Design of Multiport Converters for Distribution Grids: Sizing, Topologies and Control for Low and Medium Voltage Applications

Review article, 2026

The escalating penetration of Distributed Energy Resources (DERs) presents significant operational challenges to Low-Voltage (LV) and Medium-Voltage (MV) Distribution Networks (DNs), particularly in terms of voltage stability and bidirectional power management. Multiport Converters (MPCs) are an efficient, unified solution to aggregate diverse resources and enhance system resilience. This paper proposes a multi-stage design of MPCs. An optimisation-based methodology is presented for optimally sizing the MPC terminals, minimising total economic cost while simultaneously optimising technical indicators such as annual line losses and voltage stability. This methodology is validated across two distinct utility use cases: a four-terminal MPC in an LV network, which successfully integrates PV generation and EV charging, and a two-terminal MPC in an MV network that effectively mitigates voltage imbalances between parallel feeders. Furthermore, the work reviews suitable MPC topologies for these grid applications and proposes a qualitative comparison technique implemented in a MV application. Finally, some control architectures for the proposed topologies are thoroughly verified through Control Hardware-in-the-Loop (CHIL) and experimental converter prototype testing.