Formulating a simplified equivalent representation of distribution circuits for PV impact studies.

With an increasing number of Distributed Generation (DG) being connected on the distribution system, a method for simplifying the complexity of the distribution system to an equivalent representation of the feeder is advantageous for streamlining the interconnection study process. The general characteristics of the system can be retained while reducing the modeling effort required. This report presents a method of simplifying feeders to only specified buses-of-interest. These buses-of-interest can be potential PV interconnection locations or buses where engineers want to verify a certain power quality. The equations and methodology are presented with mathematical proofs of the equivalence of the circuit reduction method. An example 15-bus feeder is shown with the parameters and intermediate example reduction steps to simplify the circuit to 4 buses. The reduced feeder is simulated using PowerWorld Simulator to validate that those buses operate with the same characteristics as the original circuit. Validation of the method is also performed for snapshot and time-series simulations with variable load and solar energy output data to validate the equivalent performance of the reduced circuit with the interconnection of PV