Evaluation of technical losses on electric distribution systems

Associated with the delivery of customer load are demand losses which, over a period of time, are reflected as energy losses. From the system viewpoint, such losses cannot be distinguished or separated from system load. The capacity required to meet demand losses necessitates capital expenditures while production costs are incurred in satisfying the energy losses. Each electric utility can benefit from studies aimed at establishing an appropriate range of values for demand and energy losses. The authors address the overall problem of calculating such losses within the different segments of the distribution system. The methodology used by the Electric Power Research Institute to calculate such losses on a physically existing and operating electric utility is described. The losses for each major element of the electric distribution system from the high voltage side of the substation transformer to the customer´s service entrance have been identified