Fuzzy feeder models for distribution system calculations

Using fuzzy set theory, this study presents three novel distribution fuzzy feeder models to simplify complicated distribution system calculations. These fuzzy models are formulated using lumped distribution transformer(s) and lumped load(s) to represent non-uniformly distributed loads, which vary by time and type of day and relate to voltage, along a feeder. These equivalent models are developed to accurately simulate first, the total series voltage drop at the end of given feeder, and then the total copper and core losses. Finally a hybrid model is developed to simulate both voltage drop and feeder losses accurately. A physical feeder is used as a sample feeder to demonstrate the correctness of these proposed fuzzy feeder models.