1.College of Electrical Engineering, Shanghai University of Electric Power, Shanghai 200090, China;2.Wenling Power Supply Company of State Grid Zhejiang Electric Power Company Co., Ltd., Taizhou 317500, China

Due to the varying costs of distributed generators in the AC/DC hybrid microgrids, it tends to cause higher system costs with the droop control that distributes power according to the capacity ratio. A droop control based on incremental costs is proposed to address this issue. To further eliminate the impact of mismatched line impedances on the power distribution accuracy and fully consider the economic operation of the microgrid, this paper proposes a hierarchical distributed control strategy based on the consensus algorithm. This control strategy is divided into the subnetwork-level control and system-level economic control. The subnetwork-level control introduces the frequency/voltage secondary control term and cost secondary control term in the incremental cost based droop control to restore the AC frequency and DC voltage, and realizes the economic power distribution of distributed generators among the subnetworks at the same time. In the system-level economic control, the “relative frequency index” and “relative voltage index” are introduced to construct the local control strategy of the bi-directional interconnected converter. The power secondary control term based on the consensus algorithm is further introduced to realize the consistent incremental cost across distributed generators, so as to achieve the globally optimal economic operation of the system. Finally, the simulation of the AC/DC hybrid microgrid model is carried out to verify the effectiveness of the proposed control strategy.

This work is supported by National Natural Science Foundation of China (No. 52377111), Shanghai Young Scientific and Technological Talents Sailing Program (No. 21YF1414700), and “Chenguang Program” of Shanghai Municipal Education Commission and Shanghai Education Development Foundation (No. 21CGA64).