HPEM (high power electromagnetic) threats and immunity test methods

Transcription

1 HPEM (high power electromagnetic) threats and immunity test methods Nicolas Mora, Werner Hirschi September montena technology sa Route de Montena Rossens Switzerland Tel Fax products@montena.com

2 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

3 Lightning strikes Direct or indirect lightning Threat regarding to helicopters, airplanes, infrastructure, electronic equipment, missiles, ammunition,. 3

4 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

5 ESD 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 5

6 Man made electromagnetic threats HEMP Narrowband Wideband 6 Source: IEC

7 Man made electromagnetic threats Identified threats Source: IEC

8 Man made electromagnetic threats Examples of man made HPEM sources 8 Source: IEC Hyperband Mesoband Hypoband

9 Man made electromagnetic threats Hyperband 9 Source: IEC Hyperband Mesoband Hypoband

10 Man made electromagnetic threats Mesoband 10 Source: IEC

11 Man made electromagnetic threats Hypoband 11 Source: IEC

12 Example of narrowband HPEM source Source: 12

13 Flux Compression Generator (FCG) Generated current: several tens of Mega-Amps 13

14 Cathode Anode Virtual cathode Dielectric material Virtual cathode radiator (Vircator) Resonant cavity under vacuum Source for high voltage pulses Electromagnetic wave 14

15 Vircator Example of HPM test setup using a vircator 15 Source: Montena - Armasuisse, Switzerland

16 Examples of UWB sources Portable UWB sources 16 Source: Diehl, Germany

17 High power UWB source High voltage (kv to MV) pulses with very short rise time (some hundreds of ps) 1 MV / ~ 200 ps rise Radiated Field : ~ 62 kv/m at 85 m 17

18 New ideas NATO car device vows to stop suicide bombers, available in 18

19 Typical UWB test system Fast pulser + HIRA antenna 30 kv / ~ 100 ps rise time Radiated Field : 19 < 1 kv/m at 50 m

20 20 Typical UWB test system

21 21 Typical UWB test system

22 Nuclear Electromagnetic Pulse (NEMP) 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 22

23 NEMP phenomena Typical measured NEMP 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 23

24 EM pulse definition as per standard Pulses definition according to IEC

25 Coupling on systems / sub-systems Pulse type Standardized Waveform (MIL-STD) Subsystem or device Enclosure Short line 1 10 m Middle line 10 m 10 km Lines Very long line km Early time (nanosecond range) 2 / 23 ns or 20 / 550 ns Effect 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 25

26 NEMP effect on equipment Coupling on lines (and antennas) Coupling on enclosures 26

27 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

28 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

29 Radiated susceptibility test RS105 Example of NEMP test system as proposed in MIL STD

30 Radiated susceptibility test RS105 Typical NEMP simulator for subsystem tests Distributed Termination load HV generator Radiating line Ground plane Derivative field sensor 3.6m high RS105 test system with a 230kV pulse generator installed on an open area test site 30

31 Radiated susceptibility test RS105 Typical NEMP simulator for subsystem tests indoor 2.7m high RS105 test system with a 170kV pulse generator 31

32 Mobile NEMP simulator (7.2 m) 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 Up and ready in less than 3 h 7.2 m 32

33 Radiated susceptibility test RS105 Example of larger NEMP simulator system level tests 9 m high RS105 test system with a 800kV pulse generator 33

34 34 Electromagnetic field pulse propagation

35 35 What about cables?

36 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 , appendix 2 : Pulse Current Injection 36

37 37 MIL STD , PCI

38 MIL STD , PCI Pulse definition and injections levels 38

39 MIL STD , PCI Acceptable residual current levels 39

40 MIL STD , PCI Acceptable residual current levels MIL STD 461, CS116 to test the equipment 40

41 MIL STD , PCI Example of needed test equipment Intermediate pulse generator Short pulse generator 1 5 ka Charge line pulser Short pulse generator ka Coupling devices 41

42 E3 test for intersite cables? Example of test setup for E3 42

43 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 44 On going project for a 25m high, 140m long NEMP simulator with a 2MV pulse generator

45 Test of large systems Build very large EMP simulator!? 45 Trestle in the USA : largest ever built EMP simulator

46 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 accordingly 46

47 Test of fix systems Bring the simulator to the test site!? 47 MEMPS : 25 m high mobile EMP simulator

48 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

49 CWI test Test setup as proposed in MIL-STD

50 CWI test 1. Excite the EUT at level measured by the reference sensor : F illuminating (jw) 2. Measure the fields, currents or voltages inside the shelter : F internal (jw) 3. Build the transfer function : A(jw) = F internal (jw)/f illuminating (jw) 4. Take analytical form of total field HEMP excitation : F threat (jw) 5. Convolve with the transfer function to get the inside threat : S(jw) = A(jw)*F threat (jw) 6. Get the threat in time domain using inverse FFT : s(t) 50

51 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 ebomb. 51

52 52 Non nuclear EMP : already a fact

53 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:

54 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

55 55 Thank you for your attention!