View
221
Download
1
Category
Preview:
Citation preview
EMC Seminar Series
All about EMC Testing and Measurement Seminar – 1
Fundamentals of EMC Theory and Principlesy p
Dr. LEUNG, Peter Sai‐Wing 梁世榮
http://wwwee cityu edu hk/ pswleung/http://www.ee.cityu.edu.hk/~pswleung/
O i d bOrganized by :
Department of Electronic Engineering
1
l b lEElectroMMagnetic CCompatibility
The ability of an equipment or system to function satisfactorily in its environment without introducing i l bl l i i f hi intolerable electromagnetic interference to anything in that environment.
EMC = EME + EMI
EME=Electromagnetic Emission (Interference)EMI=Electromagnetic Immunity (Susceptibility)
2
EMCEMC…A complicated and difficult subject!!!!?
Talks in Order of Magnitudes Frequency from DC to daylightsq y y g magnitude µA ‐ kA; µV ‐MV works on dB for order of magnitude, and log scale in frequency
Different types of EMC requirements, methods, measurements Many different standardsy
3
Sources of Emission / Noise/
Natural / man-made / intended emission!
4
Couplingp g
5
ff f / i fEffects of EME/ EM interferenceEquipment to equipment Loss of data in digital systems or in transmission of data Interference to TV and radio reception Malfunction of medical electronic equipment Malfunction of automotive microprocessor control systems (braking) and
navigation equipment Malfunction of critical process‐control functions (e.g. oil, chemical, airports
railways) …….
Equipment to Human (Human Safety) IEEE C95.1 ‐ Standard For Safety Levels with Respect to Human Exposure to
Radio Frequency Electromagnetic Fields, 3KHz to 300GHz
ICNIRP ‐ Guidelines limiting exposure to time‐varying Electric, Magnetic, and Electromagnetic fields (Up to 300 GHz).
EME and EMI TestscEME and EMI Testsc
7
Different characteristics of emissionsRadiated Emission‐
Far field radiation near field radiation E field source H field source
Conducted EmissionConducted Emission Different paths….dc port, power port, communication port
Electromagnetic Coupling
8
RE CE RI CIRE, CE,RI,CI
9
RE, CE, RI, CI, , ,
10
RE : 40 dBµV/m ~ 0.01V/m
CE : 60 dBµV/m 0 001V/m
Examples of some limits in Radiated EmissionCE : 60 dBµV/m ~ 0.001V/m
…from CISPR22
11
EMC‐ A reasonable good margin between RE and RI, for general consideration!!and RI, for general consideration!!
RI requirement ….3V/mRE : 40 dBµV/m 0 01V/mRE : 40 dBµV/m ~ 0.01V/m
CI requirement ….3V
Examples of some limits in Radiated ImmunityCE : 60 dBµV/m ~ 0.001V/m
Examples of some limits in Radiated Immunity … from IEC 61000‐6‐1 for RCLI
12
ELECTROSTATIC DISCHARGE (ESD)
A transfer of electric charge A transfer of electric charge between bodies of different electrostatic potential in proximity orelectrostatic potential in proximity orthrough direct contact.
Effect:Cause damage to electronic equipment.
13
ELECTROSTATIC DISCHARGE (ESD)Hard failures (irreversibly)
• Junction burnout• IC metal burnout•Dielectric breakdown
Soft failures ( mainly digital circuits)Soft failures ( mainly digital circuits)Transient interference ( eg. Radio)
Logic errors, System resets, Lost data, Lost program flow
14
HUMAN BODY MODEL
LR
C VC
C = 50 to 250 pFR = 500 to 10k|VC| = 0 to 30kV ( above 30V will have corona effect )L = 50 - 200nH
First order model, TRIBOELECTRIC EFFECT
EN 61000‐4‐2 Testing and measurement techniques –
15
4 g qElectrostatic discharge immunity test
DISCHARGE INTO AN IDEAL GROUND
L=100nHR=500
I
I
IC=300pF15kV I
t=0Ipk
t0~ 1nsI
kVApk
15500
30
16
ESD TestsESD Tests
Direct Application:Discharge Electrodes
Air Discharge (sparks) EUT
Contact Discharge EUT
……..different electrostatic potential in proximity or through direct contact.
17
p p y g
ESD Generators
Some models can generate air‐or contact discharge up to 30kV.With different combination of With different combination of R‐C value for other applications…
18
Fast Transient/BurstFast Transient/BurstElectrical Fast Transients caused a spark in air or other gas ‐When a circuit is switched off, the current flowing is interrupted; large di/dt is generated. g p g g
Arcing between the contacts; first at a low voltage and high frequency; later at a higher voltage and lower frequency.
19
Electrical Fast TransientElectrical Fast TransientElectrical Fast Transients caused a spark in air or other gas ‐When a circuit is
h d ff h fl d l d d dswitched off, the current flowing is interrupted; large di/dt is generated.
Arcing between the contacts; first at a low voltage and high frequency; later at a hi h lt d l fhigher voltage and lower frequency.
IEC 61000‐4‐4 Electromagnetic IEC 61000‐4‐4 Electromagnetic Compatibility (EMC) ‐ Part 4‐4: Testing and measurement techniques –Electrical fast transient/burst immunity testElectrical fast transient/burst immunity test.
20
Fast Transient/BurstFast Transient/BurstElectrical Fast Transients caused a spark in air or other gas ‐When a circuit is
h d ff h fl d l d d dswitched off, the current flowing is interrupted; large di/dt is generated.
Arcing between the contacts; first at a low voltage and high frequency; later at a hi h lt d l fhigher voltage and lower frequency.
Coupling of the EFT into electronic products occurs when power cables handling high currents are run in close proximity to power data and/or I/O cableshigh currents are run in close proximity to power, data, and/or I/O cables.
21
Surgeg Sudden rises in voltage and/or current
to a connected load; standard household equipment can be damaged by surges of 500 volts or greater….
Indoors, caused by major equipment, such as your air conditioner switching on and off.
Outdoors, they can be caused by incidents involving electric lines power incidents involving electric lines, power equipment failures. Lightning in seasonal storms.
Electromagnetic Compatibility (EMC) —Part 4‐5: Testing and measurement techniques Surge
22
Testing and measurement techniques — Surge immunity test
23
Power frequency magnetic fieldq y gElectrical power lines, wiring, t f d h h ld li transformers and household appliances …P t ti HV t f Power stations, HV transformer builder, overhead cable, railways systemsystem….
Electromagnetic compatibility (EMC) —Part 4‐8: Testing and measurement
24
Electromagnetic compatibility (EMC) Part 4 8: Testing and measurement techniques — Power frequency magnetic field immunity test
IHlA ' IdlHI10
rH
2law;sAmpere' IdlH
l mX1210
25
Electromagnetic compatibility (EMC) —Part 4‐8: Testing and measurement techniques — Power frequency magnetic field immunity test
Voltage dips short interruptionsVoltage dips, short interruptions and voltage variationsg Electrical equipment can be affected by voltage dips short interruptions or voltage voltage dips, short interruptions or voltage variations of the power supply caused by faults in the network, in installations or by a faults in the network, in installations or by a sudden large change of load.
El i ibili (EMC) P T i d
26
Electromagnetic compatibility (EMC) —Part 4‐11: Testing and measurement techniques —Voltage dips, short interruptions and voltage variations immunity tests
Voltage dips, short interruptions and voltage variationsand voltage variations
27
I i T lImmunity Test resultsCriterion Performance
A Normal performance, specified by manufacturerp , p y
BTemporary loss of function or performance degradation during test. EUT it f ith t i t tiEUT recovers its performance without intervention
CTemporary loss of function or degradation (requiring intervention)Temporary loss of function or degradation (requiring intervention)
DLoss of function or degradation unrecoverableLoss of function or degradation unrecoverable
28
Summary
Some concept and fundamentals on EMC.RE RI CE DI ESD FT & S H Fi ld V lt RE, RI, CE, DI, ESD, FT & S, H‐Field, Voltage Dip.
El i ibili (EMC) P T i d
29
Electromagnetic compatibility (EMC) —Part 4‐11: Testing and measurement techniques —Voltage dips, short interruptions and voltage variations immunity tests
Thank You!!
Peter Sai‐Wing LEUNG, 梁世榮
http://www ee cityu edu hk/ pswleung/http://www.ee.cityu.edu.hk/~pswleung/
30
Recommended