Control and Design of a Novel Dual Multiplexing Soft Open Point With Small Volume

The soft open point (SOP) technology enables flexible power regulation in distribution networks, making it a critical tool for grid modernization. However, existing SOP topologies face challenges such as the need for numerous submodules and low efficiency. This paper addresses the flexible interconnection of 10 kV medium-voltage distribution networks by proposing a compact topology called dual multiplexing soft open point (DM-SOP), based on high-voltage SiC MOSFETs. The DM-SOP topology exhibits modular characteristics and enables decoupled power control between two feeders. It offers advantages over traditional SOP topologies, including a reduced footprint, fewer switches and high efficiency. This paper presents the novel DM-SOP topology, its operational principles, control strategies, and operational ranges. Finally, through feeder interconnection simulations and the construction of a 1.5 kW low-power prototype for experimental validation, the feasibility of the DM-SOP topology, as well as the effectiveness of the control and energy balancing strategies, are confirmed.