Advanced Modeling and Experimental Validation of an Optimized Power Transformer Tank

2018 ◽  
Author(s):  
Hélder F. G. Mendes ◽  
Cristiano J. P. Coutinho ◽  
Sérgio M. O. Tavares ◽  
Luís M. R. Félix ◽  
Agostinho N. Martins de Matos ◽  
...  
Keyword(s):  
Structural Design ◽  
Experimental Validation ◽  
Power Transformer ◽  
Electrical Machines ◽  
Power Transformers ◽  
Metallic Structures ◽  
Design Procedures ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Type Power

Even though the power transformers are electrical machines, their design includes several important steps with strong emphasis on mechanical engineering topics, such as the design of welded metallic structures. Indeed, the tank and its cover are typically manufactured from steel sheets or plates to which a group of stiffeners are added, with the objective of reducing the bending stress, transverse displacements and/or buckling. The current communication presents and discusses several incremental innovations in the structural design and simulation of tanks for Core type power transformers, including: (i) optimization of the stiffeners design and welding bead volume reduction; (ii) optimization of panels curvature; (iii) simulation of the transformer tank loaded by both hydrostatic pressure and vacuum conditions; and (iv) inclusion of non-linear behavior to more accurately simulate representative structures. Achieved numerical results are compared with obtained experimental data, to evaluate the design procedures and the potential of virtual testing of new solutions.

Experimental Validation of a CORE Type Power Transformer

2009 ◽  
Author(s):  
E. Emanuel Almeida ◽  
He´lder G. Mendes ◽  
A. Marques Pinho
Keyword(s):  
Design Methodology ◽  
Experimental Validation ◽  
Power Transformer ◽  
Current Paper ◽  
Added Value ◽  
Power Transformers ◽  
Stress And Strain ◽  
Strain Measurements ◽  
Type Power ◽  
Validation Tool

The current paper presents the validation of a finite element (FEM) design methodology for a CORE type power transformer. Any new methodology can only be implemented when it generates significant added value. The application of FEM to the design of power transformers leads to lighter, more balanced mechanical structures that are more economical to manufacture. To be sure that the methodology is a good predictor of the stress and strain effectively encountered by the power transformer, it is necessary to measure stress and strain during loading and compare those measurement values with the original FEM predictions. The current paper begins by first presenting the FEM predictions for a CORE type power transformer. Secondly, by means of extensometry, the strains induced in the tank during loading were measured and the stresses present in the tank were estimated from basic stress-strain relationships. The feedback given by the strain measurements served as a validation tool for the FEM design predictions.

scholarly journals Performance Comparison of Multi Design Method and Meta-Heuristic Methods for Optimal Preliminary Design of Core-Form Power Transformers

2017 ◽  
Vol 61 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Tamás Orosz ◽  
Bence Borbély ◽  
Zoltán Ádám Tamus
Keyword(s):  
Optimization Problem ◽  
Power Transformer ◽  
Design Method ◽  
Power Transformers ◽  
Design Stage ◽  
Preliminary Design ◽  
Grey Wolf ◽  
Grey Wolf Optimization ◽  
Three Phase ◽  
Type Power

Large power transformers are regarded as crucial and expensive assets in power systems. Due to the competing global market, to make a good and competing power transformer design, a non-linear optimization problem should be solved in a very short time in the preliminary design stage. The paper shows and compares the performance of four different methods to solve this problem for three phase core type power transformers. The first algorithm is a novel meta-heuristic technique which combines the geometric programming with the method of branch and bound. Then this conventional multi design method is solved by a simple iterative technique and two novel evolutionary algorithms to enhance the convergence speed. One of these algorithms is the particle swarm optimization technique which is used by many other researchers and the grey wolf optimization algorithm which is a new method in this optimization sub-problem. An example design on an 80 MVA, three phase core type power transformer using these four methods is presented and its performances are analyzed. The results demonstrate that the grey wolf optimization is a good alternative for this optimization problem.

scholarly journals Full-phase Voltage Restorer in a Four-wire Circuit of 0.4/0.23 kV when one of the 6 (10) kV Supply Phases of the Transformer Breaks

2021 ◽  
pp. 82-86
Author(s):  
П.С. Орлов ◽  
О.Н. Круду
Keyword(s):  
Supply Voltage ◽  
Power Transformer ◽  
Electrical Machines ◽  
Power Transformers ◽  
Phase Voltage ◽  
Electric Networks ◽  
Voltage Restorer ◽  
Three Phase ◽  
Magnetic Flows ◽  
Electrical Injuries

Рассмотрены проблемы повышения надёжности электроснабжения потребителей и снижение электротравматизма в электроустановках. При обрыве одной из питающих фаз силового трансформатора напряжением 6(10) кВ созданное авторами устройство восстановления полнофазного напряжения в четырёхпроводной сети 0,4/0,23 кВ позволяет восстановить питающее напряжение. Это достигается использованием уникальных свойств аналоговых устройств – трёхфазных электрических сетей и трёхфазных силовых трансформаторов с первичной и вторичной обмотками, включёнными по схеме «звезда с нулём - звезда с нулём», запитанных от четырёхпроводной сети. При утрате питания от любого одного из четырёх питающих проводов за счёт неразрывности магнитных потоков и обратимости электрических машин автоматически (после физического отключения утраченной фазы) устройства восстанавливают полнофазное напряжение в первичной и во вторичной обмотках трансформатора. The problems of increasing reliability of power supply to consumers and reducing electrical injuries in electrical installations are considered. When one of the supply phases of a 6 (10) kV power transformer breaks, the full-phase voltage restorer in a 0.4/0.23 kV four-wire network created by the authors allows restoring the supply voltage. This is achieved by using the unique properties of analog devices – three-phase electric networks and three-phase power transformers with primary and secondary windings, connected according to the scheme "star with zero – star with zero" powered from a four-wire network. When power is lost from any one of the four supply wires due to the continuity of magnetic flows and the reversibility of electrical machines, the devices automatically (after physically disconnecting the lost phase) restore full-phase voltage in the primary and secondary windings of the transformer.

A Solid-State On-Load Tap Changer for the Power Transformers of 10—0.4 kV Distribution Networks

Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 82-90
Author(s):  
Dmitriy I. Panfilov ◽  
◽  
Mikhail G. Astashev ◽  
Aleksandr V. Gorchakov ◽  
◽  
...  
Keyword(s):  
Solid State ◽  
Physical Model ◽  
High Speed ◽  
Power Transformer ◽  
Voltage Control ◽  
Power Transformers ◽  
Control Algorithms ◽  
Load Voltage ◽  
Tap Changer ◽  
Load Tap Changer

The specific features relating to voltage control of power transformers at distribution network transformer substations are considered. An approach to implementing high-speed on-load voltage control of serially produced 10/0.4 kV power transformers by using a solid-state on-load tap changer (SOLTC) is presented. An example of the SOLTC circuit solution on the basis of thyristor switches is given. On-load voltage control algorithms for power transformers equipped with SOLTC that ensure high reliability and high-speed operation are proposed. The SOLTC performance and the operability of the suggested voltage control algorithms were studied by simulation in the Matlab/Simulink environment and by experiments on the SOLTC physical model. The structure and peculiarities of the used simulation Matlab model are described. The SOLTC physical model design and its parameters are presented. The results obtained from the simulating the SOLTC operation on the Matlab model and from the experiments on the SOLTS physical model jointly with a power transformer under different loads and with using different control algorithms are given. An analysis of the experimental study results has shown the soundness of the adopted technical solutions. It has been demonstrated that the use of an SOLTC ensures high-speed voltage control, high efficiency and reliability of its operation, and arcless switching of the power transformer regulating taps without load voltage and current interruption. By using the SOLTC operation algorithms it is possible to perform individual phase voltage regulation in a three-phase 0.4 kV distribution network. The possibility of integrating SOLTC control and diagnostic facilities into the structure of modern digital substations based on the digital interface according to the IEC 61850 standard is noted.

The Heating System of Agricultural Facilities Using Excess Heat Power Transformers

2020 ◽  
Vol 67 (1) ◽  
pp. 42-47
Author(s):  
Anatoliy I. Sopov ◽  
Aleksandr V. Vinogradov
Keyword(s):  
System Design ◽  
Heat Supply ◽  
Cooling System ◽  
Power Transformer ◽  
Electric Heating ◽  
Heating System ◽  
Power Transformers ◽  
Large Power ◽  
Excess Heat ◽  
Power Centers

In power transformers, energy losses in the form of heat are about 2 percent of their rated power, and in transformers of large power centers reach hundreds of kilowatts. Heat is dissipated into the environment and heats the street air. Therefore, there is a need to consume this thermal energy as a source of heat supply to nearby facilities. (Research purpose) To develop methods and means of using excess heat of power transformers with improvement of their cooling system design. (Materials and methods) The authors applied following methods: analysis, synthesis, comparison, monographic, mathematical and others. They analyzed various methods for consuming excess heat from power transformers. They identified suitable heat supply sources among power transformers and potential heat consumers. The authors studied the reasons for the formation of excess heat in power transformers and found ways to conserve this heat to increase the efficiency of its selection. (Results and discussion) The authors developed an improved power transformer cooling system design to combine the functions of voltage transformation and electric heating. They conducted experiments to verify the effectiveness of decisions made. A feasibility study was carried out on the implementation of the developed system using the example of the TMG-1000/10/0.4 power transformer. (Conclusions) The authors got a new way to use the excess heat of power transformers to heat the AIC facilities. It was determined that the improved design of the power transformer and its cooling system using the developed solutions made it possible to maximize the amount of heat taken off without quality loss of voltage transformation.

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

scholarly journals HYDRODYNAMIC STUDY OF THE OIL FLOW IN A PROTECTIVE RELAY COUPLED TO A POWER TRANSFORMER: CFD SIMULATION AND EXPERIMENTAL VALIDATION

2021 ◽  
pp. 105599
Author(s):  
Ivan Xavier Lins ◽  
Hilário Jorge Bezerra Lima Filho ◽  
Valdemir Alexandre dos Santos ◽  
Júlio César Santos Pereira ◽  
Jose Mak ◽  
...  
Keyword(s):  
Experimental Validation ◽  
Cfd Simulation ◽  
Power Transformer ◽  
Protective Relay ◽  
Oil Flow ◽  
Hydrodynamic Study

Study of power transformer loading in rural power supply systems

2021 ◽  
Vol 13 (4) ◽  
pp. 282-289
Author(s):  
I. V. Naumov ◽  
D. N. Karamov ◽  
A. N. Tretyakov ◽  
M. A. Yakupova ◽  
E. S. Fedorinovа
Keyword(s):  
Energy Efficiency ◽  
Power Supply ◽  
Rural Areas ◽  
Power Transformer ◽  
Electric Energy ◽  
Power Transformers ◽  
Electric Networks ◽  
Load Factors ◽  
Optimal Load ◽  
Supply Systems

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.

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