Application of an Enhanced Generalized Integrator Based Control for an Emission-Free Marine Microgrid With Shore Grid Synchronization

The use of renewable energy sources (RESs) in the maritime industry is suggested as a promising strategy for reducing greenhouse gas emissions. This work investigates the response of an emission-free marine microgrid in various sea conditions. A new double-enhanced third-order generalized integrator based quasi-type-1 phase-locked loop (DETOGI-QT1-PLL) technique is presented for synchronization between onshore grid and marine microgrid when a ship is anchored in the harbor. The proposed PLL, consisting of enhanced third-order generalized integrator (ETOGI) as a prefilter and moving average filter as an in-loop filter, is intended to attenuate DC-offset, fundamental frequency negative sequence, and dominant harmonic components from polluted shore grid voltages. Load compensation is also accomplished using the ETOGI method. It outperforms other methods regarding harmonics attenuations and DC-offset rejections. MATLAB-based simulated and experimental results validate the efficacy and resilience of the proposed techniques under different operating conditions.