Joint transmission expansion planning and energy storage placement in smart grid towards efficient integration of renewable energy

This paper investigates the integration of renewable energy resources in power systems, using bulk energy storage technologies as well as transmission system capacity expansion. A joint transmission expansion planning and energy storage placement is proposed to satisfy the requirements of a power system model with wind farm generation. The problem is formulated as a multistage mixed integer programming problem, aiming to minimize the total investment and operational costs incurred for integrating wind generation. The operating cost captures the benefits subject to the planning decisions. Based on the DC power flow model, the optimal planning is presented, which strikes a balance between the system expansion cost and the operational cost. By leveraging the properties of the proposed optimization problem, the formulated problem is transformed into a linear mixed integer program. Numerical studies, using the modified Roy Billinton Test System (RBTS) and IEEE Reliability Test System (RTS), explore the proposed optimization method and compare the central and distributed energy storage schemes. The results demonstrate the significant benefits of the proposed approach.