Lightning protection of distribution lines by long flashover arresters (LFA)

The aim of the article is to present and analyze the processes occurring as a result of installing a long flashover arrester (LFA) and a multi-chamber arrester (MCA) as overvoltage protection of power networks. The numerical models of LFA and MCA will be made in order to carry out simulations in the scope of selected structural elements of the considered overvoltage protection device. The above research is a significant supplement to the information on the selection of an effective solution for overvoltage protection.

show abstract

“…In addition to the existing solutions, there are also new surge protection devices, such as MCA or LFA [9][10][11][12][13], among others.…”

Section: Introduction and Principle Of Operation Of Selected Surge Pr...mentioning

confidence: 99%

Comparative Simulation Analysis of Selected Medium and High Voltage Surge Protection Devices

Borecki

Kharchenko

2022

Energies

View full text Add to dashboard Cite

show abstract

“…A low-resistivity material, 2.5 Ω•m resistivity, was used in Reference [18] to cover the grounding conductor; this reduced the power-frequency grounding resistance in a region with high ground resistivity. In Reference [19], a long flashover arrester was installed between the conductor and the ground to protect the distribution line and to reduce the back-flashover rate in the event of a lightning strike. It was shown in Reference [20] that a surge arrester can be applied in severe areas to decrease the overvoltage by inducing the lightning overvoltage; however, overvoltage cannot be suppressed by surge arresters if there is a direct lightning strike.…”

Section: Introductionmentioning

confidence: 99%

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

Sestasombut

Ngaopitakkul

2019

Energies

View full text Add to dashboard Cite

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.

show abstract

“…Transmission lines in power systems (e.g. 220 V, 10 kV, 35 kV or higher) have received a huge attention for the past decades in power system research, the topic could be associated with lightning protection, for instance, overvoltages [1–4], arresters [5, 6], grounding technologies [7] etc. Direct lightning strikes on transmission lines do pose a threat to power systems.…”

Section: Introductionmentioning

confidence: 99%