Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
simple assessment procedure for 3-phase Systems
practical approach for measurements practical experiences
Andreas AbartEnergie AG Oberoesterreich also lecturer at TU GrazAsset managementPower Quality & [email protected]: +43 5 9070 2107
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
Frankfurt (Germany), 6-9 June 2011
1st. Step of Assessment:simple Estimation (magnetic field: 1 mT/kA at 0.2 m distance)
No further Assessment in case occupational Exposure: • Electric fields at rated voltage < 250 kV• generators and transformers• Any wire at maximum current < 1 kA (50 Hz)
Compliance demonstrated? – Yes => End of Assessment
2nd. Step of Assesment:regarding given compensation effects from parallel wires.
Compliance demonstrated? – Yes => End of Assessment
3rd. Step of Assesment (expert job):Measurements including all shielding effects
Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
magnetic flux density B=f(a,d)
Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limitsAbart, 15.01.2007, Seite 4
EMF-Exposure
Magnetic Flux Density Exposure of 3-Phase Electrical Power Systems (3 x 1 kA)
1,E-01
1,E+00
1,E+01
1,E+02
1,E+03
1,E+04
1,E+05
0,01 0,1 1 10 100
d Distance m
Ma
gn
eti
c F
lux
De
ns
ity
µT
/kA
approximation limits for non insulated wires
500 Action Value
U <
1kV
U <
30kV
U <
110k
V
U <
220k
VU
>22
0kV
0,5
1,5 2 3 4
d
a a
IL1 Il2 Il3
harmrms
harmrms
kdHzI
kdHzI
7500)3216(
5000)50(
1
1k
dkAI
µTB
22
kd
a
kAI
µTB
factors[]..., resbetween wi distance]...[
reclosest wi theand fieldpointbetween distance]...[
current...densityfluxmagnetic....
21 kkma
md
kAIµTB
Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
harmrms
harmrms
kdHzI
kdHzI
7500)3216(
5000)50(
harmrms
harmrms
kdHzI
kdHzI
1500)3216(
1000)50(
200
1
dkAI
µTB 350
2
d
a
kAI
µTB
240
2
d
a
kAI
µTB
occupational exposure (1000µT)
General public/office(200µT)
83,057,0 d
a
d
a 83,057,0
d
a
d
a
harmHzrms ka
dkAI
2
)50(
86,2 harmHzrms k
a
dkAI
2
)50(
17,4
harmHzrmsk
a
dkAI
2
)3216(
29,4 harmHzrms
ka
dkAI
2
)3216(
25,6
harmHzrms ka
dkAI
2
)50(
57,0 harmHzrms k
a
dkAI
2
)50(
84,0
harmHzrmsk
a
dkAI
2
)3216(
86,0 harmHzrms
ka
dkAI
2
)3216(
25,1
Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
ASSESSMENT: Estimation, Calculation Measurement Calculation
& Measurement
Messwerte der magnetischen Flussdichte KOPS I M3 Ausleitung + Schiene 102 MVA + Trafo 12,5/220 kV
0
200
400
600
800
1000
1200
1400
11:47:37 11:50:38 11:53:40 11:56:41 11:59:43 12:02:44
Flu
ss
dic
hte
µT EFD
EFD IN
GW
30 cm Distanzschale
Trafo 12,5/220 kV 102
Trafo 12,5 KV Generatorausleitung (Bremstrenner)
Stromschienengang
Trafozuleitung
Frankfurt (Germany), 6-9 June 2011
Abart-AT-RT.2c
RT 2c: EMF – Revision of magnetic field limits
Measurements in Practice applying summation Formula according to ICNIRP
Guidelines => Exp=Sum of Signal + Sum of noise
following Jokelas approach 2003 (regarding phase of each spectral component) is helpful but complicating processing of measurement data.
regarding spectral components > X% of limits like standards for welding equipement suggest.
RMS of spectral components weighted on limits following the EN 50366 approach (household appliances)
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