Coordination control for offshore wind power sending through hybrid HVDC

This paper presents operation and control strategies of Hybrid HVDC for offshore wind power sending. The Hybrid HVDC, which adopts Line-Commutated Converter (LCC) at the sending end and Voltage Source Converter (VSC) at the receiving end, can combine the advantages of the two kinds of converters and save the cost. After the analysis of properties of different types of wind generators, the direct-drive permanent magnet synchronous generators (PMSG) is chosen for integrating with the Hybrid HVDC sending. The simulation model is founded on the wind generating system, the main Hybrid HVDC circuit and the control system based on PSCAD/EMTDC. The converter at the LCC side maintains the DC current at constant which is generated by wind farm maximum power point tracking. While the VSC maintains the stability of DC voltage and AC voltage using a synchronous reference frame controller. The simulation results under both the normal and the fault conditions show that the feasibility of Hybrid HVDC for the transmission of offshore power to the main land.