JPS5683013A - Phase-conversion transformer - Google Patents

Abstract

PURPOSE:To obtain the transformer of small size and light weight as well as to eliminate the noises caused by a reactor using a method wherein a V connection is employed for the primary winding and a specific connection is employed for the secondary winding, thereby enabling to obtain the balancing circuit requiring no balancing reactor. CONSTITUTION:The primary winding of the transformer is V connected for a U phase and a V phase only, and the secondary winding is connected in such a manner that its W phase ab has reversed polarity against the W phase of normal delta connection. Further, a single phase load is connected between the terminals u and v of the secondary winding and a capacitor is connected between terminal v and w. And the windings, the forms and the like are adjusted so that the current ir of the secondary winding of the W phase will become 1/3<1/2> time of the current iL running to the single phase load, thereby balancing the three phases locatd on the primary side. Also, as the current ir varies according to the mutual inductance between the W phase winding and other phases, the capacity of the inductive reactance is brought to the normal value by adjusting the number of windings of the W phase winding. As a result, a three-phase/single-phase converting device requiring no balancer reactance is obtained, the device is miniaturized and light- weighted, and the noise caused by the reactor can be eliminated.