Annular Electric Converter Cooling Layout for Redundant Power Modules

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Solution Overview

Problem

Existing electrical converters for aircraft propulsion motors face challenges in optimizing cooling while maintaining compact size and redundancy, especially when numerous power modules are required due to redundancy constraints, leading to high cooling demands and potential electrical faults from lengthy connections.

Innovation Solution

An electrical converter with an annular design featuring inner and outer cooling baths and a dual cooling circuit system, allowing for optimal heat dissipation and reduced connection lengths by distributing power devices evenly and using fins for enhanced heat exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the number of power modules is increased to ensure redundancy, then the reliability is improved, but the cooling requirements increase significantly

Engineering Contradiction:
ImproveredundancyVSAvoidcooling requirements
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The converter is divided into two independent functional channels (first and second channels), each capable of operating independently. This segmentation allows the cooling system to manage heat from each channel separately, distributing the thermal load more effectively across the available cooling surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power modules are arranged in an annular configuration around the motor, utilizing the radial dimension for heat dissipation. The annular shape provides increased external surface area for cooling without significantly increasing the overall volume, allowing multiple power modules to be cooled effectively.

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

2Temperature

If the external surface area is increased by increasing the diameter or length of the converter, then the cooling efficiency is improved, but the size and mass increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmass
Core Design Contradiction:
TemperatureVSWeight of stationary object

Solution Approach 1:

The converter adopts an annular (curved) shape rather than a linear or rectangular configuration. This curvature allows the power modules to be arranged around the motor with their heat-generating surfaces facing outward, maximizing exposure to the cooling fluid while maintaining a compact overall size that fits within the aircraft's spatial constraints.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The converter is designed to surround the motor, with power modules positioned in the annular space between the motor housing and the outer converter casing. This nested arrangement allows the cooling surfaces to be integrated into the converter structure itself, eliminating the need for additional external cooling surfaces that would increase mass.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Temperature

If the power modules are positioned on the outer periphery to maximize heat exchange, then the cooling efficiency is improved, but the connection length to the motor increases

Engineering Contradiction:
Improveheat exchangeVSAvoidconnection length
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

The annular arrangement positions power modules at various angular positions around the motor rather than all at one location. This curved distribution allows each power module to have a relatively short radial connection to the motor while still being positioned on the outer periphery for optimal heat exchange with the cooling fluid.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution enables efficient cooling of multiple power devices with reduced pressure losses and fault risk, maintaining compact dimensions and redundancy, thus enhancing the reliability and efficiency of the electrical system.

Implementation Method 1

a cooling circuit configured to supply each inner bath and each outer bath with cooling fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the cooling circuit configured to supply each inner bath and each outer bath with cooling fluid

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

at least one power device comprises a power module associated with a dissipation radiator, the dissipation radiator being mounted in an indoor bathtub or an outdoor bathtub

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

the dissipation radiator being mounted in an indoor bathtub or an outdoor bathtub

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4413651B1Electric converter configured to supply an electric machine, electric module comprising such a converter, method of using such an electric module
Publication Date: 2025.07.30 SAFRAN ELECTRICAL & POWER
  • EP4413651B1 patent drawingFigure 1~3
  • EP4413651B1 patent drawingFigure 4~5
  • EP4413651B1 patent drawingFigure 6~7

AI summary

An electrical converter (1) configured to supply an electric machine, in particular for an aircraft, with power, comprising an annular stator and a rotor, the electrical converter (1) comprising a plurality of power inverters, each comprising a plurality of power devices (3-1; 3-18) that are configured to be connected to the annular stator so as to supply the electric machine with power, a casing (10) comprising a plurality of inner baths (11) and outer baths (12), a coolant circuit (9) configured to supply each inner bath (11) and each outer bath (12) with coolant (F), the power devices (3-1; 3-18) being mounted in the inner baths (11) and the outer baths (12) so as to allow all of the power devices (3-1; 3-18) to be cooled.