ABSTRACT
Chapter 1 discussed the nature of sequence networks and how three distinct sequence networks can be constructed as seen from the fault point. Each of these networks can be reduced to a single The´venin positive, negative, or zero sequence impedance. Only the positive sequence network is active and has a voltage source which is the prefault voltage. For unsymmetrical fault current calculations, the three separate networks can be connected in a certain manner, depending on the type of fault.
