Common Mode Inductor Thermal Coupling With Clamped Ferrite Core

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Solution Overview

Problem

Existing common mode inductances in voltage converters of electric or hybrid vehicles generate thermal energy that needs efficient cooling, as they are integral to electromagnetic compatibility filters but lack effective thermal management solutions.

Innovation Solution

A thermal coupling device comprising a prismatic ferrite core, a base, and a clamping member, configured to transfer heat to a heat sink, with a thermally conductive filling material, optimizing heat transfer and mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If common mode inductances are used in EMC filters, then electromagnetic compatibility is improved, but thermal management becomes problematic due to heat generation

Engineering Contradiction:
Improveelectromagnetic compatibilityVSAvoidheat generation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

A thermally conductive filling material is introduced as an intermediary between the ferrite core and the heat sink. This material optimizes thermal transfer from the common mode inductor to the heat sink, effectively managing the heat generated while preserving the electromagnetic compatibility function of the inductor.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thermal management system is segmented into distinct functional components: the ferrite core for electromagnetic filtering, the base for structural support and initial heat conduction, and the heat sink for final heat dissipation. This segmentation allows each component to be optimized for its specific function while working together as an integrated thermal management system.

Inventive Principle:
Principle #1Segmentation

2Productivity

If heat transfer efficiency is improved by increasing contact surface area, then cooling efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The base is designed with an annular prismatic structure that extends in the vertical dimension, allowing the ferrite core to be positioned above the base rather than requiring extensive lateral contact surfaces. This dimensional change achieves effective thermal coupling while maintaining a compact and simple overall structure.

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

Solution Approach 2:

The thermal coupling device uses a composite structure combining the ferrite core (for electromagnetic function), the base (for structural support), and the thermally conductive filling material (for optimized heat transfer). This composite approach achieves high cooling efficiency without increasing structural complexity, as each material performs its specific function within the integrated design.

Inventive Principle:
Principle #40Composite materials

3Strength

If mechanical strength is improved by securing components firmly, then thermal transfer is improved, but ease of assembly deteriorates

Engineering Contradiction:
Improvemechanical strengthVSAvoidease of assembly
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The clamping member is designed as a spring blade that provides dynamic, elastic clamping force. This allows the ferrite core to be firmly held against the base for optimal thermal contact, while the elastic nature of the spring blade accommodates manufacturing tolerances and simplifies assembly by providing self-adjusting clamping pressure without requiring precise pre-tensioning.

Inventive Principle:
Principle #15Dynamics

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

Enhances heat dissipation from common mode inductances to heat sinks, improving cooling efficiency and mechanical strength while maintaining compactness, thus addressing thermal management challenges.

Implementation Method 1

the ferrite core being configured to generate a magnetic field induced by an electric current flowing in the electrical connector of the electronic component

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the base being configured to transfer heat generated by the ferrite core to the heat sink

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the coupling device comprises a thermally conductive filling material, said material being interposed between the base and the heat sink

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4576134A1Thermal coupling device for a common mode inductor
Publication Date: 2025.06.25 VALEO ELECTRIFICATION
  • EP4576134A1 patent drawingFigure 1~2
  • EP4576134A1 patent drawingFigure 3
  • EP4576134A1 patent drawing

AI summary

The present invention relates to a thermal coupling device (2) for a common mode inductance, configured to transfer heat to a heat sink (5), the device comprising: - an annular prismatic ferrite core (4) configured to be crossed by at least one electrical connector of an electronic component (3); - a base (6) secured to the heat sink (5), the ferrite core (4) being in contact with the base (6), the base being configured to transfer heat generated by the ferrite core (4) to the heat sink (5). The thermal coupling device (2) comprises a clamping member (8) configured to hold the ferrite core (4) and the base (6) secured together, the ferrite core (4), the base (6) and the clamping member (8) extending orthogonally to the longitudinal reference plane of the electrical connector.