Inverter Temperature Abnormality Detection Without Downstream Sensors

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Solution Overview

Problem

The existing temperature abnormality detection methods for power conversion apparatuses require multiple cooling flow paths and temperature sensors, increasing costs and installation space, especially when applied to multiple power conversion apparatuses in vehicles.

Innovation Solution

The method detects temperature abnormalities by monitoring the temperature difference between power converters and the upstream cooling fluid, eliminating the need to detect cooling fluid temperatures downstream, thereby reducing the number of temperature sensors and cooling flow paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature abnormality detection is implemented for each power conversion apparatus individually, then detection accuracy is improved, but the number of temperature sensors and cooling flow paths increases

Engineering Contradiction:
Improvetemperature abnormality detection accuracyVSAvoidnumber of temperature sensors and cooling flow paths
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A single cooling flow path is designed to serve multiple power conversion apparatuses simultaneously. The cooling system cools both the power conversion apparatus and the inverter device that controls it, allowing one cooling system to perform multiple cooling functions. This reduces the total number of cooling flow paths needed while maintaining adequate cooling for each component.

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

Solution Approach 2:

The patent combines the cooling requirements of multiple power conversion apparatuses into a shared cooling flow path. By merging the cooling functions and using a common cooling medium circulation system, the design reduces redundancy while ensuring all components are properly cooled. The control apparatus monitors temperatures across all connected devices through this unified system.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If multiple temperature sensors are installed to monitor each power conversion apparatus, then temperature monitoring precision is improved, but installation space and cost increase

Engineering Contradiction:
Improvetemperature monitoring precisionVSAvoidinstallation space
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The control apparatus is designed to perform multiple functions: it controls the inverter device and simultaneously monitors temperature data from multiple power conversion apparatuses connected to the shared cooling system. This multi-functional design eliminates the need for separate monitoring systems for each device, reducing installation space while maintaining comprehensive temperature surveillance.

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

Solution Approach 2:

The cooling flow path acts as an intermediary medium that carries thermal information from multiple power conversion apparatuses to a single monitoring point. By measuring the temperature of the cooling medium at strategic locations, the system can infer the thermal state of multiple devices without installing sensors in each one, thereby reducing the number of sensors and installation space required.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces the number of necessary temperature sensors and cooling flow paths, lowering costs and installation space requirements while maintaining accurate abnormality detection.

Implementation Method 1

a cooling flow path that passes through the plurality of power converters and cools each of the power converters

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3468018B1Method for detecting temperature abnormality in power conversion apparatus, and device for detecting temperature abnormality in power conversion apparatus
Publication Date: 2020.10.07 NISSAN MOTOR CO LTD
  • EP3468018B1 patent drawingFigure 1
  • EP3468018B1 patent drawingFigure 2
  • EP3468018B1 patent drawingFigure 3

AI summary

To provide an abnormality detection method for an inverter device that can improve the abnormality detection accuracy of a power module of a subsequent stage without adding a sensor for detecting the cooling fluid temperature. An abnormality detection method for a inverter device comprises: a step (S1) for reading a first inverter temperature (tin1), a second inverter temperature (tin2), and a cooling water temperature (tw); a step (S3) for determining the presence of an abnormality in the first inverter device (10) of the preceding stage based on a first temperature difference (Δt1) between the first inverter temperature (tin1) and the cooling water temperature (tw); and a step (S6) for determining the presence of an abnormality in the second inverter device (20) in a subsequent stage based on a second temperature difference (Δt2) between a second inverter temperature (tin2) and added temperature (twa) obtained by converting a loss component of the first inverter device (10) into a temperature (addition value Tad) which is added to the cooling water temperature (tw).