A Linear Outer Approximation of Line Losses for DC-based Optimal Power Flow Problems

TL;DR

This paper introduces a simple linear outer approximation model for line losses in DC optimal power flow problems, improving accuracy and efficiency for large-scale power system optimization.

Contribution

It presents the Line Loss Outer Approximation (LLOA), a novel outer approximation method that enhances line loss modeling in linearized power flow problems.

Findings

LLOA achieves high accuracy with few iterations.

LLOA outperforms classical line loss approaches in large-scale tests.

LLOA offers a practical balance of accuracy, efficiency, and simplicity.

Abstract

This paper proposes a novel and simple linear model to capture line losses for use in linearized DC models, such as optimal power flow (DC-OPF) and security-constrained economic dispatch (SCED). The \textit{Line Loss Outer Approximation} (LLOA) model implements an outer approximation of the line losses lazily and typically terminates in a small number of iterations. Experiments on large-scale power systems demonstrate the accuracy and computational efficiency of LLOA and contrast it with classical line loss approaches. The results seem to indicate that LLOA is a practical and useful model for real-world applications, providing a good tradeoff between accuracy, computational efficiency, and implementation simplicity. In particular, the LLOA method may have significant advantages compared to the traditional loss factor formulation for multi-period, stochastic optimization problems where good reference points may not be available. The paper also provides a comprehensive overview and evaluation of approximation methods for line losses.