CONVERTER TRANSFORMERS WITH SELF-COUPLING COMPENSATION AND HARMONIC SHIELDING

摘要

A converter transformer with self-coupling compensation and harmonic shielding is disclosed. A self-coupling tap is led out from the secondary winding in the supply transformer, this tap dividing the secondary winding into two stages: the analogous auto-transformer common winding and series winding. Both of them are coupled closely, the secondary windings of the two stages and the primary winding are arranged with one center on the iron core cylinder, wherein the common winding is arranged between the primary winding and the series winding, its equivalence impedance value being zero. The both ends of the common winding connect to the bypass of external filter capacitor inductance. The invention can take reactive compensation nearby for inductive current at user's power frequency, can utilize the induced current Ampere-turn balancing action of two windings divided by the tap at relevant harmonic frequency to neutralize the harmonic magnetic linkage, thereby leading the harmonic current to return to load nearby through the series winding and preventing the harmonic current from crossing the air gap into the primary power network, accordingly effecting a radical cure to the harmonic from the stump. It also prevents the harmonic current and the harmonic magnetic flux from damaging to the transformer when taking the harmonic shielding and isolating to the primary power network.