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.

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.

scholarly journals The structure of the park of power transformers with a higher voltage of 6-10 Kv on the example of the electric grid organization of the branch of pjsc «Rosseti center»-«Orelenergo», serving rural electric networks

2022 ◽  
Vol 23 (5) ◽  
pp. 34-45
Author(s):  
A. A. Lansberg ◽  
A. V. Vinogradov ◽  
A. V. Vinogradova
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Power Transformer ◽  
Power Transformers ◽  
Electric Grid ◽  
Electric Networks ◽  
Current Standards ◽  
Implementation Of The Strategy

THE PURPOSE. Evaluation of the power transformer fleet 6-10/0,23-0,4 kV on the example of a branch of PJSC «Rosseti Center»-«Orelenergo».METHODS. In the work, based on the database of the branch of PJSC «Rosseti Center»-«Orelenergo», an analysis was made of the fleet of power transformers with a higher voltage of 6-10 kV in terms of their number, circuits and groups of connection of windings, rated power, terms of service, as well as energy efficiency classes, taking into account the current standards of the technical organization of PJSC «Rosseti».RESULTS. According to the results of the study, it was revealed that among the transformer fleet of the branch of PJSC «Rosseti Center»-«Orelenergo», the number of which is 6026 units, 4528 (73% of the total number) transformers have a circuit and a group of winding connections Y/Y0. The most numerous are transformers with rated capacities of 63 kVA, 100 kVA, 160 kVA, 250 kVA (respectively 853, 1454, 1252, 802 pieces of equipment). It was also revealed that only 268 transformers out of 6206, i.e. 4.3% of the total amount comply with the standard of PJSC «Rosseti» in terms of modern requirements for the level of energy efficiency class.CONCLUSION. A variant of the strategy for replacing power transformers in the branch of PJSC «Rosseti Center»-«Orelenergo» is proposed, within the framework of which trasformers with a given design, circuit and winding connection group, rated capacities and energy efficiency classes are replaced. The implementation of the strategy proposed in the work will make it possible to reduce total electricity losses by 2.3%, as well as increase the share of energy-efficient transformers from 4.3% to 20.4% in the branch of PJSC «Rosseti Center»-«Orelenergo».

scholarly journals Optimalisasi Material Utama Pada Auto Transformator 100 MVA

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Asep Saepudin
Keyword(s):  
Power Transformer ◽  
Power Transformers ◽  
Three Phase ◽  
Actual Use ◽  
Calculation Results ◽  
Ordinary Power ◽  
The Difference ◽  
Transformer Core ◽  
Secondary Winding ◽  
Main Material

Autotransformator is a transformer that has primary and secondary winding with the same common winding, so that it has a lighter weight compared to ordinary power transformers. The purpose of this study is to optimize the main material used in the three-phase Auto transformer in order to get the most optimum value approaching the calculation results and to know the comparison between the calculation results and the actual use of the main material in the Auto transformer and three-phase power transformer. The main material in power transformers is copper for winding and silicon steel for cores (transformer cores). Based on this research, it can be concluded that the use of main material in Auto three-phase power transformer is less than the three-phase power transformer for the same voltage and power, the magnitude of the difference in the range of 12.5% ​​for Copper and core (transformer core) range of 47.3% of the main material in the power transformer can.

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.

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.

The Protection System Design of Leakage, Undervoltage and Overvoltage for Electromagnetic Starter in Coal Mine

2014 ◽  
Vol 1049-1050 ◽  
pp. 720-725
Author(s):  
Hong Wei Ma ◽  
Wang Xing ◽  
Qing Hua Mao ◽  
Yu Liu
Keyword(s):  
Coal Mine ◽  
Supply Voltage ◽  
Phase Voltage ◽  
Voltage Transformer ◽  
Dc Power ◽  
Fault Protection ◽  
Three Phase ◽  
Protective System ◽  
Zero Sequence ◽  
Power Direction

For the problem of leakage, undervoltage and overvoltage fault protection of electromagnetic starter with supply voltage of 660 V and rated current of 200A, a leakage, undervoltage and overvoltage protective system based on PLC LM3108K was designed. This system uses voltage transformer to detect three-phase AC voltage. It protects undervoltage and overvoltage fault by judging effective value of three-phase voltage, protects leakage fault of main switch for electromagnetic starter by additional DC power and protects leakage fault of branch switch by using zero-sequence power direction. This system has good protection functions for leakage, overvoltage and undervoltage faults of electromagnetic starter in coal mine.

scholarly journals Integrated compensation model using a three-phase neutral point clamped inverter

2020 ◽  
Vol 10 (5) ◽  
pp. 5074
Author(s):  
Chau Minh Thuyen ◽  
Nguyen Hoai Thuong ◽  
Truong Khac Tung
Keyword(s):  
Supply Voltage ◽  
Neutral Point ◽  
Phase Voltage ◽  
Nonlinear Load ◽  
Compensation Model ◽  
Three Phase ◽  
Different Types ◽  
Source Voltage ◽  
Simulation Results ◽  
Bus Voltage

Normally, when research on active compensation models, previous studies only assumed that the source of harmonics is nonlinear load. The nonlinear load here is fixed and balanced, the supply voltage is considered ideal, i.e. the three-phase source is balanced and there is no distortion. However, in reality, the above assumption is difficult to achieve. Therefore, this paper aims to design an integrated compensation model for different types of harmonic sources. The types of harmonic sources considered here include: harmonic sources generated from nonlinear load and source. The requirement of the integrated compensation model is to create a balanced three-phase voltage at the terminal of the load and the supply current must be a sinusoidal wave in phase with the source voltage. In order to reduce the loss caused by the inverter switching, this paper uses a three-level Neutral Point Clamped inverter. The simulation results performed on Psim software have demonstrated the effectiveness of the proposed integrated compensation model compared to the traditional integrated compensation model in reducing harmonics and stabilizing DC-bus voltage.

Research on the PCHD Control Strategy for Three-Phase Voltage Source PWM Rectifier under Unbalanced Supply Voltage Condition

2014 ◽  
Vol 571-572 ◽  
pp. 959-964
Author(s):  
Feng Jiao Zhao ◽  
Jiu He Wang ◽  
Bai Le Zhang
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Supply Voltage ◽  
Orthogonal Transformation ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Three Phase ◽  
Unbalanced Voltage ◽  
Dynamic Performances

In order to improve the performance of the rectifier under unbalanced voltage condition, this paper adopts port-controlled Hamiltonian dissipation (PCHD) control strategy. On the basic of the mathematical model of the three-phase voltage source PWM rectifier, its PCHD model in synchronous dq coordinates was established by orthogonal transformation. The desired equilibrium point of the system was obtained according to the target of the design. The controller was designed with the method of interconnection and damping assignment, and the PI control method was introduced to restrain the steady-state error of DC side. Simulation results show that the designed control system has perfect static and dynamic performances and robustness.

Sign in / Sign up

Export Citation Format

Share Document