A New Virtual Oscillator based Grid-forming Controller with Decoupled Control Over Individual Phases and Improved Performance in Presence of Unbalanced Fault Ride-through
preprintposted on 2022-03-28, 04:49 authored by Ritwik GhoshRitwik Ghosh, Narsa Reddy Tummuru, Bharat Singh Rajpurohit
Virtual Oscillator (VO) control is the latest and promising control technique for grid-forming and grid-supporting inverters. VO Controllers (VOCs) provide time-domain synchronization with a connected electrical network. At the same time, a VOC can incorporate additional nested control loops for meets the system-level requirements such as fault ride-through capability. However, existing VOCs have two limitations. Firstly, the existing VOC does not have decoupled control over individual phases. As a result, the performance of the existing VOC is not satisfactory in presence of unbalanced grid voltages. Secondly, the fault ride-through performance of the existing VOC under an unbalanced fault is not satisfactory. The power delivery at a healthy phase gets affected by the faulty phase. This paper has introduced a modified VO based system-level controller to overcome the limitations mentioned above. Systematic development of the proposed control architecture with analytical reasoning is presented. Simulation studies and hardware experiments are conducted for validation.
Email Address of Submitting Authord17015@students.iitmandi.ac.in
ORCID of Submitting Authorritwikghoshlives@gmail.com
Submitting Author's InstitutionIIT Mandi
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