Integrated Optimal Siting and Sizing for VSC-HVDC-link-based Offshore Wind Farms and Shunt Capacitors

It is economic and secure to determine the optimal siting and sizing of the offshore wind farms (OWFs) integrated into the AC system through voltage-source converter high-voltage direct current (VSC-HVDC) links. In this paper, an integrated planning model for the VSC-HVDC-link-based OWFs and the capacitors is proposed, where a decomposition technique is presented to solve the proposed mixed-integer nonlinear programming (MINLP) problem and obtain the optimal solution. This model can optimize the siting and sizing of the OWFs to improve the voltage profile and reduce the adverse influence of the reactive power of the OWFs. With the proposed planning model, the total investment costs, operation costs and maintenance costs of the OWFs, VSC-HVDC links, and the capacitors can be minimized. Simulations on the modified IEEE 118-bus system show that the proposed integrated planning model can provide more economic scheme than the independent planning scheme, in which the capacitors are planned after the OWFs. Besides, a series of sensitivity analysis on certain equipment costs are studied to obtain the regular pattern for sizing VSC stations.