• Sonal Niranjane
• Prof. Dinesh D. Majumdar

The differential function responds to the total of all the currents of its zone of protection. Ideally, this sum equals 0 under all occurrences except for internal defects. In practise, measurement mistakes and shunt components inside the zone might provide an erroneous differential signal, necessitating the use of appropriate countermeasures. With advancements in the field of differential protection, these countermeasures became more sophisticated, progressing from adding an intentional time delay, percentage restraint, harmonic restraint, and blocking to sophisticated external fault detection algorithms and adaptive restraining techniques. Relay design and use are complicated by line current differential protection. The dispersed structure of the line current differential system restricts the amount of data that can be transferred between system terminals from a design standpoint, necessitating data alignment techniques to allow the differential protection concept. Line current differential schemes are concerned with CT saturation, particularly in dual breaker applications; in-zone reactors and line-charging current; in-line and tapped transformers; sensitivity to high-resistive faults; single-pole tripping; channel impairment security; application to lines with more than three terminals; and so on. This article examines technological solutions for line current differential design and application, taking into account typical design restrictions as well as utility-driven application requirements. The article serves as a primer in this difficult field, which combines security concepts and applications with communications and signal processing.

Differential Protection, Power Transformer

"Review: Differential Protection of Three Phase Transformer", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 8, page no.a745-a753, August-2021, Available :http://www.jetir.org/papers/JETIR2108098.pdf

"Review: Differential Protection of Three Phase Transformer", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 8, page no. ppa745-a753, August-2021, Available at : http://www.jetir.org/papers/JETIR2108098.pdf