7/28/2019 Clemson Lightning
1/53
Lightning and Lightning Protection
Todd H. HubingMichelin Professor of Vehicular Electronics
Clemson University
7/28/2019 Clemson Lightning
2/53
2007 Lightning Lecture T. Hubing 2
Course Topics
Lightning Formation
Lightning Safety
Lightning Protection
7/28/2019 Clemson Lightning
3/53
2007 Lightning Lecture T. Hubing 3
- V +
V
Dielectric Breakdown
7/28/2019 Clemson Lightning
4/53
2007 Lightning Lecture T. Hubing 4
Dielectric Breakdown
- V +
V
7/28/2019 Clemson Lightning
5/53
2007 Lightning Lecture T. Hubing 5
Dielectric Breakdown
- V +
-+
V
7/28/2019 Clemson Lightning
6/53
2007 Lightning Lecture T. Hubing 6
Dielectric Breakdown
- V +
-+
V
7/28/2019 Clemson Lightning
7/53
2007 Lightning Lecture T. Hubing 7
Dielectric Breakdown
- V +
+
V
+
+
7/28/2019 Clemson Lightning
8/53
2007 Lightning Lecture T. Hubing 8
Dielectric Breakdown
- V +
+
V
+
+
PLASMA
7/28/2019 Clemson Lightning
9/53
2007 Lightning Lecture T. Hubing 9
Warm Humid Air
Lightning Formation
7/28/2019 Clemson Lightning
10/53
2007 Lightning Lecture T. Hubing 10
Warm Humid Air
Water Droplets
Lightning Formation
7/28/2019 Clemson Lightning
11/53
2007 Lightning Lecture T. Hubing 11
Water Droplets
Ice Crystals
Lightning Formation
7/28/2019 Clemson Lightning
12/53
2007 Lightning Lecture T. Hubing 12
Water Droplets
Ice Crystals+
++
+ ++ ++
-
++
+ ++
++
- - - -
--
-
-
-
Charge Separation
7/28/2019 Clemson Lightning
13/53
2007 Lightning Lecture T. Hubing 13
++
++ ++ +
+
-
++
+ ++
++
- - - -
--
-
-
-
+ + + + + + + + + + + + ++ + ++
Charge Separation
7/28/2019 Clemson Lightning
14/53
2007 Lightning Lecture T. Hubing 14
- --
---- - - -
+ + + + + + + + + + + + ++ + ++
Charge Separation
7/28/2019 Clemson Lightning
15/53
2007 Lightning Lecture T. Hubing 15
- --
---- - - -
+ + + + + + + + + + + + ++ + ++
+
++
+
++
+
+ +
+
+
+
+
+
Stepped Leaders
7/28/2019 Clemson Lightning
16/53
2007 Lightning Lecture T. Hubing 16
- --
---- - - -
+ + + + + + + + + + + + ++ + ++
+
++
+
++
+
+ +
+
+
+
+
+
Streamers
7/28/2019 Clemson Lightning
17/53
2007 Lightning Lecture T. Hubing 17
- --
---- - - -
+ + + + + + + + + + + + ++ + ++
+
++
+
++
+
+ +
+
+
+
+
+
Attachment
7/28/2019 Clemson Lightning
18/53
2007 Lightning Lecture T. Hubing 18
- --
---- - - -
+ + + + + + + ++ + ++
++
+
+ +
+
+
+
Return Stroke
7/28/2019 Clemson Lightning
19/53
2007 Lightning Lecture T. Hubing 19
Mean Number of Thunderstorm Days in the
United States
9040
40
40
50
5
20
510
20
20
4050
70
50
30
7/28/2019 Clemson Lightning
20/53
2007 Lightning Lecture T. Hubing 20
Lightning Statistics
Peak currents are generally 10 kA
to 20 kA, but may exceed 100 kA.
First strokes generally have more
current than subsequent strokes.
7/28/2019 Clemson Lightning
21/53
2007 Lightning Lecture T. Hubing 21
Lightning Statistics
Approximately 2000 thunderstorms
are in progress in the world at anygiven time.
Commercial aircraft are struck bylightning every 5,000-10,000 flying
hours (on average).
7/28/2019 Clemson Lightning
22/53
Boeing 747 over Narita Airport
2007 Lightning Lecture T. Hubing 22
7/28/2019 Clemson Lightning
23/53
2007 Lightning Lecture T. Hubing 23
Lightning Statistics
Lightning kills approximately 100
people in the U.S. every year.
7/28/2019 Clemson Lightning
24/53
2007 Lightning Lecture T. Hubing 24
Lightning Dangers
Electrical Shock
Burns
Secondary Effects
7/28/2019 Clemson Lightning
25/53
2007 Lightning Lecture T. Hubing 25
Where is the safest place to be in a thunderstorm?
a) at home, taking a shower
b) in your car, talking on your cell phone.
7/28/2019 Clemson Lightning
26/53
2007 Lightning Lecture T. Hubing 26
Where is the safest place to be in a thunderstorm?
a) on a golf course
b) standing under a power line
c) standing under a tree
d) in a Boeing 777 flying through the storm
7/28/2019 Clemson Lightning
27/53
2007 Lightning Lecture T. Hubing 27
a) row towards shore
b) prop your paddle up in one end of thecanoe and crouch down in the other
c) swim towards shore
d) turn the canoe over and get under it
Youre in a canoe in the middle of a large lake
when a thunderstorm approaches. What shouldyou do?
7/28/2019 Clemson Lightning
28/53
Part II: Lightning Protection
Todd H. HubingMichelin Professor of Vehicular Electronics
Clemson University
7/28/2019 Clemson Lightning
29/53
2007 Lightning Lecture T. Hubing 29
Lightning Protection
Protection from currents
Protection from arcs
7/28/2019 Clemson Lightning
30/53
2007 Lightning Lecture T. Hubing 30
Lightning Protection
7/28/2019 Clemson Lightning
31/53
2007 Lightning Lecture T. Hubing 31
Lightning Protection
7/28/2019 Clemson Lightning
32/53
2007 Lightning Lecture T. Hubing 32
Lightning Rods
7/28/2019 Clemson Lightning
33/53
2007 Lightning Lecture T. Hubing 33
Lightning Rods
7/28/2019 Clemson Lightning
34/53
2007 Lightning Lecture T. Hubing 34
Cone of protection
Lightning Rods
7/28/2019 Clemson Lightning
35/53
2007 Lightning Lecture T. Hubing 35
PHONE LINE
Lightning Protection
7/28/2019 Clemson Lightning
36/53
2007 Lightning Lecture T. Hubing 36
PHONE LINE
ELECTRIC LINE
Lightning Protection
7/28/2019 Clemson Lightning
37/53
2007 Lightning Lecture T. Hubing 37
PHONE LINE
ELECTRIC LINE
Lightning Protection
7/28/2019 Clemson Lightning
38/53
2007 Lightning Lecture T. Hubing 38
PHONE LINE
ELECTRIC LINE
Lightning Protection
7/28/2019 Clemson Lightning
39/53
2007 Lightning Lecture T. Hubing 39
PHONE LINE
ELECTRIC LINE
Lightning Protection
7/28/2019 Clemson Lightning
40/53
2007 Lightning Lecture T. Hubing 40
PHONE LINE
ELECTRIC LINE
Lightning Protection
7/28/2019 Clemson Lightning
41/53
2007 Lightning Lecture T. Hubing 41
PHONE LINE
ELECTRIC LINE
PLUMBING
All wires and
pipes thatconnect theinside of thebuilding tothe outsideshould have acommon
ground.
Building Ground
7/28/2019 Clemson Lightning
42/53
2007 Lightning Lecture T. Hubing 42
PHONE LINE
ELECTRIC LINE
PLUMBING
All wires and
pipes thatconnect theinside of thebuilding tothe outsideshould have acommon
ground.
Note: Thisdoesntinclude thelightning rod
ground, sincethis does notenter the
building.
Building Ground
7/28/2019 Clemson Lightning
43/53
2007 Lightning Lecture T. Hubing 43
All wires and
pipes thatconnect theinside of thebuilding tothe outsideshould have acommon
ground.
Building Ground
7/28/2019 Clemson Lightning
44/53
2007 Lightning Lecture T. Hubing 44
Lightning currents will prefer a low inductance
(straight) path.
Inductance
7/28/2019 Clemson Lightning
45/53
2007 Lightning Lecture T. Hubing 45
Relying of Faraday Cage to protect everythinginside.
Lightning Protection for Aircraft
7/28/2019 Clemson Lightning
46/53
2007 Lightning Lecture T. Hubing 46
Provide a safe current path to the water.
Lightning Protection for Boats
7/28/2019 Clemson Lightning
47/53
2007 Lightning Lecture T. Hubing 47
Protection where a cable penetrates the building
PHONE LINE
Primary Lightning Protection
7/28/2019 Clemson Lightning
48/53
2007 Lightning Lecture T. Hubing 48
Arc Suppressors
7/28/2019 Clemson Lightning
49/53
2007 Lightning Lecture T. Hubing 49
10s of volts to 1000s of volts
High Energy
Low Capacitance (< 1 pF)
Fail open
Crowbar device
Gas Discharge Tubes
7/28/2019 Clemson Lightning
50/53
2007 Lightning Lecture T. Hubing 50
0.5 volts to 10s of volts
Medium Energy
Higher Capacitance (10s of pF)
Fail open or short
Crowbar device
Thyristors
7/28/2019 Clemson Lightning
51/53
2007 Lightning Lecture T. Hubing 51
0.5 volts to 10s of volts
Low Energy
Higher Capacitance (10s of pF)
Usually fail short
Voltage limiting device
Varistors
7/28/2019 Clemson Lightning
52/53
2007 Lightning Lecture T. Hubing 52
0.5 volts to ~10 volts
Lowest Energy
High Capacitance (10s of pF)
Usually fail short
Voltage limiting device
Diodes
7/28/2019 Clemson Lightning
53/53
Course Summary
Lightning Formation
Lightning Safety
Lightning Protection