Research on the Link for Fault Current Limiting and Voltage Compensation between Hybrid Micro-Grid and Distribution Network

Aiming at the faults pass-through between the distribution network and the AC-DC hybrid micro-grid (HMG), this paper proposes a concept of the series compensation link (SCL) which has been inserted between a distribution network and a AC-DC HMG to compensate HMG voltage and limit excessive fault current as well. The basic structure and operation modes of the SCL are introduced firstly. Then, based on deriving the mathematical models of the SCL in abc-three-phase coordinate frame and in dq synchronous rotation coordinate frame, a compound compensation and current limiting strategy is designed. A series compensation transformer (SCT) is designed. Finally, the effectiveness of the SCL and its control strategy have been verified by simulations.