Accurate Reactive Power Sharing Strategy for Droop-Based Islanded AC Microgrids

In islanded ac microgrids, the mismatched impedances of interfacing feeders between inverters and load bus cause poor reactive power sharing when conventional frequency voltage droop control technique is employed. Such operation endangers whole microgrid reliability as it may lead to overloading certain and, consequently, triggering protection relays causing cascaded failure. Thus, this article proposes an accurate strategy that considers feeder in microgrids. It based on optimal tuning virtual complex impedance for each inverter. The proposed has several advantages. First, a physical meaning establishes explicit relationship values actual resistive–inductive assigned Hence, further degradations voltages are prevented. Second, there no need prior knowledge about design stage they estimated online from available measurements. Finally, reliable fault-tolerant copes with unexpected failures such failure (or sudden switching off ) some communication disruptions/delays. ensures even under primary controllers after losing links secondary controller. simulation experimental verification results presented validate performance technique.