Patent ID: 7923867
Filing Date: 2011-04-12
Classification: H02J,H02M,Y02E

Abstract:
1. An apparatus for suppressing harmonic noise in a three-phase power supply bus, said power supply bus comprising at least a first, second and third power line, each power line corresponding to a respective phase of the three-phase power supply bus, the apparatus comprising: a) a disconnect having an input side and an output side, said input side coupled to at least said first, second and third power lines and said output side of said disconnect having a first, second and third output nodes; b) a first transformer having a primary side and a secondary side, said primary side having a first primary terminal and a second primary terminal, said first primary terminal coupled to said first output node of said disconnect, and said secondary side of said first transformer having a first secondary terminal and a second secondary terminal; c) a second transformer having a primary side and a secondary side, said primary side having a third primary terminal and a fourth primary terminal, said third primary terminal coupled to said second output node of said disconnect and to said second primary terminal, said secondary side of said second transformer having a third secondary terminal and a fourth secondary terminal, said fourth secondary terminal coupled to said first secondary terminal; d) a third transformer having a primary side and a secondary side, said primary side having a fifth primary terminal and a sixth primary terminal, said fifth primary terminal coupled to said third output node of said disconnect and to said fourth primary terminal, said sixth primary terminal coupled to said first primary terminal, said secondary side of said third transformer having a fifth secondary terminal and a sixth secondary terminal, said sixth secondary terminal coupled to said third secondary terminal; and e) a non-inductive grid resistor, coupled between said second secondary terminal and said fifth secondary terminal.