  Design and implementation of an optimal and robust single-loop voltage
controller is proposed for single-phase grid forming voltage source inverter
(VSI). The objective of the proposed controller is to have good reference
tracking and disturbance rejection. Uncertain nature of loads can significantly
alter system's behavior, especially during heavily loaded conditions, and
impose an uncertainty in the dynamic model. This deteriorates the robustness of
the controller severely. H-Infinity-based controller design is proposed in this
article to address this issue. The required objectives of the optimal
controller are formulated after modeling the loads as uncertain element of the
control system. Time-domain MATLAB/SIMULINK-based simulation study
substantiates the fact that the resulting controller exhibits superior
robustness in performance during varying loading, conditions of VSI than that
of the conventional multi-loop control architecture.

Systems and Control;Systems and Control