Evaluating strategies for reliable distribution

Improving the performance of distribution systems to meet required targets is a matter of selecting the most cost-effective technologies and operating practices. Since distribution systems tend to be very extensive with a long life span for conductors and plant, this means investigating the effect of policies on both the existing network and the network as it develops to meet changing customer demands over many years. It is not sufficient to analyze how a particular piece of the network may be modified to improve its performance today: it is a matter of determining under what conditions particular policies may be optimal when due allowance is made for uncertainties in the predictions of customer demand and government regulation. The authors discuss strategies for improving reliability of primary distribution networks (typically 6 to 30 kV) including: decrease the fault rate of the conductors; optimize the location and number of switches; increase the level of interconnection; and introduce automation. To illustrate the analyses that may be carried out, comparisons are made in this article for rural networks where performance levels tend to be considerably lower than for urban networks. Primary European and American networks are considered