Non-linear Droop Control of Parallel Split-phase Inverters for Residential Nanogrids

The coordinated operation of autonomous parallel nanogrids (NGs) is recommended for clear distribution of energy resources and economical benefits. The achievement of the latter calls for the application of advanced power-sharing techniques capable of ensuring acceptable steady-state and transient performance. This article introduces the concept of non-linear droop mechanisms to increase the maneuverability of power-frequency performance and improve transient active power sharing problems observed in parallel NGs not only limited to active power oscillations. This work considers the use of residential split-phase inverters, their low-level voltage control and the dynamics of energy storage systems. Real-time simulation results, based on a commercial energy storage system, are provided to evaluate the performance of the proposed non-linear droop control.