Development of condition evaluation for power transformer maintenance

2013 ◽  
Author(s):  
J. Haema ◽  
R. Phadungthin
Keyword(s):  
Power Transformer ◽  
Condition Evaluation ◽  
Transformer Maintenance

scholarly journals Selecting a condition monitoring system for enhancing effectiveness of power transformer maintenance

2017 ◽  
Vol 23 (4) ◽  
pp. 400-414 ◽  
Author(s):  
Maria Del Pilar Colin Hernandez ◽  
Ashraf Labib
Keyword(s):  
Condition Monitoring ◽  
Failure Modes ◽  
Power Transformer ◽  
Cost Benefit ◽  
Complex Problem ◽  
Power Transformers ◽  
Pairwise Comparisons ◽  
Content Type ◽  
Proposed Model ◽  
Transformer Maintenance

Purpose The purpose of this paper is to propose a model for assisting in the decision-making process for acquiring a condition monitoring (CM) system for an oil-immersed power transformer in order to improve its maintainability. Design/methodology/approach The proposed model is based on the analytic hierarchy process. The assessment was performed by pairwise comparisons, and a sensitivity analysis (what-if analysis) was used to identify the implications of changing the criteria weights. In order to select the criteria and alternatives, a search was conducted for the power transformer failure modes, monitored parameters and CM technologies. Findings The proposed model provides a structured solution for a complex problem: deciding the best combination of technologies for CM of power transformers. Research limitations/implications Because the pairwise comparisons were done only by the author, the results may need to be improved with the assessment of more experts. Also, it was done for a specific type of transformer; it might be necessary to customise the alternatives for other cases. Finally, as a future consideration, more levels can be added to the hierarchy to improve the accuracy of the model. Practical implications The power transformer is an asset where the most appropriate maintenance strategy for it is condition-based maintenance. In order to improve its maintainability, it is recommendable to improve its testability and diagnosability. For achieving this goal, the maintenance personnel have to decide the best combination of technologies for CM. The methodology developed can assist the decision makers to select the most appropriate cost-benefit strategy. Originality/value The paper presents a structured and generic method of selecting the most appropriate CM system for power transformers.

scholarly journals Power Transformer Fault Severity Estimation Based on Dissolved Gas Analysis and Energy of Fault Formation Technique

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Edwell T. Mharakurwa ◽  
G. N. Nyakoe ◽  
A. O. Akumu
Keyword(s):  
Decision Making ◽  
Fuzzy Logic ◽  
Total Energy ◽  
Power Transformer ◽  
Gas Analysis ◽  
Dissolved Gas ◽  
Dissolved Gas Analysis ◽  
Fault Severity ◽  
Incipient Fault ◽  
Transformer Maintenance

Decision making on transformer insulation condition based on the evaluated incipient faults and aging stresses has been the norm for many asset managers. Despite being the extensively applied methodology in power transformer incipient fault detection, solely dissolved gas analysis (DGA) techniques cannot quantify the detected fault severity. Fault severity is the core property in transformer maintenance rankings. This paper presents a fuzzy logic methodology in determining transformer faults and severity through use of energy of fault formation of the evolved gasses during transformer faulting event. Additionally, the energy of fault formation is a temperature-dependent factor for all the associated evolved gases. Instead of using the energy-weighted DGA, the calculated total energy of related incipient fault is used for severity determination. Severity of faults detected by fuzzy logic-based key gas method is evaluated through the use of collected data from several in-service and faulty transformers. DGA results of oil samples drawn from transformers of different specifications and age are used to validate the model. Model results show that correctly detecting fault type and its severity determination based on total energy released during faults can enhance decision-making in prioritizing maintenance of faulty transformers.

Research on the Transformer Condition Assessment Based on the Entropy Weight Method

2013 ◽  
Vol 732-733 ◽  
pp. 930-935
Author(s):  
Hai Feng Liang ◽  
De Shan Lin
Keyword(s):  
Power System ◽  
Electric Power ◽  
Power Transformer ◽  
Electric Power System ◽  
Entropy Weight ◽  
Analytic Hierarchy ◽  
Evaluation Indexes ◽  
Subjective Weight ◽  
Entropy Weight Method ◽  
Transformer Maintenance

As one of the important hinge equipments in the electric power system, the operating reliability of power transformer has deep influences on security and stability of power system. In order to guide transformer maintenance and assess the risk of the electric power system, it is of important significance to know the state of the running insulation of transformer in time and accurately. Based on the analysis of transformer state parameters, the method determining the evaluation index weight has been studied; methods of entropy value objective weight and improved analytic hierarchy process subjective weight have been combined to calculate the weighting coefficients of evaluation indexes. Its correctness has been verified by analyzing examples of transformer operation.

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