Line filter for reducing AC harmonics

摘要

The disclosed AC harmonic first circuit utilizes band pass and stop filters that have resonance frequencies close to but yet a few Hz or a small percent away from the harmonic frequencies intended to be attenuated, the difference being comparable to the Q factor of the respective filter. Thus, every circuit filter has a different resonance frequency, and the difference between the filter resonance and harmonic frequencies might be 0.2-5%. Each filter attenuates the energy of each harmonic by possibly 10-50%. A network filter having a resonance frequency corresponding to the AC power network frequency is in series in the hot line between the power network source and the harmonic filter circuit. The circuit uses only passive components in reducing disruptive harmonics from the AC power network.