ABSTRACT
This chapter develops accurate models for all of the major components of a distribution system. Once the models have been developed, analysis techniques for steady-state and short-circuit conditions will be developed. Of these components, the distribution system has traditionally been characterized as the most unglamorous component. The distribution system typically starts with the distribution substation that is fed by one or more subtransmission lines. In some cases, the distribution substation is fed directly from a high-voltage transmission line in which case, most likely, there is no subtransmission system. With a rare exception, the feeders are radial, which means that there is only one path for power to flow from the distribution substation to the user. Radial distribution feeders are characterized by the presence of only one path for power to flow from the source to each customer. A typical distribution system consists of one or more distribution substations consisting of one or more "feeders".
