Power Transformer Diagnostics Using Rule-Based Expert System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The field of power transformer diagnostics is hindered by inexact reasoning and uncertainty due to limited information, sparse test opportunities, and a lack of empirical data, leading to costly and unreliable fault detection and corrective actions.

Innovation Solution

A rule-based expert system utilizing sophisticated algorithms to evaluate transformer conditions by acquiring data, deriving physical conditions, computing failure mechanism indices, and determining corrective actions, providing a consistent, systematic, and repeatable diagnostic process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional diagnostic methods are used, then practitioners can perform transformer assessments, but the reasoning is inexact and results are uncertain due to limited information and sparse test opportunities

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidinformation completeness
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system performs preliminary data collection and analysis by acquiring transformer data, deriving physical conditions, and computing failure mechanism indices before making diagnostic decisions. This advance preparation reduces uncertainty by having assessment results ready prior to when maintenance decisions are needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where diagnostic results and corrective actions are systematically recorded and used to improve future assessments. The structured methodology allows practitioners to learn from past cases, reducing information loss over time and improving diagnostic accuracy through accumulated experience.

Inventive Principle:
Principle #23Feedback

2Reliability

If more comprehensive testing is performed to reduce uncertainty, then diagnostic accuracy improves, but test opportunities remain limited and costs increase

Engineering Contradiction:
Improvefault detection reliabilityVSAvoidtesting complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The diagnostic process is segmented into distinct modules: data acquisition, physical condition derivation, failure mechanism index computation, and corrective action determination. Each module handles a specific aspect of the diagnosis, reducing overall system complexity while maintaining comprehensive assessment capability through structured progression through each segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transforms raw transformer data into derived physical conditions and then into failure mechanism indices, changing parameters at each stage to make the data more meaningful and actionable. This parameter transformation approach reduces testing complexity by working with processed information rather than requiring direct measurement of all possible fault conditions.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If practitioners make educated guesses about fault conditions, then assessments can be performed with limited data, but the results lack transparency and repeatability

Engineering Contradiction:
Improveassessment feasibilityVSAvoidmethodology transparency
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The system introduces structured intermediary steps between raw data and diagnostic conclusions: physical condition derivation acts as an intermediary that systematically transforms data into meaningful conditions, and failure mechanism indices serve as intermediaries that quantify the likelihood of specific failure modes. This eliminates guesswork by providing transparent intermediate results that can be reviewed and verified.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces the mechanical process of human expert judgment with an automated computational methodology that systematically processes data through defined algorithms. This substitution eliminates the subjectivity and lack of transparency inherent in educated guesses, while maintaining ease of operation through automated execution of the assessment process.

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

4Reliability

If costly replacement is performed as the primary corrective action, then transformer failures are prevented, but asset management costs increase and replacement decisions lack nuance

Engineering Contradiction:
Improvesystem reliabilityVSAvoidasset management cost
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system enables partial corrective actions by identifying specific failure mechanisms and their severity through computed indices. Instead of always requiring full replacement, the methodology allows for targeted interventions based on the specific conditions detected, such as addressing only the affected components or performing monitored maintenance, thereby reducing unnecessary asset management costs while maintaining adequate reliability.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system changes the decision-making parameter from binary (replace or not) to a continuous scale based on failure mechanism indices and severity assessments. This allows for nuanced corrective actions that are proportional to the actual condition of the transformer, optimizing the balance between reliability maintenance and cost reduction by matching the level of intervention to the level of risk.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10488384B2System and method for assessing power transformers
Publication Date: 2019.11.26 ELECTRIC POWER RES INST INC
  • US10488384B2 patent drawing
  • US10488384B2 patent drawing
  • US10488384B2 patent drawing

AI summary

A system and method for evaluating power transformers is disclosed. The method includes the steps of acquiring data representing one or more parameters of a power transformer, using rules to derive one or more broad physical conditions of the power transformer from the acquired data, and using the broad physical conditions as inputs to compute a plurality of indices. Each index represents a category of failure mechanisms of the power transformer. The method further includes the steps of using the plurality of indices to determine a corrective action and performing the corrective action on the power transformer.