With the large-scale development of offshore wind power

the independent construction of transmission facilities tends to cause excessive investment and resource waste. To address this issue

this paper proposes an integrated framework combining bi-level optimal planning and cooperative game theory

aiming to collaboratively solve the dilemmas of site selection and capacity allocation for shared offshore wind power transmission facilities

as well as benefit allocation among multiple stakeholders. Firstly

the physical topology of the system is constructed

and a bi-level optimization model is established. The upper level model optimizes the location and capacity configuration of converter stations with the objective of minimizing initial investment

while the lower-level aims to minimize the system operation

maintenance and power loss costs. Secondly

a bi-level genetic algorithm based on Non-dominated Sorting Genetic Algorithm Ⅱ (NSGA-Ⅱ) is adopted to iteratively solve the nonlinear model and obtain the optimal life-cycle planning scheme. Finally

cooperative game theory is introduced

and the Shapley value is utilized to quantify the marginal contribution of each development participant to realize fair and reasonable benefit distribution. The case study results demonstrate that the proposed shared planning mode can significantly reduce the total life-cycle cost of the system

with the cost-saving rate of each stakeholder exceeding 25%

which demonstrates the effectiveness and practicality of the established model and method.