On Active Filtering of Harmonics Pollution-Theoretical Aspects

Abstract:- By harmonics pollution it is usually understood one of the basic problems of the electric energy supply quality – the presence of higher harmonics. In contemporary electric energy networks they are due to nonlinear loads of various natures. These higher harmonics have to be suppressed and this is done by filtering. Active filtering is done by feedback structures where the filter properties may be controlled. The present paper aims to discuss some theoretical aspects which are of the same nature as the harmonic balance applied to feedback control systems for the techniques of the describing function. Some connections to harmonics suppression in mechanical engineering (the feedback vibration absorbers) are also pointed out