Gather-and-broadcast frequency control in power systems

TL;DR

This paper introduces a novel gather-and-broadcast frequency control method for power systems that ensures stability and optimal economic dispatch by combining centralized measurement aggregation with local control.

Contribution

It presents a new control architecture that bridges centralized and distributed methods, with proven stability and optimality in complex power system models.

Findings

The control scheme guarantees local asymptotic stability.

It ensures the power system's equilibrium solves the economic dispatch problem.

Many existing strategies are special cases of the proposed approach.

Abstract

We propose a novel frequency control approach in between centralized and distributed architectures, that is a continuous-time feedback control version of the dual decomposition optimization method. Specifically, a convex combination of the frequency measurements is centrally aggregated, followed by an integral control and a broadcast signal, which is then optimally allocated at local generation units. We show that our gather-and-broadcast control architecture comprises many previously proposed strategies as special cases. We prove local asymptotic stability of the closed-loop equilibria of the considered power system model, which is a nonlinear differential-algebraic system that includes traditional generators, frequency-responsive devices, as well as passive loads, where the sources are already equipped with primary droop control. Our feedback control is designed such that the closed-loop equilibria of the power system solve the optimal economic dispatch problem.