Harmonic filters are designed for the suppression of harmonic distortion, as well as for the partial power factor correction of the loads. In fact, an increasingly widespread problem for power distribution are overloads due to harmonic currents introduced by electronic equipment, both single-phase and three-phase, for motors and drives, UPS, welders, air conditioning systems, and some types of PV installations. In these cases, the current is not perfectly sinusoidal and derives from the sum of currents with multiple frequencies, which therefore causes both functional and premature aging problems to the electrical system, components, and installed machines.
