Power Sharing of Different Distributed Generator Sets in Microgrid Based on Consensus Control

Abstract

Microgrids incorporate renewable energy sources, battery energy storage systems (BESS), and local loads to operate either with the main grid or independently. In microgrids, virtual synchronous generators (VSGs) and droop control are commonly used to regulate renewable energy sources, providing frequency and voltage control. The VSG and droop control adjust active power based on frequency deviation. However, their effectiveness depends on parameters and does not fully address power-sharing issues. Traditionally, power sharing is handled by secondary control via the microgrid central controller (MGCC), introducing a centralized, hierarchical approach. To enhance decentralization in microgrids, this paper proposes a consensus based power sharing scheme and its corresponding control for the distributed generators (DGs). The output power levels of DG units are determined by their capacities, ensuring efficient operation. Unlike existing approaches using a hierarchical framework, this work integrates primary and secondary control into a unified distributed control framework. Building on VSG control for microgrid voltage regulation, consensus control is added to manage the distribution of active power. A rigorous theoretical analysis is conducted to validate the proposed method. The method is capable of ensuring active power sharing without relying on an MGCC, and the sharing is also based on the ratio of rated capacities. The controller proposed in this paper achieves the expected control performance, effectively distributing active power sharing in the microgrid. Finally, the effectiveness and performance of the proposed method are verified through comprehensive case studies.