UNIVERSITY OF TECHNOLOGY, JAMAICA
SCHOOL OF ENGINEERING
Power Systems 2
Eng. 3EP
Lab # 1
Title: Transmission Line Parameters
OBJECTIVE:
The objective of the experiment is to determine the ABCD parameters of transmission lines and
investigate their suitability in determining the behavior of a Transmission Line under various
loading conditions.
APPARATUS
• This experiment will be conducted using the Multisim simulation software. Be sure to
allow the instrument readings to settle before recording them.
EXERCISE 1: Short Line
1. Construct the short line transmission line model shown in figure 1 below and apply a
voltage of 240 V 50Hz AC to the sending end.
Sending End
Receiving End
Figure 1: Short Line Model
2. Create an open circuit at the receiving end and insert the appropriate instruments to take
readings and complete table 1.1 below.
Table 1.1: Results for receiving end opened
Voltage (V)
Current (A)
Power (W)
Sending End
Receiving End
Developed by: Dwight Reid, SOE UTech, Ja. Feb 2016
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3. Create a short circuit at the receiving end and insert the appropriate instruments to take
readings and complete table 1.2 below.
Table 1.2: Results for receiving end shorted
Voltage (V)
Current (A)
Power (W)
Sending End
Receiving End
4. Use the results recorded in tables 1.1 and 1.2 to calculate the ABCD parameters of the
line. Show your calculations. Keep in mind the phase shift between the sending end
voltage and current.
Table 1.3: Calculated ABCD Parameters
A
B
C
D
5. Apply the loads in table 1.4 (showing calculations for inductor and capacitor values) to
the receiving end of the line and insert the appropriate instruments to take readings and
complete the table.
Table 1.4: Results for different loads
100 + j0 Ω
100 + j50 Ω
100 – j50 Ω
Sending End Voltage
(V)
Sending End Current
(A)
Sending End Power
(W)
Receiving End
Voltage (V)
Receiving End
Current (A)
Receiving End Power
(W)
6. Perform calculations of sending end voltage, current and power using the obtained
ABCD parameters for the different loads given in table 1.4 and in your discussion
compare them to the readings obtained. Show your calculations.
Developed by: Dwight Reid, SOE UTech, Ja. Feb 2016
Page 2
EXERCISE 2: Medium Line
1. Construct the medium line transmission line model shown in figure 2 below and apply a
voltage of 240 V 50Hz AC to the sending end.
Receiving End
Sending End
Figure 2: Medium Line Model
2. Create an open circuit at the receiving end and insert the appropriate instruments to take
readings and complete table 2.1 below.
Table 2.1: Results for receiving end opened
Voltage (V)
Current (A)
Power (W)
Sending End
Receiving End
3. Create a short circuit at the receiving end and insert the appropriate instruments to take
readings and complete table 2.2 below.
Table 2.2: Results for receiving end shorted
Voltage (V)
Current (A)
Power (W)
Sending End
Receiving End
4. Use the results recorded in tables 2.1 and 2.2 to calculate the ABCD parameters of the
line. Show your calculations. Keep in mind the phase shift between the sending end
voltage and current.
Table 2.3: Calculated ABCD Parameters
A
B
Developed by: Dwight Reid, SOE UTech, Ja. Feb 2016
C
D
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5. Apply the loads in table 2.4 (showing calculations for inductor and capacitor values) to
the receiving end of the line and insert the appropriate instruments to take readings and
complete the table.
Table 2.4: Results for different loads
100 + j0 Ω
100 + j50 Ω
100 – j50 Ω
Sending End Voltage
(V)
Sending End Current
(A)
Sending End Power
(W)
Receiving End
Voltage (V)
Receiving End
Current (A)
Receiving End Power
(W)
6. Perform calculations of sending end voltage, current and power using the obtained ABCD
parameters for the different loads given in table 2.4 and in your discussion compare them to the
readings obtained. Show your calculations.
For Further Discussions:
1) Compare the behavior of the short and medium lines when they are shorted, opened and
operated under the different loading conditions.
2) Calculate and compare the efficiencies of the lines for the different loading conditions.
3) Is the receiving end voltage ever higher than the sending end voltage for either of the line
models? If it is, explain why.
Developed by: Dwight Reid, SOE UTech, Ja. Feb 2016
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