Simplified bidirectional-feeder models for distribution-system calculations

Abstract

The paper presents three novel distribution-feeder models to simplify complicated distribution-system calculations. These equivalent models are developed to simulate the total series voltage drop at the end of the given feeder accurately, the total copper loss of the given feeder accurately, and a hybrid to simulate both voltage drop and feeder loss accurately. In addition, all of the proposed models are bidirectional. This means that power infeed can be at either end and the model is accurate. In contrast, unidirectional models previously developed are accurate only when power infeed is at the end specified by the model. This feature is important for a modern power-distribution system in which the power infeed of the switched feeder may change from one end to the other during service restoration or feeder reconfiguration. These bidirectional feeder models are illustrated by examples and applied to an actual feeder. The simulation results show that it is possible to reduce many complex feeders to simple equivalent models in the study of feeder-voltage profiles and losses with negligible error, even if the power infeeds of the given feeders are changed.