THREE-PHASE POWER COMPOUND TRANSFORMER WITH HARMONIC ACTIVE FILTER FUNCTION USING THREE-PHASE POWER AUTOTRANSFORMER

摘要

The objective of the present invention is to provide a three-phase active harmonic filter that is useful not only in emergencies but also in normal times since the three-phase active harmonic filter can be used in emergencies as an open phase recovery device that prevents accidents in which one phase is lost, can be used as an autotransformer that outputs three-phase 380 V and three-phase 220 V, and at the same time can be used as an active harmonic filter. A transformer according to an aspect of the present invention, for achieving said objective, comprises a plurality of zigzag connection units (130) connected to a power supply system (100) having a three-phase connection for supplying an alternating current power to a load (110), wherein the plurality of zigzag connection units (130) have a single winding core having three legs (131, 132, 133). On the legs, zigzag wires (R1, Rn; S1, Sn; T1, Tn) of a three-phase transformer and wires (R2, Rn*; S2, Sn*; T2, Tn*) symmetric to the zigzag wires of the three-phase transformer are wound. The end (Rz) of wire R2 and the beginning (Sa) of S1 of the three-phase transformer are connected to the S phase; the end (Sz) of S2 and the beginning (Ta) of T1 are connected to the T phase; the end (Tz) of T2 and the beginning (Ra) of R1 are connected to the R phase; and three Ns which are the beginnings of Rn, Sn, and Tn, and three Ns which are the ends of Rn*, Sn*, and Tn* are all connected to the N phase.