Control of converter-based generators for a single-phase microgrid

Droop control is an effective control method for autonomous control and load sharing of parallel generators in microgrid. For converter-based generator, small DC offset of the output voltage may result in saturation of the interfacing reactor and/or over current of the generators due to large circulating current. This paper presents circulating current control techniques for droop controlled converter-based parallel generators. Two methods are proposed based on the direct detection of circulating current, the insertion of resonant impedance. The simulations and experiments are carried out, and the results confirm the validation of the proposed control methods.