ABSTRACT
Radial distribution feeders are characterized by having only one path for power to flow from the source to each customer. A typical distribution system will consist of one or more distribution substations consisting of one or more “feeders.” The loading of a distribution feeder is inherently unbalanced because of the large number of unequal single-phase loads that must be served. The determination of the impedances for overhead and underground lines is a critical step before analysis of the distribution feeder can begin. Since a distribution feeder is inherently unbalanced, the most accurate analysis should not make any assumptions regarding the spacing between conductors, conductor sizes, or transposition. When a high-voltage transmission line is less than 50 miles in length, the shunt capacitance of the line is typically ignored. The determination of the shunt admittance of overhead lines starts with the calculation of the “potential coefficient matrix”.
