Robust Coordinated Distribution System Planning Considering Transactive DSO's Market

In this paper, a robust distribution system expansion planning (DSP) approach is presented to supply the load growth locally and move toward nearly zero energy local distribution areas (LDAs). In the proposed approach, a distribution system operator (DSO) is responsible for secure and optimum operation of LDAs. Therefore, investors on distribution system upgrades use this approach to maximize the profit on investments by determining the installation year of new distribution feeders and energy resources, distributed energy resource (DER) placements and sizes considered by corresponding DSOs. The accurate AC power flow solution is used and mathematical methods are developed to model the DSP as a quadratically constrained programming (QCP) problem. The Benders decomposition is applied to investigate the reliability and the optimality of the proposed plan and correspondingly modify the investment plan as required. The uncertainty of renewable DER forecast errors, locational marginal price (LMP) of an LDA at a transmission bus, and transactive power associated with a load bus is modeled using robust optimization. The proposed transactive DSP (TDSP) approach is implemented on the IEEE 33-bus distribution test system and the results are analyzed and validated. The proposed numerical results show the optimality and the robustness of the proposed approach.