Economic Operation of Multi-terminal Interlinking Microgrid Based on the Decentralized Protocol

This paper develops a decentralized control strategy based on an interlinking converter to realize the global economic optimal operation of a multi-terminal interlinking microgrid (MG). The control objective is to minimize the total generation cost (TGC) of the interlinking microgrid system. The proposed control is composed of local and global controllers, which deal with sub-MG and interlinking MG systems respectively. The local controller regulates the incremental cost (IC) value matching in the sub-microgrid based on the nonlinear dynamic droop control with equal IC to achieve the optimal load power distribution in the local DG units. The global controller controls BIC through the bus voltage signal to match the IC value of the entire interlinking MG system in a decentralized form, which significantly improves the reliability and scalability of the system and achieves the global optimal economic optimal operation under the condition of meeting the power demand and production constraints. The feasibility and superiority of the proposed controller are verified by PLECS under various test cases.