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Differences of Active and Passive PFCs

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Power factor correction can help significantly reduce power losses and reduce power drawn from the mains. Power factor ratio lower than 1 increases the reactive power returned to the mains. This also generates harmonics passed back to the power line, affecting other equipment connected to it.


Passive power faction conditioning involves using simple capacitor and inductor banks to absorb the reactive power returned. Most conditioners are LC circuits tuned to 60 Hertz. This allows only the fundamental frequency to pass and the remaining harmonics absorbed. This also allows the load to appear as a resistive load to the power line. The inductor and capacitor used are usually of high values. This  may be a simple setup, but is very bulky.

Active power factor correction is usually found in switched-mode power supplies. It has and active  circuitry to automatically adjusts the compensation depending on the amount of reactive power. This allows power factor ratios as high as 0.99. This improved efficiency allows the device to draw less power and deliver power efficiently. They’re also smaller compared to passive PFCs.

Do you need test equipment for calibrating the ideal power conditioning ? Consider renting fromProtec. We also have a wide selection test instruments like power quality analyzers, earth testers and more. Contact us for more details on test equipment rental.