In AC electrical system, Power factor is the ratio of the Real Power and Apparent Power. Real Power is the electrical power that is being consumed by the electrical resistive load, usually converted into heat, mechanical, or other form of energy. Apparent Power is the vector sum of Real Power and Reactive Power- the stored energy in the reactive component reactor and capacitor. Power Factor is a value between zero and one.
Significance of correcting Power Factor
The aim of correcting Power Factor is to minimize or lessen the Reactive Power of the system. A Power Factor of one or unity Power Factor lessens the power losses in the feeders and will incur less energy expenses to electric energy consumer, this will also result in less investment in terms of acquisition of electric generating equipment and transmission lines on the part of the Electric Utility companies.
Correcting Power Factor by adding capacitive component
Most of electrical loads have either or both resistive and inductive component. Resistive component are responsible for converting electric energy into a usable form while inductive component are the one that causes a decrease in Power Factor. To compensate the presence of inductive component in the electrical loads, a capacitor is added in parallel. Capacitor will provide the capacitive component that behaves opposite the inductive component of the load.
The economics of correcting Power Factor
Utility Company imposes penalties to electric energy consumers with a Power Factor less than their required limits and gives premiums to those consumers with a Power Factor above their set limits. The investment in acquiring a Power Factor correcting equipment can be recovered in less than one year provided that proper ratings and designed in accordance to the character of the loads. Investment can be recovered from the premiums plus the difference between the electric bills before correction of the Power Factor minus the electric bills after the correction of Power Factor.