This document contains three assignments related to electric power systems for a class. The first assignment contains two problems about determining power angle equations and reactance for systems operating normally or during a fault. The second assignment contains two problems about calculating critical clearing angles and times. The third assignment divides students into groups and assigns topics for papers on power system stabilizers, PV/QV curves, and excitation systems. Students are to submit answers to the first two assignments by a certain date and present their group papers the following week.

1. Answer questions
Subjects : Stability and control of electric power systems
Lecturer : Prof. Ir. Abraham Lomi, MT,.Ph.D
Name : Supaman, ST
NPM : 136060300111003
Class : Electric Power System
Assignments #1
1. The single line diagram of a generator connected through parallel transmission lines to a large
metropolitan system machines is delivering 1,0pu 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 0,2pu 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
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

2. 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
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 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

3. 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.
Penyelesaian:

4. 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.
Penyelesaian
Note: Answer sheets of assignment #1 and # 2 should be submitted on Tuesday, April 1,
2014.

5. Assignment #3
Rules:
1. Students are grouped into 3 groups and each group consists of 3 students.
2. Each group should write a paper in single column format based on group topics below.
3. Student may also refer to one or more IEEE papers (Journal) in related topics to enhance
4. the material quality of your paper.
5. Papers should be submitted by April 8, 2014 to abraham@itn.ac.id
6. The paper will be presented on Class meeting, Wednesday, April 9, 2014.
Group 1
AndrikSunyoto, ST, David SubanKoten,ST&Suparman, ST
(Class attendance list of 1-3) Topic:
Improvement of Damping-Power System Stabilizer and SVS supplementary controls
Group 2 (Class attendance list of 4-6)
Topic: PV and QV Curves, Impact of Load and Tap-changer Dynamics
Group 3 (Class attendance list of 7-9)
Topic: Effect of Excitation System and AVR