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Scope
• What & why of lightening• Designing factor of lightening protection• Types of protection• Lightening detection • Conclusion
What & why of lightening
• Flash that temporarily neutralizes massive electrostatic discharge within / among clouds or to earth surface
• Intra cloud , cloud to cloud , cloud to ground• 40 -50 strikes per second, 1.4 billion per year • Latitude , prevailing wind ,relative humidity,
proximity to cold and warm bodies
What & why of lightening
• Tropics freezing level is high so 10% are CG• Norway 50% are CG• Mountains of Eastern Democratic Republic of
Congo have 146 strikes per sqkm
What & why of lightening
Characteristics o Peak value of current o Steepness of lightening currento Charge of lightening current o Specific energy of lightening current
Types of protection
Air termination Rolling sphere Mesh protection Protective angle
Ground conductor method
Lightening detection
• Ground based system using multiple antennao radio detection & characteristic frequency• Mobile system o Frequency and attenuation• Space based systemo Artificial satellite
Lightening detection
Limitation(s)Rejection of cloud to cloud flash(Ground
antenna) Miss-interpretation due to attenuation tech(Mobile Antenna) Slow availability w.r.t real time application(Satellite)
References
• Lightening Detection Guide• Wikipedia• Theories of Lightening formation • Charge structure dynamics