Cebu Technological University - Main Campus
Department of Electrical Engineering
EE-PC 4111 – Midterm Examination
Power System Analysis
Instructor: Engr. Xavier Julian P. Fernandez
November 27, 2021
Name:
Degree Program, Year Level and Section:
This exam contains 6 pages (including this cover page) and 4 question. Total of points is 60.
Write your solutions legibly on a clean, separate paper.
Distribution of Marks
Question Points Score
1
15
2
15
3
15
4
15
Total:
60
1
EE-PC 4111
Midterm Examination
November 27, 2021
1. A 25-km long, 34.5-kV, 60-Hz three-phase transmission line has a positive-sequence series
impedance Z = 0.21 + j0.35 Ω/km. The load at the receiving end absorbs 15 MVA at 33
kV. Assuming a short line, calculate:
(a) (5 points) the ABCD parameters,
(b) (5 points) the sending-end voltage for a load power factor of 0.9 lagging, and
(c) (5 points) the sending-end voltage for a load power factor of 0.9 leading.
Page 2 of 6
EE-PC 4111
Midterm Examination
November 27, 2021
2. A 3-phase, 60 Hz, 100-km line has the following parameters:
Resistance/phase/km = 0.25 Ω
Inductive reactance/phase/km = 0.38 Ω
Shunt admittance/phase/km = 0.1 × 10−4 S
If the line supplies a load of 230 MW at 0.85 p.f. lagging at 69 kV, calculate by using nominal
T method:
(a) (6 points) the voltage regulation of the line,
(b) (6 points) the total sending-end power in W , and
(c) (3 points) the transmission efficiency.
Page 3 of 6
EE-PC 4111
Midterm Examination
November 27, 2021
3. A 50-Hz, 160-km long transmission line has the following distributed parameters:
R = 0.15 Ω/km; L = 1.2 mH/km; C = 8nF/km; G = 0
Determine:
(a) (3 points) the propagation constant γ, and
(b) (9 points) the ABCD constants of the line.
(c) (3 points) Write, but do not solve, the equations for VS , and IS . Plug all appropriate
values.
Page 4 of 6
EE-PC 4111
Midterm Examination
November 27, 2021
4. A hydroelectric powerplant is to deliver 5000 MW power to a substation 500 km far. Assuming
a lossless transmission line model for a base voltage of 230 kV, with VS = 1.0 per unit, VR = 0.9
per unit, ZC = 522 Ω and δ = 37.2◦ , determine:
(a) (5 points) the surge impedance loading (SIL) in MW,
(b) (5 points) the theoretical steady-state stability limit, and
(c) (5 points) the number of lines needed for power delivery.
Page 5 of 6
EE-PC 4111
Midterm Examination
November 27, 2021
This page is intentionally left blank to accommodate work that wouldn’t fit elsewhere and/or
scratch work.
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