Frequency Response Model of Offshore Wind Power Grid-Connected System via VSC-HVDC with Active Frequency Support

The large-scale offshore wind turbines are often connected to the AC grid through VSC-HVDC (Voltage Source Converter-based High Voltage Direct Current) transmission. Active frequency support provided by offshore wind power can improve various frequency stability issues in the power system. In order to analyze the frequency characteristics of the offshore wind power grid-connected system via VSC-HVDC after disturbances, a frequency response model for the offshore wind power grid-connected system via VSC-HVDC with active frequency support from wind turbines is proposed. The model takes into account the active frequency support from the offshore wind power and also calculates the variations in losses caused by the VSC-HVDC transmission process, resulting in a frequency response model for the power system with offshore wind power integration. Finally, a simulation example is built on the PSCAD/EMTDC platform to verify the accuracy of the constructed frequency response model. The results show that the frequency response model of the offshore wind power grid-connected system via VSC-HVDC with active frequency support from wind turbines accurately reflects the frequency response characteristics after disturbances.