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

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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Electrical Performance of Polymer-Insulated Rail Brackets of DC Transit Subjected to Lightning Induced Overvoltage

Materials ◽

10.3390/ma14071684 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1684

Author(s):

Farah Asyikin Abd Rahman ◽

Mohd Zainal Abidin Ab Kadir ◽

Ungku Anisa Ungku Amirulddin ◽

Miszaina Osman

Keyword(s):

Performance Comparison ◽

Absorption Capacity ◽

Electrical Performance ◽

Sensitivity Analyses ◽

Lightning Strike ◽

Rail Transit ◽

Energy Absorption Capacity ◽

Urban Transit ◽

Residual Voltage ◽

Reinforced Plastic

The fourth rail transit is an interesting topic to be shared and accessed by the community within that area of expertise. Several ongoing works are currently being conducted especially in the aspects of system technical performances including the rail bracket component and the sensitivity analyses on the various rail designs. Furthermore, the lightning surge study on railway electrification is significant due to the fact that only a handful of publications are available in this regard, especially on the fourth rail transit. For this reason, this paper presents a study on the electrical performance of a fourth rail Direct Current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was modelled by means of the Rusck model and the sum of two Heidler functions. The simulations were carried out using the EMTP-RV software which included the performance comparison of polymer-insulated rail brackets, namely the Cast Epoxy (CE), the Cycloaliphatic Epoxy A (CEA), and the Glass Reinforced Plastic (GRP) together with the station arresters when subjected by 30 kA (5/80 µs) and 90 kA (9/200 µs) lightning currents. The results obtained demonstrated that the GRP material has been able to slightly lower its induced overvoltage as compared to other materials, especially for the case of 90 kA (9/200 µs), and thus serves better coordination with the station arresters. This improvement has also reflected on the recorded residual voltage and energy absorption capacity of the arrester, respectively.

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Artificial Lightning Strike Tests and Coupled Electrical–Thermal Analysis on Roofing Glazed Tiles of Ancient Buildings

10.21203/rs.3.rs-476111/v1 ◽

2021 ◽

Author(s):

Jingxiao Li ◽

Zhiling Fang ◽

Lin Fu ◽

Shangchen Fu ◽

Lihua Shi ◽

...

Keyword(s):

Electrical Conductivity ◽

Thermal Stress ◽

High Temperature ◽

Heat Effect ◽

Element Model ◽

Joule Heat ◽

The Body ◽

Lightning Strike ◽

Lightning Current ◽

Lightning Channel

Abstract Lightning strike is one of the natural disasters to the roof components of ancient buildings. To investigate the causes and damage effects of lightning strikes on the roofing glazed tiles of ancient buildings, artificial lightning strike tests were carried out on glazed tiles. Based on the experiment results, a coupled electrical–thermal finite element model of mortar-containing glazed tiles was established and the Joule heat effect of lightning current was further investigated. The results show that when the lightning channel is attached to the surface of the enamel and body with a low electrical conductivity, the lightning current is mainly released in the form of surface flashover, and a minor damage is induced along the flashover path; when the lightning channel is attached to the mortar with a high electrical conductivity, the lightning current is injected into the mortar, resulting in significant tile damage. The spatial distributions of the temperature present clear gradient characteristics. The high-temperature area appears in the mortar while the high–thermal–stress area appears in the body connected to the grounding rail. As the peak of the lightning current increases, both the high-temperature and high–thermal–stress areas of the glazed tiles expand. The combination of the experiments and the numerical analysis results demonstrate that the damage mechanism of lightning Joule heat effect to glazed tiles may include two aspects. One is the internal explosive force generated from the sharp vaporization and expansion of the moisture inside the tiles due to rapid temperature increase, and the other is the thermal stress caused by the uneven temperature distribution.

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Evaluation of a Direct Lightning Strike to the 24 kV Distribution Lines in Thailand

Energies ◽

10.3390/en12163193 ◽

2019 ◽

Vol 12 (16) ◽

pp. 3193 ◽

Cited By ~ 2

Author(s):

Pornchai Sestasombut ◽

Atthapol Ngaopitakkul

Keyword(s):

Electromagnetic Transients ◽

Lightning Strike ◽

Significant Variable ◽

Line System ◽

Lightning Strikes ◽

Underground Cables ◽

Ground Resistance ◽

Distribution Lines ◽

Surge Arresters ◽

Distribution Line

This paper evaluates the effect of a lightning strike directly on the 24 kV distribution lines in Thailand, where such strikes are one of the main causes of power outages. The voltage across the insulator, and the arrester energy absorbed due to the lightning, need to be analyzed for different grounding distances of the overhead ground wire, ground resistance, lightning impact positions, and lightning current waveforms. Analysis and simulations are conducted using the Alternative Transients Program/Electromagnetic Transients Program (ATP/EMTP) to find the energy absorbed by the arrester and the voltages across the insulator. The results indicate that when surge arresters are not installed, the voltage across the insulator at the end of the line is approximately 1.4 times that in the middle of the line. In addition, the ground resistance and grounding distance of the overhead ground wire affect the voltage across the insulator if the overhead ground wire is struck. When surge arresters are installed, a shorter grounding distance of the overhead ground wire and a lower ground resistance are not always desirable; this is because they reduce the back-flashover rate and the voltage across the insulator if lightning strikes the overhead ground wire. However, lightning strikes to the phase conductor result in high arrester energy and the possibility that the arrester will fail. Furthermore, the tail time of the lightning waveform is a significant variable when considering the energy absorbed by the arrester, whereas the front time is important for the voltage across the insulator. In case lightning strikes directly on the connected point between the overhead lines and the underground cables, the distribution line system is protected only by the lightning arrester at the connection point. The overvoltage at the connection point is lower than the basic impulse level at 24 kV of 125 kV, but the overvoltage at the end of the cable is still more than 125 kV in case the cable is longer than 400 m. When the distribution line system is protected by the lightning arrester at both the connection point and the end of the cable, it results in overvoltage throughout the cable is lower than the critical flashover of insulation. This method is the best way to reduce the failure rate of underground cables and equipment that are connected to the distribution line system.

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Residual voltage properties of ZnO varistors doped with Y2O3 for high voltage gradient

2009 IEEE 9th International Conference on the Properties and Applications of Dielectric Materials ◽

10.1109/icpadm.2009.5252278 ◽

2009 ◽

Author(s):

Jun Hu ◽

Jun Liu ◽

Jinliang He ◽

Wangchen Long ◽

Fengchao Luo

Keyword(s):

High Voltage ◽

Voltage Gradient ◽

Residual Voltage ◽

Zno Varistors

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Artificial lightning strike tests and coupled electrical–thermal analysis on roofing glazed tiles of ancient buildings

Heritage Science ◽

10.1186/s40494-021-00581-6 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Jingxiao Li ◽

Zhiling Fang ◽

Lin Fu ◽

Shangchen Fu ◽

Lihua Shi ◽

...

Keyword(s):

Electrical Conductivity ◽

Thermal Stress ◽

High Temperature ◽

Heat Effect ◽

Element Model ◽

Joule Heat ◽

The Body ◽

Lightning Strike ◽

Lightning Current ◽

Lightning Channel

AbstractLightning strike is one of the natural disasters to the roof components of ancient buildings. To investigate the causes and damage effects of lightning strikes on the roofing glazed tiles of ancient buildings, artificial lightning strike tests were carried out on glazed tiles. Based on the experiment results, a coupled electrical–thermal finite element model of mortar-containing glazed tiles was established and the Joule heat effect of lightning current was further investigated. The results show that when the lightning channel is attached to the surface of the enamel and body with a low electrical conductivity, the lightning current is mainly released in the form of surface flashover, and a minor damage is induced along the flashover path; when the lightning channel is attached to the mortar with a high electrical conductivity, the lightning current is injected into the mortar, resulting in significant tile damage. The spatial distributions of the temperature present clear gradient characteristics. The high-temperature area appears in the mortar while the high–thermal–stress area appears in the body connected to the grounding rail. As the peak of the lightning current increases, both the high-temperature and high–thermal–stress areas of the glazed tiles expand. The combination of the experiments and the numerical analysis results demonstrate that the damage mechanism of lightning Joule heat effect to glazed tiles may include two aspects. One is the internal explosive force generated from the sharp vaporization and expansion of the moisture inside the tiles due to rapid temperature increase, and the other is the thermal stress caused by the uneven temperature distribution.

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Influence of Cr2O3 on the Residual Voltage Ratio of SnO2-Based Varistor

Journal of the American Ceramic Society ◽

10.1111/j.1551-2916.2011.04620.x ◽

2011 ◽

Vol 94 (7) ◽

pp. 1999-2002 ◽

Cited By ~ 8

Author(s):

Qiaoyuan Wei ◽

Jinliang He ◽

Jun Hu ◽

Yunchao Wang

Keyword(s):

Residual Voltage ◽

Voltage Ratio

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Computation of Lightning Current from Electric Field Based on Laplace Transform and Deconvolution Method

Energies ◽

10.3390/en14144201 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4201

Author(s):

Grzegorz Karnas

Keyword(s):

Transfer Function ◽

Electric Field ◽

Laplace Transform ◽

Vertical Component ◽

Lightning Strike ◽

Function Estimation ◽

Base Current ◽

Lightning Current ◽

Lightning Channel ◽

Lightning Impulse

A method for computation of the lightning channel base current from the corresponding vertical component of lightning electric field was presented. The algorithm was developed by applying Laplace transform. The lightning current was estimated from its deconvolution with a special transfer function. The transfer function includes information about geometry and physical properties of entire lightning impulse generation system. The method was verified for a Heidler-type base current and a MTLL model of its propagation within the lightning channel. Research was done for close, middle, and far distance to the lightning strike point. Optimum performance was obtained for the middle distance of several kilometers where the electrostatic, induction, and radiation components of the transfer function were of the same range. An analysis was done for input electric field with and without noise superimposed on its time domain waveform. Relative uncertainties for the electric field and calculated lightning channel base current were similar each other. The presented approach can substantially increase a number of lightning current parameters which can be identified on the basis of its electric field signature. This method can be applied by the lightning location systems using preprocessing which increases the timing efficiency of the transfer function estimation.

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Modelling of tall-structure lightning return-stroke current using the Electromagnetic Transients Program

10.32920/ryerson.14645919.v1 ◽

2021 ◽

Author(s):

Mohammadsadegh Rahimian Emam

Keyword(s):

Velocity Profile ◽

Electromagnetic Transients ◽

Simulation Function ◽

Return Stroke ◽

Lightning Current ◽

Lightning Channel ◽

Section Model ◽

Tall Structure ◽

Current Derivative

The main aim of this PhD work is to advance tall-structure lightning return-stroke current modelling. The Alternative Transients Program (ATP), a version of the Electromagnetic Transients program (EMTP), is used to model the lightning current distribution within a tall structure and the attached lightning channel. The tall structure, namely the CN Tower, is modeled as three or five transmission line sections connected in series. The lightning channel is represented by a transmission line with a continuously expanding length. The presented model takes into account reflections within the tower and within the lightning channel. Locations of reflections, current reflection coefficients and the parameters of the current simulation function are calculated based on the time analysis of the current derivative signal, measured at the tower. The decay parameters of the simulation function are first determined by curve fitting the decaying part of the current obtained from measurement. The other parameters are determined by curve fitting the measured initial current derivative impulse with the derivative of the simulation function, before the arrival of reflections. The simulation results substantially succeeded in reproducing the fine structure of the measured current derivative signal. The model allows for the computation of the lightning current at any point along the current path (the tower and the attached channel), which is required for the calculation of the associated electromagnetic field. Using the three-section model of the tower, the presented return-stroke current model enables the determination of a discrete return-stroke velocity profile, demonstrating that the velocity generally decays with time. Furthermore, based on the five-section model, the proposed approach enables taking into account the existence of upward-connecting leaders, which allowed, for the first time, the determination of upward-connecting leader lengths and return-stroke velocity variation profiles with more details. The return-stroke velocity profile is found to initially increase rapidly with time, reaching a peak, and then decrease less rapidly. The proposed model is also experimentally verified based on the comparison between the computed and measured electromagnetic fields. The simulated electric and magnetic field waveforms are found to reproduce important details of the measured fields, including initial split peaks that appear due to channel-front reflections in the presence of upward-connecting leaders.

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