Ability of Positive Sequence Aggregated Distributed Energy Resource Model to Represent Unbalanced Tripping of Distribution Inverters

With the spread of distribution connected inverters on a feeder being hidden from a transmission planner, the ability to represent the under voltage tripping characteristic of an aggregation of distribution inverters in a transmission planning study is becoming increasingly important. In this paper, parameters of the partial voltage trip characteristic of a recently approved positive sequence aggregated distributed energy resource model will be developed. In deriving these parameters, the uncertainty associated with the location of the inverters on the feeder, the impact of $1-\phi$ transmission voltage events, and power imbalance across the feeder, will be considered. These variations are common variations that occur in the power system. The positive sequence aggregated model's behavior is compared with detailed $3-\phi$ feeder level simulations performed on the IEEE 8500 node feeder.