Wide-area measurement-based power network protection

Abstract

Maloperation of power system protection schemes can result in escalation of a small disturbance to a severe situation in a power system. Events such as power swing, load encroachment, failure of components involved in the protection schemes leads to incorrect operation. This causes unwanted tripping or delay in clearing of faults from the system. This work attempts to use wide-area measurement data to support power system protection decisions in order to avoid maloperations. A combined feature-based decision for relay operation during power swing is developed to derive correct protection decision. Method for supporting relay decisions during stressed conditions such as power swing, voltage instability, and load encroachment by discriminating fault from these events is presented. Indices obtained from WAMS data in a power system are used for identifying malfunction of any element in a protection scheme. Further such informative data improve series compensated and three terminal line protections by applying adaptive settings for distance relays. The WAMS-based techniques enhance protection schemes by making them more reliable and speed up protection for power networks.