Transcript Changes to EN61000-3-2

Testing
Harmonics and Flicker
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Harmonics & Flicker
Two different test standards:
EN61000-3-2 & EN61000-3-3
1.
EN 61000-3-2 controls the level of distortion of the current drawn by
all equipment rated up to 16 amps.
2.
EN61000-3-3 controls the level of voltages changes that equipment
rated up to 16 amps will impose on the ac supply.
•
Both standards have evolved over time
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–
–
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Harmonic standard. originally called IEC 555 Part 2 1987
Flicker standard. originally called IEC 555 Part 3 1987
Now referred to as EN61000-3-2 & EN61000-3-3 Standards
EN is short for Euro Norm; the version enforceable in law in European
countries. The EN is usually identical to the IEC version.
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Current Harmonic Distortion
Input Voltage
Load
Input Current
Capacitor Voltage
Capacitor Current
(Charging when input voltage greater than capacitor volts)
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Most modern power supplies draw current that is nonsinusoidal.
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Current Harmonic Distortion
The distorted current causes problems for electricity
suppliers, consumers and product manufacturers.
• The extra distorted current drawn does no useful work. The
power factor is < 1, or
VxA>W
This means more electricity must be generated, distributed
and paid for than is consumed as useful energy.
• The current distortion leads to to the phenomenon of triplen
harmonic currents flowing in the neutral of three-phase
systems – a fire risk in large office installations.
• and to voltage distortion that can cause overheating in
motors.
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Current Harmonic Distortion
50HZ
100HZ
150HZ
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Fourier analysis is used to
describe any repetitive
waveform in terms of sinewaves that are at multiples of
the fundamental frequency.
EN61000-3-2 controls current
distortion by setting limits for
the amplitude of the 1st 40
current harmonics.
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Requirements of EN61000-4-7
• How to measure to the harmonics is defined by EN61000-4-7
• It is a not a simple requirement. The following measurements must be made:
• Power, Power Factor , Voltage Harmonics, Fundamental Current, POHC
(Partial Odd Harmonic Current) as well as Current Harmonics.
• And in a very specific way: NEW REQUIREMENTS
• Measurements are made every 200mS, continuously without gaps.
(10 cycles @ 50Hz, 12 cycles @ 60Hz).
• Inter-harmonics must also be measured for current harmonics
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Requirements of EN61000-4-7
t
W
V
A
PF
F
AH 01
AH 02
AH 03
AH …
AH 40
VH 01
VH 02
VH 03
VH …
VH 40
180.56
230.10
1.21322
0.6468
49.998
1.0123
0.0023
0.3129
t+
200mS
182.34
230.10
1.2542
0.6318
49.999
1.0767
0.0023
0.3134
t+
400ms
184.12
230.10
1.2672
0.6315
50.001
1.0854
0.0024
0.3256
0.0013
230.05
0.0123
0.0210
0.0013
230.05
0.0123
0.0210
0.0012
0.0012
…
…
Average
Maximum
180.05
184.12
1.0234
1.0854
0.0024
0.3256
0.0014
230.05
0.0123
0.0210
0.0013
230.05
0.0123
0.0210
0.0014
230.05
0.0123
0.0210
0.0012
0.0012
0.0012
• Harmonic measurements every 200mS - 400+ measurements!
• Continuous no-gap analysis
• All measurements filtered by 1.5s time-constant filter
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Inter-harmonic groups
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Example Inter-harmonic group
• 6th harmonic (300Hz @ 50Hz)
1/2
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1/2
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Applying Limits to Harmonics EN61000-3-2
• The limits for pass and fail are set by product groups called Classes:
• The limits are different for each harmonic and each of the 4 classes,
A, B, C &D
• Class Determination is :• If device power is 75-600W and a PC , Monitor or TV then Class D
• If handheld portable tool, then Class B
• If Luminaries then Class C
• If not Class B ,C, or D, or 3 phase then class A.
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Applying Limits to Harmonics - EN61000-3-2
Example Class C limits - calculated from AH01 and PF
• Information from the PC Software ‘Help’ system
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Applying Limits to Harmonics - EN61000-3-2
Limit 2
Limit 1
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Applying Limits to Harmonics - EN61000-3-2
Maximum reading Vs Limit 2
Average reading Vs Limit 1
• Limits are set for the average of each harmonic during the test (L1)
AND the maximum of each harmonic (L2).
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Flicker - Causes
The AC supply cabling to a building will have a source impedance
Any variation of loads will cause a voltage change at the distribution point
This fluctuation of voltage will then make the lamps “Flicker”
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Flicker –The Pst = 1 Curve
• The Human tolerance to light flicker is mapped on the Pst = 1curve.
• Any point on the curve has the same perceived level of annoyance
• Pst = Perceptibility short term
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EN61000-4-15 – The Flickermeter
• For real-life random voltage changes, a flickermeter is used is used to
duplicate the human perception of flicker.
• A flickermeter measures rms voltage changes every half-cycle (10ms)
and filters the measurements just like the lamp-eye-brain chain.
• The filtered changes are classified to generate a table of the probability
that a ‘class’ of voltage change will occur.
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Flicker Pst test results from Voltech software
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Measurement Equipment
The Harmonics and Flicker standards require fast and accurate analysis of
electrical power quantities:
• Continuous harmonics:
• 400+ measurements every 200ms.
• Discrete Fourier Transform for a reference instrument.
• Continuous voltage changes:
• every 10ms (1/2 cycle@50 Hz),
• real-time flickermeter processing.
• Limit checking and reports
• Calculation of harmonic limits from averaged and maximum readings
• Comparison to different class limits
• Recording and presentation of results
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The PM6000
 Up to 6 wattmeter channels
 Accuracy: 0.02% of reading, 0.05% of range
 Bandwidth: 10MHz
 Sampling rate: 40 MSPS
 Display: Bright color VGA
 Connectivity: RS232, IEEE488, Printer, Ethernet
 Connectivity (Future Release): PCMCIA for analog I/O including
torque and speed, USB
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PM6000 Measurement Channel
• Built on 15+ years of Voltech
analog know-how
• Unrivalled accuracy and
bandwidth combination
• Layout and timing minimise
phase delay for best Watts
accuracy
A- D Convertor
• 14-bit
• 40MSPS Max
• 5MSPS Min
PCI Bus
• Continuous 5
MSPS data from
every channel.
• No analysis gaps,
no missing data
±5V
i
DSP
200MHz
Isolation
• 4kVpk
• CMRR:
• 140dB @ 60Hz
• 95dB @ 1MHz
20
v
±12V
Pulse Transformers
• Data and control.
• Provide superior
CMRR than optoisolators
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Why the Voltech PM6000?
Processing power to perform discrete Fourier transform (DFT) analysis,
harmonics and inter-harmonics every 200mS
P
Simultaneous voltage, current, power (W) and PF measurements as required
P
EN61000-4-7 calls for synchronization accuracy of +/- 0.03%.
P
0.02%
EN61000-4-7 calls for crest factor of up to 4.
P
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EN61000-4-7 calls for nominal current input overload times 10 for 1 second.
P
250A
Accuracy of voltage and current measurements 10 to 100 times better than
standard requires.
P
Powerful PC software with comprehensive ‘help’ system
P
Full compliance tests with an AC source, or accurate pre-compliance from the ac
line
P
20 years of digital power analyzer know-how.
P
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References
Harmonic Limits
IEC 61000-3-2 -Consol.Ed.2.1 (2001)
All electrical and electronic equipment up to 16A. 220 to 240V 50 or 60Hz.
IEC 61000-3-12.
All electrical and electronic equipment rated 16A to 75A. 230/400V 50 or 60Hz.
Harmonic Measuring Equipment
IEC 61000-4-7 (2002)200ms window and Interharmonics requirement mandatory end 2007
Flicker Limits
IEC 61000-3-3 -Consol.Ed.1.1 (2001)
All electrical and electronic equipment up to 16A. 220 to 250V line to neutral at 50Hz.
IEC 61000-3-11 Ed.1 (2000)
All electrical and electronic equipment 16A to 75A. 220 to 250V 50Hz.
Flickermeters
IEC 61000-4-15 Ed.1.1.(2003)
Help information
Voltech IEC61000 software for the PM6000.
Standards from: www.iec.ch
Software from: www.voltech.com (free download).
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End of Presentation
Thanks for listening!
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