Distributed Extended-State-Observer Based Backstepping Control of a Photovoltaic Integrated AC Microgrid

Abstract

In this paper, a distributed extended state observer (ESO) based backstepping control is presented for an AC microgrid (MG) integrated with photovoltaic (PV) sources. The proposed controller addresses the voltage restoration problem in the presence of uncertainties of the system, such as pulse width modulation (PWM) switching functions associated with voltage source inverter (VSI). It is necessary to achieve successful control of MG in the face of uncertainties. We employ an ESO to estimate the accurate state information of each DG. A backstepping control approach is used to design for achieving distributed control of the MG to track the MG reference voltage in face of uncertainties. The effectiveness of the proposed controller is verified in MATLAB/Simulink environment for different conditions such as plug and play operations and sudden changes in local loads in the system. Compared with feedback linearization-based cooperative control, the proposed controller shows better performance in terms of steady-state performance and robustness.