ABSTRACT
The distribution system is unique in that it uses not only many types of transformers but also many different transformer connections. The purpose of this chapter is to present some of the major concepts that concern the distribution systems engineer and operator. Things like types of transformers, loading of transformers, construction and rating are applied to the distribution system. Also, those special transformers, like autotransformers and grounding transformers, are presented since they, too, are common to the distribution system. The basic transformer consists of two windings, which are electrically insulated from each other and wound around a laminated core of magnetic sheet steel. They are usually regulated by LTC which adjusts voltage level depending on loading conditions. The secondary bus is usually split to reduce the number of short circuits seen by each transformer as well as to reduce the short circuit level of the system.
