International Journal of Advancements in Electronics and Electrical Engineering
Author(s) : CHILAKA RANGA , NAVNEET THAKUR , NEELAM SRINIVASULU
Transmission and distribution networks should be tailored to function smoothly for reliable evacuation of power from generating power plants. Catastrophic failures in the power transformers may lead to capital and human loss. Therefore frequent online monitoring of the same is must. To avoid the needless trip of power system relays by magnetizing inrush current, the second harmonic component is commonly used for blocking differential relay in power transformers. The major drawback of the differential protection of power transformer is the possibility for false tripping caused by the magnetizing inrush current during transformer energization. In this situation, the second harmonic component present in the inrush current is used as a discrimination factor between fault and inrush currents. This paper presents the development of a wavelet based scheme, for distinguishing between transformer inrush currents and power system fault currents, which proved to provide a reliable, fast, and computationally efficient tool.