Using the fuzzy set theory, this study presents three changeable single-feeding-end fuzzy feeder models that simplify complicated distribution system calculations. The proposed models are generated using lumped loads to represent discretely distributed tapped-off loads along a feeder. These models accurately simulate total series voltage drop at the end of given feeder, total copper loss and a hybrid to accurately simulate voltage drop and feeder loss. Moreover, power can be fed into either feeder end. To demonstrate the accuracy of the proposed fuzzy feeder models, a physical feeder is utilized as a sample feeder. Simulation results indicate that reducing numerous complex feeders to simple equivalent models is possible when investigating feeder voltage profiles and losses with negligible error.
