Study on the Power Frequency Overvoltage and Reactive Power Allocation in Interconnected Offshore HVAC Transmission Systems

Abstract

With the development of large-scale offshore wind power systems in recent years, there are some potential issues to be solved in a large number of offshore wind farms for AC system connected to grids, especially for the studies of the impacts of offshore wind farms to the power system in terms of reactive power and voltage disturbance. In practical electrical engineering, restriction on the voltage should also be considered in determining the scheme of reactive power compensation. This paper theoretically analyzed the reactive power distribution of offshore wind farms. Also, it obtained and analyzed the frequency overvoltage of an interconnected offshore high-voltage AC transmission project under four operating conditions by using ATP/EMTP software. It checked whether shunt reactors need to be installed and whether the capacity of reactors can meet the requirements for frequency overvoltage protection. Finally, a reactive power compensation device selection and allocation scheme is proposed, and the corresponding feasibility is verified.