Mitigation of DC Component and Suppression of Inrush Current for Power Transformer Protection

Author(s):

MANSI BHANOT , JANNAYAK CH. DEVI LAL VIDYAPEETH, SIRSA, GURU JAMBESHWAR UNIVERSITY, HISAR; GURPREET SINGH, JANNAYAK CH. DEVI LAL VIDYAPEETH, SIRSA, GURU JAMBESHWAR UNIVERSITY, HISAR

Keywords:

DC Components, Inrush Current, Taylor Series, SHR

Abstract:

When a transformer is energized, magnetizing inrush current arises due to short-term overfluxing in the transformer core. The quantity of inrush current may be as high as ten times of transformer rated current which causes maloperation of differential protection system. This inflow current comprises decaying DC and superior second harmonic components which may cause unwanted effects like poor power quality and minimized mean lifespan of transformer. At the moment of transformer energizing if fault transpires, the protection system crash to distinguish between inrush and fault current. This paper provides a method for ejection of DC component and discrimination between inrush and fault condition to intend power transformer protection. For elimination of DC component, a compensating signal is generated with help of algorithm based on Taylor series expansion of inrush current. As second harmonic component is supreme in inrush current, discrimination is carried out utilising harmonic restraint. Based on ratio of second harmonic component to fundamental component algorithm is evolved to discriminate inrush from fault current, which is validated on a case study developed in Matlab/Simulink.

Other Details:

Manuscript Id	:	IJSTEV2I7102
Published in	:	Volume : 2, Issue : 7
Publication Date	:	01/02/2016
Page(s)	:	143-149

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