Operational risk quantification of power grids using graph neural network surrogates of the DC OPF

TL;DR

This paper develops graph neural network surrogates for the DC optimal power flow problem to enable fast and accurate risk quantification in power grid operations, addressing computational challenges of Monte Carlo simulations.

Contribution

It introduces GNN-based surrogate models specifically evaluated for risk quantification in power grids, focusing on their accuracy and generalizability for operational risk assessment.

Findings

GNN surrogates accurately predict grid states at multiple levels.

Surrogates enable fast, reliable risk quantification for real-world power grids.

Models perform well across different synthetic grid test cases.

Abstract

A DC OPF surrogate modeling framework is developed for Monte Carlo (MC) sampling-based risk quantification in power grid operation. MC simulation necessitates solving a large number of DC OPF problems corresponding to the samples of stochastic grid variables (power demand and renewable generation), which is computationally prohibitive. Computationally inexpensive surrogates of OPF provide an attractive alternative for expedited MC simulation. Graph neural network (GNN) surrogates of DC OPF, which are especially suitable to graph-structured data, are employed in this work. Previously developed DC OPF surrogate models have focused on accurate operational decision-making and not on risk quantification. Here, risk quantification-specific aspects of DC OPF surrogate evaluation is the main focus. To this end, the proposed GNN surrogates are evaluated using realistic joint probability distributions, quantification of their risk estimation accuracy, and investigation of their generalizability. Four synthetic grids (Case118, Case300, Case1354pegase, and Case2848rte) are used for surrogate model performance evaluation. It is shown that the GNN surrogates are sufficiently accurate for predicting the (bus-level, branch-level and system-level) grid state and enable fast as well as accurate operational risk quantification for power grids. The article thus develops tools for fast reliability and risk quantification in real-world power grids using GNN-based surrogates.