Purpose
of this documentation is to understand –
(1)
Power System Modeling: The
methodology of representing the power system elements numerically so as to
model the power system for fault current calculations.
(2)
Fault Calculations: The method for
calculating fault currents during symmetrical and un-symmetrical faults. The
calculated fault currents are used for deciding protective relay settings and
short circuit ratings of equipment.
There
are many great text books available about the subject. Also there are good
reference books for power system modeling. This documentation is neither a text
book nor the reference book it can be considered as practice book where protection engineer working in a transmission
system shall get the knowledge for modeling simple systems which is generally
sufficient for routine work.
Thus
first we will go through examples of modeling and fault current calculations
for some simple system and then we will discuss theory behind formulae and
fault current calculation method. After
going through the theory part you will do the same calculations and by same way
but with better insight. Hence it is highly recommended to go through theory
part also.
Note: - Readers are requested
to go through text books and reference books for more details and during un-common
situations.