Distributed Voltage Frequency Control of Isolated Microgrids

Abstract

This study proposes the use of a hierarchical distributed consensus control method based on voltage frequency control (VFC) and active power regulation to regulate the frequency of isolated microgrids. The proposed control scheme is divided into two levels. The first level employs voltage-dependent loads to modulate the frequency of the system by adjusting its voltage, thereby increasing the active power reserves of the system while accurately sharing reactive power among distributed energy resources. The second level uses the active power reserves generated by the VFC to stabilize the frequency of the system and strengthen its resistance to disruptions. Time-domain analysis is used to validate the proposed control method and compare its performance with those of the existing approaches. Furthermore, the proposed method is demonstrated via simulations in the context of a test system based on the CIGRE medium voltage benchmark under various scenarios. The results of these simulations confirm the superior performance of the new approach over that of existing control approaches.