scholarly journals Analysis of the number of switches of on-load tap changer of a power transformer for field substation, taking into account discrete time and voltage level sampling

2020 ◽  
Vol 220 ◽  
pp. 01056
Author(s):  
T.V. Tabachnikova ◽  
L.V. Shvetskova ◽  
A.V. Yumalin

The introduction of “smart grids” technologies poses the problems of multi-criteria determination of the optimum voltage in the main substation of the object under study. In this study the busbar sections of the field substation of the oil and gas company is considered as the main substation. This paper studies regulation of voltage level in an electrical network using on-load tap changer (OLTC) of a power transformer for field substation of an oil and gas enterprise. Considered are approaches for voltage regulation taking into account the development of smart grid technologies. The authors have developed a universal method for determining the optimal voltage level on the busbar sections of a field substation, which allows for selection of the optimum voltage in accordance with certain parameters: loss of active, reactive power, voltage, electricity consumption, specific consumption or efficiency factor of artificial oil lift. The actual daily graphs of consumption of active, reactive power and voltage level at one of the field substations of PJSC Tatneft were studied. The operation mode of on-load tap-changer drive of the field transformer was modeled, taking into account the calculated optimal values of voltage and the dead zone. The paper presents the results of study of automatic voltage regulation on busbar sections of a field substation, taking into account the constraints for tap changer switches of a power transformer.

2020 ◽  
Vol 178 ◽  
pp. 01068
Author(s):  
I.O. Golikov ◽  
A.V. Vinogradov ◽  
V.E. Bolshev ◽  
A.V. Vinogradova ◽  
M. Jasinski ◽  
...  

This article describes the features of voltage regulation in electrical networks of 35, 110, 220 kV. The structural diagram of the 35/10/0.4 kV network is presented. The paper also describes the adaptive automatic voltage regulation system which allows regulating the voltage taking into account the actual voltage values at the consumers’ inputs. The structural diagram of the adaptive automatic voltage regulation system in the 0.4 kV electrical network using a boost transformer as an additional means of voltage regulation is given. The system is based on voltage sensors installed in different parts of an eletcrical network sending information on voltage values to to the processing unit which generates a signal for voltage regulating supplied to the executive device and the working body whuch, in turn, change the on-load tap-changer position of a transformer. The paper justifies the need for the enhancement of the adaptive automatic voltage regulation system for different voltage classes wich allows controlling a voltage change at different power supply system levels and regulating voltage level in accordance with this change. For this problem the multi-level adaptive automatic voltage regulation systemis proposed. The system allows regulating the voltage not only in the 0.4 kV network but also in networks of higher voltage classes. The proposed system can be integrated into the structure of intelligent electrical networks.


This research article demonstrates how to protect the power transformer from over load time. It is to controlling our desired voltage on various load times but the research gives some solution to avoid over voltage problem by automatic tapping technique. In this research tapping of transformer is selected automatically with the help of Peripheral Interface Controller (PIC) microcontroller. Effective use of potential transformer is to find out the precision in the system. The load voltage is measured by potential transformer which is given to precision rectifier. It will produce the accurate voltage levels. Here the things are using PIC microcontroller which is a flash type reprogrammable device in which system was already programmed. The Model was fabricated with Triode for Alternating Current (TRIAC) switches just as a switching devices and Peripheral Interface Controller microcontroller just as a control unit. In this research automatic control sections by using tap changer. In conventional methods industrialist used mechanical on load tap changer which is highly risk, because it does not produces constant output voltage and can create voltage dips. In this research it will be overcome above problem by using automatic electronic tap changer. It will produce constant voltage regulation and to measure variation of current.


Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 82-90
Author(s):  
Dmitriy I. Panfilov ◽  
◽  
Mikhail G. Astashev ◽  
Aleksandr V. Gorchakov ◽  
◽  
...  

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.


Author(s):  
Mogaligunta Sankaraiah ◽  
Sanna Suresh Reddy ◽  
M Vijaya Kumar

<p>Wind is available with free of cost anywhere in the world, this wind can be used for power generation due to many advantages. This attracts the researchers to work on wind power plants. The presence of wind power plants on distribution system causes major influence on voltage controlled devices (VCDs) in terms of life of the devices. Therefore, this paper proposes grey wolf optimization method (GWO) together with forecasted load one day in advance. VCDs are on load tap changer (ULTC) and capacitors (CS), there are two main objectives first one is curtail of distribution network (DN) loss and second one is curtailing of ULTC and CS switching’s. Objectives are achieved by controlling the reactive power of DFIG in coordination with VCDs. The proposed method is planned and applied in Matlab/Simulink on 10KV practical system with DFIG located at different locations. To validate the efficacy of GWO, results are compared with conventional and dynamic programming methods without profane grid circumstances.</p>


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2173
Author(s):  
Álvaro Rodríguez del Nozal ◽  
Esther Romero-Ramos ◽  
Ángel Luis Trigo-García

Voltage control in active distribution networks must adapt to the unbalanced nature of most of these systems, and this requirement becomes even more apparent at low voltage levels. The use of transformers with on-load tap changers is gaining popularity, and those that allow different tap positions for each of the three phases of the transformer are the most promising. This work tackles the exact approach to the voltage optimization problem of active low-voltage networks when transformers with on-load tap changers are available. A very rigorous approach to the electrical model of all the involved components is used, and common approaches proposed in the literature are avoided. The main aim of the paper is twofold: to demonstrate the importance of being very rigorous in the electrical modeling of all the components to operate in a secure and effective way and to show the greater effectiveness of the decoupled on-load tap changer over the usual on-load tap changer in the voltage regulation problem. A low-voltage benchmark network under different load and distributed generation scenarios is tested with the proposed exact optimal solution to demonstrate its feasibility.


Author(s):  
Maximilian Wiesmüller ◽  
Beate Glaser ◽  
Franz Fuchs ◽  
Oliver Sterz

Purpose – The purpose of this paper is to report on the simulation of an on-load tap-changer (OLTC) in a power transformer. During design and test of the electrical insulation the influence of the environment on the OLTC is normally neglected. The authors investigate how large these influences are. Design/methodology/approach – The environment of the OLTC is taken into account by modeling tap leads in detail as well as transformer windings. The electric fields are computed and resulting breakdown voltages are estimated by using the streamer criterion. The results are compared to the ones of an OLTC without transformer and leads. Findings – For the investigated typical example the influence of the transformer and the tap leads on the internal OLTC insulation is small enough to neglect them during design optimization and test procedures. Originality/value – New is the execution of a finite element simulation and breakdown evaluation of such a complex geometric structure as the complete system consisting of OLTC combined with tap leads and windings. Furthermore, standard design and test procedures used by OLTC manufacturers are justified.


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