Virtual synchronous generator based multi-loop control of renewable DGs in island microgrids

This paper presents a novel virtual synchronous generator (VSG) based multi-loop control solution aiming to manage the embedded inverter-based renewable DGs in a “plug and play” and cost-effective fashion. The VSG-based control method manifests as a multiple-loop control to obtain timely current response and carry out static error free tracking control of output current while providing enough inertia and damping to the microgrid which will contribute a lot to the frequency support especially for some weak ones. With such multi-loop control structure, the virtual flux oriented control (VFOC) is adopted to avoid the harmonic interference and guarantee accurate control of vector orientation process in frequency regulation to help the system reach steady state through a more smooth process. The proposed control solution is assessed through a set of simulation experiments in island microgrid, and the numerical result confirms its technical benefits.