A Linear Model for Distributed Flexibility Markets and DLMPs: A Comparison with the SOCP Formulation

TL;DR

This paper compares a new linear flexibility market model with a traditional SOCP formulation, highlighting trade-offs in accuracy and practicality for congestion management in power systems.

Contribution

It introduces a linear model for flexibility markets that simplifies implementation while maintaining reliability compared to the SOCP benchmark.

Findings

Linear model preserves system reliability better with increased flexibility.

Relaxed voltage limits improve price and flow approximation.

Linear model offers a practical alternative to SOCP for congestion management.

Abstract

This paper examines the performance trade-offs between an introduced linear flexibility market model for congestion management and a benchmark second-order cone programming (SOCP) formulation. The linear market model incorporates voltage magnitudes and reactive powers, while providing a simpler formulation than the SOCP model, which enables its practical implementation. The paper provides a structured comparison of the two formulations relying on developed deterministic and statistical Monte Carlo case analyses using two distribution test systems (the Matpower 69-bus and 141-bus systems). The case analyses show that with the increasing spread of offered flexibility throughout the system, the linear formulation increasingly preserves the reliability of the computed system variables as compared to the SOCP formulation, while more lenient imposed voltage limits can improve the approximation of prices and power flows at the expense of a less accurate computation of voltage magnitudes.