A direct method for assessing distance-protection behavior during power swings

作者：Azbe Valentin^*; Mihalic Rafael; Jaeger Johann

来源：International Journal of Electrical Power & Energy Systems, 2017, 90: 94-102.

DOI：10.1016/j.ijepes.2017.02.003

• Direct methods
• Lyapunov methods
• Distance protection
• Power swings
• Power system transient stability

The aim of this work is to include the distance-protection behavior in direct methods for transient stability assessments. In this way the direct methods assess an electric-power system's behavior more realistically and hence more reliably. In order to consider the delayed tripping zones of distance-protection relays, the time component was added to the Lyapunov energy function. The main innovation is that the dwell time of the post-fault impedance trajectory inside various tripping zones is calculated based on the speed of the transformation between the kinetic and the potential energy parts of the Lyapunov function. It enables the identification of unwanted trips during power swings. The tripping-zone settings can be revised accordingly. The method was verified by a comparison between the direct method and the well-known, time-domain, numerical-simulation method on a single-machine, infinite-bus test system where the results have to be identical. The application of the proposed method on a multi-machine power system gives good results.

• 出版日期2017-9