Hierarchical Coordination Control for Interconnected Operation of Electric-thermal-gas Integrated Energy System with Micro-energy Internet Clusters

At present, the natural gas network, thermal network and power grid can be coupled in the integrated energy system(IES) to provide users with different forms of energy such as heat, electricity and gas, but the relevant coordinated control strategies have not been sufficiently investigated. In this paper, a hierarchical distributed coordinated control strategy is proposed. The system is organized into three levels, namely IES-level, Micro-energy Internet(MEI)-level and component-level based on multi-agent system approach. To achieve accurate control of voltage and frequency of distributed devices and accurate distribution of the tie-line power in case of load fluctuations in MEI, a second-level optimization controller based on distributed sparse communication network is designed. In addition, in order to analyze the impact of communication delay on the coordinated control of MEI-level agents, the communication topology is optimized according to the basic graph theory. Finally, taking IES with three MEIs as an example, the validity of the proposed control strategy is verified on the PSCAD/EMTDC simulation platform.