Stability and optimality of distributed secondary frequency control schemes in power networks

摘要

We present a systematic method for designing distributed generation anddemand control schemes for secondary frequency regulation in power networkssuch that stability and an economically optimal power allocation can beguaranteed. A dissipativity condition is imposed on net power supply variablesto provide stability guarantees. Furthermore, economic optimality is achievedby explicit decentralized steady state conditions on the generation andcontrollable demand. We discuss how various classes of dynamics used in recentstudies fit within our framework and give examples of higher order generationand controllable demand dynamics that can be included within our analysis. Incase of linear dynamics, we discuss how the proposed dissipativity conditioncan be efficiently verified using an appropriate linear matrix inequality.Moreover, it is shown how the addition of a suitable observer layer can relaxthe requirement for demand measurements in the employed controller. Theefficiency and practicality of the proposed results are demonstrated with asimulation on the Northeast Power Coordinating Council (NPCC) 140-bus system.