Virtual DC machine Control for PV converters in DC Distribution System

Abstract

Due to the wide-range power fluctuation of renewable energy resources, the stability enhancement of DC bus voltage is becoming a key issue in DC distribution system with the increasing penetration level of converter-based resources featured by low inertia. This paper proposes a virtual DC machine control scheme that brings inertia characteristic to PV converters in DC distribution system and fully considers the operation principles of renewable power generation. Both the overall control scheme and the small-signal modeling are investigated. Meanwhile, the performance of the proposed VDCM control is analyzed based on derived model and a brief comparative study with traditional PI regulation is presented. Finally, simulation is carried out to verify the theoretical analysis.