ABSTRACT
The operation of switching power devices implies the presence of harmonics due to their intrinsic nonlinearity, so in a distribution network, the presence and mutual interaction of several harmonic generators have to be accounted for. The most common source of harmonics and harmonic problems in power systems is the three-phase Graetz bridge. “Active filtering” is something included inside the more general term of “power conditioning” used to take into consideration several features in addition to harmonic filtering like harmonic damping, harmonic isolation, reactive power control for power factor correction and voltage regulation, load balancing, and voltage-flicker reduction. Harmonic currents can be generated both by load nonlinearity and by harmonic voltages in the power system. The Fryze method aims to minimize the rms value of the compensated currents; in this case, the ohmic losses are minimized too, and the average active power supplied by the grid remains the same as the power given by the original current.
