POWER QUALITY ISSUES ABOVE
2 KHZ
Cees Keyer
Amsterdam University of Applied Sciences
University Twente. IEEE TC7
On behalf of CNROOD.
THE ISSUE
Conducted emissions
• Limits to 40th harmonic (2 kHz or 2,4 kHz@60Hz) EN61000-…..
• No standards for 2 <-> 150 kHz
EMC directive versus Electricity law.
• EMC Directive is embedded in Dutch Telecom law --> AT
• Electricity Law /netcode
• ITU states 8,3 kHz up to 3000 GHz is used for radio communications
(WRC2012)
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POWER GRID ASYMMETRIC
So every unused cable is an effective antenna
for example a light bulb switched off (neutral wire is antenna..)
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AN EXAMPLE
Transponder issues in a cow shed
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PROBLEM
Cow feeding system doesn’t work according to plan.
necessities:
1. Wellingtons
2. Boiler suit (Overalls)
3. Spectrum analyser
4. Probes, LISN
5. a student to help out Wei Wang (foto’s)
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RFID
RFID tag, is activated on 126 kHz and answers back on 80 kHz.
Feed supply to the individual cow depends on the amount of
“body exercise” .
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A MANURE ROBOT
Charger connections
Charging system
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ROOT CAUSE.
Battery charging system of the manure robot.
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THE SMPS COMPLIES WITH THE
STANDARDS.
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SMPS OPENED UP.
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SOLUTION.
Power supply replaced with a better one (ham radio smps).
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THE REAL PROBLEM.
Is that there are no standards for the band
2 kHz <-> 150 kHz.
Power quality standards are available up to 2 kHz.
EMC standards are available for conducted emission from
150 kHz.
Due to Dutch law, conducted emissions on the grid are
governed by the electricity law. EMC is governed by
Telecom law. Hence we’ve got a problem.
Is Power Quality and EMC issue, according to the Dutch
law, NO; according to the EMC community Yes it is.
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MEASUREMENT METHODS
Wide band up to 30 MHz
• LISN + spectrum analyser or measurement reciever.
• Draw back Measurement of a single contraption.
Other equipment:
• Power Quality analysers:
• draw back up to 25 kHz depending on the model.
New Power Qube 3
Does measure the garbage band (2 – 150 kHz) as well.
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PQUBE 3
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ADVANTAGES
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•
•
•
Full compliance IEC 61000-4-30
HF impulse 4 MHz
2-150 kHz conducted emissions
L1 L2 L3 N and E voltage & current (probe)
Rapid voltage changes (lighting transients)
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ADVANTAGES CNT.
Web interface power over Ethernet (cat5)
Conducted emissions 2=150 kHz
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PQUBE 3
Solves continuous measurements of power quality related issues.
• Can be used in permanent machinery
• In your power distribution cabinet.
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OTHER MEASUREMENT METHODS
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•
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Problem shooting
8 channel oscilloscope (picoscope 4824)
USB connected so data on laptop (≥ windhoos7 or linux)
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450 KW SOLAR PANELS.
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CURRENT DECOMPOSITION
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EQUIPMENT USED
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•
•
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Picoscope 4824
1:1000 resistive voltage divider
Current probes TA167 ( 20 kHz 200 or 2000 A)
Available current probe TA189 (100 kHz 30 A)
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QUESTIONS?
Measurement of a singe LED lamp spec.
up to 100 MHz, conducted emission.
Gamma LED ruins your radio reception.
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