Date-03/09/2014
(THD MEASUREMENT WITH EXAMPLES AND FIGURES)
ByEMBUILT TECHNOLOGIES
www.embuilt.com
www.energylogger.blogspot.com
Embuilt.tech@gmail.com
Auxiliary Supply : 180 – 240 Volts
Input Voltage
: 3V – 300 Volts
Current
: 10mA – 2.0 A*
(200mA,500mA,10A,20A range are also
available)
Frequency 45-55 Hz (45-65 Hz is
also available)
Measures upto 55th Harmonic
Accuracy Class : 0.2%
Voltage Harmonics
Current Harmonics
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THDPM-1 is THD analyzer which measures upto
55th harmonic.
It provides Voltage and Current THD.
It shows the net effect on THD due to load.
It also shows following parametersVoltage
Current
Watt
Frequency
Power Factor
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It is useful for testing of LED Drivers, SMPS, CFL,
CHOKES, Charger, AC to DC Converter, UPS etc.
VOLTAGE
VOLTAGE THD
CURRENT
WATT
CURRENT THD
PF
NET THD
(Frequency and PF shows alternately )
Press
to see Voltage Harmonics
Voltage rms Value
1st Harmonic
THD %
Voltage
3rdHarmonic
5th Harmonic
7th Harmonic
Press
to see more Harmonics (upto 55th harmonic can be seen)
Press
Press
to see Previous Harmonic
to see Current Harmonics
Current
3rd Harmonic
5th Harmonic
7th Harmonic
Press
Current rms Value
1st Harmonic
Current THD %
to see more Harmonics (upto 55th harmonic can be seen)
Press
Press
to see previous Harmonic
to see to go to main page
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Lets start testing with only Bulb load.
We take a 100 Watt Bulb load and connect it to
load side.
Voltage THD is 2.90% and Current THD is 4.85%.
So Bulb causes a small distortion in current.
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Experiment with only CFL load.
We take a normal 14 Watt CFL and connect it to
load side.
Voltage THD is 3.56% and Current THD is 26.99%.
A CFL distorts the current more.
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Experiment with Bulb and CFL load.
Bulb specification is 100 Watt .
CFL specification is 14W.
Voltage THD is 3.23% and Current THD is 5.99% .
Bulb has more power than CFL and also linear in
nature so it tends to decrease the current
distortion.
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Experiment with Bulb and Capacitor.
We take a capacitor of 3.15µF and connect to load
side with a normal Bulb load.
Voltage THD is 3.12% and Current THD is 15.34%.
A Capacitor also distorts the current.
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Experiment with Laptop load.
We take a laptop and connect it to supply with
charger of 65watt.
Voltage THD is 7.92% and Current THD is 113.1%.
AC to DC Converters provides high distortion in
current.
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Experiment with Laptop and Bulb load.
We Connect Bulb and Laptop at load side.
Voltage THD is 8.83% and Current THD is 69.59% .
A linear load reduces the current distortion.
BULB has more power than Laptop Charger and also
linear in nature so it tends to decrease the current
distortion.
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Experiment with LED and LED Driver Load.
We Connect 60 LEDs of 1Watt each at load side
through LED Driver.
Voltage THD is 1.68% and Current THD is 133.9%
.
LED Driver produces high distortion in current.
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Experiment with LED Bulb.
We Connect LED Bulb at at load side.
Voltage THD is 2.55% and Current THD is 63.40%
.
LED Driver produces distortion in current.
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Experiment with LED Bulb and normal Bulb load.
We Connect LED Bulb and normal Bulb at load
side.
Voltage THD is 1.78% and Current THD is 7.02%.
Bulb is linear device and has power more than
LED Bulb so it reduces the Current distortion.