Observer-Based Current Controller for Virtual Synchronous Generator in Presence of Unknown and Unpredictable Loads

Abstract

This article proposes an observer-based current controller for virtual synchronous generators (VSG) in the presence of unmeasured and unpredictable loads. First, the considered models are described, notably the selected VSG model, as well as the grid-connected inverter. Then, the proposed controller is detailed, which consists in a linear quadratic regulator incorporating an integrator and a state observer. Finally, experimental results validate the capacity of the VSG solution, based on the presented controller, to supply unknown and unpredictable loads represented as nonlinear and unbalanced loads, as well as survive short circuits and operate in parallel with other power sources. This extensive set of tests proves the relevance of such controller in the wake of the industrialization of the proposed VSG solution, as well as the necessity to incorporate a nonsimplified synchronous machine model and an advance, reactive controller.