Analysis of Restrike Overvoltage of Circuit Breakers in Offshore Wind Farms

The stability of power system will be threatened when large-scale wind turbines trip off from the power grid because of overvoltage. The electric equipment in offshore wind farms will be seriously impacted by the restrike overvoltage due to the multiple reignition of circuit breakers. To investigate this problem, a model of reignition process is established by ATP-EMTP with detailed analysis of the multiple reignition mechanism of vacuum circuit breakers. It is verified that this model can simulate the reignition process of circuit breakers effectively. With this model, the restrike overvoltage inside an offshore wind farm is studied continuously. An offshore wind farm model with multiple turbines is established to simulate the restrike overvoltage when reignition in circuit breaks happens. The influence of the submarine cables and other parameters of an offshore wind farm on the restrike overvoltage are analyzed. Finally, the installation of proper arresters is verified to suppress the restrike overvoltage effectively.