Patent ID: 6249108
Filing Date: 2001-06-19
Classification: H02J,Y02E

Abstract:
A circuit comprising:an AC source having a source current, i.sub.s, and a source voltage, v.sub.s ;a nonlinear load coupled to said AC source having a reactive current drawn therefrom;a switching converter having a conversion ration M(D), where D is a duty ratio of said switching converter, and a voltage- or current-energy storage element, said switching converter being coupled to said AC source in parallel with said nonlinear load and configured so that it has a current draw opposite to said reactive current draw of said nonlinear load so that said reactive current draw of said nonlinear load is substantially cancelled out by said current draw of said switching converter; anda controller coupled to said switching converter to control performance of said switching converter so that said reactive current of said nonlinear load is substantially cancelled by current from said switching converter, which cancellation is indirectly performed by sensing said source current, i.sub.s, and setting a control goal function to i.sub.s =v.sub.s /R.sub.e, which in turn is approximately realized by adjusting said duty ratio, D, of said switching converter according to R.sub.s i.sub.s =v.sub.m /M(D), where R.sub.e is an equivalent resistance by which the source is loaded including said nonlinear load and where v.sub.m is a low frequency signal generated from said voltage- or current-energy storage element in said switching converter.