Distribution systems reliability-Lakeland Electric case study

The case study presented in the paper combines the distribution substation and the distribution feeders in one analysis to evaluate the reliability of supply at a customer location. This approach provides a more realistic set of reliability indices, because it includes the outage impact of both distribution feeder(s) and the substation components. The indices can be used to rank needed reliability improvements on a feeder, multiple feeders and/or a substation. The reliability indices reported in this paper were calculated for the customers that are served by Palmetto Substation, one of the Lakeland Electric distribution substations. The indices are used in developing reliability initiatives and to rank various projects based on improvement in reliability as seen by a customer. The paper discusses both customer-based indices such as SAIFI, SAIDI, CAIDI, MAIFIe, and energy based indices such as EUE, which can be used in selecting the best option from various alternatives available to a planner. Different conclusions are obtained if customer reliability is only quantified by modeling, without making due consideration of the tie support from neighboring feeders. It is expected that this analysis will help Lakeland Electric plan, design and operate the distribution facilities in a cost-effective manner while meeting its obligations to its customers, city council, and regulators.