Non-Iterative Power Flow Analysis for Droop-Controlled Islanded AC Microgrid

With the increasing integration of renewable energy sources, AC microgrids have become an essential medium for renewable energy utilization. However, the rapid expansion of microgrids necessitates efficient methods to evaluate their steady states. This paper proposes an efficient, non-iterative linear power flow analysis method for droop-controlled islanded AC microgrids. The frequency-dependent bus admittance matrix is approximated by linearization to indicate the power change under a frequency deviation, and then a closed-form formula is derived to ensure efficient and non-iterative power flow solving. Simulation results show that the proposed method can 1) calculate the steady state of the droop-controlled AC microgrids with an acceptable accuracy and 2) address the convergence issues of the existing methods and greatly enhance the computational efficiency, achieving a speedup of 12 times for a large stacked microgrid with 8,500 buses when compared with an exiting method.