Multi-Winding Transformer and Series $LC-\text{Based}$ Voltage Balancer for Photovoltaic MVDC Integration

Input independent and output series (IIOS) modular DC-DC converter is a promising method for medium voltage DC (MVDC) interface of distributed photovoltaics (PVs) due to its excellent voltage boosting capability. However, the uneven output voltage caused by the variable PV input energy has become a pressing problem. To address this issue, a topology with multi-winding transformer (MWT) and series LC-based voltage balancer (SLCBVB) is proposed in this paper. Each submodule (SM) adopts a semi-dual active half-bridge (DAHB) structure. By grouping the SMs in pairs, the SLCBVB is used to achieve voltage balancing within the group, and the MWT is used to achieve voltage balancing between the groups, which can effectively solve the unbalanced output voltage problem. The circuit configuration, working principle, power transfer mechanism are presented in detail. Finally, the Matlab/Simulink simulations is given to verify the system feasibility.