Inverter Switching Element Temperature Estimation via Linearized Voltage

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Solution Overview

Problem

Existing methods for estimating the temperature of switching elements in inverters require complex calculations and large memory storage due to non-linear parameter variations with temperature, leading to increased data storage and computational complexity.

Innovation Solution

A parameter determining apparatus and method that linearizes collector-emitter voltage variations with temperature, reducing data storage and simplifying calculations by using a first-order function to estimate temperature, thereby eliminating the need for storing multiple temperature-specific parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If non-linear parameter variations with temperature are used for temperature estimation, then measurement precision is improved, but device complexity and memory storage requirements increase

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

Solution Approach 1:

The patent transforms the non-linear parameter variation into a linear relationship by changing the mathematical form of the equation. Instead of using complex non-linear functions that require extensive computation and memory storage, the invention uses a simplified linear equation that maintains temperature estimation accuracy while significantly reducing computational burden and memory requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts only the essential parameters needed for temperature estimation from the complex non-linear model. By identifying and utilizing only the critical linear relationships, the invention eliminates unnecessary computational steps and memory storage requirements while preserving the core functionality of accurate temperature estimation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If non-linear parameter variations with temperature are used for temperature estimation, then measurement precision is improved, but memory storage capacity increases

Engineering Contradiction:
Improvetemperature estimation accuracyVSAvoidmemory storage capacity
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent changes the mathematical representation from non-linear to linear form, which dramatically reduces the memory storage capacity required. The linear model requires storing only a few simple parameters whereas the non-linear model would require extensive lookup tables or complex function definitions, thereby reducing memory usage while maintaining estimation precision.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple temperature-specific parameters are stored, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvetemperature estimation accuracyVSAvoiddata storage and computational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a universal linear equation that can estimate temperature across different conditions without requiring separate parameters for each temperature range. This single linear model serves multiple functions and temperature ranges, eliminating the need for complex multi-parameter storage and conditional computation logic.

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

Data Source

PatentEP3236223B1Parameter determining apparatus for estimating temperature of switching element of inverter
Publication Date: 2021.01.27 LSIS CO LTD
  • EP3236223B1 patent drawingFigure 1
  • EP3236223B1 patent drawingFigure 2
  • EP3236223B1 patent drawingFigure 3~4

AI summary

A parameter determining apparatus for estimating temperature of a switching element of an inverter is disclosed. The parameter determining apparatus of the present disclosure includes an inverter unit (30) including a power semiconductor module configured with at least one or more switching elements, and a control unit (40) configured to determine an initial collector-emitter voltage of each of the switching elements and collector-emitter resistance of each thereof by linearizing a collector-emitter voltage of each of the switching elements at a certain temperature.