Primary frequency regulation with load-side participation: stability and optimality

TL;DR

This paper introduces a distributed control method for power networks that guarantees stability, fairness, and optimality in primary frequency regulation by incorporating load-side participation and demand response.

Contribution

It provides a passivity-based framework ensuring stability and optimality with explicit steady state conditions, including demand control, and demonstrates improved system performance through simulations.

Findings

Inclusion of demand response reduces steady state frequency deviations.

Demand-side participation improves transient and steady state stability.

Dynamic demand response enhances robustness to time delays.

Abstract

We present a method to design distributed generation and demand control schemes for primary frequency regulation in power networks that guarantee asymptotic stability and ensure fairness of allocation. We impose a passivity condition on net power supply variables and provide explicit steady state conditions on a general class of generation and demand control dynamics that ensure convergence of solutions to equilibria that solve an appropriately constructed network optimization problem. We also show that the inclusion of controllable demand results in a drop in steady state frequency deviations. We discuss how various classes of dynamics used in recent studies fit within our framework and show that this allows for less conservative stability and optimality conditions. We illustrate our results with simulations on the IEEE 68 bus system and observe that both static and dynamic demand response schemes that fit within our framework offer improved transient and steady state behavior compared with control of generation alone. The dynamic scheme is also seen to enhance the robustness of the system to time-delays.