A Review on Topology, Operating and Control Methods of HVDC Transmission System for Offshore Wind Farms

High-voltage direct current (HVDC) transmission systems are a promising solution for long distances power transmission offshore wind farms. In order to satisfy the reliability requirements of receiving-end grid and system, the topology, operation and control of HVDC transmission systems for offshore wind farms should be paid more attention. Thus, the aim of this manuscript is to offer a comprehensive summary of existing topology, operation and control methods applied to HVDC transmission system for offshore wind farms. Special attention is provided to the ac grid fault through control methods, droop control methods, power sharing rules and specific requirements of HVDC system planning, model, design and investment. The results are important for understanding the operation of VSC-HVDC in offshore wind farms.