The symmetrical components and their applications

The solution of unbalanced electrical circuits has been found to be most practical by the method of Symmetrical Components. It is very powerful analytical tool and is based on sound theory. This project is intended to meet the needs of the practicing engineer and the engineering student. It presupposes a knowledge of fundamental single phase and poly phase circuit theory and the operating characteristics of the more important types of alternating current apparatus. A theoretical analysis is based on the assumption of three phase abc system. The paper was undertaken to investigate the characteristics of loads, when the systems are connected in three different ways . These three connections are star connected loads, grounded star connected loads and delta connected loads. Results from these informations are then developed into the “a” matrix transformation in each case, The advantages of these matrix trans formations are essential to be able to look at the phase diagram and immediately write the necessary sequence components from it. This paper also deals with the three phase, two winding transformers, From the knowledge of the Symmetrical Components are then decomposed the voltages and currents into a matrix equation which lead us to the solution of the equivalent circuits of the trans formers. Three different connections of two winding transformers were created to study (Delta-Delta connection, Star-Star connection and Star-Delta connection). The illustration involving the applications of the Symmetrical Components to solve the unbalanced three phase system is also presented in this paper.