Distributed Event-Triggered $H_\infty$ Consensus Based Current Sharing Control of DC Microgrids Considering Uncertainties

Abstract

The uncertainties caused by sources [such as wind power and photovoltaic (PV)], load switchings, and the equivalent negative impedance of constant power loads (CPLs) commonly exist in microgrids and often undermine the system stability and damping. In this article, a distributed secondary $H_\infty$ consensus approach with an event-triggered communication scheme is proposed for dc microgrids to achieve accurate current sharing and satisfactory performance in the presence of CPLs and uncertainties. Different from many existing works, the proposed event-triggered communication scheme only requires the information at every fixed sampled interval without the Zeno-behavior and continuous-time information. Then, global large-signal stability of the dc microgrid with CPLs and uncertainties under the proposed distributed control is analyzed, where a primary plug-and-play (PnP) voltage controller is considered for each distributed generator (DG). Furthermore, effects of key controller parameters and CPLs on the dynamic performance is analyzed, and a PnP design method is presented for the primary–secondary controllers. With the proposed method, full PnP operation of the dc microgrid can be realized and communication burden can be considerably reduced. Finally, simulation results are presented to validate the proposed method.