Design and Stability of Market-Oriented Frequency Regulation in Power Systems With CHP Units and Renewable Sources

Electricity industry marketization and combined heat and power (CHP) systems are actively considered efficacious approaches for balancing supply and demand in future energy systems with high penetration of renewable sources. Relevant research to date has paid little attention to the interaction of economic behaviors with the dynamics of the CHP system, focusing only on optimal bidding at the economic level or stability at the physical level. By leveraging the primal-dual method and the insights from reverse engineering, we propose a unified economic-physical model to investigate how market dynamics interact with its underlying physical CHP systems. The market clearing optimization is redesigned as a controller that restores the nominal frequency while maximizing social welfare. This work steps further toward developing a novel control scheme for frequency regulation in market-oriented power systems with CHP units and renewable sources. As the proposed model can be formulated in port-Hamiltonian form, the stability of the closed-loop system can be assessed using Lyapunov's direct method. The capability and effectiveness of the proposed model are demonstrated through simulations.