Study on FRT compliance of VSC-HVDC connected offshore wind plants during AC faults including requirements for the negative sequence current control

摘要: Abstract In this paper three new control modules are introduced for offshore wind power plants with VSC-HVDC transmission. The goal is to enhance the Fault Ride Thought (FRT) capability of HVDC system and connected plant during balanced unbalanced AC faults. Firstly, a positive-sequence-voltage-dependent (PSVD) active current reduction loop turbines. method enhances performance voltage drop FRT compliance strategy. Secondly, an adaptive limiting strategy which operates simultaneously on positive negative sequence discussed. It enables injection, while at same time respecting maximum fault capacity converter station. Finally, state machine proposed turbines respectively. coordinates post-fault response as well faults, ensuring smooth shift from normal operating point towards period. test consists two level link, rated ±250 kV, connecting 700 MW generation capacity. Simulation results detailed EMT type model in PSCAD/EMTDC environment presented.