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Date-03/09/2014 (THD MEASUREMENT WITH EXAMPLES AND FIGURES) ByEMBUILT TECHNOLOGIES www.embuilt.com www.energylogger.blogspot.com [email protected] 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 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 parametersVoltage Current Watt Frequency Power Factor 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 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. 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. 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. 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. 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. 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. 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. 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. 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.