Bi-Level Optimization of Microgrids Considering Electric Vehicles under the Worst Conditions of Renewable Resource Output

In this paper, a two-level optimization model of mixed quadratic integer programming (MIQP) is presented in order to optimally operate microgrids under worst-case output conditions of renewable energy sources. This two-level model is divided into two high-level and low-level problems. In the high-level problem, the goal is to reduce energy loss and load shedding in the demand response program, optimal charging and discharging of electric vehicles and energy storage systems. In the low-level problem, the objective is to maximize the power outage of renewable energy sources. In this model, a new method for solving the optimization problem is proposed, which is based on the reformulation of the problem to Karush-Cohen-Tucker (KKT) optimality conditions. For the analysis, a 33 bus microgrid is considered. The simulation results show that the proposed model maintains the flexibility of the network in the worst output conditions of renewable energy sources and no load interruption occurs in the network.