Webinar «Methods of active influence on lightning strike. How ESE lightning rods are effective and feasible?», page 2

Let's discuss the following thing. It is necessary to reduce voltage on charge capacities and increase the number of stages, arrange voltage multiplication system inside an ESE lightning rod. But if you, reducing the voltage, want to keep the energy capacity, you need to come out of the well-known correlation of energy equality. And if you reduced the voltage 10 times, for example from 500 kV to 50 kV, then you need to increase the capacity in 100 times. And instead of 1000 pF you will get 0,1 mcF. And now at 50 kV on the same capacity, you need to collect the charge of 5 mCl. What's this? What to compare this charge with?

Ток короны, мкА – Corona current, mcA

Одиночный электрод – single electrode

Мульти система с расстояниями между вершинами – multi system with the distance between the tops

Время, с – time, s

And since I can't, people start to invent various things. For example, on the image you see, it is a picture at the laboratory tests of a lightning rod, which is called M-200. Look, what is it on the lightning rod? There is not one shielding point, but several. The idea is quite simple. Since one point doesn't manage the condenser's charge, I made them 5,10,20. As many as necessary. The situation is as follows. I can make the electrodes I need. But it doesn't increase the summary corona current.

The channel of the downward lightning enhances the electric field of the atmosphere, but practically doesn’t change the charge on the cumulative capacity of the active lightning rod

Заряд , мКл – charge, mCl

Погонный заряд канала молнии – Linear charge of the lightning channel

Скорость роста – growth rate

Время роста молнии, мc – lightning growth time , ms

Синхронизацию нельзя осуществить по ростку заряда на накопительной – Synchronization can’t be carried out by the charge spire on the cumulative

All this together makes us think about the following. It makes us think, that those technical problems which constructors of ESE lightning rods have, are hard to be resolved.

According to CIGRE data from 80 to 90% of downward negative lightning are multi-component

Average number of components – 2

Average pause between the components – 60-70 ms

Average percent of channels not repeating the source trajectory – 50^

There is no time for the charge of the cumulative capacity in the inter-component pause!

Now I want to look at these ESE lightning rods. I took various pictures from the Internet.

French standard NFC 17-102

1. Test on the absence of damages by 100 kA pulse 10/350 ms

2. Test for electromagnetic inductance at the presence of electronic components

3. Test in salt fog

4. Test in sulphur atmosphere

DO NOT have direct relation to the efficiency estimation!

1. Test for preventing streamer emission formation

ESE lightning rod and a conventional lightning rod of equal height are compared

• Height of lightning rod is not less than 1 meter
• The distance surface-surface H is not less than 2 m
• Relation h/H= 0,25 – 0,5 m
• Stable electric field 20-25 kV/m
• Pulse field 250/2500 ms (typical parameter)

The difference of counter charge start time is measured (streamer leader???)

(!!! Optical registrations are not required!!! Only deformation of voltage pulse)

Let's have a look at another moment. And this is the following. What do companies producing ESE lightning rods show? What do these companies show to their customers? I studied the modern French standard, which shows how to test ESE lightning rods and how to judge whether they are fine or not. I am showing you the real extracts from the standards. The first test - is a test for lightning current equal to 100 kA 10/350 ms to make sure the device is not damaged and remained mechanically safe. The next test for electromagnetic compatibility, if there are some semi-conductor or micro-processor managing devices. If there are none, they must not be tested. Then device test for its functioning in a salt fog. And a test in sulphur atmosphere. All these tests have no relation to the efficiency of ESE lightning rods operation. It is the same as if you were allowed to test an airplane and you would test the strength of chairs, brightness of light and volume of petrol tanks. But when it was time to test an airplane, you would say - why to test it? It's an airplane, it should fly. Companies do practically the same. What do they offer to test? They offer to test the following. It offers to put the head of an active lighting rod into a discharge gap, less than 2 meters long, and put an ordinary lightning rod near. Then give a voltage pulse with the front of 250 ms to it and see from which lightning rod - ESE or ordinary - streamer flash appears. If this streamer flash from an active lightning rod overhauls the ordinary lightning rod to 10 ms, the French standard considers this active lighting rod applicable for practical use. That's it!

Время старта стримерной вспышки – streamer flash start time

Конус - cone

Полусфера - semi sphere

Время старта встречного лидера – counter leader start time

Между электродами – between the electrodes

Удары в острие – strike into the edge

Such experiments were held in Russia, at ENIN. And in order to ignite the early streamer emission, it turned out that no additional voltage was necessary. It is enough to put two electrodes. Take one electrode with a sharp conic head, and the second - of the same height with a hemi-sphere head. And we get time scatter statistics. It is time statistics with the conic head, and this - with a hemisphere head. The leader at the hemi-sphere head was always late. So, if to trust the French, the charge should always hit the sharp electrode, it should strike here. And here is the statistics. If to part the electrodes to one meter, the number of strikes into these two electrodes will differ in the range of 8%. So, roughly speaking doesn't differ at all. Now you can judge the efficiency of French tests.

William Rison report 

At the session “Untraditional lightning protection means – myth or reality

Observations o the mountain about 3200 m high with a flat top

Out of 13 lightning strikes, fixed by video cameras and registers on the base of fuse links, no strike got into ESE lighting rod, though they were mounted at the distance of 6 meters from the conventional rods of the same height

You see? Before them, there was a special session of the association of engineers, electricians and electronic engineers in 2003 which was called "ESE lightning rods - myth or reality?". And a ground of American specialists under the head of Rison reported the results of comparative tests of ESE and conventional lightning rods at this session. They did the following thing. There is a mountain 3200 meters high with a flat top near the university in New Mexico and they put a group of ESE and a group of conventional lightning rods there. They had been monitoring them during 3 years. And during 2 years there were automatic cameras which recorded the strike point. The result was impressive. Lightning did not strike into a conventional lightning rod, neither they hit the ESE lightning rod at all. Now there's a question. What to think about all that? What to think about ESE lightning rods in this situation? Ad what to think about the experiments held. These are serious people. It is impossible to believe that they lied in their experiments or measured something improperly. But there should be some explanation.