Lightning protection system in wind turbines
Electric lightning strikes and how to protect them
Lightning strikes result from the formation of electrostatic charges and their polarization in thunderstorms. Thunder clouds form either as a result of an increase in the temperature of the air in contact with the earth’s surface and its upward movement, then cool, moist air is displaced from the layers of ‘upper air down, or due to the collision of a block of cold air with moisture with a mass of hot air.
And if the mechanism of cloud formation is very well known today, but how the loads in thunderstorms and their precipitation are still not definitively confirmed, and with this, most theories confirm that the upper layers of the clouds Containing frozen water crystals acquire positive charges while lower layers contain liquid water droplets Negative charges Consequently, the surface of the Earth closest to the lower layers of clouds acquires positive charges Ce which represents a large difference in force between the clouds and the earth’s surface because the storm clouds are low and close to the earth’s surface. Also charged with different electrical charges, which causes a discharge of charges, including lightning in the clouds and not reaching the ground.
Fortunately, the highest percentage of lightning strikes occurs between clouds and does not lead to direct direct danger, while the percentage of dangerous lightning strikes to Earth does not exceed 10-15 of the total Lightning strikes, and even if this ratio seems low, the lightning strikes mentioned cause if affected. Buildings, installations and direct persons other than these, serious damage often associated with the occurrence of fires due to the high currents which circulate at the place of the lightning strike, which can reach tens of kilometers, and air strikes can cause indirect negative effects, in particular on electrical and electronic installations, causing them by an increase in The percentage of internal forces on these devices can seriously damage or damage these devices.
It should be noted that the occurrence of lightning strikes varies geographically from region to region, so that maps are generally produced showing the distribution of air strikes and the rates of their occurrence.
Based on technical rules and standards require that the necessary measures be taken to protect against the potential risk of lightning strikes, depending on the geographic area and another group of factors. One of the global lightning protection systems can be adopted as 1-2-1 IEC 42016 or British 1496: 326 BSCP or German 0675 .VDE
When a lightning strike strikes one of the wind turbines, as in the form, the large electric current passes through the good grounding system of the turbine on the ground and instead, we protect the turbine from destruction because a good path for the passage of electric current to the ground is created and the question increases when installing wind turbines in areas where the occurrence of a lightning phenomenon occurs especially in the country In Europe, where the winter experiences extreme weather fluctuations.
Lightning strike facts:
- The lightning current is around 30,000 amps.
- The current voltage is 1 billion volts.
- Thunderbolt’s speed is 220,000 km / h.
- The temperature is 30,000 ° C.
- The amount of energy it has is around one megajoule
