An Optimized Grid-Forming Control Strategy for the Flexible Interconnection System in Distribution Transformer Areas

The flexible interconnection system (FIS) in distribution transformer areas can improve the local consumption capacity of high penetration rate distributed photovoltaics and solve the problem of the high loading rate of distribution transformers. This paper presents an optimized grid-forming control strategy for the FIS in distribution transformer areas. First, the DC side impedance small signal model of the FIS is built, and the reason for the stability difference of the FIS is analyzed when the active power flows in different directions. An optimized control structure is then presented based on the conventional grid-forming control strategy. The theoretical analysis shows that the optimized grid-forming control strategy can improve the stability of the FIS. Finally, the controller hardware-in-the-loop experiments based on RT-LAB confirm the effectiveness of the presented optimized control strategy. (c) 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.