Generalized Power Flow Algorithm for Islanded DC Microgrids based on Accelerated Iterative Search

This letter proposes an accelerated iterative search (AIS)-based generalized power flow (PF) algorithm for PF calculation of islanded dc microgrids without a fixed slack bus voltage. The proposed approach improves conventional PF algorithms by incorporating an external search loop that adjusts the slack bus voltage using a novel binary-Lagrange interpolation (BLI) search approach. Accurate slack bus voltages can be efficiently derived with at least 33.3% to 66.7% reduction in iterations compared to the binary search. In addition, any bus in the proposed algorithm can be selected as a slack bus with an initialized dc voltage, the value of which is corrected in the search loop based on the actual power balance equation specific to the chosen bus. Simulations performed in RSCAD on a 6- bus dc microgrid confirm the effectiveness of the proposed AIS-based generalized PF algorithm, while its scalability is demonstrated on a modified 69-bus system. Open source code: https://github.com/pingyangsun/IslandedPFDCMicrogrids