Distributed demand-side contingency-service provisioning while minimizing consumer disutility through local frequency measurements and inter-load communication

TL;DR

This paper introduces a distributed algorithm for flexible loads to provide grid contingency reserves by coordinating through local frequency measurements and inter-load communication, ensuring privacy and minimizing consumer disutility.

Contribution

It presents a novel Distributed Gradient Projection (DGP) algorithm that converges for convex disutility functions and outperforms existing dual algorithms in certain scenarios.

Findings

DGP algorithm effectively stabilizes grid frequency during contingencies.

DGP performs better or similarly to dual algorithms in simulations.

The algorithm preserves load privacy by only exchanging gradient information.

Abstract

We consider the problem of smart and flexible loads providing contingency reserves to the electric grid and provide a Distributed Gradient Projection (DGP) algorithm to minimize loads' disutility while providing contingency services. Each load uses locally obtained grid-frequency measurements and inter-load communication to coordinate their actions, and the privacy of each load is preserved: only gradient information is exchanged---not disutility or consumption information. We provide a proof of convergence of the proposed DGP algorithm, and we compare its performance through simulations to that of a "dual algorithm" previously proposed in the literature that solved the dual optimization problem. The DGP algorithm solves the primal problem. Its main advantage over the dual algorithm is that it is applicable to convex---but not necessarily strictly convex---consumer disutility functions, such as a model of consumer behavior that is insensitive to small changes in consumption, while the dual algorithm is not. Simulations show the DGP algorithm aids in arresting grid-frequency deviations in response to contingency events and performs better or similarly to the dual algorithm in cases where the two can be compared.