Improving Transient Stability of Power Synchronization Control for Weak Grid Applications

Power synchronization control (PSC) has apromising potential to be used in interface converters of largescalerenewable generations operating under weak-gridcondition. This paper presents a modified PSC-based controlstructure that provides an enhanced dynamic response,reinforced synchronization, and reduced vulnerability againstgrid transients. By utilizing a back-calculation scheme, theactive power reference in the synchronization loop of PSC isconfigured to be adapted to the grid transients for avoiding lossof synchronization (LOS). Furthermore, the proposed controlstructure prevents power-injection collapse (PIC) and mitigatesthe dc current components of the converter caused by transientsin weak grids. Performance and feasibility of the proposedcontrol structure are highlighted and verified by simulation ofvarious scenarios and operating conditions.