How do harmonic filter inductors differ from “standard” inductors and reactors?
There are three major differences between harmonic filter inductors and standard inductors or line reactors. These differences are: 1. Tighter Inductance Tolerance When the harmonic filter inductor is used in a “detuned” circuit, or a filter circuit, the inductance value is very critical to the correct operation of the system. Harmonic filter inductors need inductance tolerances no greater than +/- 5%, and under some instances as tight as +/-2% or less. Standard inductors will have inductance tolerances of +/- 10%. 2. Multiple Frequency Current Spectrum Ratings Typically, harmonic filter inductors have multiple frequencies of current flowing through them simultaneously. Each of these currents, at their respective frequency, contribute to the heating effects on the inductor. A standard inductor such as a line reactor, has a current rating assigned to it that is determined at a single frequency only. More often than not, the heating effect of the multiple frequency currents, is much grea
