L'power it can be active or reactive. L'reactive energy of the user causes greater consumption and commitment on the lines of the company that provides electricity, which consequently charges higher costs to the user in the form of penalties for low power factor.
The result of the presence of reactive energy translates into a higher bill for a power that the user does not actually use since it does not produce work (only active energy produces work) but that the supplier regularly bills.
This problem often suffers those who use electric motors, welding machines, power supplies for fluorescent lamps and transformers, small and large companies to be clear, that the voice reactive energy if they find it in reading the electricity bill. The remedy consists of a technical operation called power factor correction.
But what is thereactive energy? By applying the AC mains voltage V to an electric motor the result is twofold: an active current that partly produces the work of the motor and partly dissipates in heat, and a reactive current which does no work but simply serves to excite the magnetic circuits of the motor. Active energy corresponds to active power,reactive energy reactive power.
Reactive energy it always amounts to economic damage. For the electricity user because, having to increase the value of the current circulating in the electric cable, the energy losses due to the joule effect on the internal network increase. For the supplier, because it forces him to oversize his generators at the expense of efficiency as the greater electrical power involves a phase shift which translates into further losses of active power.
To avoid the damage of the phase shift for the electricity supplier, the energy distribution body has imposed clauses that actually oblige the user to re-phase their systems for a better and more economical use of energy. This is particularly the case for low voltage systems with a committed power greater than 15 kW.
The power factor correction to eliminate the presence of reactive energy usually consists of inserting a suitably sized battery of capacitors into the electrical circuit of the laboratory or plant. The operation must be entrusted to a specialized company following an energy audit