1. Tugas :Stability an Control of Electric Power Systems
Name : David S. Koten,ST
NIM : 136060300111002
Class : Electric Power System
Lecturer : Prof. Abraham Lomi, ST,. MT,. Ph.D
1. The single line diagram of a generator connected through parallel transmission lines to a large
metropolitan system machines is delivering 1,0 pu power and both the terminal voltage and
the infinite bus voltage are 1,0 pu respectively. Number on the diagram indicate the values of
the reactances on a common system base. The transient reactances of the generator is 0,2 pu
as indicated, determine the power angle equation for the given system operating conditions.
Reactance diagram in the figure above is.
Because the generator has output of 1.0 pu then its angle can be obtained as below
| || | ( )

2. so that the voltage angle (ϑ) can be calculated as follows
So that the terminal voltage is
Output current of the generator can be calculated as follows
And stress in the transition is obtained as follows
( ) ( ) ( )
The equation connecting the power angle transition voltage E,
and V rail Voltage can be
calculated from the overall reactance:
so that

3. 2. If the system in (1) is operating under the indicated conditions when a three phase fault
occurs at point F in fig. 1 determine the power angle equation for the system with fault on
load and swing equation, take H=5 mj / mva
Answer:
Reactance in the image above if terterjadi disorder as described in the above position and
switching voltage of 1,05 ∟28,240
with the assumption that the constant flux in the
machine
[ ]
If the rail 3 will be eliminated matrix obtained as follows admintansi
[ ] [ ]
The amount of the transfer is 0.769 so admintansi
| || || | ( )( )( )
Equations power angle disorder in the system is:

4. Assignments #2
1. A generator having H = 6.0 MJ /MVA is delivering power of 1.0 per unit to an
infinite bus through a purely reactive network when the occurrence of a fault reduces
the generator output power to zero. The maximum power that could be delivered is
2.5 per unit. When the fault is cleared, the original network conditions again exist.
Determine the critical clearing angle and critical clearing time.
Completion:
[( ) ]
[( ( )) ]
[( ) ]
( )
√
( )
√
( )

5. 2. A 60-Hz generator is supplying 60% of Pmax to an infinite bus through a reactive
network. A fault occurs which increases the reactance of the network between the
generator internal voltage and the infinite bus by 400%. When the fault is cleared, the
maximum power that can be delivered is 80% of the original maxi mum value.
Determine the critical clearing angle for the condition described.
Completion:
( ) ( )
Note: Answer sheets of assignment #1 and # 2 should be submitted on Tuesday,
April 1, 2014.