An Improved Hierarchical Control Structure for Robust Microgrid Operation and Seamless Mode Transfer under Linear and Nonlinear Loads conditions

This paper proposes the improved hierarchical- based control of Microgrid on proportional and multi-resonance controllers to compensate for harmonic distortion nonlinear loads. Moreover, probable transition MG, especially from grid-connected unplanned islanding unintentional MG resources outage are studied. In current voltage three-phase VSIs which located in inner level, multi-resonant implemented. To attain proper decoupled (P-Q) power-sharing, a selective type virtual impedance, droop-based implemented at primary level. Next, reach better restoration subsequently, seamless accidental islanding, MG-DG’s outage, synchronization process, advanced SRF-PLL with in-loop MAF along simple adaptive lookup table secondary level control. The MATLAB/Simulink simulation results verified that proposed method performance control, effectiveness, robustness upstream or local grid variation.