Assessment of High Voltage Power Transformer Aging Condition Based on Health Index Value Considering Its Apparent and Actual Age

2020 ◽  
Author(s):  
Winanda Riga Tamma ◽  
Rahman Azis Prasojo ◽  
Suwarno Suwarno
Keyword(s):  
High Voltage ◽  
Power Transformer ◽  
Health Index ◽  
Aging Condition ◽  
Index Value

scholarly journals Power transformer health index estimation using evidential reasoning

2020 ◽  
Vol 33 (4) ◽  
pp. 571-581
Author(s):  
Srdjan Milosavljevic ◽  
Aleksandar Janjic
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Transformer ◽  
Real Data ◽  
Condition Assessment ◽  
Evidential Reasoning ◽  
Health Index ◽  
Power Distribution System ◽  
Index Value ◽  
Shafer Theory

Market-oriented power distribution system requires a well-planned budget with scheduled preventive and corrective maintenance during a replacement of units that are in an unsatisfactory condition. In recent years, the concept of the transformer health index as an integral part of resource management was adopted for the condition assessment and ranking of ETs. However, because of the lack of regular measurement and inspections, the confidence in health index value is greatly reduced. The paper proposes a novel methodology for the ET condition assessment and the lifetime increase through the establishment of priorities for control and maintenance. The solution is based on the upgraded health index, where the confidence to the measurement results is calculated using Evidential reasoning algorithm based on Dempster - Shafer theory. A novel, two - level hierarchical model of ET health index is proposed, with real weighting factors values. This way, the methodology for ET ranking includes the value of available information to describe ET current state. The proposed methodology is tested on real data of an installed ET and compared with the traditional health index calculation.

Investigation of failure of high voltage bushing at power transformer

2018 ◽  
Vol 96 ◽  
pp. 49-56 ◽  
Author(s):  
A.J. Christina ◽  
M.A. Salam ◽  
Q.M. Rahman ◽  
Md Aminul Islam ◽  
Fushuan Wen ◽  
...  
Keyword(s):  
High Voltage ◽  
Power Transformer

Partial Discharge Detection Using Acoustic and Optical Methods in High Voltage Power Equipments: A Review

2013 ◽  
Vol 845 ◽  
pp. 283-286 ◽  
Author(s):  
Malik Abdul Razzaq Al Saedi ◽  
Mohd Muhridza Yaacob
Keyword(s):  
Acoustic Emission ◽  
High Voltage ◽  
Power Transformer ◽  
Partial Discharge ◽  
Optical Detection ◽  
Detection Threshold ◽  
Optical Methods ◽  
Detection Methods ◽  
Detection Techniques ◽  
Advantages And Disadvantages

There is a high risk of insulation system dielectric instability when partial discharge (PD) occurs. Therefore, measurement and monitoring of PD is an important preventive tool to safeguard high-voltage equipment from wanton damage. PD can be detected using optical method to increase the detection threshold and to improve the performance of on-line measurement of PD in noise environment. The PD emitted energy as acoustic emission. We can use this emitted energy to detect PD signal. The best method to detect PD in power transformer is by using acoustic emission. Optical sensor has some advantages such as; high sensitivity, more accuracy small size. Furthermore, in on-site measurements and laboratory experiments, it isoptical methodthat gives very moderate signal attenuations. This paper reviews the available PD detection methods (involving high voltage equipment) such as; acoustic detection and optical detection. The advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages from the consideration of accuracy and suitability for the applications when compared to other techniques.

scholarly journals Status of Coral Reefs in the Water of Spermonde, Makassar, South Sulawesi

2021 ◽  
Vol 324 ◽  
pp. 03007
Author(s):  
Ni Wayan Purnama Sari ◽  
Rikoh Manogar Siringoringo ◽  
Muhammad Abrar ◽  
Risandi Dwirama Putra ◽  
Raden Sutiadi ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coral Cover ◽  
Public Awareness ◽  
Live Coral ◽  
Health Index ◽  
Point Count ◽  
Live Coral Cover ◽  
Reef Health ◽  
Index Value

Observations of the condition of coral reefs have been carried out in Spermonde waters from 2015 to 2018. The method used in this observation uses Underwater Photo Transect (UPT), and the data obtained is analyzed using CPCe (Coral Point Count with Excel Extensions) software. The results show that the percentage of coral cover has increased from year to year. The percentage of live coral cover in 2015 was 19.64%, 23.60 in 2016, 23.72% in 2017, and 27.83% in 2018. The increase in live coral cover from year to year is thought to occur due to the availability of nutrients. or increasing public awareness, considering this location is one of the most famous tourist attractions in Makassar. Coral reef health index values can be used to classify coral reef health. Through the analysis of the coral reef health index, an index value of 4 was obtained, which means that the condition of the coral reefs is in the “moderate” category.

An approach to power transformer asset management using health index

2009 ◽  
Vol 25 (2) ◽  
pp. 20-34 ◽  
Author(s):  
A. Jahromi ◽  
R. Piercy ◽  
S. Cress ◽  
J. Service ◽  
Wang Fan
Keyword(s):  
Asset Management ◽  
Power Transformer ◽  
Health Index

Idejno rešenje regionalnog Data Centra kod Beograda napajanog iz obnovljivih izvora energije

2021 ◽  
Vol 23 (3) ◽  
pp. 10-17
Author(s):  
Ivan Vujović ◽  
Željko Đurišić ◽  
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Wind Farm ◽  
Low Voltage ◽  
Power Transformer ◽  
Renewable Energy Sources ◽  
Geographical Location ◽  
Electrical Energy ◽  
Economic Benefits ◽  
Infrastructure Development

Telecommunications and computer equipment centralisation trends for the purpose of achieving economic benefits, usage of technological innovations and new technical solutions implementation leads to the requirements for building bigger Data Centres (DCs). An increase in the size of the DC facility i.e. the number of racks inside occupied with equipment and the number of devices that enables the proper functioning of that equipment leads to necessarily power energy requirements increasing for power supply. For the DCs that require a large amount of energy, the building of their own, usually renewable energy sources (RES) is cost-effective. In such a caser, RES are primary and Power System (PS) is secondary and redundant power source. A concept of a DC primary powered from RES is presented in this paper. Generated electrical energy in RES is transmitted in PS through high voltage switch-gears (SGs) while DC is power supplied from PS through low voltage, medium voltage and high voltage SG-s. For the purpose of realisation of such facility, it is necessary to enable adequate conditions related to geographical location, physical access to the facility, possibility of connecting to the PS and possibility of connecting to the telecommunications centres. Based on carried out researches related to RESs potential, available roads, power supply infrastructure and telecommunication infrastructure, development conditions for DC on location near to Belgrade, close to power transformer station „Belgrade 20“ are analysed in this paper. From the aspect of DC power supply, proposed solution includes wind farm, solar plant and landfill gas power plant, as well as related SGs. Telecommunication connections from DC to the PS and other important telecommunication centres are provided. These connections are realised through optical cables placed next to the electrical lines and cables, and, when that is not possible, placed independently in the ground. The design of the DC interior is given and calculations of the required electrical energy for the power supply of the equipment and devices in the facility are performed. Based on calculation results, capacity calculation of the RES and calculation of SGs are performed. Design of the interior optical connections inside DC is also given. A General assessment of the investment and economics of building such DC are given at the end of the paper.

Dynamic Interaction of High-Voltage Power Transformer Bushings, Turrets, and Tanks

2018 ◽  
Vol 34 (1) ◽  
pp. 397-421 ◽  
Author(s):  
Guo-Liang Ma ◽  
Qiang Xie ◽  
Andrew Whittaker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Voltage ◽  
Power Transformer ◽  
Bending Moment ◽  
Dynamic Interaction ◽  
Electrical Performance ◽  
Element Analysis ◽  
Ground Shaking ◽  
Input Motion

High-voltage (HV) bushings are attached to a power transformer tank either directly or indirectly via turrets. Turrets are used to achieve electrical performance requirements, but their potential impact on the seismic performance of the supported bushings has not been considered. Earthquake simulator testing and finite-element analysis were used to quantify the amplification of ground shaking through tanks (220- and 500-kV) and turrets to the points of attachment of roof- and sidewall-supported bushings. Substantial amplification of motion was seen in both physical experiments and numerical simulations. Sample bracing schemes external to the transformer tank were investigated to potentially reduce the motions experienced by the bushings. Bushing tip displacements were reduced in all stiffening cases studied, but the outcomes for bending moment at the bushing-turret connection were mixed, with no change in some cases and significant reductions in others. The physical and numerical studies described in this paper make clear the importance of dynamic interaction of bushings, turrets, and the power transformer tank. The methods currently used to address the amplification of input motion from the base of a tank to the points of attachment of its bushing are inadequate. The seismic design of HV power transformer tanks and turrets should be supported by finite-element analysis of validated models to avoid dynamic interaction in the bushing-turret-tank system, to minimize seismic demand on the transformer bushings, and to minimize the risk of substation damage in earthquakes.

scholarly journals Frequency and time fault diagnosis methods of power transformers

2018 ◽  
Vol 18 (4) ◽  
pp. 162-167 ◽  
Author(s):  
Miroslav Gutten ◽  
Daniel Korenciak ◽  
Matej Kucera ◽  
Richard Janura ◽  
Adam Glowacz ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
High Voltage ◽  
Impact Test ◽  
Power Transformer ◽  
Short Circuit ◽  
Small Deformation ◽  
Short Circuit Current ◽  
Diagnostic Methods ◽  
Response Analysis ◽  
Short Circuit Currents

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.

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