NETWORK FILTER FOR A CONVERTER FOR CONNECTION OF THE CONVERTER TO A THREE-PHASE SUPPLY NETWORK

摘要

The invention relates to a network filter (1) for a converter for connection of the converter to a three-phase supply network (3), one annular self-induction coil (13) per phase being connected in series to a commutation inductor (11) of the converter. The network filter also comprises a Y-connected capacitor circuit (15) having at least four capacitors, a first, a second and a third of the four capacitors being connected to one of the phases of the three-phase supply network (3) each and a fourth of the four capacitors being connected to ground. In a most preferred embodiment, the network filter (1) is mounted on the commutation inductor (11) of the converter and the windings of the annular self-induction coil (13) are formed by connecting lines which connect the first, second and third capacitor to the three phases of the supply network (3). The windings of the annular self-induction coil (13) for every phase can be wound onto a common toroidal core, preferably a ferrite core.