A mixed-integer quasi-convex optimization model for joint transmission network and wind power investment problem

•A model for joint transmission network and wind power investment problem is presented.•The objective function is defined as the ratio of the total cost to the total wind power generation.•The uncertainty in wind power and demand is modeled considering several scenarios.•The proposed model is a mixed-integer quasi-convex optimization problem that is converted into a mixed-integer convex programming problem.•The results verify that the model can effectively mitigate the wind curtailment.