scholarly journals OLTC Transformer Model Connecting 3-Wire MV with 4-Wire Multigrounded LV Networks

2020 ◽  
Author(s):  
Evangelos Pompodakis
Keyword(s):  
Low Voltage ◽  
Comprehensive Model ◽  
Medium Voltage ◽  
Proposed Model ◽  
Tap Changer ◽  
Bus Network ◽  
Transformer Model ◽  
Load Tap Changer

<b>This letter presents a comprehensive model of on-load tap-changer (OLTC) transformers that connect 3-wire medium voltage (MV) with 4-wire multigrounded low voltage (LV) networks. The proposed model enables the inclusion of the 3-wire MV network and the 4-wire multigrounded LV network into a single Y<sub>BUS</sub> matrix without any assumption or simplification. Its distinct feature is that the tap changer of the transformer is simulated outside the Y<sub>BUS</sub> matrix, thus a refactorization of the Y<sub>BUS</sub> matrix is not required in every tap change. The proposed transformer model has been validated in a 4-Bus network, while its performance has been tested in the IEEE 8500-Node and IEEE 906-Bus test networks. </b>

scholarly journals OLTC Transformer Model Connecting 3-Wire MV with 4-Wire Multigrounded LV Networks

2020 ◽  
Author(s):  
Evangelos Pompodakis
Keyword(s):  
Low Voltage ◽  
Comprehensive Model ◽  
Medium Voltage ◽  
Proposed Model ◽  
Tap Changer ◽  
Bus Network ◽  
Transformer Model ◽  
Load Tap Changer

<b>This letter presents a comprehensive model of on-load tap-changer (OLTC) transformers that connect 3-wire medium voltage (MV) with 4-wire multigrounded low voltage (LV) networks. The proposed model enables the inclusion of the 3-wire MV network and the 4-wire multigrounded LV network into a single Y<sub>BUS</sub> matrix without any assumption or simplification. Its distinct feature is that the tap changer of the transformer is simulated outside the Y<sub>BUS</sub> matrix, thus a refactorization of the Y<sub>BUS</sub> matrix is not required in every tap change. The proposed transformer model has been validated in a 4-Bus network, while its performance has been tested in the IEEE 8500-Node and IEEE 906-Bus test networks. </b>

scholarly journals OLTC Transformer Model Connecting 3-Wire MV with 4-Wire Multigrounded LV Networks

2020 ◽  
Author(s):  
Evangelos Pompodakis
Keyword(s):  
Low Voltage ◽  
Comprehensive Model ◽  
Medium Voltage ◽  
Proposed Model ◽  
Tap Changer ◽  
Bus Network ◽  
Transformer Model ◽  
Load Tap Changer

<b>This letter presents a comprehensive model of on-load tap-changer (OLTC) transformers that connect 3-wire medium voltage (MV) with 4-wire multigrounded low voltage (LV) networks. The proposed model enables the inclusion of the 3-wire MV network and the 4-wire multigrounded LV network into a single Y<sub>BUS</sub> matrix without any assumption or simplification. Its distinct feature is that the tap changer of the transformer is simulated outside the Y<sub>BUS</sub> matrix, thus a refactorization of the Y<sub>BUS</sub> matrix is not required in every tap change. The proposed transformer model has been validated in a 4-Bus network, while its performance has been tested in the IEEE 8500-Node and IEEE 906-Bus test networks. </b>

scholarly journals Accurate Assessment of Decoupled OLTC Transformers to Optimize the Operation of Low-Voltage Networks

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2173
Author(s):  
Álvaro Rodríguez del Nozal ◽  
Esther Romero-Ramos ◽  
Ángel Luis Trigo-García
Keyword(s):  
Distributed Generation ◽  
Optimization Problem ◽  
Low Voltage ◽  
Optimal Solution ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Rigorous Approach ◽  
Tap Changer ◽  
Load Tap Changer ◽  
Active Distribution Networks

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.

Optimal location of voltage sensors in low voltage networks for on-load tap changer application

2017 ◽  
Vol 11 (15) ◽  
pp. 3756-3764 ◽  
Author(s):  
Kalle Rauma ◽  
Florent Cadoux ◽  
Guillaume Roupioz ◽  
Adrien Dufournet ◽  
Nouredine Hadj-Said
Keyword(s):  
Low Voltage ◽  
Optimal Location ◽  
Voltage Sensors ◽  
Tap Changer ◽  
Load Tap Changer

scholarly journals PROPOSAL FOR MANAGING ELECTRIC ENERGY QUALITY IN THE LV GRID USING ON-LOAD TAP CHANGER WITH A STATIC SYNCHRONOUS COMPENSATOR

2018 ◽  
Vol 8 (2) ◽  
pp. 72-78
Author(s):  
Bartłomiej Mroczek ◽  
Karol Fatyga
Keyword(s):  
Reactive Power ◽  
Low Voltage ◽  
Power Grid ◽  
Electric Energy ◽  
Auxiliary Equipment ◽  
Static Synchronous Compensator ◽  
Voltage Quality ◽  
Tap Changer ◽  
Load Tap Changer

The paper proposes the use of auxiliary equipment in the low voltage network: an on-load tap changer and a static synchronous compensator (STATCOM) to improve the quality of energy supply to end users. As part of the research, a section of medium and low voltage power grid was modelled using Matlab & Simulink software, which was tested in three scenarios. The first scenario presents the operation of the power grid with the on-load tap changer installed in the transformer block. The second scenario uses the STATCOM for local reactive power compensation. Additionally, the third scenario is the combined work of the on-load tap-changer along with the STATCOM. According to the authors, the method discussed does not bring the expected results in the area of voltage quality improvement, indicating that further research is required, including tests with energy storage.

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

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

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

Sign in / Sign up

Export Citation Format

Share Document