Liquid-Cooled Power Module With Wedge-Shaped Duct

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Solution Overview

Problem

Existing power electronics devices face challenges in achieving even cooling liquid flow and reducing temperature around power components, particularly when components are connected in parallel, leading to inefficiencies and increased costs due to the need for additional components and fans for cooling.

Innovation Solution

A power unit design with symmetrically fixed power modules on opposite outer sides of a frame, featuring a wedge-shaped liquid duct and protrusions on the cooling surface to ensure turbulent flow and direct heat transfer, eliminating the need for separate fixing parts and internal fans by using a common substrate for mechanical support and cooling liquid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If power components are connected in parallel to handle high power, then power handling capability is improved, but flow evenness between components deteriorates

Engineering Contradiction:
Improvepower handling capabilityVSAvoidflow evenness
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The liquid duct is designed with asymmetric cross-sectional areas to compensate for flow distribution issues. Specifically, the duct cross-sectional area is made larger on the side with higher flow resistance and smaller on the side with lower flow resistance, thereby achieving even flow distribution to parallel-connected power components without requiring additional balancing components

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The duct cross-sectional area is locally adjusted along its length to optimize flow distribution. By varying the cross-sectional area at different locations, the design compensates for differences in flow resistance to parallel components, ensuring even cooling liquid flow without affecting the overall power handling capability

Inventive Principle:
Principle #3Local quality

2Temperature

If cooling liquid flow is increased to improve cooling effectiveness, then cooling performance is improved, but turbulence difficulty increases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidturbulence achievement
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Protrusions are added to the cooling surface to disrupt laminar flow and promote turbulence. These surface irregularities create flow separation and mixing, enhancing heat transfer efficiency without requiring complex internal duct geometries or additional turbulence-generating components

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If circuit boards are disposed close to power components for electrotechnical reasons, then electrical connection efficiency is improved, but temperature control deteriorates

Engineering Contradiction:
Improveelectrical connection efficiencyVSAvoidtemperature control
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The device is segmented into thermally isolated zones. Power components are cooled by direct liquid contact, while circuit boards are positioned in separate air-cooled compartments. This spatial segmentation allows electrical proximity for efficiency while maintaining thermal independence to protect sensitive electronics from high temperatures

Inventive Principle:
Principle #1Segmentation

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

This design ensures even cooling liquid flow and reduced temperature around power components, minimizing the need for fans and lowering manufacturing costs and thermal resistance, while maintaining the flexibility of parallel or different task functionality for power modules.

Implementation Method 1

by transferring the dissipation power produced in the components via liquid circulating in the device to outside the device

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

transferring the dissipation power produced in the components via liquid circulating in the device

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

turbulence that enhances cooling are difficult to achieve

Methodology Applied
Scientific EffectTurbulence: Turbulence

Data Source

PatentEP2744316B1Power electronics device and its cooling arrangement
Publication Date: 2020.03.04 VACON OY
  • EP2744316B1 patent drawingFigure 1~3
  • EP2744316B1 patent drawingFigure 4~5B

AI summary

Liquid-cooled power unit of a power electronics device, which power unit comprises at least two power modules (200), the cooling surface of which power modules is provided with pin-type protrusions (205) and which power modules (200) are fixed to the frame part (402) of the power unit. A liquid duct (403) is arranged inside the frame part (402) of the power unit, and the power modules (200) are fixed to the points of the apertures situated in the frame part on both sides of the liquid duct (403) in such a way that the pin-type protrusions (205) of the power modules (200) are situated in the liquid duct (205). A wedge-shaped part (404) is disposed in the liquid duct, which wedge-shaped part comprises a wedge-shaped front part (409) for spreading the liquid flow (405) into two essentially equal flows at the point of the power modules (200).