Offshore wind integration to a weak grid by VSC-HVDC links using power-synchronization control: A case study

In this paper, the application of recently invented power-synchronization control is proposed for integrating a doubly-fed induction generator (DFIG) based offshore wind farm to a weak ac grid through voltage-source converter (VSC) based high-voltage dc (HVDC) link. The control strategy along with the anti-windup techniques and the bumpless transfer between two different control modes is elaborately discussed. Two different fault cases, namely onshore and offshore faults are considered and the fault-ride-through techniques are presented. In case of onshore fault, both with-chopper and without-chopper solutions are investigated. For offshore fault, a coordinated fault-ride-through scheme is proposed when both the offshore HVDC converter and the wind farm are in voltage control modes. The entire study is carried out in real-time digital simulator (RTDS) platform.