Technical and Economical Comparisons of 2 GW Offshore Wind Power Transmission Schemes by Symmetrical Monopole and Symmetrical Bipolar VSC-HVDC
At present,the voltage source converter based high voltage direct current(VSC-HVDC)transmission technology is usually adopted for the access of large-capacity offshore wind power to the power grid.Symmetrical monopole wiring scheme is adopted for the offshore DC projects that have been put into operation.Although the symmetrical bipolar scheme has higher initial investment,its high reliability can improve the power generation profit in the operation stage.Based on the scale of 2 GW offshore wind power VSC-HVDC transmission,the design comparison of symmetrical monopole system and symmetrical bipolar system are conducted.Two schemes of offshore converter station platform layout and structure design are proposed,and the initial construction investments and full life cycle profits of the two schemes are calculated.The results show that the symmetrical monopole scheme has advantages in whole life cycle economy compared with the symmetrical bipolar scheme.