A Three-Phase Sensitivity-Based Approach for Smooth Line-Switching in Islanded Microgrids

This paper deals with a new line-switching method that facilitates the network reconfiguration of islanded microgrids. Its distinct features include the ability to handle network asymmetries and the minimization of the line current during the switching action. This is attained by developing a sensitive-based three-phase model predictive method to determine the operating set-points of the distributed generators (DGs) that minimize the current of the candidate line participating in the switching action. These set-points correspond to the positive-sequence powers as well as the negative- and zero-sequence currents of all DGs. Furthermore, the network constraints such as voltage limits and power limits of DGs are always satisfied. Simulations are performed in a balanced 33-bus islanded network as well as in the unbalanced IEEE 8500-node network to evaluate the performance of the proposed method.