  Power flow calculation methods have been developed in decades using power
injections and Newton-Raphson method. The nonlinear characteristics of the
power flow to the bus voltage require Jacobian matrix reformation and
refactorization in each iteration. Power network is composed by resistors,
reactors, and capacitors which is a linear circuit when investigating the node
voltages with the node current injections. To take the advantage of the
linearity, this paper proposed to use terminal circuit model and PMU voltage
phase angle measurements to simplify power flow calculation. When updating
current injections at the righthand side of power flow equations and using PMU
voltage phase angle measurements representing PV buses voltage phase angle, the
Jacobian matrix is constant during the iteration. The simplification reduces
the computational efforts and improves the computation efficiency. The proposed
method is tested on the IEEE 14-bus and IEEE 118-bus standard systems. The
results are validated by traditional power flow solution and the computation
efficiency is demonstrated.
