Optimized Distribution and Subtransmission Planning by Digital Computer III-Primary Main Circuit Design

A computer program has been developed for studying the design of the primary main circuit. This program is part of a series of programs developed jointly by the Arizona Public Service Company and the General Electric Company. The program, which can be used independently or in conjunction with programs for studying secondary and subtransmission system economics, examines each of many possible primary circuit designs, determines investment and operating costs, and compares the total cost with that of other possible designs. Use of the program at four different load levels and two primary circuit voltage levels has produced much significant data and has resulted in optimization of conductor size and of the dimensions of the substation load area. In addition, a lower annual cost for higher primary circuit distribution voltage has been demonstrated.