Lightning Protection - All you want to know
Updated: Jun 12, 2022
Lightning Kills 1000’s of people annually in India
(Note: Videos of all programs are available in this blog)
Lightning is a natural hazard that causes serious personal injuries, death and economical losses in many parts of the world. Lightning ignites fires that may bring an entire building or a house down to ashes. At a lower degree of damages, the lightning current may destroy electrical, electronic and communication equipment beyond repair. Many of these dangers and losses could be minimized by educating the general public and the engineers on lightning and its safety needs.
Considering the important of Lightning Protection as cone of the needful areas of awareness and research in India, the Centre for Innovation in Science and Social Action (CISSA) and the Lightning Awareness & Research Center (LARC), are continuously organizing training programs since 2006. This year the program is made as a part of VIDYUT SURAKSHIT BHARAT ABHIYAN, an yearlong awareness program on electrical safety in buildings.
The training will be made by the most eminent personality in the subject, Dr. G R Nagabhushana (retd), Former Professor & Chairman, Dept. of High Voltage Engg., Indian Institute of Science, Bengaluru.
This webinar series is organised on 4 Sundays (22 & 29 May, 05 & 12 June)
11 AM and 1 PM (2 hours each)
No registration required.
I. Lightning and atmospheric event’s: (22 May 2022)
Atmospheric electric phenomena. (Lightning and transient luminous events)
Atmosphere – Different layers. (Particularly troposphere (+300kV above earth), Global capacitor, Role of lightning)
Physics of lightning phenomena. (Mechanism of cloud electrification, Intracloud, Intercloud and cloud-ground lightning, Initiation and properties of cloud to ground lightning, Dependence of lightning incidence on latitude)
Hazards due to lightning – Basics.
The first part of this program was attended by 120 participants
Video Part 1
II. Details of hazards due to lightning and basics protection of human: (29 May 2022)
Electric shock hazards to humans and animals. (Contact with tall poles trunks – Role of inductance of current path, effect of rate of rise of stroke current, Step potential –Role of soil resistivity, typical soil resistivities, resistivity of concrete blocks, Shocks due to contact with objects carrying lightning currents, Activities prove to lightning strokes and types of injuries or fatalities)
Protective measures for humans.
Video Part II
0:00 Fire Hazard
6:49 Hazard to humans and animals
56:31 Summery of type of Hazard and methods of avoidance
1:05:10 Lightning injury photographs
III. Protection techniques for buildings(IS/IEC 62305): (05 June 2022)
Electro geometric method (Semi vertical angle α).
Method based on striking distance.
(Rod + Mesh) method.
Protection system. (Aerial terminal (+Bonding), Down conductor system Earth conductor system (+Bonding), (- When is ground a ground?!), Soil resistivity (Presented earlier also))
Simulation (Computer based) for verifying (1)& (2) above
1:50 Main presentation
1:15:50 Protection of transmission towers
1:33:50 Q & A
IV. Additional Important Topics: (12 June 2022)
Some illusory methods of protection (ESE or equivalent method, single pole with metal ring of bicycle wheel)
Possible laboratory testing & limitations(Lightning test facility (CABS)
Lightning and power transmission system - Basics of insulation co-ordination.
All the four programs were successful with more than 600 participation (4 programs together). The Q&A will be included in this blog soon.
About Dr. G R Nagabhushana.
Prof. Dr. G. R. Nagabhushana, (Retd. IISC)
BSc (Mysore University), BE, ME, PhD (all from Indian Institute of Science, Bengaluru)
Formerly Professor & Chairman, Dept. of High Voltage Engg.,Indian Institute of Science, Bengaluru,
Presently Professor Emeritus, MSRIT, Bengaluru,
1963, joined as faculty in department of high voltage engineering, IISc. From 1965, he has been dealing with various aspects of lightning and protection from lightning of Transmission lines, Satellite Launch Pads (of ISRO), Power equipment & Insulation coordination.
The unique Lightning Test Facility of ADA (DRDO) having 4 million volts Impulse (Lightning) Voltage Generator, 200,000 A, 100,000 A, 2000 A and 200A Impulse (lightning) Current Generators was designed and commissioned by him. This facility was and even now being used under his guidance to evaluate the lightning performance of Light Combat Aircraft, Hansa Aircraft, other Aircraft components of HAL.
He is the advisor for several companies to develop high voltage laboratories involving lightning voltage and current generator.