scholarly journals Investigation of overvoltage on square, rectangular and L-shaped ground grids of high voltage substations by ATP/EMTP

2021 ◽  
Vol 11 (6) ◽  
pp. 4689
Author(s):  
Krung Luewattana ◽  
Paweena Rattanasena
Keyword(s):  
High Voltage ◽  
Preliminary Investigation ◽  
Electromagnetic Transients ◽  
Lightning Strike ◽  
Fault Current ◽  
Grid System ◽  
Grid Systems ◽  
Different Shapes ◽  
Ground Grid ◽  
To Receive

<span lang="EN-US">Ground grid system is important for preventing the hazardous effects of overvoltage in high voltage substations due to fault current perhaps from lightning strike or device malfunction. Therefore, this study aimed to investigate the effects of overvoltage on square, rectangular and L-shaped ground grids with ground rods being distributed in mesh-pattern by using alternate transients program/electromagnetic transients program (ATP/EMTP) program. The models were simulated in the cases that 25 kA-fault current being injected into the center or one of the corners of ground grids. The results showed that the highest level of overvoltage (6.3349 kV) was detected at the corner of rectangular ground grid when the fault current was injected into its corner. However, the lowest level of overvoltage was found when the fault current was injected into the center of square ground grid. The results from this study indicated that ATP/EMTP program was useful for preliminary investigation of overvoltage on ground grids of different shapes. The obtained knowledge could be beneficial for further designing of ground grid systems of high voltage substations to receive the minimal damages due to fault current.</span>

Overvoltage Effects on Ground Grid Systems of Single and Two Neighboring High Voltage Substations

2016 ◽  
Vol 6 (6) ◽  
pp. 2545
Author(s):  
Krung Luewattana ◽  
Aphibal Pruksanubal
Keyword(s):  
High Voltage ◽  
Distribution Systems ◽  
High Reliability ◽  
Fault Current ◽  
Power Networks ◽  
Grid Systems ◽  
Reliable Transmission ◽  
Ground Grid ◽  
Transmission And Distribution

<p><span style="font-family: Times New Roman;">The power networks<em> </em>with reliable transmission and distribution systems require high voltage substations with effective ground grid systems. Therefore, this study aimed to analyze the effects of overvoltage on ground grid systems within high voltage substations in two cases, including a single substation and the two neighboring substations, by using ATP/EMTP and ANSYS softwares. The simulations were performed to show both graphs and 3D results when the fault current flowed into the ground grids of substations at various positions. In case of the single high<em> </em>voltage substation, the overvoltage was highest when the fault current was injected at the corner of ground grid. However, in case of two neighboring high voltage substations, the levels of overvoltage were similar between that caused by injecting the fault current at the center and at the corner of ground grid. The simulation showed that overvoltage which occurring at the ground grid of high voltage substation A could permeate to the ground grid of nearby high voltage substation B, which nevertheless depending on the how the fault current was injected at different spots. The data from these simulations and analysis can be useful for future designs of ground grid systems with high reliability. </span></p>

scholarly journals Overvoltage Effects on Ground Grid Systems of Single and Two Neighboring High Voltage Substations

2016 ◽  
Vol 6 (6) ◽  
pp. 2545
Author(s):  
Krung Luewattana ◽  
Aphibal Pruksanubal
Keyword(s):  
High Voltage ◽  
Distribution Systems ◽  
High Reliability ◽  
Fault Current ◽  
Power Networks ◽  
Grid Systems ◽  
Reliable Transmission ◽  
Ground Grid ◽  
Transmission And Distribution

The power networks with reliable transmission and distribution systems require high voltage substations with effective ground grid systems. Therefore, this study aimed to analyze the effects of overvoltage on ground grid systems within high voltage substations in two cases, including a single substation and the two neighboring substations, by using ATP/EMTP and ANSYS softwares. The simulations were performed to show both graphs and 3D results when the fault current flowed into the ground grids of substations at various positions. In case of the single high voltage substation, the overvoltage was highest when the fault current was injected at the corner of ground grid. However, in case of two neighboring high voltage substations, the levels of overvoltage were similar between that caused by injecting the fault current at the center and at the corner of ground grid. The simulation showed that overvoltage which occurring at the ground grid of high voltage substation A could permeate to the ground grid of nearby high voltage substation B, which nevertheless depending on the how the fault current was injected at different spots. The data from these simulations and analysis can be useful for future designs of ground grid systems with high reliability.

Study on the Performance of Distribution Grid System in Different Neutral Grounded Modes

2011 ◽  
Vol 101-102 ◽  
pp. 348-351
Author(s):  
Lan Yu ◽  
Qing Hai Wu ◽  
Hai Yun Bian
Keyword(s):  
Single Phase ◽  
Fault Current ◽  
Grid System ◽  
Fault Line ◽  
Distribution Grid ◽  
Parallel Connection ◽  
Grid Systems ◽  
Fault Line Selection ◽  
Line Selection ◽  
Simulation Results

In order to reduce grounded current and restrain arc-grounded over voltage during single-phase grounded faults in transmission line and realize fault-line selection, the neutral grounded mode with Peterson coil in parallel with big reactor is proposed in the paper. The simulation and comparative analysis of the performance of the 10 kV distribution grid systems in different neutral grounded modes have been done. The simulation results have shown that the neutral grounded mode via Peterson coil in parallel connection with big resistances can restrain the fault current effectively and it is the best mode.

scholarly journals Solid-State DC Circuit Breakers and their Comparison in Modular Multilevel Converter Based-HVDC Transmission System

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1204
Author(s):  
Gul Ahmad Ludin ◽  
Mohammad Amin Amin ◽  
Hidehito Matayoshi ◽  
Shriram S. Rangarajan ◽  
Ashraf M. Hemeida ◽  
...  
Keyword(s):  
Solid State ◽  
High Voltage ◽  
Direct Current ◽  
Circuit Breaker ◽  
Transmission System ◽  
Simulation Software ◽  
Fault Current ◽  
Circuit Breakers ◽  
Hvdc Transmission ◽  
Dc Circuit Breakers

This paper proposes a new and surge-less solid-state direct current (DC) circuit breaker in a high-voltage direct current (HVDC) transmission system to clear the short-circuit fault. The main purpose is the fast interruption and surge-voltage and over-current suppression capability analysis of the breaker during the fault. The breaker is equipped with series insulated-gate bipolar transistor (IGBT) switches to mitigate the stress of high voltage on the switches. Instead of conventional metal oxide varistor (MOV), the resistance–capacitance freewheeling diodes branch is used to bypass the high fault current and repress the over-voltage across the circuit breaker. The topology and different operation modes of the proposed breaker are discussed. In addition, to verify the effectiveness of the proposed circuit breaker, it is compared with two other types of surge-less solid-state DC circuit breakers in terms of surge-voltage and over-current suppression. For this purpose, MATLAB Simulink simulation software is used. The system is designed for the transmission of 20 MW power over a 120 km distance where the voltage of the transmission line is 220 kV. The results show that the fault current is interrupted in a very short time and the surge-voltage and over-current across the proposed breaker are considerably reduced compared to other topologies.

scholarly journals Analysis of Subsynchronous Torsional of Wind–Thermal Bundled System Transmitted via HVDC Based on Signal Injection Method

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 474
Author(s):  
Junxi Wang ◽  
Qi Jia ◽  
Gangui Yan ◽  
Kan Liu ◽  
Dan Wang
Keyword(s):  
Wind Power ◽  
High Voltage ◽  
Direct Current ◽  
Computer Aided Design ◽  
Large Scale ◽  
Electromagnetic Transients ◽  
Torsional Mode ◽  
High Voltage Direct Current ◽  
Operation Conditions ◽  
Signal Injection

With the development of large-scale new energy, the wind–thermal bundled system transmitted via high-voltage direct current (HVDC) has become the main method to solve the problem of wind power consumption. At the same time, the problem of subsynchronous oscillation among wind power generators, high-voltage direct current (HVDC), and synchronous generators (SGs) has become increasingly prominent. According to the dynamic interaction among doubly fed induction generators (DFIGs), HVDC, and SGs, a linearization model of DFIGs and SGs transmitted via HVDC is established, and the influence of the electromagnetic transient of wind turbines and HVDC on the electromechanical transient processes of SGs is studied. Using the method of additional excitation signal injection, the influence of the main factors of DFIG on the damping characteristics of each torsional mode of SG is analyzed, including control parameters and operation conditions when the capacity of HVDC is fixed. The mechanism of the negative damping torsional of SGs is identified. A time-domain simulation model is built in Electromagnetic Transients including DC/Power Systems Computer Aided Design (EMTDC/PSCAD) to verify the correctness and effectiveness of the theoretical analysis.

scholarly journals Computation of Energy Absorption and Residual Voltage in a Fourth Rail LRT Station Arresters in EMTP-RV: A Comparative Study

2021 ◽  
Author(s):  
Farah Asyikin Abd Rahman ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Ungku Anisa Ungku Amirulddin ◽  
Miszaina Osman
Keyword(s):  
Electromagnetic Transients ◽  
Lightning Strike ◽  
Voltage Gradient ◽  
Urban Transit ◽  
Residual Voltage ◽  
Voltage Ratio ◽  
Lightning Channel ◽  
Breakdown Region ◽  
Current Region ◽  
Performance Results

AbstractThis paper presents a study on the performance of a fourth rail direct current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was replicated and represented by a lightning-induced overvoltage by means of the Rusck model, with the sum of two Heidler functions as its lightning channel base current input, on a perfect conducting ground. This study aims to determine whether an indirect lightning strike has any influence with regard to the performance of the LRT Kelana Jaya line, a fourth rail DC urban transit station arrester. The simulations were carried out using the Electromagnetic Transients Program–Restructured Version (EMTP–RV), which includes the comparison performance results between the 3EB4-010 arrester and PDTA09 arrester when induced by a 90 kA (9/200 µs). The results demonstrated that the PDTA09 arrester showed better coordination with the insulated rail bracket of the fourth rail. It allowed a lower residual voltage and a more dynamic response, eventually resulting in better voltage gradient in the pre-breakdown region and decreased residual voltage ratio in the high current region.

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