hpem (high power electromagnetic) threats and immunity ... · pdf fileemission of an...
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montena technology sa
Route de Montena 89 ▪ 1728 Rossens ▪ Switzerland ▪ Tel. +41 26 411 84 84 ▪ Fax +41 26 411 17 79
[email protected] ▪ www.montena.com
HPEM (high power
electromagnetic)
threats and immunity test
methods
Nicolas Mora, Werner Hirschi
September 5 2016
Natural <-> man made HPEM threats
Natural
Lightning strikes
Geomagnetic storms
Electrostatic discharges
Man made
Nuclear Electromagnetic pulse (NEMP)
Non nuclear EMP : narrowband and wide
band electromagnetics sources
2
Lightning strikes
Direct or indirect lightning
Threat regarding to helicopters, airplanes,
infrastructure, electronic equipment,
missiles, ammunition,….
3
Geomagnetic storms
Caused by a solar wind shock wave
and/or cloud of magnetic field which
interacts with the earth’s magnetic field
Induces high currents on long lines
(hundreds of A)
4
ESD
5
Charging by
air friction of rotor blades
and airfoils
ion emission from the engine
charged particles in air (rain,
snow, dust)
Voltage: up to 300 kV
Man made electromagnetic threats
6
HEMP
Narrowband
Source: IEC 61000-2-13
Wideband
Man made electromagnetic threats
Identified threats
7
Source: IEC 61000-4-36
Man made electromagnetic threats
Examples of man made HPEM sources
8 Source: IEC 61000-4-36
Hyperband Mesoband Hypoband
Man made electromagnetic threats
Hyperband
9 Source: IEC 61000-4-36
Hyperband Mesoband Hypoband
Man made electromagnetic threats
Mesoband
10 Source: IEC 61000-4-36
Man made electromagnetic threats
Hypoband
11 Source: IEC 61000-4-36
Example of narrowband HPEM source
12
Source: http://www.globalsecurity.org/military/library/report/1996/apjemp.htm
Flux Compression Generator (FCG)
13
Generated current: several tens of Mega-Amps
Virtual cathode radiator (Vircator)
14
Source for
high voltage
pulsesC
ath
od
e
An
od
e
Vir
tua
l
ca
tho
de
Electro-
magnetic
wave
Die
lec
tric
ma
teri
al
Resonant cavity under vacuum
Vircator
Example of HPM test setup using a vircator
15 Source: Montena - Armasuisse, Switzerland
Examples of UWB sources
Portable UWB sources
16 Source: Diehl, Germany
High power UWB source
High voltage (kV to MV) pulses with very
short rise time (some hundreds of ps)
17
1 MV / ~ 200 ps rise
Radiated Field :
~ 62 kV/m at 85 m
New ideas
18
NATO car device vows to stop suicide bombers, available in
http://www.cnet.com/au/news/nato-car-device-vows-to-stop-suicide-
bombers/
Typical UWB test system
Fast pulser + HIRA antenna
19
30 kV / ~ 100 ps rise time
Radiated Field :
< 1 kV/m at 50 m
Typical UWB test system
20
Typical UWB test system
21
Nuclear Electromagnetic Pulse (NEMP)
22
Explosion in an altitude of
several hundreds of km
Gamma ray impulse
Compton effect in the stratosphere
(and other effects)
Emission of an electromagnetic pulse
Irradiation of an area with a diameter of
several hundreds of km on earth
The pulse emission can be
divided in:
Early time: fast rise time /
high amplitude / low energy
Intermediate time: moderate
rise time / amplitude / energy
Late time: slow pulse / low
amplitude / high energy
Typical measured NEMP
NEMP phenomena
23
EM pulse definition as per standard
Pulses definition according to IEC 61000-2-9
24
Coupling on systems / sub-systems
25
Pulse type
Standardized
Waveform
(MIL-STD)
Subsystem
or device
Short line
1 – 10 m
Middle line
10 m – 10 km
Very long line
10 – 5’000 km
Enclosure Lines
Early time
(nanosecond range)
2 / 23 ns or
20 / 550 nsEffect Effect Effect Effect
Intermediate time
(microsecond range)1.5 µs / 5 ms No effect No effect Effect Effect
Late time
(seconds range)0.2 / 25 s No effect No effect No effect Effect
NEMP effect on equipment
Coupling on lines (and antennas)
Coupling on enclosures
26
Subsystems or stand alone systems
Typical standalone systems and
subsystems
System directly exposed to EMP threat
Radiated susceptibility of the subsystem
to E1 pulse
27
Radiated susceptibility test RS105
Test at threat level in a
NEMP simulator
MIL STD 461, RS105
Fast E-field pulse
Rise time : 2.3 ns
Duration : 23 ns
Intensity : 50kV/m
Test all orthogonal polarisations
At least 5 pulses
28
Radiated susceptibility test RS105
Example of NEMP test system as proposed in
MIL STD 461
29
Radiated susceptibility test RS105
Typical NEMP simulator for subsystem tests
30
3.6m high RS105 test system with a 230kV pulse generator
installed on an open area test site
Distributed
Termination
load
HV
generator
Radiating
line
Ground
planeDerivative
field sensor
Radiated susceptibility test RS105
Typical NEMP simulator for subsystem tests
31
indoor 2.7m high RS105 test system with a 170kV pulse generator
32
7.2 m high radiation line
Approx. EUT size: 5 x 3.5 x 3 m (L x W x H)
Indoor or outdoor installation
Mobile NEMP simulator (7.2 m)
7.2 m
Up and ready
in less than 3 h
Radiated susceptibility test RS105
Example of larger NEMP simulator system level tests
33
9 m high RS105 test system with a
800kV pulse generator
Electromagnetic field pulse propagation
34
What about cables?
35
What about cables?
Split the test in two parts :
Radiated susceptibility tests
Conducted susceptibility tests
Intrasite and intersite cables couple with
E1, E2 (and E3)
Protections are installed at each electrical
entry point and shall be tested according
to MIL STD 188-125, appendix 2 : Pulse
Current Injection
36
MIL STD 188-125, PCI
37
MIL STD 188-125, PCI
Pulse definition and injections levels
38
MIL STD 188-125, PCI
Acceptable residual current levels
39
MIL STD 188-125, PCI
Acceptable residual current levels
MIL STD 461, CS116
to test the equipment40
MIL STD 188-125, PCI
Example of needed test equipment
41
Short pulse generator 1 – 5 kA
Short pulse generator 0.1 – 1.3 kA
Intermediate pulse generator
Charge line pulser
Coupling devices
E3 test for intersite cables?
Example of test setup for E3
42
E3 test for intersite cables?
Very expensive test
Only affects long lines -> high voltage
power grid.
Better approach with modelling and
simulations.
To be considered together with power grid
switching issues and possibly
geomagnetic storms threat.
43
44
Test of large systems
On going project for a 25m high, 140m long NEMP simulator
with a 2MV pulse generator
Test of large systems
Build very large EMP simulator ! ?
45 Trestle in the USA : largest ever built EMP simulator
Test of large systems
Usually impossible to test whole system
at threat level
Test at lower level
Measure currents
and field on each
sub system
Interpolate to get
threat level for each
subsystem
Test each subsystem
accordingly46
Test of fix systems
Bring the simulator to the test site ! ?
47 MEMPS : 25 m high mobile EMP simulator
Test of fix systems
Usually impossible to expose fix
equipment of system to EMP threat
Perform CW shielding effectiveness test.
Perform PCI for electrical entry points
Validate with a CWI (continuous wave
immersion) test in frequency domain
48
CWI test
Test setup as proposed in MIL-STD 188-125
49
CWI test
1. Excite the EUT at level measured by the referencesensor : Filluminating(jw)
2. Measure the fields, currents or voltages inside the shelter : Finternal(jw)
3. Build the transfer function : A(jw) = Finternal(jw)/Filluminating(jw)
4. Take analytical form of total field HEMP excitation : Fthreat(jw)
5. Convolve with the transfer function to get the inside threat : S(jw) = A(jw)*Fthreat(jw)
6. Get the threat in time domain using inverse FFT : s(t)
50
Non nuclear EMP : already a fact
In spring 2003, stories leaked to the press
suggested that the Pentagon, after decades of
research, had finally deployed such a device in Iraq.
And when news footage showed a U.S. bomb
destroying an Iraqi TV station, many informed
onlookers suspected it was an electromagnetic “e-
bomb.”
51
Non nuclear EMP : already a fact
52
Already a fact
Public literature has reported criminal usages of electromagnetic tools:1. In Japan, criminals used an EM disruptor to interfere with the computer of a
gaming machine and falsely triggered a win.
2. In Kizlyar, Dagestan, Chechen rebel command disabled police radio communication using RF jammers during a raid.
3. In St. Petersburg, a criminal used an EM disruptor to disable a security system of a jeweller store. The reports mentioned that building the EM disruptor posed a technological challenge similar to assemble a home microwave oven.
4. In multiple European cities (e.g. Berlin) criminals used GSM-Jammers to disable the security system of limousines.
5. In London, UK, a city bank was the target of a blackmail attempt whereby the use of EM disruptors was threatened to be used against the banks IT-system.
6. In Russia, Chechen rebels used an EM disruptor to defeat a security system and gain access to a controlled area.
7. In the Netherlands an individual disrupted a local bank IT network because he was refused loan. He constructed a briefcase-size EM disruptor, which he learned how to build from the internet. Bank officials did not realize that they had been attacked or what had caused the disruption until the assailant was caught.
8. In Moscow, the normal work of one automatic telephone exchange station has been stopped as a result of remote injection of a voltage in to a telephone line. As a result two hundred thousand people had no phone connection for one day
53 Source: www.ursi.org/proceedings/procga11/ursi/E03-9.pdf
Conclusion
Immunity assessment to HPEM of subsystems or mobile small-medium size systems is quite simple
Assessment of large systems against HPEM requires : An system analysis and identification of each
subsystem
An specification of the threat level for each subsystem (by analysis, CWI or low level exposure)
An assessment of the susceptibility of each subsystem at specified exposure level.
54
Thank you for your attention !
55