Impact of DFIG Based Offshore Wind Farms Connected Through VSC-HVDC Link on Power System Stability

With the increased levels of offshore wind power penetration into power systems, the impact of offshore wind power on stability of power systems require more investigation. In this paper, the effects of a large scale doubly fed induction generator (DFIG) based offshore wind farm (OWF) on power system stability are examined. The OWF is connected to the main onshore grid through a voltage source converter (VSC) based high voltage direct current (HVDC) link. A large scale DFIG based OWF is connected to the New England 10-machine 39-bus test system through a VSC-HVDC. One of the synchronous generators in the test system is replaced by an OWF with an equivalent generated power. As the voltage source converter can control the active and reactive power independently, the use of the onshore side converter to control its terminal voltage is investigated. The behaviour of the test system is evaluated under both small and large grid disturbances in both cases with and without the offshore wind farm.