A System Integrity Protection Scheme for Supervising Higher Operating Zones of Distance Relay Under Large Wind Power Integration

The impedance seen by the distance relay is highly prone to disturbances and major cause of wide-area blackouts. The source impedance of grid-connected large wind farms is variable in nature and thus affects the impedance measured by the distance relay. During faulty conditions, this variation in impedance is responsible for the inaccurate identification and localization of faults using the distance relay. This article presents a system integrity protection scheme (SIPS) for accurate fault localization and classification for supervising the higher operating zones operation of distance relay integrated with the network having large wind power integration. Simulations are carried out on a modified wind farm integrated IEEE-14 bus test system on the PSCAD platform. The proposed SIPS measures the voltage signals using a wide area monitoring system (WAMS). The discrete wavelet transform (DWT) of voltage signals measured from different locations are utilized for information extraction. The detailed coefficient of DWT is further extracted to get the feature sets to reduce the data size. Due to the large feature set, random forest (RF) is used for feature ranking to select important features. Finally, the selected features are utilized for the classification and localization of faults using the RF classifier that further supervises the operation of the distance relay. The results of the RF-based classifier are compared with the ANN classifier with multiple and selected features. The proposed SIPS accurately supervised the relay operation during faulty conditions under large wind power generation.