Cost-Aware Bound Tightening for Constraint Screening in AC OPF

TL;DR

This paper introduces a cost-aware bound tightening method for constraint screening in AC optimal power flow problems, considering the impact of the objective function and convex relaxations to improve operational efficiency.

Contribution

It proposes a novel constraint screening approach that incorporates the objective function's role and evaluates its effectiveness under various convex relaxations.

Findings

Objective function influences constraint screening outcomes.

Convex relaxations affect the accuracy of constraint elimination.

The method improves efficiency in power system operational planning.

Abstract

The objective of electric power system operators is to determine cost-effective operating points by resolving optimization problems that include physical and engineering constraints. As empirical evidence and operator experience indicate, only a small portion of these constraints are found to be binding during operations. Several optimization-based methods have been developed to screen out redundant constraints in operational planning problems like the optimal power flow (OPF) problem. These elimination procedures primarily focus on the feasible region and ignore the role played by the problem's objective function. This letter addresses the constraint screening problem using the bound tightening technique in the context of the OPF problem formulated with a full ac power flow characterization. Due to the non-convexity of the ac OPF, we investigate line constraint screening under different convex relaxations of the problem, and we evaluate how the economics of the objective function impacts screening outcomes.