The development of offshore wind power base (OWPB) offers advantages in coordinated layout and unified planning. However

planning methods suitable for small-scale offshore wind farms are no longer adequate for OWPB at the ten-gigawatt level. Transmission system planning for such bases involves partitioning the wind power base

locating offshore booster and aggregation stations

optimizing transmission routes

and selecting grid connection points. To address these complexities

this paper proposes a planning method for grid integration of OWPB based on a coded planning matrix. First

the improved K-means cluster method is introduced to partition the OWPB. Second

the improved gravity center method is adopted to locate the offshore collector and booster stations

considering varying cable transmission loss and capacities of wind turbines. Then

aiming for optimal economic performance

a planning model based on a coded planning matrix is established to achieve coordinated planning of partitioning

station locating and sizing

cable selection

and grid connection point optimization. Finally

simulations are conducted using a real OWPB for verification

and the results show that the proposed method achieves faster computation and more economical planning outcomes than traditional planning methods.