Abstract :
Synchronous machine is the main generating unit in electric power system
so that synchronous machine modeling is very important for analysis study of
electric power system. This synchronous machine is the same as a synchronous
generator, the only difference is that the rotor synchronous generator is rotated to
produce a voltage, while the stator synchronous machine is given a voltage so
that the rotor rotates. In the operational practice of synchronous generators, often
the manufactured data on the physical generator has been damaged or lost,
making it difficult to obtain or determine the parameters that will be calculated in
the simulation and analysis of the electric power system. One of the methods used
in estimating these parameters is the time constant method.
This research begins by conducting a no-load and short circuit experiment
on a synchronous generator, then modeling a synchronous generator equation
system into the dq axis form. The dq axis modeling system used aims to simplify
and facilitate the analysis of response characteristics. Next, record the frequency
response in both the d and q axes and then compare it between the standard
method and the time constant derivation method.
The results obtained in this study are to analyze the response values for
electromagnetic torque, rotor rotation speed, stator current, field winding
current, and dampers winding current, all of which are compared to changes in
time. At the initial state of the no-load synchronous generator, with the derivation
method the electromagnetic torque time constant produced is lower with a
maximum value difference of 33 Nm with difference percentage is 206,25 % .
Then when the synchronous generator serves the nominal load, the active power
generated at steady state is lower with a difference of 35 W with difference
percentage is 2,8 % , and the stator current is also 1.9 Amps with difference
percentage is 40,43 % lower when compared to the standard time constant
method.