Generator Power Swing Out-of-Step Protection and Analysis of Misoperation Events

This paper details the Power Swing and Out-of-Step (OOS) protective element as applied for generator protection. Various element characteristics and styles are compared for performance during real-world conditions including failure to trip and false trip power swing events. Planning studies and setting verifications can be used to calculate settings and provide insight into system performance during events. Setting validation using event data is reviewed. Analysis of recent events involving generator out-of-step conditions is presented, as well as a review of what protection may operate when the OOS element fails and conditions that could cause false OOS trips.