Insulated Fluid-Cooled Power Converter Submodules for High Heat Dissipation

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Solution Overview

Problem

Existing power converter modules face challenges in effectively cooling electrical components at high power densities due to high power losses, with air cooling inadequate for higher power densities and liquid cooling increasing complexity and maintenance requirements.

Innovation Solution

A power converter module design with submodules encapsulated in fluid-tight housings filled with electrically insulating fluid coolant, allowing direct contact with electrically active components for efficient heat dissipation, and modular design for easy replacement and compatibility with existing systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If air cooling is used for power converter modules, then the cooling system is simple and cost-effective, but it cannot achieve sufficient heat dissipation at higher power densities

Engineering Contradiction:
Improvecooling system complexityVSAvoidheat dissipation capability
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent applies liquid cooling by circulating a cooling medium through channels in the housing to remove heat from electrical components. This hydraulic approach enables sufficient heat dissipation at high power densities while maintaining relatively simple system integration, resolving the contradiction between cooling effectiveness and system complexity

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If liquid cooling with external pump and coolant lines is used, then sufficient heat dissipation is achieved at high power densities, but the device complexity and maintenance requirements increase

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent integrates the cooling medium circulation function directly into the housing structure by forming cooling channels within the housing itself. This merging of cooling functionality into the existing housing eliminates the need for separate external pumps and complex piping systems, achieving high heat dissipation capability while reducing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing serves multiple functions: it provides structural support, electrical insulation, and integrated cooling through internal channels. This multi-functionality eliminates the need for separate dedicated cooling components, reducing device complexity while maintaining effective heat dissipation at high power densities

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

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

Achieves effective heat dissipation with low complexity and maintenance, enabling higher power densities and modular upgrades without external connections, while maintaining electrical safety and efficiency.

Implementation Method 1

the fluid cooling medium can circulate and flow towards an electrically active section of an electrical element within the respective sub-module

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the fluid cooling medium can circulate and flow towards an electrically active section of an electrical element

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4704505A1Power converter module and operating method
Publication Date: 2026.03.04 SIEMENS AG
  • EP4704505A1 patent drawingFigure 1
  • EP4704505A1 patent drawingFigure 2
  • EP4704505A1 patent drawingFigure 3

AI summary

A power converter module (1) is specified, comprising: - a main housing (3) which collectively encloses a plurality of submodules (10, 20, 30, 40), - a plurality of electrical elements (13, 23, 33, 43), each assigned to one of the submodules (10, 20, 30, 40) and selected from the following list: - power electronic switching elements (13), - circuit arrangements (33) configured as gate drivers for a power electronic switching element, - electrical capacitors (32) and/or - electrical inductors, - and a number of submodule housings (11, 21, 31), each assigned to a submodule (10, 20, 30) and enclosing the electrical elements (13, 23, 33) of that submodule (10, 20, 30), - wherein each of the submodule housings (11, 21, 31) contains a media chamber (15,25,35) is formed by means of an outer wall of the respective sub-module housing (11,21,31) is fluid-tightly encapsulated against the environment of the respective submodule (10, 20, 30), wherein the respective media chamber (15, 25, 35) is filled with an electrically insulating fluid cooling medium (M1, M2) in the ready-to-use state, and wherein the fluid cooling medium (M1, M2) can circulate within at least one of the existing media chambers (15, 25, 35) in such a way that it flows onto an electrically active part of an electrical element (13, 23, 33) of the respective submodule (10, 20, 30). Furthermore, a method for operating such a power converter module (1) is specified.