Advanced Screening Techniques for Sub-Synchronous Interaction in Wind Farms

This paper aims to outline comprehensive screening guidelines associated with the Sub Synchronous Control Interaction (SSCI) and Sub Synchronous Torsional Interaction (SSTI) for wind power plants. Specific guidelines and methodologies to identify the critical system conditions to be assessed for screening analysis are presented. The application of these techniques on a portion ERCOT grid model with series compensated lines has been demonstrated. Current injection based frequency scans on the system and turbine side are utilized. Based on these scans a guideline to identify the specific candidates for further investigation using Electro Magnetic Transient (EMT)-type simulation is proposed. The results of the screening study are further corroborated by the EMT based simulation case studies. An electrical damping analysis based screening technique for the analysis of SSTI has been presented. The SSTI screening studies have been further corroborated by means of EMT simulations.