Real-time implementation and testing of a WPT based technique for differential protection of synchronous generator

This paper presents real-time development, implementation and testing of a hybrid technique, based on d-q axis components and a wavelet packet transform (WPT), for differential protection of a salient pole synchronous generator. The high frequency sub-band contents of the d-q axis components of the output generated currents are analyzed using the WPT. It has been found that this analysis provides enough information to detect any fault in the synchronous generator. This hybrid technique provides good accuracy and fast fault clearance speed with only one level of WPT of the d-q components of the generated current. Real-time experimental test results are provided in this paper for different cases of disturbances on the output terminal of the salient pole synchronous generator.