# Lightning Protection of Large Territories: Parks, Grounds, Plant Territories. Page 2

## Webinar text. Page 2

Effect of a forest land along the HVPL route

Влияние лесного массива по трассе ВЛ - Effect of a forest land along the HVPL route
Число прорывов молнии - Number of lightning strikes
Высота леса, м - Forest height, m
Расстояние до леса – 20 м - Distance to the forest — 20 m
Лес с одной стороны ВЛ - Forest on one side of the HVPL
ВЛ по лесной просеке - HVPL along the forest way
Пролет длиной 400 м - Passage 400 m
Опоры ПБ4 - PB4 supports
Высота повеса провода – 23 м - Height of the wire— 23 m
Провес провода - 6 м - Wire slack — 6 m
Тросы демонтированы - The wires are removed

In general, the following question arises: how to deal with these data if the power line is located in forest lands? The same thing takes place here as described in the beginning. If forest lands are located from one or both sides along the power line, then the actual height of the power line, its elevation over the land is reduced. As a result of this, the number of lightning strikes into the power line is reduced. I have shown how the number of breakthroughs into the power line varies, if a forest land is located from one or both sides. These calculations can be easily performed using the calculation technique provided for you by ZANDZ. As far as I understand, it is completely free of charge. It is correct, isn't it? This is the situation we can talk about with certainty. For me, the use of ground wires is a very important point.

Real objects with large territories

Реальные объекты с большими территориями - Real objects with large territories
Хранилища углеводородною топлива, - Storages of oil fuel,
нефте и газоперекачивающие станции, - Oil and gas transfer stations,
электрические нодстации высокого напряжения, - High voltage electrical substations,
заводские территории плотной застройки - Densely built plant territories
Стержневые молниеотводы не выход - Lightning rods are not a good solution

You can see a crossed-out photo. It is an oil tank, and the lightning rods are installed thereon. Four, six, or even eight rods can be installed on this tank. "This is great! Let’s design the lightning protection this way!" This is how the design is made. And you can see the result of this on the right. The lightning rod protection is not a very reliable thing for the tank farm. This is because, in order to ignite and make a fire in this tank farm, you do not necessarily need a lightining strike to the tank. If it gets to the lightning arrester, then a high strength of the electrical field will be generated around the lightning arrester. And this high strength of the electrical field may form incomplete electrical crown discharges similar to the St. Elm's fire, which can burn the gas discharge zones over the tank. And if the protection of breathing valves of these tanks is poor, then the flame will go to the tank and you will see what happens in the photo.

Wire lightning arresters

Что делать? Перед вами рисунок, который сделал не я. Это рисунок проекта молниезащиты на одном из резервуарных парков, я не буду говорить на каком резервуарном парке, но суть дела здесь такая: шесть больших резервуаров с топливом и три грозотроса, которые идут по всей длине территории занятыми резервуарами. Теперь молния находится достаточно далеко от резервуара, тросовая молниезащита обеспечит действительно надежную защиту. А опоры этих грозотросов вынесены за территорию резервуарных парков и ток, который будет стекать с этих самых опор через заземлители, он будет растекаться не по территории резервуарного парка, а за этой территорией и не вызовет таким образом никаких наводок. Здесь тросовые молниеотводы – явно очень серьезное преимущество в отношении тех, которые нужно было бы поставить на резервуарах. Есть одна маленькая зацепка – проект был, а тросовых молниеотводов не было. Поэтому я вам и не хотел называть, откуда это.

Тросовые молниеотводы вместо стержневых

Тросовые молниеотвод - Wire lightning arresters
Единственное решение для больших территорий - The only solution for large territories

What should we do? You can see a picture; it is not mine. This is the drawing with the lightning protection design for a tank farm. I will not say what reservoir farm exactly, but the point is as follows: six large fuel tanks and three ground wires that go along the length of the territory occupied by the tanks. Now, the lightning is far enough from the tank, and the ground wire will provide a really good protection. And the supports for these ground wires are located outside of the tank farm territory, and the current that flows from these supports through the earthing devices will flow not in the tank farm territory but outside of it, and will not thus cause any interference. Here, the wire lightning arresters are a very good advantage compared to those you should have installed on the tanks. We have a small clue: there was a design but there were not any wire lightning arresters. Therefore, I did not want to tell you where it was taken from.

Wire lightning arresters instead of rods

Тросовые молниеотводы вместо стержневых - Wire lightning arresters instead of rods —
- лучшее средство борьбы с электромагнитными наводками от тока молнии в цепях вторичной коммутации — are the best solution to struggle with the electromagnetic interference from the lightning current in the secondary switch circuits

What should we do? You can see a picture; it is not mine. This is the drawing with the lightning protection design for a tank farm. I will not say what reservoir farm exactly,

DAS system

Кратность снижения числа ударов - Factor of reduction in the strike number
Радиус многоэлектродной системы, м - Multi-electrode system radius, m
Останкинская телебашня - Ostankino TV Tower
Система DAS - DAS system

We have already discussed the lightning protection using shielding systems. We had a special seminar where we discussed that by using the shielding system (such as an umbrella whereupon large number of needles are located), we can close the surface and protect it against the lightning strike. But this umbrella is not a very good lightning arrester because the only thing it protects is itself. Now you can see that the umbrella is installed over the airport lighting tower. It protects the tower against lightning strikes. The lightning cannot penetrate here; they do not strike either a tower or an umbrella. And such protection system is suitable for struggling against the electromagnetic interference.

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