A new virtual oscillator control without third-harmonics injection for dc/ac inverterA new virtual oscillator control without third-harmonics injection for dc/ac inverter Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2022-10-102021enThis work was supported in part by the program “Bilateral and Multilateral Research & Technology Co-operation between Greece and China” under Grants 2017YFGH001164 and eSOLAR/T7ΔKI-00066.Virtual oscillator control (VOC) is a type of nonlinear grid-forming controller for dc/ac inverters. Compared with the droop control method, the original VOC has a faster transient response in islanded mode. However, its output voltage always contains a third-order harmonic, resulting in a significant third-harmonic current, especially in the grid-connected mode. In order to eliminate this harmonic, a notch-type filter is typically employed, but it affects the synchronization speed of multiple dc/ac inverters connected in parallel in an islanded mode. In this article, by analyzing the nonlinear dynamical equations of the oscillator and simplifying its nonlinear current source, a novel VOC for three-phase dc/ac inverters is proposed, which can successfully eliminate the third-order harmonic in the output voltage of the oscillator. Further, compared with the traditional VOC with notch filter, the grid-synchronization response of the proposed VOC-based dc/ac inverters can be significantly improved. A 3-kW/3-phase/120-V experimental prototype system designed on the DSPACE DS1202 platform has been developed to verify the feasibility of the proposed control strategy.http://creativecommons.org/licenses/by/4.0/IEEE Transactions on Power Electronics36910879-10888 Luo Siyi Wu Weimin Koutroulis Eftychios Κουτρουλης Ευτυχιος Chung Henry Blaabjerg, Frede, 1963- Institute of Electrical and Electronics Engineers Grid synchronization Harmonic elimination Microgrids Virtual oscillator control