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Journal articles on the topic 'Transformer Taps'

Author: Grafiati
Published: 6 September 2023

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1

Lailypour, Chia, and Murteza Farsadi. "A New Structure for Sen Transformer Using Three Winding Linear Transformer." International Journal of Power Electronics and Drive Systems (IJPEDS) 7, no. 2 (June 6, 2016): 440. http://dx.doi.org/10.11591/ijpeds.v7.i2.pp440-449.

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<p>In this paper a new structure for "Sen" transformer is introduced, by using three winding transformers with neutral point in order to use negative value of compensating voltage. Combination of taps will be adjusted by a novel algorithm, to control the required active and reactive powers, separately. This paper tries to focus on three parts. First of all there is an introduction on the concept of ST structure what comes next is a try to work on power flow control by using PI controllers and an algorithm to find the best and efficient combination of taps, finally proposed idea and algorithm will be implement on a practical system. Implementation of the system consist of two separated and related parts. The first one is about transmission line and Sen Transformer and the<em> </em>interaction between them. The second part is programing codes that adjust taps for required active and reactive powers.</p>
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2

Paoli, Joshua, Bernd Brinkmann, and Michael Negnevitsky. "A Practical Approach to Optimising Distribution Transformer Tap Settings." Energies 13, no. 18 (September 18, 2020): 4889. http://dx.doi.org/10.3390/en13184889.

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This paper proposes a method of determining the optimal tap settings for no-load distribution transformers with tap-changing capabilities that is practical to apply in real distribution networks. The risk of low voltage distribution networks violating voltage constraints is impacted by the increasing uptake of distributed energy resources and embedded generation. Some of this risk can be alleviated by suitably setting no-load transformer tap settings, however, modifying these taps requires customer outages and must be infrequent. Hence, loading over the entire year must be considered to account for seasonal variations when setting these taps optimally. These settings are determined using evolution strategy optimisation based on an average loading case. Monte Carlo simulations are used to calculate the probability that the terminal voltages on the distribution transformer secondary terminals violate the network voltage limits when the optimal set of taps for the average case is applied over a whole year. This algorithm was tested on several cases of a real distribution feeder of varying complexity, and produces a sufficiently-optimal set of taps without significant computation time.
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3

Mohamed, Mofreh. "Data Processing with Uncertain Transformer Taps.(Dept.E)." MEJ. Mansoura Engineering Journal 13, no. 1 (May 27, 2021): 73–81. http://dx.doi.org/10.21608/bfemu.2021.172666.

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4

Adibi, M. M., D. P. Milanicz, and T. L. Volkmann. "Simulating transformer taps for remote cranking operations." IEEE Computer Applications in Power 9, no. 3 (July 1996): 24–29. http://dx.doi.org/10.1109/67.526850.

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5

Eissa, M. M. "Local area supervisory protection system transformer taps." Electric Power Systems Research 62, no. 2 (June 2002): 105–10. http://dx.doi.org/10.1016/s0378-7796(02)00045-7.

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6

Kor, Ahmad, Hossein Zeynal, Zuhaina Zakaria, and Seyed Hamid Hosseini. "Optimal reactive power pricing with transformer variable taps using genetic algorithm." International Journal of Electrical and Computer Engineering (IJECE) 13, no. 2 (April 1, 2023): 1272. http://dx.doi.org/10.11591/ijece.v13i2.pp1272-1280.

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<span lang="EN-US">Ancillary services in interconnected networks are crucial to secure real power transfers, maintaining network reliability, improving power quality as well as network stability. Reactive power has always been of special importance as one of the most substantial ancillary services required to control the voltage in power grid. This paper presents a fresh reactive power pricing approach by embedding variable transformer taps into voltage ampere reactive (var) pricing method. To carry out the resultant optimization problem with a set of complicating constraints, the genetic algorithm takes part and guarantees the global optimal solution. The simulation results show that when transformer tap works as a control variable, the total cost of reactive power can be decreased. However, the incorporation of transformer taps in the pricing model can slightly complicates voltage profiles as the sensitivity of bus voltages to the reactive power variations in the system is increased. Further, the findings reiterate that by optimal position of transformer taps, technically, the security index of the system can be enhanced while the var price for end-users (lowest purchase cost for independent system operator) being more reasonable. To simulate the proposed reactive pricing method, the standard IEEE 30-bus system is employed to analyze the proposed method.</span>
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7

Baran Junior, Antonio Rubens, Thelma S. Piazza Fernandes, and Ricardo Augusto Borba. "Voltage Regulation Planning for Distribution Networks Using Multi-Scenario Three-Phase Optimal Power Flow." Energies 13, no. 1 (December 29, 2019): 159. http://dx.doi.org/10.3390/en13010159.

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Active distribution networks must operate properly for different scenarios of load levels and distributed generation. An important operational requirement is to maintain the voltage profile within standard operating limits. To do this, this paper proposed a Multi-Scenario Three-Phase Optimal Power Flow (MTOPF) that plans the voltage regulation of unbalance and active distribution networks considering typical scenarios of operation. This MTOPF finds viable operation points by the optimal adjustments of voltage regulator taps and distribution transformer taps. The differentiating characteristic of this formulation is that in addition to the traditional tuning of voltage regulator taps of an active network applied for just one scenario of load and generation, it also performs the optimal adjustment of distribution transformer taps, which, once fixed, is able to meet the voltage limits of diverse operating situations. The optimization problem was solved by the primal-dual interior-point method and the formulation was tested using the IEEE 123-bus system.
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8

Zhao, ZG, SQ Zhang, HC Cheng, ZY Xu, and RJ Tan. "Research on Short-Circuit Impedance Analysis Method of Auto-transformer for Side Column Voltage Regulation." Journal of Physics: Conference Series 2476, no. 1 (April 1, 2023): 012066. http://dx.doi.org/10.1088/1742-6596/2476/1/012066.

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Abstract In order to realize the accurate analysis of the impedance of transformers with complex connection relations, this paper derives the impedance calculation method of low-voltage excitation side column linear voltage regulating autotransformer by using the power method. The transformer network with different taps is analyzed, and the calculation formulas of transformer HV-MV impedance, HV-LV impedance and MV-LV impedance are derived. The analysis is simplified to the solution of concentric column coil impedance and magnetic potential of each coil. By comparing the calculated data of actual products with the measured data, the calculation deviation of this method is controlled within 2.03%; By using the finite element method, the impedance of the transformer with the measures to control the magnetic shielding is analyzed and calculated. By comparing the impedance of the transformer with different measures, it can be confirmed that the magnetic leakage measures have an impact on the impedance of the transformer.
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9

Attia, Hussain. "Novel 9-Steps Automatic AC Voltage Regulator based on Two Step-down Transformers." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 2 (April 1, 2017): 576. http://dx.doi.org/10.11591/ijece.v7i2.pp576-583.

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<p class="IEEEAbtract">A novel design and simulation results of 9-steps automatic AC voltage regulator based on one step-down transformer is presented in this paper. Avoiding the problem of surge at the AC load during controlling jump steps is done through the proposed design. Accurate and smooth controlling function is achieved as well. Instead of the necessity of increasing the number of taps of the used multi tap transformer for wide controlling range of fluctuated AC supply voltage, the proposed designed adopts using only two step down transformers with 10 Vrms, and 30 Vrms secondary voltages respectively. Through the controlling of the proposed design of AV voltage regulator, the resultant load voltage is equal the AC supply voltage as well as the suitable voltage step which may one of the following voltages; +40V, +30V, +20V, +10V, 0V, -10V, -20V, -30V, -40V. The electronic design is done Multisim software while the electrical circuit connection of step down transformers and relays contacts that is made by using PSIM software for power circuit design.</p>
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10

Al-Ameri, S., A. A. Alawady, M. F. M. Yousof, H. Ahmad, Ali A. Salem, and M. A. Talib. "Frequency response analysis for transformer tap changer damage detection." International Journal of Power Electronics and Drive Systems (IJPEDS) 11, no. 1 (March 1, 2020): 350. http://dx.doi.org/10.11591/ijpeds.v11.i1.pp350-358.

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Frequency response analysis (FRA) method has been proven to detect the transformer winding damage. However, there is no practical study which investigates the damages on transformer tap changer even though it has a high failure rate. Hence, this paper investigates normal and faulty transformer tap changer using FRA. The FRA measurements conducted using four different test configurations. Also, normal tap changer, pitting and coking tap changer contact were investigated. In addition to FRA measurement, winding resistance measurement has been conducted. The transformer turn ratio measurement also conducted to identify the taps positions. This study results significant to understand the effect of pitting and coking tap changer on the transformer frequency response. The results showed that pitting has a slight influence on the frequency response. However, coking shows a huge variation in low-frequency response. This effect observed during the winding resistance measurement.
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11

Nakachi, Yoshiki, Satoshi Kato, and Hiroyuki Ukai. "Coordinated Voltage Control of Transformer Taps on account of Hierarchical Structure in Power System." IEEJ Transactions on Power and Energy 126, no. 5 (2006): 525–31. http://dx.doi.org/10.1541/ieejpes.126.525.

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12

Nakachi, Yoshiki, Satoshi Kato, and Hiroyuki Ukai. "Coordinated voltage control of transformer taps with provision for hierarchical structure in power system." Electrical Engineering in Japan 166, no. 4 (March 2009): 48–55. http://dx.doi.org/10.1002/eej.20531.

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13

Liu, Zhi, Xingyu Mu, Shidu Dong, Yunhua Lu, and Mingzi Jiang. "Constructing Adaptive Multi-Scale Feature via Transformer-Aware Patch for Occluded Person Re-Identification." Symmetry 14, no. 7 (July 15, 2022): 1454. http://dx.doi.org/10.3390/sym14071454.

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Person re-identification (Re-ID) aims to retrieve a specific pedestrian across a multi-disjoint camera in a surveillance system. Most of the research is based on a strong assumption that images should contain a full human torso. However, it cannot be guaranteed that all the people have a clear foreground because they are out of constraint. In the real world, a variety of occluded situations frequently appear in video monitoring, which impedes the recognition process. To settle the occluded person Re-ID issue, a new Dual-Transformer symmetric architecture is proposed in this work, which can reduce the occluded impact and build a multi-scale feature. There are two contributions to our proposed model. (i) A Transformer-Aware Patch Searching (TAPS) module is devised to learn visible human region distribution using a multiheaded self-attention mechanism and construct a branch of distributed information attention scale. (ii) An Adaptive Visible-Part Cropping (AVPC) Strategy, with two steps of cropping and weakly-supervised learning, is used to generate a fine-scale visible image for another branch. Only ID labels are utilized to restrain TAPS and AVPC without any extra visible-part annotation. Extensive experiments are conducted on two occluded person Re-ID benchmarks, confirming that our approach performs a SOTA or comparable effect.
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14

Panfilov, Dmitriy I., Mikhail G. Astashev, and Aleksandr V. Gorchakov. "A Solid-State On-Load Tap Changer for the Power Transformers of 10—0.4 kV Distribution Networks." Vestnik MEI 6, no. 6 (2020): 82–90. http://dx.doi.org/10.24160/1993-6982-2020-3-82-90.

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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.
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15

Panfilov, Dmitriy I., Mikhail G. Astashev, and Aleksandr V. Gorchakov. "A Solid-State On-Load Tap Changer for the Power Transformers of 10—0.4 kV Distribution Networks." Vestnik MEI, no. 6 (2020): 82–90. http://dx.doi.org/10.24160/1993-6982-2020-6-82-90.

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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.
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16

Mitiche, Imene, Tony McGrail, Philip Boreham, Alan Nesbitt, and Gordon Morison. "Data-Driven Anomaly Detection in High-Voltage Transformer Bushings with LSTM Auto-Encoder." Sensors 21, no. 21 (November 8, 2021): 7426. http://dx.doi.org/10.3390/s21217426.

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The reliability and health of bushings in high-voltage (HV) power transformers is essential in the power supply industry, as any unexpected failure can cause power outage leading to heavy financial losses. The challenge is to identify the point at which insulation deterioration puts the bushing at an unacceptable risk of failure. By monitoring relevant measurements we can trace any change that occurs and may indicate an anomaly in the equipment’s condition. In this work we propose a machine-learning-based method for real-time anomaly detection in current magnitude and phase angle from three bushing taps. The proposed method is fast, self-supervised and flexible. It consists of a Long Short-Term Memory Auto-Encoder (LSTMAE) network which learns the normal current and phase measurements of the bushing and detects any point when these measurements change based on the Mean Absolute Error (MAE) metric evaluation. This approach was successfully evaluated using real-world data measured from HV transformer bushings where anomalous events have been identified.
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17

Zasypkin, Alexander. "Transverse-Longitudinal Multifunctional Transformer Protection with Input in the Middle of the Winding." Известия высших учебных заведений. Электромеханика 65, no. 4 (2022): 79–85. http://dx.doi.org/10.17213/0136-3360-2022-4-79-85.

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Developing one of the improvement directions of transformer and autotransformer relay protection with mid-height input winding is proposed. The fundamental issues of creating the complex "power transformer-integrated current sensors-multifunctional relay protection and diagnostics device" being considered. The connection of the micropro-cessor-based relay protection device to the built-in current sensors on the transformer (autotransformer) winding out-puts allows to realize the principles: transverse differential, longitudinal differential, zero sequence longitudinal dif-ferential. The protection, due to the features of the system structure is multifunctional (triggering at all types of inter-nal short circuits (SC) in windings and taps, recognition of the SC type and location, deformation diagnosis and wind-ing shifting during an external short circuit). To verify the sensitivity of the protection to the winding SC, a method based on the calculation of the inductances of dissipation using the method of average geometric distances has been proposed.
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18

Du, Yu. "Research on Reactive Power and Voltage Optimization of Regional Distribution Network." Applied Mechanics and Materials 58-60 (June 2011): 474–79. http://dx.doi.org/10.4028/www.scientific.net/amm.58-60.474.

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The high-medium voltage level distribution networks have their own characters. Because of the radiation characteristic of the network, this paper looks on the network as the combination of some small optimization unit. The paper simplifies the resolution of the reactive power optimization by the way of alternatively solving the adjusting transformer taps and switching capacity banks. At the same time, considering the practical operation request, the paper evaluates the regulation effect and improves the practicability of the software.
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19

Londoño Tamayo, Daniel C., Walter M. Villa-Acevedo, and Jesús M. López-Lezama. "Multi-Period Optimal Reactive Power Dispatch Using a Mean-Variance Mapping Optimization Algorithm." Computers 11, no. 4 (March 22, 2022): 48. http://dx.doi.org/10.3390/computers11040048.

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Optimal reactive power dispatch plays a key role in the safe operation of electric power systems. It consists of the optimal management of the reactive power sources within the system, usually with the aim of reducing system power losses. This paper presents both a new model and a solution approach for the multi-period version of the optimal reactive power dispatch. The main feature of a multi-period approach lies on the incorporation of inter-temporal constraints that allow the number of switching operations in transformer taps and capacitor banks to be limited in order to preserve their lifetime and avoid maintenance cost overruns. The main contribution of the paper is the constraint handling approach which consists of a multiplication of sub-functions which act as penalization and allow simultaneous consideration of both the feasibility and optimality of a given candidate solution. The multi-period optimal reactive power dispatch is an inherently nonconvex and nonlinear problem; therefore, it was solved using the metaheuristic mean-variance mapping optimization algorithm. The IEEE 30-bus and IEEE 57-bus test systems were used to validate the model and solution approach. The results allow concluding that the proposed model guarantees an adequate reactive power management that meets the objective of minimizing power losses and keeping the transformer taps and capacitor bank movements within limits that allow guaranteeing their useful life.
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20

Iida, Shoji, Shigeo Masukawa, Manabu Tamura, and Shota Miyairi. "A new method for reducing harmonics of single phase rectifier by changing taps on interphase transformer." IEEJ Transactions on Industry Applications 109, no. 1 (1989): 25–32. http://dx.doi.org/10.1541/ieejias.109.25.

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21

Pijarski, Paweł, Piotr Kacejko, and Marek Wancerz. "Voltage Control in MV Network with Distributed Generation—Possibilities of Real Quality Enhancement." Energies 15, no. 6 (March 12, 2022): 2081. http://dx.doi.org/10.3390/en15062081.

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Connecting an increasing number of distributed sources in MV (medium voltage) and LV (low voltage) distribution networks causes voltage problems resulting mainly from periodic power flows towards the HV/MV (HV—high voltage) transformer station. This temporarily changes the nature of distribution networks from receiving to supply networks and causes an increase in the voltage values deep within the network, often above the permissible level. Therefore, it is necessary to search for new voltage control methods that take into account the active participation of distributed sources. The article proposes a concept of such a system in which the control signals are transformer taps in the HV/LV station and the values of reactive powers generated or consumed by RES (renewable energy sources). These values can be determined either by solving the optimisation problem (according to a given quality indicator criterion) or on the basis of appropriately selected settings of the Q(U) characteristics of the inverters and the HV/LV transformer ratio. The article describes both approaches, pointing to the advantages and disadvantages of each of them.
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22

Li, Jian Hui, and Jia Xin Zou. "Research on the Coordination Control between STATCOM and VQC in Substation Based on the Identification of System State." Advanced Materials Research 905 (April 2014): 469–75. http://dx.doi.org/10.4028/www.scientific.net/amr.905.469.

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For traditional voltage and reactive power control (VQC) of substation will cause frequent adjustment of transformer taps and switching of capacitor banks, which exerts a certain impact on system voltage, the static synchronous compensator (STATCOM) is supposed to be installed in the substation to improve the effect of VQC. A coordination control strategy between STATCOM and VQC in substation based on the identification of system state is proposed in this paper to coordinate the operation between on-load tap changers (OLTC), capacitors and STATCOM. In addition, we have a research on the application effect of this strategy with BPA. The simulation results show that STATCOM plays an important role in improving the substation performance in both steady state and transient state and it can effectively reduce the frequency of tap changing and capacitor switching. Besides, the system will perform better if both of the main transformers are equipped with STATCOM than only one is configured.
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23

Gomes, Mário Helder, and João Tomé Saraiva. "A market based active/reactive dispatch including transformer taps and reactor and capacitor banks using Simulated Annealing." Electric Power Systems Research 79, no. 6 (June 2009): 959–72. http://dx.doi.org/10.1016/j.epsr.2008.12.014.

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24

Iida, Shoji, Shiceo Masukawa, Manabu Tamura, and Shota Miyairi. "A new method of reducing the harmonics of single-phase rectifier by changing taps on interphase transformer." Electrical Engineering in Japan 109, no. 1 (January 1989): 108–16. http://dx.doi.org/10.1002/eej.4391090112.

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25

Wang, XM, HB Wang, J. Zhang, SC Liu, YF Ma, and W. Yan. "Reactive Power Optimization Based on AVC Time-division Control Strategy." Journal of Physics: Conference Series 2158, no. 1 (January 1, 2022): 012011. http://dx.doi.org/10.1088/1742-6596/2158/1/012011.

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Abstract In order to avoid frequent actions of transformer taps and capacitor banks caused by reactive power optimization, this paper proposes a reactive power optimization based on AVC time division control strategy. The time division control strategy is used to segment the load curve of the next day, and the reactive power optimization process of each period is calculated by genetic algorithm. The strategy and algorithm are applied to the reactive power and voltage optimization of IEEE 30 bus system. The simulation results show that the method can realize reactive power optimization more efficiently.
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26

Szcześniak, Paweł. "A modelling of AC voltage stabilizer based on a hybrid transformer with matrix converter." Archives of Electrical Engineering 66, no. 2 (June 27, 2017): 371–82. http://dx.doi.org/10.1515/aee-2017-0028.

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AbstractThis article presents a study of an AC voltage stabilizer based on a three-phase hybrid transformer combined with a matrix converter. The proposed solution is used to control AC voltage amplitude and phase shift. By adjustment of these voltage parameters we can reduce the effects of overvoltage, voltage dips or lamp flicker. Such negative phenomena are very significant, particularly from the perspective of the final consumer and sensitive loads connected to the power network. Often the voltage in the power system can be adjusted using a mechanical or thyristor controlled regulator, which in a stepwise manner switches the taps of the electromagnetic transformer. The method for obtaining continuous control of the voltage magnitude and phase shift with the use of a conventional transformer with two output windings and a matrix converter is presented in this paper. The operating principles, mathematical model and properties of the proposed voltage stabilizers are discussed in this paper. The main part of the article will be devoted to the mathematical model which is based on an averaged equation. Computer simulation results are presented and compared with the results of a mathematical study.
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27

Lypkivskyi, K. O., and A. G. Mozharovskyi. "FEATURES OF SECTIONING THE TURNS OF THE TRANSFORMING ELEMENT OF THE TRANSFORMER-KEY ACTUATING STRUCTURE IN THE BOOST CHANNEL OF THE DC POWER SYSTEM." Tekhnichna Elektrodynamika 2020, no. 6 (October 21, 2020): 25–31. http://dx.doi.org/10.15407/techned2020.06.025.

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One of the effective ways to ensure the normalized operation of the electricity consumer with an unstable primary power source is the organization of the corresponding voltage supply channel. In a system with a direct current source, the voltage supply is implemented by introducing a rectifier semiconductor bridge in series with the load, into the diagonal of which AC energy is supplied, the voltage level of which is purposefully changed by a corresponding converter with a transformer- and-switches executive structure (TSES). To achieve high efficiency of the use of key elements of TSVS, it is proposed to assign the functions of rectification and voltage regulation to a specific class of TSES – a multilevel rectifier consisting of a transformer and a finite set of parallel connected pairs of serially connected thyristors, the common points of which are connected to the corresponding taps of the sectioned secondary turns of the transformer. By discrete-time control of thyristors, it is necessary to regulate voltage levels, it is attached. The linearity of the scale of these levels is ensured by the proposed transformer sectioning law. This power supply system is characterized by small energy losses in semiconductor elements (only two thyristors work at a time), and the a priori impossibility of emergency situations during transitions from one level to another. References 14, figures 3, tables 3.
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28

Shoiko, V. P., and K. V. Dukhanina. "Use of a phase-shifting transformer for increasing the power transmission capacity, taking into account the mode of the adjacent network." Proceedings of Irkutsk State Technical University 25, no. 3 (July 6, 2021): 369–79. http://dx.doi.org/10.21285/1814-3520-2021-3-369-379.

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In this research, we develop measures aimed at improving the efficiency of power systems by increasing their transmission capacity. To this end, a FACTS system based on the phase-shifting transformer with a thyristor switch developed at the Power Engineering Institute named after G.M. Krzhizhanovsky was used. The efficiency of the phaseshifting transformer under study for increasing the transmission capacity of power systems was determined by the maximum permissible cross-section flows of the Barnaul-Biysk node-2. The calculations were performed for normal and various post-accident schemes using the RastrWin3 software package. Such factors as the regulation of the taps of the phase-shifting transformer and various places of its installation were considered. For the section under consideration, the phase-shifting transformer increased the maximum permissible flow by 4–12%. The determining factor limiting the maximum permissible flow in the Barnaul-Biysk node-2 was found to be the current overload of the 110 kV lines of the adjacent network. The greatest effect of increasing the maximum permissible overflow was noted when the phase-shifting transformer was installed on the 220 kV line adjacent to the section, parallel to the 110 kV lines (which were overloaded when the mode became heavier), rather than on the 220 kV line included in the section. Similar calculations were performed for normal and post-accident schemes of an alternative option, which involved replacing wires and installing automatic equipment for limiting equipment overload on overloaded 110 kV lines. The obtained results show that the effect of increasing the transmission capacity for this option comprised 4%.
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29

Ivankov, V. F., А. V. Basova, and І. V. Khimjk. "REDUCTION OF LOCAL HEATING IN TANKS OF POWERFUL TRANSFORMERS BY HEAT-REMOVING LOCAL RADIATORS WITH RIBBED." Praci Institutu elektrodinamiki Nacionalanoi akademii nauk Ukraini 2021, no. 58 (May 19, 2021): 82–89. http://dx.doi.org/10.15407/publishing2021.58.082.

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The main approaches, the results of numerical modeling, and examples of the practical application of heat-dissipating radiators made of aluminum, with a flat base, and with ribbing to reduce local heating in ferromagnetic covers and walls of transformer tanks, which arise in cases of concentration of magnetic fluxes from multi-ampere taps or magnetic shunts are presented. The case of thermal coupling of a non-magnetic flange of a yoke beam with a flat base of a radiator (copper plate) is considered, which shows the possibility of reducing local heating of the beam using conductive heat transfer between the shelf and the plate and convection heat transfer from their surfaces to cooling oil. References 4, figures 7.
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Fang, Huan Huan, Xin Mei Shu, Jun Wang, and Ming Qin Wang. "The Design and Simulation of Voltage and Reactive Power Fuzzy Controller in Substation." Advanced Materials Research 591-593 (November 2012): 1441–45. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.1441.

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This paper analyzes the existing problems of the present substation of substation voltage and reactive power integrated control. A design for substation’s voltage and reactive power integrated control based on fuzzy 17-area control method is proposed. We build a substation simulation model base on voltage and reactive power fuzzy integrated controller. In this way, we analyze and simulate this control system dynamic performance. The simulation results show that this kind of control idea is feasible and it can effectively improve the voltage qualification rate, reduce frequency of the adjusted taps of transformer and switch action of the capacitor. It has a good control effect.
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31

Paul, Dev, and Kor Yan. "A Case History of Shore Power Transformer Taps Arcing During a No-Load Condition: Understanding the Cause of Arcing." IEEE Industry Applications Magazine 27, no. 5 (September 2021): 14–23. http://dx.doi.org/10.1109/mias.2021.3069730.

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32

Samet, Haidar, Teymoor Ghanbari, and Jafar Ghaisari. "Maximum Performance of Electric Arc Furnace by Optimal Setting of the Series Reactor and Transformer Taps Using a Nonlinear Model." IEEE Transactions on Power Delivery 30, no. 2 (April 2015): 764–72. http://dx.doi.org/10.1109/tpwrd.2014.2336693.

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33

Sahli, Zahir, Abdellatif Hamouda, Abdelghani Bekrar, and Damien Trentesaux. "Reactive Power Dispatch Optimization with Voltage Profile Improvement Using an Efficient Hybrid Algorithm." Energies 11, no. 8 (August 16, 2018): 2134. http://dx.doi.org/10.3390/en11082134.

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This paper presents an efficient approach for solving the optimal reactive power dispatch problem. It is a non-linear constrained optimization problem where two distinct objective functions are considered. The proposed approach is based on the hybridization of the particle swarm optimization method and the tabu-search technique. This hybrid approach is used to find control variable settings (i.e., generation bus voltages, transformer taps and shunt capacitor sizes) which minimize transmission active power losses and load bus voltage deviations. To validate the proposed hybrid method, the IEEE 30-bus system is considered for 12 and 19 control variables. The obtained results are compared with those obtained by particle swarm optimization and a tabu-search without hybridization and with other evolutionary algorithms reported in the literature.
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Chen, Baichao, Wei Gao, Yaojun Chen, Cuihua Tian, Yuxiong Zhou, and Gang Xue. "A High Efficiency Linear Power Supply with Pure Sine Wave for High Voltage Test." Electronics 10, no. 1 (December 24, 2020): 18. http://dx.doi.org/10.3390/electronics10010018.

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The input part of the high-voltage test power supply is usually composed of switching devices; however, the pulse-type periodic interference caused by the switching devices makes the monitoring of the test power supply partial discharge more difficult. Therefore, this paper proposes a high-efficiency and distortion-free linear power supply based on piecewise-linearization with all N-type transistor. Under the same DC input, multiple power transistors are connected to different taps of the same transformer. By controlling the period of linear conduction of each power transistor in turn, we ensure that the power transistor works on the linear side (biased towards saturation) to reduce its conduction voltage drop and the output realizes sinusoidal piecewise linearization, so that the converter can greatly improve the system efficiency. After that, from the perspective of the lowest sum of the transistor loss, an optimization method for the design of the multi-winding transformer ratio at each stage is proposed. Finally, a power supply prototype based on four-piece linear converter with an output voltage of 220 V was built. The experimental efficiency reaches 87.03%, and, additionally, if the linear amplification is divided into more sections, the efficiency can be further improved.
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Shri, Shaima Hamdan, and Ayad Fadhil Mijbas. "Chaotic theory incorporated with PSO algorithm for solving optimal reactive power dispatch problem of power system." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 3 (June 1, 2021): 1739. http://dx.doi.org/10.11591/ijeecs.v22.i3.pp1739-1747.

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In this paper, the chaotic particle swarm optimization (CPSO) algorithm is combined with MATPOWER toolbox and used as an optimization tool for attaining solving the optimal reactive power dispatch (RPD) problem, by finding the optimal adjustment of reactive power control variables like a voltage of generator buses (VG), capacitor banks (QC) and transformer taps (Tap) while satisfying some of equality and inequality constraints at the same time. CPSO and Simple PSO algorithms will be checked in a large system such as IEEE node -118. CPSO and Simple PSO algorithms have been implemented and simulated in the MATLAB program, version (R2013b/m-file). Then compassion these results with the results obtained in the other algorithms in the literature like the comprehensive learning particle swarm optimization (CLPSO) algorithm. The simulation results confirm that the CPSO algorithm has high efficiency and ability in terms of decrease real power losses (P loss), and improve voltage profile compared with the obtained by using the simple (PSO) algorithm and (CLPSO) at light load.
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36

Sahli, Z., A. Hamouda, S. Sayah, D. Trentesaux, and A. Bekrar. "Efficient Hybrid Algorithm Solution for Optimal Reactive Power Flow Using the Sensitive Bus Approach." Engineering, Technology & Applied Science Research 12, no. 1 (February 12, 2022): 8210–16. http://dx.doi.org/10.48084/etasr.4680.

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This paper presents the design and application of an efficient hybrid algorithm for solving the Optimal Reactive Power Flow (ORPF) problem. The ORPF is formulated as a nonlinear constrained optimization problem where the active power losses must be minimized. The proposed approach is based on the hybridization of Particle Swarm Optimization (PSO) and Tabu-Search (TS) technique. The proposed PSO-TS approach is used to find the settings of the control variables (i.e. generation bus voltages, transformer taps, and shunt capacitor sizes) which minimize transmission active power losses. The bus locations of the shunt capacitors are identified according to sensitive buses. To show the effectiveness of the proposed method, it is applied to the IEEE 30 bus benchmark test system and is compared with PSO and TS without hybridization, along with some other published approaches. The obtained results reveal the effectiveness of the proposed method in dealing with the highly nonlinear constrained nature of the ORPF problem.
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Bragin, Mikhail A., Bing Yan, Akash Kumar, Nanpeng Yu, and Peng Zhang. "Efficient Operations of Micro-Grids with Meshed Topology and Under Uncertainty through Exact Satisfaction of AC-PF, Droop Control and Tap-Changer Constraints." Energies 15, no. 10 (May 17, 2022): 3662. http://dx.doi.org/10.3390/en15103662.

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Micro-grids’ operations offer local reliability; in the event of faults or low voltage/frequency events on the utility side, micro-grids can disconnect from the main grid and operate autonomously while providing a continued supply of power to local customers. With the ever-increasing penetration of renewable generation, however, operations of micro-grids become increasingly complicated because of the associated fluctuations of voltages. As a result, transformer taps are adjusted frequently, thereby leading to fast degradation of expensive tap-changer transformers. In the islanding mode, the difficulties also come from the drop in voltage and frequency upon disconnecting from the main grid. To appropriately model the above, non-linear AC power flow constraints are necessary. Computationally, the discrete nature of tap-changer operations and the stochasticity caused by renewables add two layers of difficulty on top of a complicated AC-OPF problem. To resolve the above computational difficulties, the main principles of the recently developed “l1-proximal” Surrogate Lagrangian Relaxation are extended. Testing results based on the nine-bus system demonstrate the efficiency of the method to obtain the exact feasible solutions for micro-grid operations, thereby avoiding approximations inherent to existing methods; in particular, fast convergence of the method to feasible solutions is demonstrated. It is also demonstrated that through the optimization, the number of tap changes is drastically reduced, and the method is capable of efficiently handling networks with meshed topologies.
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Li, Jianying, Yunchang Xiao, Minsheng Yang, Jianqi Li, and Jingying Wan. "The Research on Harmonic Transfer Characteristics of Integrated Multi-Winding Inductive Filtering Converter Transformer and Its Filter System." Electronics 11, no. 13 (July 3, 2022): 2088. http://dx.doi.org/10.3390/electronics11132088.

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A novel integrated multi-winding inductive filter converter and its filter system used in HVDC conversion station are proposed. Specifically, the schemes include two paralleled-connected delta filter windings with zero impedance, and the 11th and 13th tuned filtering branches are installed at the taps. On this basis, the 5th and 7th harmonic filters are eliminated and the 5th, 7th, 11th, and 13th harmonics of the valve-side are suppressed. Moreover, the cost of the filter is reduced, and the negative impact on the converter transformer body caused by the transfer of harmonic current is avoided, such as vibration, noise, and harmonic loss. In this paper, first, the mathematical models of integrated multi-winding inductive filter converter and its filter system are established. Accordingly, the current relationships between the primary winding side and two secondary winding sides are derived. Then, the transfer path of each characteristic harmonic current in the new system is analyzed and discussed. Moreover, a simulation model is established to study the operation characteristics of the system. Finally, through the designed experimental prototype, a new DC transferring system platform is constructed to testify the operation characteristics of an integrated multi-winding inductive filter converter and its filter system. The experimental results show that the total harmonic distortion rate of the grid-winding current can be reduced to 4.68% only by installing the 11th and 13th tuned filters, so the effect of active filtering is approximated realized by the passive filtering method.
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39

Baliuta, S., L. Kopilova, Iu Kuievda, V. Jovbak, M. Kondrashevsky, P. Kandybka, and V. Kuievda. "Ensuring energy-efficient work modes in electrical supply systems of industrial and civil facilities by voltage regulation." Scientific Works of National University of Food Technologies 29, no. 2 (April 2023): 61–76. http://dx.doi.org/10.24263/2225-2924-2023-29-2-7.

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The development of voltage regulation methods in the energy supply system of industrial and civil facilities using continuous and discrete sources of reactive power, tap-changer of GPP transformers and PBZ of shop transformers is an urgent task. It allows maintaining energy-efficient modes of powerconsuming equipment, elements of power supply and power consumption systems and reduce financial expenses for payment for electric energy. The article presents approaches to solving the task of determining energy-efficient voltage levels at different hierarchical levels of the power supply system and ensuring them by using voltage regulators (TAPs) of GPP transformers, PBZ switches of workshop transformers, as well as power regulation of reactive power sources. For the calculation of energy-efficient voltages, an appropriate algorithm has been developed, which provides the separate execution of operations for calculating the parameters of the current mode of the power supply system and its optimization. This allows to monitor the state of the power supply system and ensure the maximum efficiency of the use of voltage regulation devices. A method of determining the static load characteristics of asynchronous motors by voltage is proposed, taking into account their design features, mechanical load characteristics and magnetizing currents. A method of de termining the static characteristics of the load by voltage at the levels of the shop transformer, RP and GPP has been developed. With the use of the MATLAB/SIMULINK package, calculation studies of static characteristics by voltage at different levels of the hierarchical power supply system were carried out. The selection of the method for calculating the modes of shop and distribution electric networks of an industrial enterprise was reasoned. The static characteristics of the load according to the voltage, the action of the voltage regulators of the GPP trans formers, the position of the PBZ of the shop transformers, the power of the reactive power sources were taken into account. Algorithm for controlling discrete and continuous sources of reactive power and voltage regulators of GPP transformers was proposed taking into account static load characteristics to ensure energy-efficient operation modes of shop and distribution electrical networks of an industrial enterprise.
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Brito, Vinícius Henrique Farias, José Carlos de Oliveira, and Fabricio Parra Santilio. "Modeling and Performance Evaluation of an Electromagnetic Voltage Regulator via Series Compensation." Transactions on Environment and Electrical Engineering 4, no. 1 (June 14, 2020): 12. http://dx.doi.org/10.22149/teee.v4i1.138.

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Although there currently exists a wide range of voltage regulators that are commercially available, the search for devices with a simpler physical design remains the focus of research studies. Following this line, an electromagnetic voltage regulator (EVR) arrangement has been proposed. The EVR is constituted of an autotransformer that supplies, via discrete taps, a series transformer that injects voltage for regulating the feeder voltage. Even though its operating principle is shown as being similar to that of other devices on the market, the physical arrangement and operating strategy of EVR show novelties which result in properties such as: economic attractiveness, constructive simplicity, and operational reliability. Moreover, when installing voltage regulators, efficacy studies must be carried out to optimize equipment design. In this context, this paper aims at evaluating the factors that influence the effectiveness of the EVR in restoring voltage variations according to the determinations imposed by regulatory agencies. The ultimate goal of this study is to determine the voltage deviation range that the EVR is able to restore. To achieve this goal, a mathematical modeling of the EVR is given and study cases are computationally carried out to investigate its performance when connected to a typical distribution feeder.
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41

Iglesias-Rojas, Juan Carlos, Erick Velázquez-Lozada, and Roberto Baca-Arroyo. "Online Failure Diagnostic in Full-Bridge Module for Optimum Setup of an IGBT-Based Multilevel Inverter." Energies 15, no. 14 (July 18, 2022): 5203. http://dx.doi.org/10.3390/en15145203.

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An online failure diagnostic test is essential to ensure the robustness and reliability of high-powered systems. Furthermore, the overall design must comprise diagnostic strategies to detect in-service and high-powered module defects. This paper describes the critical failure mechanisms––cross-conduction, inductive avalanche, second turn-on, VS-undershoot, inrush current, and thermal runaway––that directly affect insulated gate bipolar transistor (IGBT) operation. The constructed inverter contains 18 transformer-based taps (six per phase); however, this work studied a single tap (IGBT-based full-bridge module) to understand the reasons for failure and the routes to mitigate them. Moreover, a cost-effective solution using the IR2127STRPBF driver circuit was implemented to reduce the probability of thermal runaway in case of overcurrent, short-circuit, or avalanche events. For this reason, the electrical current state was adjusted using an FPGA digital resource to perform dynamic PWM control signals. The obtained correlation waveforms are valuable for verifying diagnostic data at the design stage to emphasize the significance of evading premature failure events. The comprehensive study on failure diagnosis enabled successful design strategies to construct a robust 45 kVA three-phase multilevel inverter for a 22 kW eolic-photovoltaic generation plant.
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42

Duong, Thanh Long, Ngoc Anh Nguyen, and Thuan Thanh Nguyen. "A Newly Hybrid Method Based on Cuckoo Search and Sunflower Optimization for Optimal Power Flow Problem." Sustainability 12, no. 13 (June 30, 2020): 5283. http://dx.doi.org/10.3390/su12135283.

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The paper proposes a new hybrid method based on cuckoo search (CSA) and sunflower optimization (SFO) approach (called HCSA-SFO) for improving the performance of solutions in the optimization power system operation problem. In the power system, the optimal power flow (OPF) problem is one of the important factors which usually minimizes total cost and total active power losses while satisfying all constraints of the output power of generators, the voltage at buses, power flow on branches, the capacity of capacitor banks and steps of transformer taps. HCSA-SFO utilizes the mutation and selection mechanism in the SFO algorithm to replace the Lévy flights function in CSA. Hence, this makes HCSA-SFO avoid the fixed step size in the CSA from that can reduce run time and improve the quality of solution for the HCSA-SFO algorithm in the OPF problem. The proposed hybrid technique is simulated on the 30-buses and 118-buses systems. The obtained simulation results from the suggested technique are compared to many other approaches. The result comparisons in different cases showed that the suggested HCSA-SFO can achieve a better result than many other optimization approaches. Therefore, the suggested HCSA-SFO is also an effective approach for dealing with the OPF problem.
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43

Wu, Renbo, and Shuqin Liu. "Deep Learning Based Muti-Objective Reactive Power Optimization of Distribution Network with PV and EVs." Sensors 22, no. 12 (June 7, 2022): 4321. http://dx.doi.org/10.3390/s22124321.

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With the high penetration of photovoltaic (PV) and electric vehicle (EV) charging and replacement power stations connected to the distribution network, problems such as the increase of line loss and voltage deviation of the distribution network are becoming increasingly prominent. The application of traditional reactive power compensation devices and the change of transformer taps has struggled to meet the needs of reactive power optimization of the distribution network. It is urgent to present new reactive power regulation methods which have a vital impact on the safe operation and cost control of the power grid. Hence, the idea that applying the reactive power regulation potential of PV and EV is proposed to reduce the pressure of reactive power optimization in the distribution network. This paper establishes the reactive power regulation models of PV and EV, and their own dynamic evaluation methods of reactive power adjustable capacity are put forward. The model proposed above is optimized via five different algorithms and approximated through the deep learning when the optimization objective is only set as line loss and voltage deviation. Simulation results show that the prediction of deep learning has an incredible ability to fit the Pareto front that the intelligent algorithms obtain in practical application.
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44

Manusov, V. Z., and D. M. Ivanov. "Study of Electromagnetic and Thermal Transients in a High-temperature Superconducting Transformer during a Short Circuit." Problems of the Regional Energetics, no. 2(58) (May 2023): 1–12. http://dx.doi.org/10.52254/1857-0070.2023.2-58.01.

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Today, high-temperature superconducting (HTS) current limiters and transformers allow to limit the surge short circuit current during failure without negatively affecting on the power grid complex at the normal operation mode. However, the transition of a superconductor to a resistive state at the moment of current limitation can cause significant heat generation, which can destroy the transformer windings. The research goal is to provide optimal technical characteristics of the HTS transformer to achieve effective short circuit current limitation and prevent thermal breakdown of its windings. To achieve this goal, a mathematical model of a HTS transformer was developed. The presented method considers the material type and geometry of the superconducting tape, the critical parameters of the superconductor (current and temperature), the parameters of the cryogenic liquid, dependence of the resistance and heat capacity of the HTS tape layers on temperature. The simulation model was created in the Matlab/Simulink software. The most important result is the possibility of obtaining optimal electrical and thermal parameters of the HTS transformer windings during the short circuit current limitation, as well as ensuring the thermal stability of the superconducting tape at the quench moment. The obtained results are significant in the design and operation of HTS transformers. For efficient and safe operation in the current-limiting mode, it is necessary to take into account heat generation on the transformer windings. It is important for the superconductor returning to the superconducting state without causing significant overheating of the windings.
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45

Rotem-Yehudar, R., S. Winograd, S. Sela, J. E. Coligan, and R. Ehrlich. "Downregulation of peptide transporter genes in cell lines transformed with the highly oncogenic adenovirus 12." Journal of Experimental Medicine 180, no. 2 (August 1, 1994): 477–88. http://dx.doi.org/10.1084/jem.180.2.477.

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The expression of class I major histocompatibility complex antigens on the surface of cells transformed by adenovirus 12 (Ad12) is generally very low, and correlates with the high oncogenicity of this virus. In primary embryonal fibroblasts from transgenic mice that express both endogenous H-2 genes and a miniature swine class I gene (PD1), Ad12-mediated transformation results in suppression of cell surface expression of all class I antigens. Although class I mRNA levels of PD1 and H-2Db are similar to those in nonvirally transformed cells, recognition of newly synthesized class I molecules by a panel of monoclonal antibodies is impaired, presumably as a result of inefficient assembly and transport of the class I molecules. Class I expression can be partially induced by culturing cells at 26 degrees C, or by coculture of cells with class I binding peptides at 37 degrees C. Analysis of steady state mRNA levels of the TAP1 and TAP2 transporter genes for Ad12-transformed cell lines revealed that they both are significantly reduced, TAP2 by about 100-fold and TAP1 by 5-10-fold. Reconstitution of PD1 and H-2Db, but not H-2Kb, expression is achieved in an Ad12-transformed cell line by stable transfection with a TAP2, but not a TAP1, expression construct. From these data it may be concluded that suppressed expression of peptide transporter genes, especially TAP2, in Ad12-transformed cells inhibits cell surface expression of class I molecules. The failure to fully reconstitute H-2Db and H-2Kb expression indicates that additional factors are involved in controlling class I gene expression in Ad12-transformed cells. Nevertheless, these results suggest that suppression of peptide transporter genes might be an important mechanism whereby virus-transformed cells escape immune recognition in vivo.
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46

Zhadanos, O., I. Derevyanko, D. Chaika, and O. Kukushkin. "Situational model of technological operations for secondary metallurgy." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 89 (July 1, 2018): 27–34. http://dx.doi.org/10.5604/01.3001.0012.6669.

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Purpose: The aim of this study was development of a computer situational model of heat and power processes and transport operations for secondary steelmaking (SSM) to evaluate the effectiveness of the proposed SSM energy regimes and minimization the consumption of energy resources. Design/methodology/approach: For the solution of the tasks were used next methods: analytical and statistical methods of mathematical modeling; method of dynamic programming for the development of technological recommendations for energy modes on LF; Harel state charts to evaluate the effectiveness of the applied models. Findings: In order to provide rational energy regimes for SSM, it is necessary to introduce a new controlled parameter - the optimum time to start heating the melt at the ladle furnace unit (LF), which is determined by solving the dynamic programming task. The melt heating start time must be selected in such a way as to ensure that all the necessary technological operations are performed during metal processing in the LF, taking into account schedule constraints, and that the heating of the metal must be carried out with the maximum energy efficiency. Research limitations/implications: The main objective of the present study was to apply the mathematical modeling methods to ensure rational energy regimes of SSM. Practical implications: The developed situational model of technological operations for SSM will allow finding reserves to increase the productivity and quality of the process, and to evaluate the effectiveness of new technological solutions. Originality/value: To ensure an energy-efficient treatment of steel in LF, it is necessary: the time for starting the heating of the metal is chosen such that the energy efficiency of the LF, which depends on the thickness of the slag layer, is maximum at each stage; increase the power that is supplied to the heating of the melt by switching the voltage taps of the transformer as the thickness of the slag cover increases.
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47

Tixador, Pascal. "Concepts for HTS and MgB2 in Transformers." Advances in Science and Technology 47 (October 2006): 195–203. http://dx.doi.org/10.4028/www.scientific.net/ast.47.195.

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After the emergence of AC NbTi strands, superconducting transformers were successfully built. But the very high cost of 4 K cryogenics made these transformers economically not attractive. The high Tc superconductors (HTS), operating at much higher temperatures, change these conclusions with low cost HTS conductors. The high cost of PIT tapes and the relatively large AC losses remain issues. The second generation HTS wires, the REBCO coated conductors, are under development and achieved substantial progress recently. They operate at higher temperatures and intrinsically show lower AC losses especially for transformers. MgB2 is the third option. The magnetic flux density conditions make possible the operation at 27 K and they show low costs. This paper provides a preliminary design for an on-board 40 MVA transformer using YBCO coated conductors and MgB2 wires. Both superconducting transformers show similar volume and weight. The power density per unit mass and volume is improved by a factor about two, cryogenic included, compared to resistive systems. This makes them very attractive for on-board mobile systems. The economical point of view will be discussed based on some targets price/performance for superconductors and cryocoolers. MgB2 is penalized by its operation at lower temperature (27 K / 77 K), which makes cryogenics very expensive. The advantage of the low cost of MgB2 compared to REBCO may be lost except with very low AC loss MgB2 tapes.
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48

JAROSZYŃSKI, Leszek. "Current distribution in parallel tapes of superconducting transformer windings." PRZEGLĄD ELEKTROTECHNICZNY 1, no. 10 (October 5, 2015): 286–89. http://dx.doi.org/10.15199/48.2015.10.59.

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49

Yamada, Yutaka, Teruo Izumi, and Yuh Shiohara. "Progress of YBCO Coated Conductor in JAPN and Recent Advance of PLD and IBAD Method." Advances in Science and Technology 47 (October 2006): 124–30. http://dx.doi.org/10.4028/www.scientific.net/ast.47.124.

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In the present 5-year national project since 2003, the development of YBCO coated conductors (CC) has advanced rapidly. The high performance processing group of SRL-ISTEC and Fujikura Ltd. has been working on the long tape of the PLD-YBCO superconductor on the IBAD-Gd2Zr2O7 buffered substrate tape. Very recently the SRL group achieved the highest value on the product of Ic x L in the world, 51,940 Am (212 m x 245 A). Fujikura Ltd. also realized the longest buffered substrate tape of 500m long IBAD tape and obtained a 200 m long coated conductor with Ic value of 88 A. In the low cost processing group using MOD, CVD and so on, the high Ic value of 525 A was obtained by SRL using the TFA-MOD method on the IBAD substrate. The 45m long TFA-MOD tape was also obtained with the Ic value of 155 A by Showa Electric Wire and Cable Company. Similarly 100- 200 m class long tapes were also obtained by the MOCVD (Chubu Power Electric Company) and PLD-HoBCO processes (Sumitomo Electric Industry Ltd.). Both groups above are further developing for the final goal of 500 m long tapes with the Ic of 300 A/cm-w at the production rate of 5 m/h. Furthermore, the feasibility study for the application has started due to the above success of long tape production. Several kinds of preliminary experiments using long coated conductors are now in progress for the power applications such as (1) Power Cable, (2) Transformer, (3) Motor and so on.
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50

Niemi, Teemu, Antti O. Karilainen, and Sergei A. Tretyakov. "Synthesis of Polarization Transformers." IEEE Transactions on Antennas and Propagation 61, no. 6 (June 2013): 3102–11. http://dx.doi.org/10.1109/tap.2013.2252136.

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