The simulation analysis is carried out from the following
two aspects. One is verified the mathematical model of
switch-on unload transformer by the basic characteristics of
magnetic inrush current. Another is confirmed the proposed
method of limiting inrush current. By fig. 1, the equivalent
circuit model of switch-on unloaded transformer has been
built in Matlab/Simulink. The transformer model considers
magnetic hysteresis, saturation and residual flux. The initial
phase angle of voltage is controlled by breaker. The main
parameters of transformer describes in table 1. The voltage
of power source is 127kV. The short resistance and
inductance are 3.5¡ and 0.11H respectively. The power
factor angle of the loop circuit is 89.90
.