Modeling and Adaptive Control and Power Sharing in Islanded AC Microgrids

Abstract

This paper deals with the problem of control and power sharing for distributed generators in AC islanded microgrids. A one-layer adaptive control strategy based on two fixed-time adaptive control methods is designed to ensure voltage and frequency regulation and reference tracking and accurate active and reactive power sharing. The main advantage of the proposed approach is accurate power sharing and voltage and frequency reference restoration before the desired pre-fixed time despite the unknown disturbances and without requiring a secondary control loop. Compared to the existing microgrid adaptive controllers such as adaptive neural network-based controllers and adaptive fuzzy logic controllers among others, the design and tuning of the proposed techniques is simple and straightforward and does not require any knowledge of the microgrid parameters, lines impedance or load power demand. The developed adaptive control law has also a simple mathematically expression and thus it’s easily implemented and does not require a heavy computational performance. A comparative simulation study with conventional secondary control and power sharing is provided to highlight the effectiveness of the control strategy in term of reference tracking, robustness to load power variations and to distributed generators plug-and-play.