Control System of Voltage Source Converter to Interconnect Offshore AC Hub with Multiple Onshore Grids

This paper presents the control scheme of voltage source converter to establish an offshore AC hub to integrate several wind power plant at multiple onshore grids. Offshore AC hub can be formulated by connecting offshore wind power plant that are within the vicinity of 20 km from each other and far from shore. In this research, reference frequency and voltage of the offshore network are controlled by three voltage source converters. Droop control system is designed to share power among the converters. A power flow algorithm is developed to determine the required droop gains according to the contribution factor of each converter to share power. Vector control method is used for developing voltage source converter control system. For design verification, system is modelled and simulated in MATLAB/Simulink.