CISEC: intégration systèmes et CEM phénomènes électromagnétiques 1/
cesic cesic2013-2014
Le lundi mardi, de 17h à 19h
Série de Conférences
Ingénierie des systèmes embarqués critiques 1- Introduction, systèmes critiques
Aéronautique (P. Traverse, Airbus, 18/11/2013)
Espace (JP. Blanquart, Astrium, 25/11/2013)
Automobile (H. Foligné, Continental Automotive, Reportée,au 11/03/2014
2- Sûreté, historique
Histoire de la sécurité du Concorde à l’A380 (JP. Heckmann, Apsys, 9/12/2013)
Comparaison de normes de sûreté (JP. Blanquart, Astrium, JM. Astruc, Continental, 16/12/2013)
3- Développement logiciel, assurance (H. Bonnin, Capgemini, 21/1/2014)
4- Développement matériel, assurance
Automobile (JP. Loncle, Continental, 28/1/2014)
Aéronautique (P. Pons, Airbus, 11/2/2014)
5- Intégration système et compatibilité électromagnétique (JC. Gautherot, ex DGA/CEAT)
Partie 1, 18/2/2014
Partie 2, 25/2/2014
6- Interactions homme-système (F, Reuzeau, Airbus, P. Palanque, IRIT, 18/3/2014)
7- Chaîne de production d’électronique pour l’automobile (Continental, 25/3/2014)
8- Diagnostic et maintenance de systèmes (Actia, 1/4/2014)
9- Systèmes autonomes dans les transports (drones, aide à la conduite automobile) (ONERA, Continental, 8/4/2014)
10- Les systèmes domotiques (R. Alami, LAAS, 15/4/2014)
Plus d’information à http://asso-cisec.org
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 2/
SUMMARY
PART1
GENERAL CONTEXT in the AERONAUTICAL FIELD
• 1/3 Structures composite materials
• 2/3 Electronics and critical functions
• 3/3 New architectures and System evolution
ELECTROMAGNETIC PHENOMENA
• Panorama of electromagnetic phenomena and threats
• High intensity radiated field HIRF
• LIGTHNING direct effect
PART2
• LIGTHNING indirect effect
• Electromagnetic Compatibility EMC
• Hardening and electromagnetic protection
APPENDIX:
• Technical elements necessary to work out a financial estimate
CONCLUSION
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 3/
GENERAL CONTEXT 1/3: New Materials
COMPOSITES STRUCTURES
• Better mechanical properties
• Mass gain and improved stiffness
• Reduced delay and manufacturing process
• Maintenance (external corrosion? & Ref: refer 787 li-battery fire)
• Absorbing properties (STEALTH military aircraft)
• But poor Faraday performances (attenuation ) and poor
electrical properties VS light alloys (aluminum) i.e. grounding
and metallization problems (resistivity of carbon fiber 1000 more
greater than aluminum alloy)
• Bad electrochemical compatibility (emf: 900 mV with aluminum)
which need in particular locations the use of TITANE in order to
avoid corrosion phenomena
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 4/
Aircraft composites structure 1/3
B787 & A350
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 5/
GENERAL CONTEXT 1/3: A380 COMPOSITES
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 6/
Aircraft composites structure 1/3
Military aircraft & helicopter
Rafale
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 7/
General view of the trend to increased use of
composites materials 1/3
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 8/
GENERAL CONTEXT 2/3: Electronic & critical functions
Even more Electronic
• FMS,GPWS,TCAS,IFE (2500 kg for A 380 2 à 3 Mips 4,7 M€)
• Increased density of electronic equipment
• Analogical electronic disappear for the profit all numerical electronic
• Easy change thanks to embedded soft
Critical functions (no mechanical back-up)
• FADEC (Engine control)
• Fly by wire (FBW)
• etc.
FREQUENCY SPECTRUM
• Up to 18 GHz or more (40 GHz)
• Increased sensitivity (ex. GPS, )
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 9/
Illustration of avionics changes 2/3:
Example of old helicopter
generation analogical Electronic
(AS 355)
Example of new helicopter (EC 725)
Numerical electronic
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 10/
GENERAL CONTEXT 2/3: Electronic critical functions natural
stability VS artificial which need computer operating with high safety
Aircraft with natural stability
Aircraft with artificial stability provided by electronic computer
P
P
Fv
Fv
Fe
Fe
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 11/
General context Frequency spectrum 2/3
Frequency spectrum in the world
Typical radio-navigation
frequencies for civil aircraft
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 12/
GENERAL CONTEXT 3/3: New architectures and concepts
for the aircraft system
INCREASED ELECTRIC POWER
• Even more electric actuators and less hydraulic
• Deicing & no Engine bleed air (ex B 787)
• Air conditioning compressor driven with electric motor (ex B 787)
• Mass gain (more particularly starter-generator )
• Regulations and control law more easy
• Cable routing more easy than hydraulic rigid pipes
• Improved Maintenance opposite hydraulic (drain, leakage, pollution,
fire risk….)
• but….
• Electromagnetic disturbances to be solved
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 13/
GENERAL CONTEXT 3/3: TREND to INCREASED ELECTRIC POWER
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 14/
Change in the aircraft architecture 3/3
conventionnal architecture
New architecture: example air
conditioning system driven with
electrical motor
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 15/
Just a look inside aircraft body: you can see……
Of course many hydraulic
pipes…..
But also even more electrical
cables (low level signal &
power supply wires)
This the reason why electromagnetic threats shall be taken into account
at the first step of the design This was the case for A 320 airworthiness
with Special condition 75 for lightning & 76 for HIRF
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 16/
Evolution to more electric Aircraft 3/3
AIRBUS A 380
500 km of cables
More than 9 000 connectors
1 600 electrical harness
BOEING 787
95 km of cables
More than 60 000 electrical bonding
40 000 cables segments
1 500 Electrical harness
400 optical bonding
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 17/
ELECTROMAGNETIC PHENOMENA & THREATS
PHENOMENES
ELECTROMAGNETIQUES
DES
Décharges
électrostatiques
Bruit
Terrestre
Atmosphérique
Galactique
Solaire
DRAM
Dommages des rayonnements
sur armes et munitions
Transitoires
d'alimentation
CEM
Compatibilité
Electromagnétique
MFP
Micro-onde
Forte Puissance
IEMN
Artificial sources
FOUDRE
Natural sources
inte
nti
on
al
SPIKE
HERO
EMC
LEMP
ESD
HPM
EMP
Stealth
CHAMPS FORTS
HIRF
Sécurité du
Personnel
HERP
PHENOMENES
ELECTROMAGNETIQUES Anticompromission
Furtivité
no
n-i
nte
nti
on
al
Tempest
CRE
Couplage Radioélectrique
ERC
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 18/
Nuclear Electromagnetic Pulse
Generated by a High altitude
nuclear explosion
Compton effect in the atmosphere
Principal Characteristics
bi-exponential
Crest Amplitude 50 kV/m
Rise time approximately:10 ns
Half time duration 200 ns
Capture area notion
Military system are essentially
concerned
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 19/
Electromagnetic tests / Electrostatic discharges
created by rubbing:
On isolating or low
conductivity materials with low
air moisture ratio
Principal characteristics
Bi exponential waveform
Crest amplitude approximately
15 kV
Rise time: some ns
Half time duration : 20 ns
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 20/
Example measurement of electrostatic charging due to
blades rotation and hot gas turbine exhaust during load
winching operation for helicopter : equivalent to a capacitor
of 1nF charged up to 40 kV which can be lethal
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 21/
Electrostatic charges: Example of efficiency
measurement of e-discharger. The objective of the
design is to get a continuous flow of low current in order to avoid high
discontinuous high current discharges and then to reduce the noise
which can introduce disturbances & a loss of sensitivity on aircraft radio
receiver. But as we will see those devices are often damaged in the case
of aircraft lightning event
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 22/
Example of High Power transmitter antenna balanced hardening notion (limit in the level of electromagnetic protection)
Military aircraft or helicopter has enough agility to avoid collision, this
is not the case for civil aircraft, in that way safety distance which are
taken into account in regulatory document are increased
Curtain antenna
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 23/
HIGH INTENSITY RADIATED FIELD : Power transmitter OTHB 12 elements 1MW EIRP = 100 MW 5 to 28 MHz
41,70 N 121,18 W
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 24/
Some example of Incidence due to HIRF
Tornado crash in the vicinity of VOA Transmitters (was at the
origin of CS 76 for A320 Certification)
ECMU failure of Ecureuil AS 355N In the vicinity of CENTAURE
Radar
INS ALIZE MARINE Failure on Aircraft Carrier
AS332 disturbance of NG DNG T4 indicators when landing on
ship
Phone which was forget « on » in the freight compartment near
fire detector unit
Inopportune opening of hydraulic barrage gate during security
inspection due to TW emission
Don’t make confusion for turning “off “ portable computer
during take off and landing operation: it’s an EMC problem
(noise and or radio interference with radio navigation system
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 25/
HIGH INTENSITY RADIATED FIELD : near field for electric dipole
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 26/
HIGH INTENSITY RADIATED FIELD: near field for magnetic loop
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 27/
HIGH INTENSITY RADIATED FIELD Example of Radiated field in the vicinity of high power transmitter
Curtain antenna 250 kW 15 MHz Rhombic antenna 150 kW 15 MHz
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 28/
HIGH INTENSITY RADIATED FIELD: formulas simplification
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 29/
HIGH INTENSITY RADIATED FIELD: formulas
simplification substantiation
According that the
electromagnetic field in
the vicinity of antenna
vary strongly with the AC
distance and if we
observe for example the
radiation pattern of
aperture it can be seen
that the law in 1/R2 for
the value power density
is an overestimation but
conservative and then
acceptable
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 30/
HIGH INTENSITY RADIATED FIELD
simple formulas for field calculation field calculation
Basic formulas for a radiated electromagnetic field approximate calculation
P=E2/Z0 W/m2
with Z0 = E/H = 120 p = 377 W
- E Electric field V/m
- H magnetic field A/m
Knowing the transmitter power and the numerical antenna gain
We can calculate the power radiated density and then the field for the distance R
P = GW/4 p R2
E = (30GW)1/2/R
For Near field (if R< D2/2l) this formula is majoring
l Is the wavelength in m calculated with l = f (in MHz)/ 300
D (in m) is the greatest antenna dimension en (Ex RADAR parabola diameter)
Don’t make confusion between effective mean value and effective peak value Em
For rectangular signal as for typical radar modulation with pulse duration t et repetition time T
Em = Ec (t /T)1/2
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 31/
HIGH INTENSITY RADIATED FIELD:
Special condition SC76 was edited for the certification of A320
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 32/
HIGH INTENSITY RADIATED FIELD:
value and distance
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 33/
HIGH INTENSITY RADIATED FIELD: average value and peak value (for RADAR modulation)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 34/
HIGH INTENSITY RADIATED FIELD: acceptable method of demonstration 1/2
Acceptable methods of demonstration are :
1° low level method based on electric field attenuation measurements performed
where critical or essential equipments are located and also for the cables
induced current coming from exposed zones, thus one have 2 transfer basic
functions
After extrapolation to the external threat (linearity hypothesis) comparison of
the value obtained in laboratory test center with the value to be demonstrated.
The quantified margin between this the extrapolated value and the laboratory
value shall be positive
However this method is sometime problematic if we take into account the
representativeness of test s in the FARADAY chamber
2 high level demonstration directly on the aircraft
this method is not possible in the whole frequency domain particularly for low
frequency due to the great dimensions of civil aircraft
Example direct injection in a coaxial line for a military aircraft limited to 100 MHz
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 35/
HIGH INTENSITY RADIATED FIELD:
demonstration methods 2/2 3° Calculation codes
Approximately valid up to 400 MHz for internal electromagnetic parameters, but important problems to get a true representative model
In any case the model shall be validated with the help of great experimental means associated with high performance measuring equipment on particular points
In practice:
this different methods are combined in order to take into account:
- aircraft dimensions
- test center facilities (amplifier power and antenna gain…)
- data on similar aircraft (same technology)
- New concept and technologies
In any case it is necessary to quantify a hardening margin face to the specified external threat. This margin shall include :
- a consumable part (putting back to initial level thanks to defined periodic maintenance operations in order to cover wear , aging and corrosion phenomena…)
- and a permanent part in order to cover error measurements, manufacturing process drift etc., in order to get a good level of safety.
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 36/
HIGH INTENSITY RADIATED FIELD: low level method or transfer function measurement
Radiated field in the vicinity of
avionic bay
Cable induced Current
measurement probe
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 37/
HIGH INTENSITY RADIATED FIELD:
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 38/
HIGH INTENSITY RADIATED FIELD: a minimum of 4
incidences and polarizations are performed for each frequency
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 39/
HIRF TEST PROBLEMATIC: amplitude accuracy
Taking for example this recorded
curve where we get high resonant
and anti resonant amplitude in
relation with the frequency, in order
to get an error less than 3 db we have
to calculate the sampling by using
this formula
N=log(F2/F1)/log (1+1/Q)
F1, and F2 lower and upper
frequency
For F1= 400 MHz and F2= 18 GHz for
Q= 10 a minimum of 40 frequencies
and for Q=100 382 frequencies are
necessary to cover correctly the
spectrum
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 40/
HIRF TEST PROBLEMATIC: data to be recorded
For a aircraft qualification we have to take into account
4 to 5 Equipment locations
10 to 20 critical or essential equipments (mean 15)
2cables minimum per equipment
4 incidences minimum
2 polarizations H et V
Consequences:
For wire induced current
Frequency domain10kHz à 100 MHz
Q= 10 or 100
i.e. 96 (100) or 925 (1000) spot frequencies
that leads to:
15x2x4x2x100 = 24 000 ou 240 000 measurements
For internal radiated Field:
Frequency domain1 MHz to18 GHz
Q= 100
i.e. 984 (1000) spot frequencies
that leads to:
2x5x4x 1000 = 40 000 measurements
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 41/
Danger of the non ionizing radiations:
Electric Field (thermal effects only)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 42/
Danger of the non ionizing radiations: Electric Field thermal effects only
ICNIRP (International Commission on Non-Ionizing Radiation Protection)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 43/
LIGHTNING STROKE from CLOUD TO GROUND
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 44/
Some examples of Lightning incidence & accident
Loss of 2 engines of small jet above Atlantic Sea (acoustic phenomena)
Mirage F1 of CAMBRAI AAAF Base ejector seat was energized
Helicopter replenishment service from BRISTOW ditching in north SEA
after loss of tail rotor JAN 19 1995
Personal experience during Paris Toulouse A 300 Flight and
discussion after landing: pilot tell me he was in North Sea stroked by
lightning 6 times in 10 minutes
ULM flight actuator blocked due to ARC WELDING crash follow
Amateur Video recording from tower during 747 take off
Important Studies were performed in USA by NASA F106B and
USAF with CV 580 and in France by ONERA /CEV&CEAT on Transall
C160 instrumented with electromagnetic sensor for measuring
condition of occurrences amplitude and rise time, duration time, nbr of
stroke…..
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 45/
Two example of Helicopter struck by Lightning
incidence & accident
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 46/
Different cases of aircraft lightning event to consider
Intra or inter-cloud: in those cases the aircraft in the vicinity of clouds has
triggered the arcing phenomena. it’s 80 % of lightning recorded cases. In
flight measurement (CV 580 USAF or C160 AAF in France has shown that
the amplitude is less than 40 kA)
Intercept stroke from cloud to ground: amplitude taken actually for
airworthiness authority is 200kA
Civil aircraft are struck by lightning every 4000 hrs, military: 7000 hrs
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 47/
Cockpit glass illumination due to high electrical field
before lightning stroke holy ELME effect
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 48/
LIGHTNING: result off the process electric cloud
charge
Cloud to ground Lightning process precursors
Return stroke
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 49/
Lightning threat modelization
Lightning Process Precursor (fires of the holy ELME)
Return stroke
Intermediate current
DC current
Secondary discharges
Phenomena inter cloud & Intra cloud frequently aircraft initiated (cf. flight test CV 580 &
Transall C160)
Cloud to ground (strongest values from the contained energy point of view)
high voltage strong current and pulse repetition impossible to generate simultaneously Points of attachment related to the tension
Damages related to the current
Coupling related to the local densities of current (see lightning simulation slides
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 50/
attachement Courant établi re-attachement Courant établi
Multiple
burst
Multiple
burst
Multiple stroke Multiple stroke
Composante
persistante Composante
persistante
Definition: multiple burst / multiple stroke
LIGHTNING
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 51/
Lightning current amplitude and probability
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 52/
Aircraft lightning interaction: Directs & indirects effects
As it was said previously, one cannot simulate in experiments at the same time
the effects of the high electric field and the strong current; one thus studies
with large simulators the specific ones:
Direct effects
Return stroke or secondary lightning waveform A &t D
Impact of the arc, lightning currents flow
Structural thermo mechanical damages
Spark between poor metalized part (cover and structure) above vapor in fuel tank ( shall be
less than 200m J)
Indirect effects
multistroke, multiburst phenomena
Electromagnetic coupling
Over voltage or current surges, noise
Reversible Functional disturbances or non reversible equipment damages
( ) ( ) ( )
dt
tde,
dt
tid,
dt
tdi,axIm
2
( ) ( )dtti,dtti,axIm 2∫∫
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 53/
Civil aircraft: First recorded lightning stroke
with direct effects (thermal….)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 54/
Direct lightning effects on a weapon system
Illustration
of CORONA
Effect !!!
Example of
irreversible
damages
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 55/
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 56/
LIGHTNING: waveform characteristics for direct effects
current
durée
waveform B: intermediate current I mean = 2 kA
idt 10C
waveform C: sustaining current I mean = 200 A
idt 200C
waveform A: 1er return stroke I max = 200 kA
i2dt 2.10
6A2.s
waveform D: secondary stroke Imax = 100 kA
i2dt 0,25.10
6A2.s
< 500µs 5 ms 0,1 à 1 s < 500µs
*non representative scale
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 57/
LIGHTNING Direct effect: ZONING concept
Zone 1
• Zone 1A: initial attachment point with a low probability of arc hang on
• Zone 1B: initial attachment point with a high probability of arc hang on
Zone 2
• Zone 2A: swept zone attachment point with a low probability of arc hang on
• Zone 2B: swept zone attachment point with a high probability of arc hang
on
Zone 3
• All the other zones of the plane other than those of zones 1 and 2, there is a
low possibility of attachment of the direct arc the lightning. Surfaces of
Zone 3 can be traversed by important currents but only by direct
conduction between 2 point of initial attachment or sweeping
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 58/
LIGHTNING Direct effect: ZONING concept
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 59/
LIGHTNING Direct effect: ZONING concept
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 60/
Lightning as a function of Flight altitude
0 5 10 15 20 25 30
Ground
0-30
30-60
60-90
90-120
120-150
150-180
180-210
210-240
240-270
270-300
300-400Civilian A/C
Military A/C
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 61/
Aircraft damages distribution
47,3
0,3
5,98,7
17,7
4
16,1
4,56,9
0
5
10
15
20
25
30
35
40
45
50
No
damag
e
A/C
lost
Sta
bilise
rs
Fusela
ge
Ant
ennas
Eng
ine
Rad
ome
Rad
ar
Win
gs
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 62/
Example of lightning AIR SAFETY REPORT
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 63/
Example of high voltage test with MARX generator
25 stages charged at 200 kV = 5 MV
Test on instrumented mock –up in
order to study electro-charge
distribution just before first arc
junction under high electrical field
Blade attachment
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 64/
Effectiveness test of lightning strip diverter: Marx
generator 5 MV pek current limited to 10 kA
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 65/
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 66/
LIGHTNING direct effect:
example of radome damage
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 67/
cesic cesic2013-2014
Le lundi mardi, de 17h à 19h
Série de Conférences
Ingénierie des systèmes embarqués critiques 1- Introduction, systèmes critiques
Aéronautique (P. Traverse, Airbus, 18/11/2013)
Espace (JP. Blanquart, Astrium, 25/11/2013)
Automobile (H. Foligné, Continental Automotive, Reportée,au 11/03/2014
2- Sûreté, historique
Histoire de la sécurité du Concorde à l’A380 (JP. Heckmann, Apsys, 9/12/2013)
Comparaison de normes de sûreté (JP. Blanquart, Astrium, JM. Astruc, Continental, 16/12/2013)
3- Développement logiciel, assurance (H. Bonnin, Capgemini, 21/1/2014)
4- Développement matériel, assurance
Automobile (JP. Loncle, Continental, 28/1/2014)
Aéronautique (P. Pons, Airbus, 11/2/2014)
5- Intégration système et compatibilité électromagnétique (JC. Gautherot, DGA)
Partie 1, 18/2/2014
Partie 2, 25/2/2014
6- Interactions homme-système (F, Reuzeau, Airbus, P. Palanque, IRIT, 18/3/2014)
7- Chaîne de production d’électronique pour l’automobile (Continental, 25/3/2014)
8- Diagnostic et maintenance de systèmes (Actia, 1/4/2014)
9- Systèmes autonomes dans les transports (drones, aide à la conduite automobile) (ONERA, Continental, 8/4/2014)
10- Les systèmes domotiques (R. Alami, LAAS, 15/4/2014)
Plus d’information à http://asso-cisec.org
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 68/
Lightning indirect effect on complex system
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 69/
Lightning waveform to take into account for indirect
effect assessment
10 kA
50 kA
100 kA
200 kA
3 fois 20 pulses
30 ms < dt < 300 ms
Onde H
50 µs < dt < 1 ms
Onde Adi/dt = 140 kA/µs
2 MJ/ohm
Onde BQ = 10 C
Onde Dd/dt = 140 kA/µs
0.25 MJ/ohm
Onde D/2
13 pulses
1.5 s
Onde C200 C
dI/dt = 200 kA/µs
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 70/
From external lightning stroke to internal induced
pulses
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 71/
Lightning indirect effects :
From external to internal pulses
( ) ( )
( ) ( ) ( )
( )( ) ( )
( ) ( )( )
dt
tdIktRItV
dt
tdIk
dt
tintφdte
textφfAtintφ
tkItextφ
+=
==
=
=
Homothetic form Derivative form
In a very simplified manner one can write :
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 72/
Long waveform
Fast waveform
Fast waveform
Oscillatory waveform
Long waveform
(A, D,D/2)
Fast waveform
(H)
Typical induced waveform at equipment level
Fast rise time= DIRAC pulse
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 73/
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 74/
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 75/
Functional susceptibility: incidence of the occurrence of the
pulses with respect to the computer cycle
1 pulse many
Pulses
pulses
burst
1 erroneous bit
Error Detection
code
Message
repeated
1 erroneous
data
equipment
declared
faulty
many
erroneous
data
Necessity to achieve lightning tests on iron bird
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 76/
Simulator in order to inject mutiple pulses
computer
Equipment under test
control
Pulsed Power amplifier
waveform
de
synthesizer
converter
voltage Vco current It
Aircraft installation representative Cable
Test
Equipement
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 77/
BASIC ELECTROMAGNETIC COUPLING
EXTERNAL
ENVIRONMENT
INTERNAL
ENVIRONMENT
AGRESSION
E external
H external
Equipement
E internal
I cable
I bulkhead
Structure
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 78/
External and internal Threats Modelization 2/2
Electromagnetic parameters
Electric Field E : (volt/meter)
Magnetic Field H : (amps/meter)
current: I (amps)
Time domain: Voltage or current waveform
Frequency Domain : current or field amplitude VS frequency curves (mean value , peak value)
Examples
LIGHTNING (LEMP): time domain current waveform
EMP: time domain electric field
HIRF: frequency domain
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 79/
External and internal Threats Modelization 1/2
The current means of theoretical modeling of the electromagnetic
phenomena make it possible to predict the electromagnetic
constraints intern of a system subjected to an electromagnetic
aggression
The computer code and the grid are selected according to the
accuracy which one wants to obtain for the field time/frequency that
one wants to explore
It is necessary, however, to validate the models by putting into
operation great experimental means
These great experimental means are complex of a high cost and
immobilize the system to be evaluated in a context of increasingly
tended programs
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 80/
Electromagnetic Simulation & Modelization 1/5: different methods
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 81/
Electromagnetic Simulation & Modelization 1/5: different methods 2/5: advantages
& drawback of each methods
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 82/
Electromagnetic Simulation & Modelization 3/5: examples for lightning
probability
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 83/
Example Lightning current distribution on
the structure (arc between aircraft nose and right wing)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 84/
Electromagnetic Simulation & Modelization : theoretical demonstration in seven
steps experimentation/validation
du modèle
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 85/
Experimental simulation on mock up limited to external phenomena applications examples: antenna pattern, ESR
It is possible in particular cases as for aero dynamical model in wind tunnel (cf. Reynolds number) to perform measurement at reduced scale
However some electromagnetic law for similarity shall be applied in order to be representative
Non linear phenomena are not taking into account such as :
Hysteresis
Magnetic Saturation
Ionization
It’s necessary to reproduce skin effect dielectric & magnetic losses
emf2= e’m’f’2/r2
smf = s’m’f’/r2
If the tests are achieved in the same surrounding (see mock up inthe following table
then e = e’ et m = m’
In particular cases conductivity can not be enough increased (problem of copper Vs aluminum and also ground for which it’s necessary to inject salt with water solution)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 86/
Electromagnetic law for experimental simulation on
mock-up at reduced scale
parameter Real system reduced scale Mock up
Length L ( meter) l’ = l/r L’ = L/r
Time T (second) t’ = t/g t’ = t/r
Electrical field E (V/m) E’ = E/a E’ = E/a
Magnetic field H (A/m) H’ = H/b H’ = H/a
Magnetic permeability m (H/m) m’ m x (rb/ga) m’ m
permittivity e (F/m) e’ e x (ra/bg) e’ e
Electrical conductivity s (W/m) s’ s x (ra/b) s’ s x r
voltage V (V) V’ = V /(ra) V’ = V /(ar)
current I (A) I’ = I /(br) I’ = I /(ar)
Surface current J (A/m2) J’ = J/b J’ = J/a
frequency f (hertz) f’ = f x g f’ = f x r
Résistance R (W) R’ = R x (b/a) R’ = R
Inductance L (Henry) L’ = L x (b/ag) L’ = L/r
Capacitance C (Farad) C’ = C x (a/bg) C’ = C/r
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 87/
Example of Antenna characterization on typical mock up
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 88/
Electromagnetic phenomena & threats
CEM Aptitude d’un dispositif, d’un équipement ou d’un système à
fonctionner de façon satisfaisante dans son environnement
électromagnétique sans produire lui même des perturbations
électromagnétiques intolérables pour tout ce qui se trouve dans cet
environnement
EMC The ability of equipments (or Systems) to operate satisfactorily in its
electromagnetic environments without introducing intolerable
disturbances to anything in that environment
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 89/
ELECTRO MAGNETIC COMPATIBILITY
Definition & related basic documents
Electromagnetic disturbance is any phenomenon that may
degrade the performance of a device, equipment, or system or
adversely affect living or inert matter
DO 160 F (equipment) for civil aircraft
MILSTD 461 E (equipment) & MIL STD 464 (system) for military
qualification
And many other documents: FCC, IEC , CISPR…….OTAN
document (AETCP 500 & 250) including French document in the
past such as GAM EG13 (AIR 7306 for military aircraft)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 90/
ELECTRO MAGNETIC COMPATIBILITY
COUPLING MODE
interconnexion
masse
supply
radiation : (wire, antenna or aperture) towards (wire, antenna or aperture)
conduction : towards supply or interconnecting cables
EMITTER
CULPRIT
RECEIVER
VICTIM
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 91/
ELECTRO MAGNETIC COMPATIBILITY
4 basic tests ref:
DO 160 (for civil aircraft) & MILSTD 461 (for military aircraft)
CEM
Emission Susceptibilité
CE
Section 19
RE
Section 21
CS
Section 18 & 20
RS
Section 20
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 92/
Fundamental principle of the CEM: trilogy
EMITTER
CULPRIT
RECEIVER
VICTIM COUPLING
Emission level
Susceptibility level
frequency
A B
B disturbed B non disturbed
Positive margin
Negative margin
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 93/
CEM: example limit for radiated emission taking into
account radio receiver sensitivity an not only intrinsic EMC
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 94/
EMC: Type of signal which are measured, spectrum in
frequency domain (radiation or conduction)
There are narrow band signal and broadband signal (d is pulse duration at 50% &T is
rise and fall time between 10 & 90 %)
Example of unique ( non repetitive ) pulse spectrum
amplitude in frequency domain is given for example in dBm or dBµV/m or dBµA /Hz
Time to frequency representation
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 95/
EMC: BROADBAND or NARROWBAND ? Measurements value will vary
with the width of the filter used with the spectrum analyzer
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 96/
EMC: measurement specification
In order to avoid misinterpretation in the value of amplitude measurement
results, bandwidth filter and time between each frequency step used for
emission are defined in normative document for different frequency band
measurement. Example
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 97/
What’s About PED ?
25
35
45
55
65
75
85
95
Le
ve
l, d
Bu
V/m
1E-2 1E-1 1E0 1E1 1E2 1E3 1E4Frequency, MHz
MAXIMUM VALUESMeasured PEDs
WB Switching Power Supplies
and Video Display Sweeps
NB Local Oscillators
and Clocks
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 98/
CEM & PED: front door and back door coupling
Front-Door coupling
• PED Undesired Emissions Coupled Through Fuselage Windows and Door
Seams to Radio, Navigation, and Radar Antennas (receiving mode) trans-
modulation effect • 75 MHz: Marker Beacons
• 108-136 MHz: ILS Localizer, VDT, VOR, VHF Com, VDL
• 329-335 MHz: ILS Glide Slope
• 962-1215 MHz: DME (Military TACAN)
• 982 MHz: ADS-B UAT
• 1030, 1090 MHz: ATC & TCAS
• 1530-1610 MHz: Satellite Com
• 1575.42 MHz: GPS
• 4200-4400 MHz: Radar Altimeter
• 5030-5090 MHz: Microwave Landing System
• 5350-5470, 9300-9500, 15500-15700 MHz: Weather Radar
Back-Door Coupling
• PED Undesired Emissions Coupled to Avionics Boxes
• PED Undesired Emissions Coupled to Avionics Wiring
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 99/
CEM: example of equipment conducted
emission measurement
Power supply switching fondamental & harmonics Microprocessor
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 100/
CEM: Example of radiated emission measurement
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 101/
CEM: Example of radiated susceptibility measurement
in RADAR frequency domain on FADEC
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 102/
Test with Reverberating chamber by using cavity resonance
frequencies (starting only above 6 times the first low resonance frequency
can be used for radiated susceptibility but also for emission tests)
Calibration for the Em. FIELD
Testing equipment or System
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 103/
Example of Specific test which are not
included in aeronautical norm or specification
This helicopter was used by
EDF for the maintenance of
electric line and the
cleaning with KARCHER of
Isolators
The objective of test was to
see if there is no mis-
operating of ECMU under
High voltage & high
magnetic field at low
frequency (50 Hz)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 104/
ELECTROMAGNETIC PROTECTION:
don’t forget embedded software
Software example: ECMU (Electronic control motor unit)
Tolerances accuracy (prediction of periodic maintenance)
Gradient test
Consistency test
Numeric filtering
Consequences
Many features
Opposite part:
• Response time
• Memory size
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 105/
ELECTROMAGNETIC PROTECTION:
overview of basic protections
Shielding
Bonding
Grounding
Clamping
Filtering
Segregation
Optical fiber link
Clean and dirty zones design
Balanced Hardening concept
And….
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 106/
Protection device:typical filter structure Linear filter are commonly used to protect equipment against the adverse effect of wire
induced current in the frequency domain or of power switching supply rejected
signal . Different structure are possible taking into account simultaneously source
and load impedances in order to get the maximum mismatching
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 107/
Example of filter attenuation curve for different structure and of cells Nbr
Note: in general cases attenuation curve are given for nominal value of source and load resistance
but in the real practice it’s never the case in a large frequency domain
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 108/
Example of different filter set-up
Coaxial structure reduce connection inductance
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 109/
Basic limitation of filter
For the correct design of filters there are important parameter to take into
account
For inductance:
– Serial resistance (loss of nominal supply voltage)
– Parasitic capacitance between wounding (high frequency limitation)
– saturation of ferromagnetic material due to permanent supply current CC or CA
– Ferromagnetic losses (EDDY current et hysteresis cycle)
– Ferromagnetic material maxi temperature en temperature coefficient
For capacitance:
– Parallel resistance (leak current)
– Serial inductance of connection (high frequency limitation)
– Breakdown voltage CC et CA
– Diverted current for CA supply
– Dielectric losses
– Dielectric material maxi temperature en temperature coefficient
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 110/
Non linear devices basic set for protection in the time domain
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 111/
Non linear protections: typical value of different devices such as zener
diodes, varistor or gaz spark
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 112/
Time domain pulses: in order to get a safe design, hypothesis of matching
of source and load resistance is taken (max transmitted energy)
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 113/
Electromagnetic protection devices: design rules
Protection against time
domain threat:
•LEMP
•NEMP
•ESD
Protection against
frequency domain threat:
•HIRF
•HPM
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 114/
PROTECTION DEVICES
COMPREHENSIVE & CONSISTENT HARDENING CONCEPT
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 115/
Appendix
Electromagnetic environment and tests
Information necessary for a technical and
commercial proposal
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 116/
Technical elements necessary to work out an estimate
Test
Program
Technical
&
Commercial
proposal
System Or
Equipment
Under test
Configurations Furniture's
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 117/
System or equipment under test
Equipment overall dimensions
Maximum ground metallic plane and direction of radiation VS equipment aircraft positionning
Blowing/Cooling
Air or fluid Flow
intermittent operation or not
Power supply
Permanent & peak power
Start current
Cabling (representativeness)
Access, Break boxes
Equipment mass
Handling (support, mounting)
Maximum load on floor and on ground metallic plane
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 118/
Equipment under test : configuration
How many Configurations ?
Different operating modes
– Example:
» light or full load (computer must operate and acquire external signal & data
coming from sensors or simulators
» Fault detection
» susceptibility: signal of sensor adjusted to low tolerance value
» emission: signal of sensor adjusted to high tolerance value
» Energized or not or both
Software Version
– Specific test or true and last flight version
Cables
With or without over shielding
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 119/
TEST PROGRAM
Applicable norms and documents
Severity and test procedures
Progressive increase of test level ( 3dB? 6dB?….)
Test file
– From most severe to less severe : objective to get asap first results
to modify the equipment
– From less severe to most severe : demonstration to the buyer that
first results are already positive
Correct operation checking before, during and after,
tests
Acceptable or not susceptibility criteria definition
Necessity to identify the origin of dysfunctions or
breakdowns
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 120/
Furnitures/constraints
Stimulis
Means necessary to obtain representative operation
– availibility
– Particular software test
– BUS access for spying data flow without disturbances
Instrumentation
sensors: voltage, current, position, temperature etc.
Internal accessibility
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 121/
CONCLUSION
Information's described previously very seldom appears in the
request for proposal or are incomplete
They are however necessary to determine the feasibility of the
all tests which is not always acquired
They have a direct impact over the duration of tests and thus on
the cost
the customer does not control all subtleties of the tests within a program. The tests center must also play the part of council
Before providing a credible offer, one, even
several meetings with the customer are
necessary to tackle the problems mentioned
above
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 122/
CONCLUSION &……. QUESTIONS
Necessity for designing
electromagnetic
protections
in comprehensive &
Consistent manner
about the functional level:
Role of the HARDWARE
and SOFTWARE:
Attention with the differences
Between the TEST version for
laboratory
and the real embedded Version
80 to 90%of disturbances
come from cables
Future:
Optical numeric BUS
but mechanical, thermal
properties
and maintenance
to be improved
According to the field
of frequency to be treated
Used tools
for simulation
will not be the same ones
Whatever
computer code has been used
It is necessary to validate
the ideal model
using
large Experimental
simulators
CISEC: intégration systèmes et CEM phénomènes électromagnétiques 123/
And perhaps for next CISEC conference cycle !!!