A Novel Power Sharing Scheme of Controlling Parallel-Operated Inverters in Islanded Microgrids

Virtual impedances are often used in droop-controlled paralleled-voltage-sourced inverters (VSIs) to achieve proper power sharing. However, different and unknown output of VSIs will affect the decoupling sharing performances. To solve this problem, article proposes a novel controller for by using disturbance observer (DOB). The DOB is adopted observe currents without any extra current sensors. On one hand, observed fed forward voltage compensators, thereby eliminated. other introduced into virtual complex impedance loops, which not only reconstruct but also realize Besides, improve reactive accuracy, synchronization control proposed strictly synchronize local measurements. Each VSI operates at constant frequency, so inherent frequency deviation traditional droop A universal parameter design method presented based on detailed discussion system stability quality. Finally, simulation experimental results clearly validate scheme method.