between 10 kHz and 150 kHz, electrical conductors are subject to a 'skin effect,' meaning that electrons only flow through a superficial layer of the conductors. This reduces the effective cross-sectional area of ​​the conductors, generates heat, and degrades the performance of power converters.

Methodology Applied
Scientific EffectSkin effect: Skin Effect

Implementation Method 2

Furthermore, when two separate conductors are placed close to each other and carry the same current in the same direction, a 'proximity effect' is added to the skin effect, further limiting the effective cross-sectional area of ​​the electrical conductors.

Methodology Applied
Scientific EffectProximity effect:

Data Source

PatentEP4047755B1Electrical connector, electrical system comprising such a connector and railway vehicle comprising such a system
Publication Date: 2023.07.05 ALSTOM HOLDINGS SA
  • EP4047755B1 patent drawingFigure 1
  • EP4047755B1 patent drawingFigure 2
  • EP4047755B1 patent drawingFigure 3

AI summary

This electrical connector (10) comprises a pair of plates (20), with a first electrically conductive plate (12) and a second electrically conductive plate (14), each plate having a central portion (24) and two connecting tabs (32, 34). The connecting tabs of each plate extend longitudinally from opposite edges (28, 30) of the central portion, offset laterally from each other. The first and second plates are stacked one on top of the other, with the central portions overlapping and separated by a gap (36). The connecting tabs of the first and second plates are, on each of said opposite edges, offset laterally from each other.The electrical connector includes an insulation structure comprising an interlayer of an electrically insulating material housed in the gap (36) between the central parts of the first and second plates.