Chapter 7: Symmetrical Components and Representation of Faulted Networks

Orthogonal Transformation

Instead of the transformation matrix given in (7.13), let us instead use the transformation matrix

(7.19)

 

 

 

We then have

(7.20)

 

 

 

Note from (7.19) and (7.20) that C -1 = ( CT )* . We can therefore state C( CT )* = I3 , where I3 is (3 × 3) identity matrix. Therefore the transformation matrices given in (7.19) and (7.20) are orthogonal. Now since

 

 

 

we can write from (7.17)

(7.21)

 

 

We shall now discuss how different elements of a power system are represented in terms of their sequence components. In fact we shall show that each element is represented by three equivalent circuits, one for each symmetrical component sequence.