V. CONCLUDING REMARKS
Inverter-interfaced microgrids are difficult to control due to fast dynamics, uncertainty, and a wide range of operating conditions. The virtual inertia based control solutions are simple but cannot fully unlock the potentials and advantages of such microgrids. The solutions that integrate droop-based primary control and distributed secondary control cause unnecessary V and f oscillations and cannot effectively manage the magnitude of transient line currents. To overcome these problems, control objectives should be better prioritized and power line dynamics need to be considered. The proposed control solution can not only realize better V and f control by maintaining constant |V| and f references, but also ensure bounded transient line currents during normal operating conditions. By properly adjusting phase angles of bus voltages, both fair load sharing and variable uncertain operating conditions are addressed. The requirement of inter-subsystem communication is also not difficult to be realized with nowadays communication techniques. The effectiveness of the proposed solution has been demonstrated through simulations.
Microgrid control is a challenging topic and deserves long-term and extensive investigation. Future work includes studying more complicated microgrid model, designing improved control algorithms, lowering communication requirements, addressing cyber uncertainties, and testing such control solutions through hardware experimentation.
