Enhanced Dynamic Voltage Stability Support by VSC-HVDC for Offshore Wind Applications using Trajectory Sensitivity Analysis

The integration of large-scale wind power plants changes the structure, configuration and operation of conventional power systems and brings challenges to the security and stability of power systems. Dynamic voltagestability of power systems with high wind penetration is one of the critical issues. In this paper, VSC-HVDC transmission system is used to integrate a large-scale wind power plant into the onshore power grid. For different voltage support strategies of VSC-HVDC, a trajectory sensitivity analysisbased approach is proposed to find the minimum onshore VSC capacity with which the VSC-HVDC can provide enough support for the improvement of system voltage stability after a disturbance. Sensitivities of reactive power output of VSC to its capacity increase are calculated instead of the sensitivities of bus voltage magnitude towards the reactive power injection variation of VSC. Simulation results are presented to verify the effectiveness of the proposed method