Abstract

The high complexity of realistic-size power systems have led to simplified stability studies in order to obtain the system dynamic response under contingencies within acceptable computational time and resources. In these studies, also known as Transient Stability (TS) assessments, simplified fundamental frequency (FF) simulations are carried out based on the assumption that fast transients do not affect system stability. In this context, this paper aims to verify the validity range of traditional TS studies in power systems with high levels of converted-based variable generation technologies (VGTs). To do this, first, a detailed modal analysis is carried out to understand the evolution of the system’s modes as VGTs increases. Then FF and detailed electromagnetic simulations are performed considering different penetration levels of VGTs. Simulations are carried out in the IEEE 9-bus system using DIgSILENT Power Factory.