Large-scale centralized exploitation of intermittent wind energy resources has become popular in many countries. However

as a result of the frequent occurrence of largescale wind curtailment

expansion of corresponding transmission projects has fallen behind the speed at which installed wind capacity can be developed. In this paper

a coordinated planning approach for a large-scale wind farm integration system and its related regional transmission network is proposed. A bilevel programming model is formulated with the objective of minimizing cost. To reach the global optimum of the bi-level model

this work proposes that the upper-level wind farm integration system planning problem needs to be solved jointly with the lower-level regional transmission planning problem. The bi-level model is expressed in terms of a linearized mathematical problem with equilibrium constraints (MPEC) by Karush-KuhnTucker conditions. It is then solved using mixed integer linear programming solvers. Numerical simulations are conducted to show the validity of the proposed coordinated planning method.