scholarly journals Effects of VA Rating on the Fault Diagnosis of Power Transformer Using SFRA Test

2021 ◽  
Vol 23 (5) ◽  
pp. 381-389
Author(s):  
Khalid H. Ibrahim ◽  
Nourhan R. Korany ◽  
Saber M. Saleh

The electric power transformer is an essential part of an electrical power system since it is used to step up or down voltage levels to maintain the system performance as well as possible. Frequency response analysis (FRA) is one of the most widely used techniques for detecting various types of mechanical damage in transformers. The equivalent circuit of the transformer will be represented by a complex network of R, L, and C elements in the FRA technique. For transformer faults diagnosis, various calculation techniques and diagnostic techniques may be used, such as acoustic emission analysis, thermal images of electromagnetic radiation, transformer temperature, and humidity analysis. SFRA test is one of these techniques that could be used to determine the fault type based on its response over a wide frequency range. The main challenge of the SFRA test is that the functional interpretation requirement for this test is not universally accepted Also statistical features are defined for this SFRA response to be used in fault detection and classification. In this paper, the effect of the transformer rating on the fault diagnosis techniques using SFRA is tested. Also, the effect of the transformer VA rating on the statistical parameters and the classification rules of fault diagnosis is discussed. Finally, the features used in fault diagnosis are ranked according to its independence of the transformer rating resulting in a more accurate matching fault diagnosis technique.

2018 ◽  
Vol 18 (4) ◽  
pp. 162-167 ◽  
Author(s):  
Miroslav Gutten ◽  
Daniel Korenciak ◽  
Matej Kucera ◽  
Richard Janura ◽  
Adam Glowacz ◽  
...  

Abstract The authors describe experimental and theoretical analyses of faults of power transformer winding. Faults were caused by mechanical effect of short-circuit currents. Measurements of transformer were carried out in high-voltage laboratory. Frequency and time diagnostic methods (method SFRA - Sweep Frequency Response Analysis, impact test) were used for the analyses. Coils of transformer windings were diagnosed by means of the SFRA method and the time impact test. The analyzed methods had a significant sensitivity to a relatively small deformation of coil. In the analysis a new technique for analyzing the effects of short-circuit currents is introduced. This technique is developed for high-voltage transformers (different types of power). The proposed analyses show that it is necessary to analyze the value of short-circuit current. Short-circuit current represents a danger for the operation of the power transformer. The proposed approach can be used for other types of transformers. Moreover, the presented techniques have a potential application for fault diagnosis of electrical equipment such as: transformers and electrical machines.


2018 ◽  
Vol 218 ◽  
pp. 04008
Author(s):  
Siswanto ◽  
Agus Indarto ◽  
Radin Rahmatullah ◽  
Chairul Hudaya

Power transformer (PT), essential equipment in electrical power system proceeds complicated manufacturing process to meet high standard design. During manufacturing process of PT, the drying stage is of importance to remove excessive moisture contaminant on the solid insulation. This study investigated the effects of drying duration on partial discharge test of 83.3 MVA 275/160 kV PT. The partial discharge test measurements were carried out using IEC 60270 standards comprising of the capacitive network model based on the main quantity apparent charge concept. We found that the lowest partial discharge of 21 pC was achieved at 68 hours drying duration, while the highest value of 60 pC was reached at 81 hours drying time. The longer drying time may lead to initial degradation of cellulose insulation due to excessive heating. The amount of water extracted during drying effect to partial discharge also investigated. We conclude that the drying time at a higher and lower than 68 hours significantly contributes to the increased partial discharge values of PT.


Author(s):  
Hui Hwang Goh ◽  
Sy yi Sim ◽  
Mohamad Amirul Hafiz Mohamed ◽  
Abdul Khairi Abdul Rahman ◽  
Chin Wan Ling ◽  
...  

<p>Electric fault is the main challenge in the process of providing continues electric supply. Fault can occur at anytime and anywhere. Due to the fault causes are mainly based on natural disaster or accident. Most fault occurrence hardly predicted nor avoided. Therefore, a quick response fault detection is necessary to ensure that the fault area is maintained to ensure a continuous power supply system. Hence, a system is required to detect and locate the position of the fault in the power system especially in the transmission line and distribution line. This paper will review the type of fault that possibly occurs in an electric power system, the type of fault detection and location technique that are available together with the protection device that can be utilized in the power system to protect the equipment from electric fault.</p><p> </p>


2020 ◽  
Vol 9 (3) ◽  
pp. 862-869
Author(s):  
Ali N. Hamoodi ◽  
Bashar A. Hammad ◽  
Fawaz S. Abdullah

Transformer is one of main components in electrical power system which role to increase or reduce voltage. Characteristics of transformer would be vital to ensure the voltage is fully transferred. A single-phase transformer is a type of power transformer that utilizes single-phase alternating current, meaning the transformer relies on a voltage cycle that operates in a unified time  phase. This article describes a workflow executed with Mat lab simulation and practical measurements for single-phase power transformer, no-load, short-circuit test and load test are achieved in this work. The test procedures are implemented on areal transformer (terco-type) which has a specification (1 KVA, 220/110 V, 50 Hz). Finally, the simulation results are appeared a proximately seminar from the practical results. The results indicated that the the technique and manner which presented in the current study can be depended as a miniproject in electrical technology mater for undergraduate studies.


2012 ◽  
Vol 452-453 ◽  
pp. 975-979 ◽  
Author(s):  
Josep Franklin Sihite ◽  
Takehisa Kohda

The electricity needs of Indonesia grow an average 10% each year. Therefore, PLN (Perusahaan Listrik Negara) as the only power utility business in Indonesia, has a master plan to develop new power plant, switchyard and transmission system. One of the new developed systems is GI Simangkuk switchyard of Sumatra interconnection system. This switchyard is prepared to improve reliability of Sumatra interconnection system. This site utilizes power transformers of 275 kV. Power transformer is one of the main equipments in power systems. When a failure occurs in a power transformer, the whole system will be failed and the electricity could not be delivered to customer. Each utility has to assure their reliability in order to maintain electrical power system stability by assessing transformer condition. There is an increasing need for better diagnostic and monitoring tools to assess the condition of transformers. Modern power transformers are equipped with software and computer system control. The reliability of this computer systems are needed to evaluate for assurance of system safety. This paper describes the need of assessment and maintenance of power transformers such as outages effect of failures, high cost of maintenance and replacement, increase of world demand, aging effect and used of old transformer, and computer protection system failure. Monitoring and diagnostic methods of transformers assessment have been developing in recently years. They can be separated into traditional and non-traditional methods that have been used in many years and are still in research stage. In this paper we propose a new approach in order to assess power transformer condition by using fault tree analysis.


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