Reliability Modeling of Power Transmission System Connected to Offshore Wind Farm Considering Typhoon Effect

With the large-scale development of wind power resources, the installed capacity of offshore wind power increases rapidly. Due to climate and other factors, typhoon disasters occur frequently. Considering that the wind speed is influenced by the typhoon, the offshore wind power output is highly uncertain. Besides, the typhoon may lead to physical failure of the power transmission equipment and endanger the reliable operation of the power transmission system. Therefore, it is necessary to assess the reliability of power transmission system connected to offshore wind farms affected by typhoon. The model proposed in this paper adopts the hierarchical structure of wind turbine, wind farm, direct current(DC) transmission equipment and DC transmission system. Considering the effect of typhoon on wind speed, failure rate of equipment and overhead transmission lines, the multi-state model of each module is established based on the Markov process. The system states are combined by the available capacity of the wind farm and the available capacity of the DC transmission system. In order to effectively quantify the impact of typhoon on the reliability of offshore wind power transmission system, a reliability index is established.