雷击过电压的危害与预防

Equipment / Cables / Conductors
Impulse Sparkover/ Puncture Voltages
Longituninal volt. UL Electrical power units to enclosure/
ground
Telecommunications equipment
2c 1b
1a
Rst Information Technology System
S535e
Power Supply System
2a Distant stroke: Stroke into the mediumvoltage overhead line
2b Overvoltage travelling waves on overhead line due to cloud to cloud lightning
3 ... 1*0) e0nerVgy *)depend. values
Impulse Sparkover/Puncture Voltages in Electr. Systems and Equipment up to 1000 V
Equipment / Cables / Conductors
Impulse Sparkover/ Puncture Voltages
Reinforcing Steel
S665e
665e.ppt / 09.09.97
ROOF UF LF
Bonding of Roof Structures
Direct bonding
Bonding via spark gap
Max. Voltage
ûs
=
ku3
·l
·

di dt

max.
b
ûs
l
s
Calculation Example
(di / dt) max. Distances
100 kA/µs s l ku3
b = 3 mm
= 1m
= 10 m
V
= 0.6 m ·kA/µs
ûs 600 V
91-1e.ppt / 04.09.97
Integrated circuits , bipolar technique high level HTTL and operation amplifiers
Integrated circuits, MOS technique
5 ... 8 kV 1 ... 3 kV 0.5 ... 5 kV
6 ... 100 V *) 3 ... 300 V *)
103
3 104
3
105
3 106 f
(Hz)
761e.ppt / 06.09.97
Reinf. Facade
Shielding of Structures
Concrete Structure
Insulating Support Ring Earth Electrode
Earthing Ref. Point Ground Plate
Causes and Effects of Overvoltages 雷击过电压的危害与预防
Causes of Thunderstorm Overvoltages
Direct/nearby stroke:
1 Stroke into external lightning protection system,
2c Fields of lightning channel
535e.ppt / 04.09.97
Calculation of lightning voltage
Prot. Level Current Amplit. kA
i
I
200
II
150
î
III - IV
100
Lit.: IEC 61024-1-1
V
10
110
20
1
1100
200
0.1
11000
Source: Clark, O.; Gavender, R. : Lightning Protection for Microprocessor based Electronic Systems. Recond of Conference Papers Industrial Applications Society, 36th Annual Petroleum and Chemical Industriy Conference 11-13 Sept. 1989, San Diego, CA, USA
1000
60
316
50
100
40
31.6
30
10
Fra Baidu bibliotek20
w
3.16
10
w = 12 mm d = 2 mm
w = 10 cm d = 12 mm
w = 20 cm d = 18 mm
w = 40 cm d = 25 mm
w = mesh width d = rod diameter
1
S761e
0
102 3
process frame (in industrial install.), cables, etc.
2b
1a Voltage drop at the surge earth resistance Rst
2a
1b Induced voltages in loops
1 L1 L2 L3 PEN
20 kV
EBB
PS
External LPS
Water Gas
Cathodic protection of filler pipe
S532/3e
Z
Foundation earth electrode
532-3e.ppt / 08.09.97
Standardization in IEC TC 81
Standard IEC 61312 "Protection against lightning electromagnetic impulses (LEMP)"
some kA some
230 V~ some kA
Water / Gas some kA
553e.ppt / 26.10.98 / ESC
ûs
S91/1e_a
Maximum Induced Voltages in Installation Loops
Max. Voltage
ûs
=
ku2
·
Structure 2
Telecom. cable
i1
S341
U1
some 100kV
i2
U2
0V
341e.ppt / 04.09.97
Impulse Sparkover/Puncture Voltages in Electr. Systems and Equipment up to 1000 V
IEC 61662
"Assessment of risk of damage
due to lightning"
IEC 61663
"Protection of telecommunication
lines against lightning"
S877e_a
877e.ppt / 10.09.97
External Lightning Protection System (Interception System, Down Conductor, Foundation
Telecommunications cables
Signalling and measurement cables, electrical power cables
Electrical power cables
5 ... 8 kV
up to 20 kV up to 30 kV
S216e_b
216e.ppt / 04.09.97
Earth Electrode)
S801e_a
Foundation earth electrode
801e_a.ppt / 09.09.97
Lightning Protection Equipotentialization for Line Entries
Lightning Protection Equipotentialization
di dt

max.
s a
Calculation Example
(di / dt) max. Distances
100 kA/µs s ku2
a = 10 m = 1m = 5000
V kA/µs
ûs 500 kV
91-1e.ppt / 04.09.97
S91/1e_b
Maximum Induced Voltages in Installation Loops
Dangerous Surges in Neighbouring Buildings
some 100 kA
some 10 kV
some 100 kV
some 10 kV 230V OV
Telecomm. Line
some kA
some 10 kA
some
553e
some kA
some
some 10 kA
2000
S738e
738e.ppt / 05.09.97
Surge Voltage Produced by Switching on a Fluorescent Tube
50 V div
2 µs div
S701e
701e.ppt / 05.09.97
Current International Standardization
Devices
Part 4: LEMP for existing structures
Part 5: Application
Guide
S877e_c
877e / 10.09.97
Screening factor Sf Magnetic screen attenuation (dB)
d
Magnetic Screen Attenuation of
Standardization in IEC TC 81 in November 1996
IEC TC 81
"Lightning Protection"
IEC 61024
"Protection of structures against lightning"
IEC 61312
"Protection against lightning electromagnetic impulses (LEMP)"
Transverse volt. Uq between the
of electronic equipment / circuits
Circuits with discrete components (resistances, capacitors etc.) input terminals Integrated circuits, bipolar technique (TTL)
ûE = î·Rst
t Waveform 10/350 µs
Example:
Rst ûE = 100 kA ·1 = 100 kV
S88e
88e.ppt / 04.09.97
Voltages due to lightning inside a building
100 kA
230 V
S1500e
Part 1: General Principles
Published: 1995-02
Part 2: Electromagnetic fields inside structures in the case of
direct or nearby lightning
Part 3: Requirements of Surge Protective
Reinforcing Steel
Ref. Excerpt from Standard VG 96 907 Part 2/Issue Sept. 1986 “Protection against nuclear electromagnetic impulses.”
subsequent stroke
first stroke
230 V
100 kV 100 kV
100 kV 1
1500e.ppt / 04.09.97
A Direct Lightning Stroke into Structure 1 Causes Damage due to Overvoltages in Structures 1 and 2
i
Structure 1
Voltage Induced by Lightning within Distances of 0.1, 1 and 10 km
Distance to point of stroke
km
Electromagnetic field
V/m
Induced voltage in a 1m long cable