Composite Thermal Modeling for Electrical Machine-Device Heat Prediction

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Solution Overview

Problem

Current thermal modeling of electrical machines connected to other devices lacks accuracy in predicting temperature and heat distribution, as existing methods fail to effectively integrate the thermal behavior of both components, leading to inaccuracies in monitoring and control.

Innovation Solution

A method is developed to generate a composite thermal model by connecting geometric entities of individual thermal models of an electrical machine and a connected device through heat sources and thermal impedances, with adjustments made based on measured and estimated temperatures to achieve an accurate representation of the system's thermal behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If individual thermal models of electrical machine and device are connected to form composite thermal model, then thermal behavior of system can be described, but accuracy of temperature prediction is insufficient

Engineering Contradiction:
Improvetemperature prediction accuracyVSAvoidthermal model integration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system is divided into discrete geometric entities (nodes, edges, faces, volumes) that represent different physical components and their thermal characteristics. Each entity can be independently defined and connected to form the complete thermal model, allowing complex systems to be built from manageable segments while maintaining prediction accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method automatically adjusts thermal parameters (thermal conductivity, heat generation rates, thermal impedances) based on measured temperature data and operating conditions. This dynamic parameter adaptation enables the model to accurately predict temperatures across different operating scenarios without requiring manual recalibration of the entire model structure.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If thermal model accurately predicts temperature distribution, then monitoring and control can be improved, but model integration of multiple components becomes complex

Engineering Contradiction:
Improvemonitoring and control accuracyVSAvoidmodel integration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The geometric entity-based thermal model framework is designed to be universally applicable to different component types (electrical machines, power converters, loads) and thermal model formats (FEM, FVM, LPTN). The same connection principles and parameter adjustment methods work across diverse systems, enabling accurate multi-component modeling without requiring component-specific complex integration procedures.

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

3Measurement precision

If geometric entities are connected through heat sources and thermal impedances, then thermal behavior is captured, but model accuracy requires iterative adjustment

Engineering Contradiction:
Improvetemperature estimation accuracyVSAvoidmodel generation and adjustment time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The method uses measured temperature data as feedback to automatically adjust thermal parameters in the model. By comparing predicted temperatures with actual measurements and iteratively refining parameter values, the system converges to an accurate representation of the thermal behavior, reducing the need for manual trial-and-error adjustments.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The model structure and initial parameter values are predetermined based on geometric entity connections and standard thermal relationships. This preliminary setup provides a reasonable starting point that requires minimal adjustment, significantly reducing the time needed to achieve accurate temperature predictions compared to building models from scratch.

Inventive Principle:
Principle #10Preliminary action

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 approach allows for the creation of an accurate composite thermal model that accurately predicts temperature distribution and heat flow between the electrical machine and the connected device, enhancing monitoring and control capabilities by iteratively adjusting thermal impedances and heat sources to align measured and estimated temperatures.

Implementation Method 1

a composite thermal model describing the thermal behaviour of a system comprising the electrical machine connected to the device

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

each connection comprising at least one of a heat source and a thermal impedance

Methodology Applied
Scientific EffectHeat generation: Heating

Data Source

PatentEP4047336B1Method of generating a thermal model of a system comprising an electrical machine
Publication Date: 2024.08.28 ABB (SCHWEIZ) AG
  • EP4047336B1 patent drawingFigure 1~3b

AI summary

A method of generating, from a first thermal model (11) describing the individual thermal behaviour of an electrical machine and a second thermal model (13) describing the individual thermal behaviour of a device, a composite thermal model (9) describing the thermal behaviour of a system comprising the electrical machine connected to the device, the method comprising: a) connecting at least one geometric entity (15,17,19) of one of the first thermal model (11) and the second thermal model (13) to a plurality of geometric entities (15, 17, 19) of the other one of the first thermal model (11) and the second thermal model (13), each connection comprising at least one of a heat source and a thermal impedance, wherein the first thermal model (11) and the second thermal model (13) connected to each other form an initial composite thermal model, b) comparing measured temperatures with corresponding estimated temperatures obtained from the initial composite thermal model, and in case an estimated temperature deviates with more than a threshold value from a measured temperature, c) adjusting at least one of a thermal impedance and a heat source between a pair of geometric entities connected in step a).