Practical Implementation of High-Efficiency Multiple-Input Converter Embedding Renewables and Energy Storage for DC-Microgrid Applications

The use of high frequency power converters to enhance power density and energy efficiency has become widely used in grid-connected hybrid DC microgrids. This article presents a new modularized high frequency DC-link integration methodology that connects multisource renewable energy sources involving battery energy storage system (BESS) to the AC-grid. A grid-tie-inverter with a line inductor is introduced to control the active-reactive power flow. To minimize the converter physical size with improved system efficiency, a high frequency-based front-end multisource bridgeless boost (MBB) architecture is proposed here. A direct-mount decoupling snubber capacitor and a soft switching are used to reduce the switching losses resulting from the high-frequency operation. The performance of the proposed system is investigated. A direct digital approach is used to design the system controller in MATLAB/Simulink R2022a environment. To validate the system performance, a 10 kW multi-source grid-connected experimental setup with dSPACE-1104 controller is constructed, tested, and compared with other conventional topologies. The test results verify the proposed topology effectiveness for hybrid grid-connected renewable energy resources integration.