Partial Discharge Factor Estimation in Power Semiconductor Modules
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Solution Overview
Problem
Identifying the factor causing partial discharge in power semiconductor modules is challenging due to the time-dependent changes in void sizes within insulation materials, and existing methods do not effectively distinguish between voids in soft and hard resins.
Innovation Solution
A method and device for estimating the partial discharge factor in power semiconductor modules using time-series data from a partial discharge test, involving a measurement step with a changing voltage pattern, feature quantity extraction, and classification of the partial discharge factor based on these quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If disassembly and analysis of the power semiconductor module is performed to identify the factor causing partial discharge, then the accuracy of identifying the partial discharge factor is improved, but the time and cost required increase significantly
Solution Approach 1:
The patent replaces the mechanical disassembly and physical analysis system with an electrical measurement and data processing system. By using partial discharge measurement devices to capture electrical signals and applying image processing techniques to analyze the temporal patterns of discharge events, the system identifies void locations and characteristics without physical disassembly, thereby substituting mechanical inspection with electrical-field-based detection and computational analysis
Solution Approach 2:
The patent creates a virtual representation of the partial discharge phenomenon through measured electrical signals and processed images. By capturing the temporal and spatial characteristics of partial discharge events and generating visual images that represent void locations and sizes, the system creates a digital copy of the insulation defect state, eliminating the need for physical disassembly while preserving all diagnostic information
2Measurement precision
If the size of void in soft resin is measured to identify partial discharge factor, then the identification accuracy is improved, but the measurement becomes difficult due to time-dependent changes in void size
Solution Approach 1:
The patent performs preliminary measurement of the partial discharge characteristics at the initial state before significant void deformation occurs. By capturing the temporal pattern of partial discharge events early in the product lifecycle when void sizes are relatively stable and representative, the system establishes a baseline for identifying the original void configuration, preventing the need for complex long-term tracking of changing void dimensions
Solution Approach 2:
Instead of directly measuring void size which changes over time in soft resin, the patent inverts the approach by measuring the partial discharge electrical signals and using image processing to infer void characteristics. The temporal pattern of discharge events is converted into an image representation that reveals void location and size information without requiring direct physical measurement of the changing void dimensions
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 easy and automatic estimation of the partial discharge factor, improving the durability and reliability of power semiconductor modules by accurately identifying the cause of partial discharge.
Implementation Method 1
The partial discharge is weak discharge (corona discharge) that occurs in a defective part of an insulator
Data Source
AI summary
A method for estimating a partial discharge factor of a power semiconductor module which is capable of automatically estimating a partial discharge factor is provided using time-series data of a quantity of charge discharged during a partial discharge test. The method includes: a measurement step of applying, to the power semiconductor module, a test voltage pattern in which a voltage pattern changes, and measuring a quantity of charge that is due to partial discharge of the power semiconductor module; a feature quantity extraction step of extracting a plurality of feature quantities including at least a first feature quantity that is an average value of a quantity of charge in a first time period and a second feature quantity that is an average value of a quantity of charge in a second time period; and an estimation step of estimating the partial discharge factor based on the plurality of feature quantities.