A Proportional-Integral Model for Fractional Voltage Tripping of Distributed Energy Resources

TL;DR

This paper introduces a simple yet effective proportional-integral model to predict DER disconnection during voltage disturbances, improving accuracy over existing models while maintaining computational efficiency.

Contribution

The paper presents a novel aggregate model for DER tripping based on voltage, with a parameter tuning method, outperforming standard models in prediction accuracy.

Findings

Model accurately predicts DER disconnection fractions.

Outperforms the DER_A model in simulations.

Maintains low complexity with 14 parameters.

Abstract

In regions with high shares of distributed energy resources (DERs), massive disconnection of small-scale DERs in low-voltage distribution grids during disturbances poses a serious threat to power system security. However, modeling this effect in a computationally efficient way remains challenging. This paper proposes a novel proportional-integral aggregate model for predicting the fraction of tripped DERs based on the voltage at the substation connection point. The model effectively captures the cumulative behavior of the system, is simple to implement, and includes seven parameters for undervoltage tripping and seven for overvoltage tripping behavior, each with a distinct physical meaning. We further propose an optimization-based approach to tune the model parameters. Simulation results show significantly more accurate predictions compared to the DER\_A model -- a standard dynamic model for aggregate DER behavior -- even when the latter is optimized, with only a minor increase in model complexity.