Analysis of Resonant Frequency of Transmission Line Based on Large Scale Offshore Wind Farm

Most offshore wind farms use a large capacity offshore collector substation in order to stably transfer generated power. Many bundles of wind turbines are connected to offshore platforms by using submarine cables that contain bigger capacitance than the overhead one. This means that the line impedance has a resonant frequency, and it will be changed depending on the connection of offshore wind turbines. When the additional offshore wind turbines are linked to an existing offshore substation, the resonant phenomenon may be caused by submarine cables due to the fact that the inverter system of a wind turbine can make harmonics through the switching operation. From this perspective, this paper analyses the resonant frequency of a transmission line based on a large-scale offshore wind farm. In order to verify this analysis, the models of a 75 MW wind farm will be simulated by using the PSCAD/EMTDC program. The simulation results presented the response of a wind farm injecting resonant frequency in accordance with the composition of offshore submarine cables.