The power flow analysis (also known as load-flow study) is
an importance tool involving numerical analysis applied to a
power system. Unlike traditional circuit analysis, a power flow
study usually uses simplified notation such as a one-line diagram
and per-unit system, and focuses on various form of AC power
(i.e: reactive, real and apparent) rather than voltage and current.
The advantage in studying power flow analysis is in planning the
future expansion of power systems as well as in determining the
best operation of existing systems. Power flow analysis is being
used for solving power flow problem by Newton-Raphson
method and Gauss Seidel method. This sub-chapter will discuss
all two methods generally on formula or mathematical step in
order to solve power flow problem.