Distributed ℋ∞ Frequency Control for Inverter Connected Microgrids

Abstract

Microgrids are small-scale power networks where distributed generation and inverter interfaced power sources are common. These networks are faced with more significant control challenges; a smaller system can less effectively dampen and distribute power disturbances or fluctuations, and the system frequency is less robust without synchronous generators to provide rotational inertia. In this paper we will develop optimal control algorithms to control the voltage and frequency in an islanded inverter-based microgrid. The voltages and frequency of this system are controlled using decentralized ℋ∞ control. The decentralized controllers operate using only local data, making the control methodolgy scalable. In addition, the studied controllers can be tuned to achieve the desired transient behavior. For voltage and frequency control of microgrids, transient performance is still an area of weakness. The proposed control scheme extends optimal control to the field of microgrid control and can improve the state of microgrid technology.