Hybrid Direct-Injection Power Flow and Control Circuit for Low-Voltage Grids
Recent advances in renewable energy distributed generation have brought up power flow problems in low-voltage grids. To address this issue, this paper proposes a novel power flow and quality control circuit. The circuit eliminates any bulky transformer and instead utilizes a shunt active front end and high-frequency links that power floating modules per phase. These floating modules, without any ground connection, only handle a small portion of the voltage difference, allowing the use of the latest low-voltage high current devices. Additionally, the floating module adopts a hybrid structure to minimize the required filtering inductor, leveraging high-frequency switching GaN transistors for regular operation and Si transistors for higher current scenarios, including short-circuit current faults. Overall, the proposed circuit topology offers several advantages, including smaller size and fault tolerance. These features make it a promising solution for power flow and quality control in low-voltage grids.
