Concept of Symmetrical Component as a Technique for analysis of fault and Improvement of Over current Protection Scheme

Electrical energy is one of the fundamental resources of the modern industrial society. Electrical power is available to the user instantly, at the correct voltage and frequency, at exactly the amount needed. The power system maintains its steady state mainly because of the correct and quick remedial action taken by the protective relaying equipment. The response of the protection system must be automatic, quick, and should cause a minimum amount of disruption to the power system. Concept of Symmetrical component for an enhancing protection scheme shows an outstanding feature. The method of symmetrical components provides a practical technology for understanding and analyzing power system operation during unbalanced conditions. Such as those caused by faults between phases and/or ground, open phases, unbalance impedances, and so on. Also, many protective relays operate from the symmetrical component quantities. Thus a good understanding of this subject is of great value and very important tool in protection. In this paper how the concept of symmetrical components helps for improvement of different protection schemes