A Port-Hamiltonian Approach to Optimal Frequency Regulation in Power Grids

TL;DR

This paper introduces two distributed, port-Hamiltonian based controllers for optimal frequency regulation in power grids, ensuring stability and social welfare maximization through real-time dynamic pricing models.

Contribution

It develops novel port-Hamiltonian controllers for frequency regulation that are fully distributed and stabilizing, integrating physical network dynamics with economic optimization.

Findings

Both controllers achieve stability and optimality in simulations.

The port-Hamiltonian framework facilitates stability analysis.

Controllers are flexible in communication network design.

Abstract

This paper studies the problem of frequency regulation in power grids, while maximizing the social welfare. Two price-based controllers are proposed; the first one an internal-model-based controller and the second one based on a continuous gradient method for optimization. Both controllers can be implemented in a fully distributed fashion, with freedom in choosing a controller communication network. As a result, two real-time dynamic pricing models described by port- Hamiltonian systems are obtained. By coupling with the port- Hamiltonian description of the physical network we obtain a closed-loop port-Hamiltonian system, whose properties are ex- ploited to prove asymptotic stability of the set of optimal points. Numerical results show the performance of both controllers in a simple case study.