JPS5734320A - Single-phase three-winding transformer - Google Patents

Abstract

PURPOSE:To reduce the voltage generated at polarity switching and to prevent damage to a contact, by a method wherein the size thereof at the time of transportation is reduced without applying other windings to the outside of a high-voltage winding and a tap winding is faced to the tertiary low-voltage winding. CONSTITUTION:A medium-voltage winding 3A, and a high-voltage winding 2A are provided starting from an iron core side at the first iron core main leg 1A of single phase four legs. A tap winding 4, a medium-voltage winding 3B, and a high- voltage winding 2B at a neutral point side is provided starting from the iron core side at the second iron core main leg 1B. The medium-voltage windings 3A and 3B are connected in parallel and the high-voltage windings 2A and 2B and a tap winding 5 are connected in series to compose a single-phase tertiary winding transformer. In this compostion, it is not required to lengthen the winding diameter and consider a special counterplan for damage to a contact by tap switching at on-load and breaking capacity in the tertiary circuit and mechanical force acting on the tertiary winding at the time of short-circuit in the tertiary circuit are reduced and the low- cost single-phase tertiary winding transformer having a small dimension suitable for transportation can be obtained.