Off-line testing of a d-q axis WPT based hybrid digital technique for differential protection of a salient pole synchronous generator

This paper presents the development and implementation of d-q axis components and wavelet packet transform (WPT) based hybrid technique for digital differential protection of salient pole synchronous generator. In this paper, the analysis is concentrated on the high frequency sub-band contents of WPT obtained from the d-q components of the differential currents of the relay. It has been found that the analysis in this approach provides information to detect any fault in the synchronous generator. This hybrid technique provides good accuracy and fast fault clearance with only one level of WPT of the d-q axis components of the current. Off-line results of the collected data from an experimental work are utilized for different cases of system disturbances.