Power Converter Casing Cooling With Resin-Metal Composite Structure

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional cooling systems for power conversion devices are heavy due to metal casings and face processing challenges with complex metal cooling water paths, leading to inadequate cooling and increased casing temperatures, which can heat electric components.

Innovation Solution

A cooling system using a resin-based casing with a metallic cover portion and a radiator fan to facilitate airflow cooling, allowing for efficient heat dissipation even when the resin-based cooling water path has limited heat transfer, while securing strength and reducing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the casing is formed of metal to provide sufficient cooling, then the cooling effect is improved, but the weight of the power conversion device increases

Engineering Contradiction:
Improvecasing temperatureVSAvoidweight of power conversion device
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The casing is formed by combining resin and metal materials. The resin portion provides lightweight structure while the metal cooling water path portion provides efficient heat conduction. This composite structure reduces overall weight compared to full metal casing while maintaining sufficient cooling capability through the metal cooling paths.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If the casing is formed of resin to reduce weight, then the weight is reduced, but the cooling effect is insufficient due to high heat resistance of resin

Engineering Contradiction:
Improveweight of power conversion deviceVSAvoidcasing temperature
Core Design Contradiction:
Weight of moving objectVSTemperature

Solution Approach 1:

The casing uses a composite structure where metal cooling water path portions are embedded in the resin casing. The metal portions form heat conduction paths that extend from the power module contact areas to the cooling water flow paths, enabling efficient heat transfer from the power modules through the resin casing to the cooling water.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metal cooling water path portions act as intermediary heat conduction elements between the power modules and the cooling water. These metal paths bridge the thermal gap created by using resin material, providing dedicated heat conduction channels that overcome the high heat resistance of resin.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If a complicated cooling water path is provided in metal casing, then the cooling performance is improved, but the processing difficulty and number of processes increase

Engineering Contradiction:
Improvecooling performanceVSAvoidprocessing ease
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The cooling water paths are formed using resin molding techniques combined with metal embedding, which simplifies the manufacturing process compared to traditional metal casing with complex cooling channels. The resin material allows for easier integration of cooling paths through molding processes rather than requiring complex metal machining or casting operations.

Inventive Principle:
Principle #40Composite materials

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 system achieves sufficient cooling, is lightweight, and easy to process, effectively managing heat transfer and maintaining component temperatures within safe limits.

Implementation Method 1

when the casing is formed of the resin material, a cooling effect obtained by the cooling water path is not transferred to the entire casing because the resin material has high heat resistance

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

A cooling system using a resin-based casing with a metallic cover portion and a radiator fan to facilitate airflow cooling

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3836380B1Cooling system for power conversion device
Publication Date: 2023.12.20 NISSAN MOTOR CO LTD
  • EP3836380B1 patent drawingFigure 1
  • EP3836380B1 patent drawingFigure 2
  • EP3836380B1 patent drawingFigure 3

AI summary

Provided is a cooling system for a power conversion device that includes a radiator, a radiator fan supplying air to the radiator, and a power conversion device including a plurality of electric components and a casing housing the plurality of electric components inside. The casing includes a base portion which is formed of a non-metallic material and on which the plurality of electric components is placed and a cover portion formed of a metallic material, fixed to the base portion, and covering a periphery of the plurality of electric components. A refrigerant channel through which a refrigerant cooling the plurality of electric components flows is formed in the base portion of the casing, and the casing is disposed at a position where an airflow of the radiator fan is applied to the cover portion.