System Stability-Constrainted Optimal Protection Coordination in the Microgrid Including Renewable Energy Sources and Energy Storage

In this paper, the system stability-constrianted optimal protection coordination (SSCOPC) as stochastic problem in the microgrid with grid-connected and islanded operation modes, including renewable energy sources (RESs) and energy storage systems (ESSs), is presented. This problem to optimal regulation of the dual setting overcurrent relays (DSORs) and selecting the reactance size of fault current limiter (FCL), it minimizes the total relays operation time in the primary and backup protection modes. Also, it subjects to limits of the coordination time interval (CTI), DSORs setting parameters, FCL size and microgrid stability in the fault condition.Generally, the microgrid includes RESs and ESSs, thus, the proposed SSCOPC needs to the dailty operation of microgrid as stochastic model to calculate the network variables before fault occurrence. Hence, this problem minimizes the microgrid operation cost and load shedding cost of islanded microgid subject to optimal power flow equations in the presence of RESs and ESSs with considering load and generation uncertainty. Therefore, with appling the proposed problem on the 9 and 32 bus microgrid, solving the problem by the crow search algorithm (CSA), and selecting optimal size to RESs and ESSs based on operation and protection coordination indices, the proposed SSCOPC can be obtained fast protection solution that is considered system stability in the fault condition.