Distributed Approach for DC Optimal Power Flow Calculations

TL;DR

This paper introduces a fully distributed method for solving the DC Optimal Power Flow problem, enabling decentralized control in power systems with proven convergence and tested on standard IEEE systems.

Contribution

It presents a novel distributed algorithm for DC-OPF that iteratively updates local variables through simple computations and neighbor communication, with proven convergence to optimality.

Findings

Method converges to the optimal solution

Effective on IEEE Reliability Test System

Enables decentralized power system control

Abstract

The trend in the electric power system is to move towards increased amounts of distributed resources which suggests a transition from the current highly centralized to a more distributed control structure. In this paper, we propose a method which enables a fully distributed solution of the DC Optimal Power Flow problem (DC-OPF), i.e. the generation settings which minimize cost while supplying the load and ensuring that all line flows are below their limits are determined in a distributed fashion. The approach consists of a distributed procedure that aims at solving the first order optimality conditions in which individual bus optimization variables are iteratively updated through simple local computations and information is exchanged with neighboring entities. In particular, the update for a specific bus consists of a term which takes into account the coupling between the neighboring Lagrange multiplier variables and a local innovation term that enforces the demand/supply balance. The buses exchange information on the current update of their multipliers and the bus angle with their neighboring buses. An analytical proof is given that the proposed method converges to the optimal solution of the DC-OPF. Also, the performance is evaluated using the IEEE Reliability Test System as a test case.