A Distributed Consensus-Based Optimal Dispatch Control Strategy for Hybrid AC/DC Microgrids

Abstract

This paper proposes a consensus-based distributed control strategy for optimal power dispatch, frequency control, and DC voltage regulation in islanded hybrid AC/DC microgrids (HMGs). For the primary control, local control of AC/DC DGs is implemented using the droop-based control. Regarding the secondary control, a coordination-based distributed optimal control approach is initially introduced. Subsequently, control objectives, including AC frequency restoration, DC voltage regulation, and optimal economic operation of all participating AC/DC DGs with power limit consideration in the hybrid AC/DC microgrid, are achieved based on the proposed optimal consensus based controller. Moreover, the proposed controller integrates frequency regulation with optimal dispatch, reactive marginal dispatch with voltage regulation in AC microgrid (MG), and optimal dispatch with voltage regulation in DC MG, all at the secondary control level, eliminating the need for a tertiary controller. Furthermore, a distributed active power control method is proposed for managing multiple bi-directional interlinking converters (BICs), ensuring proportional active power sharing for BICs to prevent overloading. Extensive simulations are conducted using MATLAB/Simulink to showcase the effectiveness of the suggested coordination-based control.

Keywords

• Distributed control
• economic dispatch (ED)
• hybrid AC/DC microgrids (HMGs)
• multi-objective control
• secondary control