Electrical Fuse Fatigue Monitoring via Resistance-Based Temperature Estimation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High voltage electrical power systems in electric vehicles face challenges with complex, costly, and large fuses for temperature monitoring, leading to premature fuse element fatigue and unplanned downtime due to cyclic thermal and mechanical stress, which is not effectively addressed by existing technologies.

Innovation Solution

A computationally-efficient and cost-effective system for estimating the temperature of a fuse element with non-linear resistance by deducing current flow, applying a state-space model with ambient temperature, and using compensation circuitry to calculate and monitor temperature cycles, providing alerts and notifications for impending fuse failure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex temperature monitoring systems are installed in high voltage fuses, then temperature monitoring capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature monitoring capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical/physical temperature sensing systems with an electrical measurement system. By measuring the voltage across the fuse element and using its known resistance characteristics, the system calculates temperature through electrical parameters rather than requiring physical temperature sensors, thereby reducing device complexity while maintaining monitoring capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The fuse element itself serves as the temperature sensor. Its electrical resistance, which naturally changes with temperature, is used to monitor thermal conditions. This eliminates the need for separate monitoring components, as the fuse element's inherent electrical properties provide the temperature information needed

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional fuse monitoring systems are used, then reliability is improved, but cost and size increase

Engineering Contradiction:
Improvefuse monitoring accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a pre-characterized resistance-temperature relationship curve (obtained during manufacturing) to determine actual temperature during operation. This allows the system to achieve accurate temperature monitoring without requiring complex real-time sensing hardware, thereby reducing manufacturing costs while maintaining reliability

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system monitors changes in electrical parameters (voltage and resistance) of the fuse element to infer temperature changes. By tracking parameter variations rather than directly measuring temperature, the system achieves reliable monitoring with simpler, less expensive components

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If real-time temperature monitoring is implemented, then prediction accuracy is improved, but computational requirements and system complexity increase

Engineering Contradiction:
Improvetemperature estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies a simplified thermal model that considers only the most significant thermal factors (electrical heating and ambient temperature) rather than attempting to model all thermal pathways. This partial modeling approach achieves sufficient prediction accuracy for practical applications while keeping computational requirements manageable

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system pre-characterizes the fuse element's resistance-temperature relationship during manufacturing and stores this data for later use. This preliminary characterization eliminates the need for complex real-time calculations, as the system can directly reference pre-computed relationships to determine temperature from measured resistance values

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 accurate and timely prediction of fuse fatigue, enabling proactive replacement and reducing downtime, while being more affordable and compact than existing solutions, thus enhancing the reliability and efficiency of high voltage electrical systems.

Implementation Method 1

estimating a temperature of a fuse element (208) having a non-linear resistance

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

based at least in part on the deduced current in the fuse element and an ambient temperature of the electrical power system, an first temperature differential between a temperature of the fuse element and a temperature of an arc quenching medium is estimated

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Data Source

PatentEP3575763B1Monitoring system for estimating thermal-mechanical fatigue in an electrical fuse
Publication Date: 2024.03.06 EATON INTELLIGENT POWER LTD
  • EP3575763B1 patent drawingFigure 1
  • EP3575763B1 patent drawingFigure 2
  • EP3575763B1 patent drawingFigure 3

AI summary

Thermal-mechanical fatigue assessment systems and methods include a controller operable to estimate a temperature of the conductor having a non-linear resistance based on an ambient temperature input and a current input for current flow through the conductor when connected to an energized electrical power system. A state of fatigue of the conductor may be assessed in view of an estimated first temperature differential between the conductor and an arc extinguishing medium surrounding the conductor, an estimated temperature differential between the temperature of the arc quenching medium and the ambient temperature, and the estimated temperature of the conductor.