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Improve Power Factor

Let us consider simple network of RLC and power supply. The current with the voltage will generate power in the resistance. The current and the voltage in the inductor will generate the magnetic field in the inductor, this field increase and collapse 50 times per second (due to the frequency) so every collapse the source will compensate the requirement (imaginary power). The inductor will build the field which will induce back EMF that will act against direction so it will cause the current to lag and can't follow and be in phase with the voltage.

The current and voltage in the capacitor will generate the electrical field between the capacitor sides. this field increase and collapse 50 times per second (due to the frequency) so every collapse the source will compensate the requirement (imaginary power). The capacitor will allow the current to pass through it initially and voltage builds up and this voltage gradually resist the current causing it to decrease exponentially. So the high initial current before voltage build up means the current leads the voltage and become max before the voltage.

Don't forget that all currents are from the source and the load is the key which cause portion of the current to be lead or lag, and the source current is the vector summation of all currents with their respective phase angles (lead or lag).

The source will continue to supply all currents, some will go to the resistance and be heat, some to the inductance and other to the capacitance to be magnetic, electrical fields. (NOTHING RETURN TO THE SUPPLY AND REMOVE THIS IDEA FROM YOUR HEAD) both fields (Electrical and magnetic) increase -reach maximum-decrease - become max in negative the increase) and such alternation require current from the source.

As you see, we don't gain power in both the inductor or capacitor, only the useful power in the resistance, that is the reason the electricity authority insist to imply in their regulations that consumers should delete the induction part in their networks to reduce the inductive currents (capacitance Is so rare only in long distance HT transmission lines and can't be exist in residential buildings).

And when you as client improve you power factor by adding power factor compensation, then you cancel the induction and capacitance effect and the result is only resistance effect and less absorbed current from the authority, and authority will be so happy to give you less current and give the eliminated current to other consumer.

Remember, the authority will take money only on the KWH you absorb (that is the reason we call the meter KWHmeter, and they don't take money for the reactive power which you consumed free, this is the reason of the regulation of PF compensation).

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