Diagnostic techniques to evaluate internal condition of power transformer

2009 ◽  
Author(s):  
Thanapong Suwanasri ◽  
Juthathip Haema ◽  
Rattanakorn Phadungthin ◽  
Cattareeya Suwanasri
Keyword(s):  
Power Transformer ◽  
Diagnostic Techniques ◽  
Internal Condition

scholarly journals Towards Precise Interpretation of Oil Transformers via Novel Combined Techniques Based on DGA and Partial Discharge Sensors

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2223 ◽  
Author(s):  
Sayed A. Ward ◽  
Adel El-Faraskoury ◽  
Mohamed Badawi ◽  
Shimaa A. Ibrahim ◽  
Karar Mahmoud ◽  
...  
Keyword(s):  
Power Transformer ◽  
Partial Discharge ◽  
Electrical Power ◽  
Diagnostic Techniques ◽  
Gas Analysis ◽  
Economic Losses ◽  
Dissolved Gas ◽  
Electricity Transmission ◽  
Dissolved Gas Analysis ◽  
Precise Interpretation

Power transformers are considered important and expensive items in electrical power networks. In this regard, the early discovery of potential faults in transformers considering datasets collected from diverse sensors can guarantee the continuous operation of electrical systems. Indeed, the discontinuity of these transformers is expensive and can lead to excessive economic losses for the power utilities. Dissolved gas analysis (DGA), as well as partial discharge (PD) tests considering different intelligent sensors for the measurement process, are used as diagnostic techniques for detecting the oil insulation level. This paper includes two parts; the first part is about the integration among the diagnosis results of recognized dissolved gas analysis techniques, in this part, the proposed techniques are classified into four techniques. The integration between the different DGA techniques not only improves the oil fault condition monitoring but also overcomes the individual weakness, and this positive feature is proved by using 532 samples from the Egyptian Electricity Transmission Company (EETC). The second part overview the experimental setup for (66/11.86 kV–40 MVA) power transformer which exists in the Egyptian Electricity Transmission Company (EETC), the first section in this part analyzes the dissolved gases concentricity for many samples, and the second section illustrates the measurement of PD particularly in this case study. The results demonstrate that precise interpretation of oil transformers can be provided to system operators, thanks to the combination of the most appropriate techniques.

scholarly journals Diagnostic Techniques of Liquid Cooled Gas Insulated Large Power Transformer

1991 ◽  
Vol 111 (7) ◽  
pp. 764-770
Author(s):  
Taizou Hasegawa ◽  
Takashi Betsui ◽  
Shuuichi Ohnishi ◽  
Yoshihiro Makino ◽  
Satoshi Hayashi ◽  
...  
Keyword(s):  
Power Transformer ◽  
Diagnostic Techniques ◽  
Large Power

Enhanced optimal trained hybrid classifiers for aging assessment of power transformer insulation oil

2020 ◽  
Vol 17 (3) ◽  
pp. 407-426
Author(s):  
Harkamal Deep Singh ◽  
Jashandeep Singh
Keyword(s):  
Prediction Models ◽  
Power Transformer ◽  
Electrical Equipment ◽  
Diagnostic Techniques ◽  
Assessment Model ◽  
Content Type ◽  
Lion Algorithm ◽  
Hybrid Classifiers ◽  
Transformer Insulation ◽  
Insulation Oil

Purpose As a result of the deregulations in the power system networks, diverse beneficial operations have been competing to optimize their operational costs and improve the consistency of their electrical infrastructure. Having certain and comprehensive state assessment of the electrical equipment helps the assortment of the suitable maintenance plan. Hence, the insulation condition monitoring and diagnostic techniques for the reliable and economic transformers are necessary to accomplish a comprehensive and proficient transformer condition assessment. Design/methodology/approach The main intent of this paper is to develop a new prediction model for the aging assessment of power transformer insulation oil. The data pertaining to power transformer insulation oil have been already collected using 20 working power transformers of 16-20 MVA operated at various substations in Punjab, India. It includes various parameters associated with the transformer such as breakdown voltage, moisture, resistivity, tan δ, interfacial tension and flashpoint. These data are given as input for predicting the age of the insulation oil. The proposed aging assessment model deploys a hybrid classifier model by merging the neural network (NN) and deep belief network (DBN). As the main contribution of this paper, the training algorithm of both NN and DBN is replaced by the modified lion algorithm (LA) named as a randomly modified lion algorithm (RM-LA) to reduce the error difference between the predicted and actual outcomes. Finally, the comparative analysis of different prediction models with respect to error measures proves the efficiency of the proposed model. Findings For the Transformer 2, root mean square error (RMSE) of the developed RM-LA-NN + DBN was 83.2, 92.5, 40.4, 57.4, 93.9 and 72 per cent improved than NN + DBN, PSO, FF, CSA, PS-CSA and LA-NN + DBN, respectively. Moreover, the RMSE of the suggested RM-LA-NN + DBN was 97.4 per cent superior to DBN + NN, 96.9 per cent superior to PSO, 81.4 per cent superior to FF, 93.2 per cent superior to CSA, 49.6 per cent superior to PS-CSA and 36.6 per cent superior to LA-based NN + DBN, respectively, for the Transformer 13. Originality/value This paper presents a new model for the aging assessment of transformer insulation oil using RM-LA-based DBN + NN. This is the first work uses RM-LA-based optimization for aging assessment in power transformation insulation oil.

scholarly journals An Alternative Approach for Oil-immersed High Voltage Power Transformer Dissolved Gas Analysis Diagnostic Techniques

2019 ◽  
Vol 18 (2) ◽  
pp. 1-7
Author(s):  
Ahmad Karimi Mehrabadi ◽  
Asaad Shemshadi ◽  
Hossein Shateri
Keyword(s):  
Fuzzy Logic ◽  
Power Transformer ◽  
Diagnostic Techniques ◽  
Inference Engine ◽  
Gas Analysis ◽  
Transformer Oil ◽  
Power Transformers ◽  
Fuzzy Logic Inference ◽  
Triangle Method ◽  
Logic Inference

This article presents alternative analyzing method of extracted dissolved gases related to insulating oil of power transformers. Analysis of soluble and free gas is one of the most commonly used troubleshooting methods for detecting and evaluating equipment damage. Although the analysis of oil-soluble gases is often complex, it should be expertly processed during maintenance operation. The destruction of the transformer oil will produce some hydrocarbon type gases. The development of this index is based on two examples of traditional evaluation algorithms along with fuzzy logic inference engine. Through simulation process, the results of the initial fractures in the transformer are obtained in two ways by the "Duval Triangle method” and "Rogers’s ratios". In continue, three digit codes containing the fault information are created based on the fuzzy logic inference engine to achieve better results and eliminate ambiguous zones in commonly used methods, especially in the “Duval Triangle method”. The proposed method is applied to 80 real transformers to diagnose the fault by analyzing the dissolved oil based on fuzzy logic. The results illustrate the proficiency of this alternative proposed algorithm. Finally, with utilization of a neural network the alternative practical inference function is derived to make the algorithm more usable in the online condition monitoring of power transformers.

Impairment Tutorial: Neurological Impairment Evaluation: Overview of Sixth Edition Approaches

2008 ◽  
Vol 13 (2) ◽  
pp. 6-8
Author(s):  
Lorne Direnfeld ◽  
Christopher R. Brigham ◽  
Elizabeth Genovese
Keyword(s):  
Spinal Cord ◽  
Neurological Impairment ◽  
Diagnostic Techniques ◽  
Neurological Deficits ◽  
Sixth Edition ◽  
Pain Disability ◽  
Whole Person ◽  
Disability Questionnaire ◽  
Cervical Plating

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), does not provide a Diagnosis-based estimate of impairment due to syringomyelia, a disorder in which a cyst (syrinx), develops within the central spinal cord and destroys neural tissue as it expands. The AMA Guides, however, does provide an approach to rating a syringomyelia based on objective findings of neurological deficits identified during a neurological examination and demonstrated by standard diagnostic techniques. Syringomelia may occur after spinal cord trauma, including a contusion of the cord. A case study illustrates the rating process: The case patient is a 46-year-old male who fell backwards, landing on his upper back and head; over a five-year period he received a T5-6 laminectomy and later partial corpectomies of C5, C6, and C7, cervical discectomy C5-6 and C6-7; iliac crest strut graft fusion of C5-6 and C6-7; and anterior cervical plating of C5 to C7 for treatment of myelopathy; postoperatively, the patient developed dysphagia. The evaluating physician should determine which conditions are ratable, rate each of these components, and combine the resulting whole person impairments without omission or duplication of a ratable impairment. The article includes a pain disability questionnaire that can be used in conjunction with evaluations conducted according to Chapter 3, Pain, and Chapter 17, The Spine.

Effect of No-load and Load Condition on Transformer Sound

2018 ◽  
pp. 11-15
Author(s):  
Dr. Hitesh Paghadar
Keyword(s):  
Experimental Study ◽  
Power Transformer ◽  
Load Condition ◽  
Noise Pollution ◽  
Sound Level ◽  
Measurement Scale ◽  
Dominant Factor ◽  
Public Attention ◽  
Level Measurement ◽  
Human Ear

Increasing environment noise pollution is a matter of great concern and of late has been attracting public attention. Sound produces the minute oscillatory changes in air pressure and is audible to the human ear when in the frequency range of 20Hz to 20 kHz. The chief sources of audible sound are the magnetic circuit of transformer which produces sound due to magnetostriction phenomenon, vibration of windings, tank and other structural parts, and the noise produced by cooling equipments. This paper presents the validation for sound level measurement scale, why A-weighted scale is accepted for sound level measurement, experimental study carried out on 10MVA Power Transformer. Also presents the outcomes of comparison between No-Load sound & Load sound level measurement, experimental study carried out on different transformer like - 10MVA, 50MVA, 100MVA Power Transformer, to define the dominant factor of transformer sound generation.

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