LAB SHEET-Experiment 5
Electrotechnic Lab (SME2921), FKE UTM Skudai
Fakulti:
FAKULTI KEJURUTERAAN ELEKTRIK
Semakan
Nama Matapelajaran : MAKMAL KEJ. ELEKTRIK
Tarikh Keluaran
Pindaan Terakhir
Kod Matapelajaran
: SME 2921
No. Prosedur
:3
: Jun 2010
: 2008
: PK-UTM-FKE-(O)-08
FAKULTI KEJURUTERAAN ELEKTRIK
UNIVERSITI TEKNOLOGI MALAYSIA
KAMPUS SKUDAI
JOHOR
SME 2921
ELECTROTECHNIC LABORATORY
(Experiment
5)
VOLTAGE REGULATION AND
EFFICIENCY OF A TRANSFORMER
Disediakan oleh:
1. PM Dr. Azhar bin Khairuddin
2. Prof. Dr. Abdullah Asuhaimi Mohd Zin
3. En. Alias Mohamad Yusoff
4. Dr Saiful Nizam Khalid
5. Dr Asiah Mohamad
6. PM Md Shah Majid
7. Jasrul Jamian
8. Madihah Md Rasid
Disahkan oleh:
Tandatangan:
Cop:
Tarikh:
Tandatangan:
Cop:
Tarikh:
1
© 2010 Universiti Teknologi Malaysia – All Rights Reserved
LAB SHEET-Experiment 5
Electrotechnic Lab (SME2921), FKE UTM Skudai
I.
PRELIMINARY EXERCISE
Important Note: You are required to do this exercise BEFORE the lab
session
1. Draw and label complete equivalent circuit of a single phase transformer. From this
circuit, draw approximate equivalent circuit of a single phase transformer referred to
the primary side.
2. List parameters in the circuit that can be obtained from
(i)
Open circuit test
(ii)
Short circuit test.
3. A single phase transformer 240VA 120/120 V is tested on open and short-circuit. The
results of the test are as follows:
Open-circuit test:
120 V, 0.6 A, 18 W, the readings on primary.
Short-circuit test:
16 V, 2.3 A, 32 W, the readings on secondary.
Calculate:
(i)
The parameters of the transformer equivalent circuit referred to the secondary
side.
(ii)
The efficiency and voltage regulation on full load at power factor of 0.8
lagging.
Recommended Reference:
E. Hughes, ‘Electrical Technology’, 7th Ed. , Longman.
2
© 2010 Universiti Teknologi Malaysia – All Rights Reserved
LAB SHEET-Experiment 5
Electrotechnic Lab (SME2921), FKE UTM Skudai
II.
EXPERIMENT:
.
‘Voltage Regulation And Efficiency Of A Transformer’
1. Aims:
i.
ii.
iii.
To perform an open circuit and a short circuit test.
To determine the parameter of transformer equivalent circuit.
To calculate the voltage regulation and the efficiency at different loading.
2. Equipments:
i.
ii.
iii.
TT179 Transformer Trainer.
PS189 Power Supply.
EW604 Electronic Wattmeter.
3. Procedure:
Precaution: Make sure that power supply knob of ps189 at 0 position before
starting the experiment.
Open Circuit Test
i.
The equipment and the connection for the open circuit test is as shown in
Figure 1.0.
ii.
Make sure the wattmeter ranges are at 120 V (for voltage range) and 1 A
(for current range). The wattmeter reading is the deflection multiply with
the voltage range and the current range.
iii.
Set the switch position of AC/DC at PS189 to AC.
iv.
Pull down the safety lid (cover) and switch ON PS189 and TT179.
v.
Increase the output of PS189, until primary voltage (V1) reaches 120 V.
vi.
Measure the voltage, current, and power at the primary winding and the
voltage at the secondary winding. Record all the results in Table 1.0 (in
short report).
vii.
Reduce voltage supply of PS189 to zero and then switch OFF TT179.
3
© 2010 Universiti Teknologi Malaysia – All Rights Reserved
LAB SHEET-Experiment 5
Electrotechnic Lab (SME2921), FKE UTM Skudai
Short Circuit Test
i.
Before switching on the supply, ensure that the power supply knob of
PS189 is at the zero position.
ii.
The equipment and the connection for the short circuit test is as shown in
Figure 2.0.
iii.
Set the load switch of TT179 to the ON position.
iv.
Switch on TT179 and increase the output of PS189 gradually so that the
ammeter A2 reads 0.5 A. Measure the primary voltage, primary current
and power. Record the readings in Table 1.0 (in short report).
v.
Repeat the measurement until the load current reaches 2.5 A with an
increment of 0.5 A. Record all the readings in Table 1.0. ( CAUTION: the
current range for the watt meter must be suitable with the load current)
WATTMETER
W1
OFF
±
120V
240v
140V
1A
5A
35V
AMMETER 1
280V
70V
VOLTMETER 1
140V
1A
VOLTMETER 2
5A
LOAD ON
AMMETER 2
TRANSFORMER
L
I1
I
ac
Supply
0-120
V
5A max
V
W1
PRIMARY
CIRCUIT BREAKER
v1
B
F
C
K
W2
E
v2
150K
L
LOAD
SWITCH
M
2µF
N
P
G
N
A
POWER SUPPLY PS189
B
C
D
E
F
G
R
CONNECT TO TEST TRANSFORMER
ON
DC
RESET
+
AC
_
J
I
D
A
V
1Ω
H
I2
TRANSFORMER TRAINER TT 179
Figure 1.0
4
© 2010 Universiti Teknologi Malaysia – All Rights Reserved
Q
CONNECT TO LOAD UNIT
1A
SECONDARY
±
W2
LAB SHEET-Experiment 5
Electrotechnic Lab (SME2921), FKE UTM Skudai
WATTMETER
W1
OFF
±
120V
240v
140V
1A
5A
35V
AMMETER 1
280V
70V
VOLTMETER 1
140V
1A
VOLTMETER 2
5A
LOAD ON
AMMETER 2
TRANSFORMER
L
I1
I
ac
Supply
0-120
V
5A max
V
W1
v1
B
F
C
K
W2
E
PRIMARY
CIRCUIT BREAKER
v2
150K
L
LOAD
SWITCH
M
2µF
N
P
G
N
POWER SUPPLY PS189
A
ON
B
C
D
E
F
CONNECT TO TEST TRANSFORMER
DC
R
G
Q
TRANSFORMER TRAINER TT 179
RESET
+
AC
_
J
I
D
A
V
1Ω
H
I2
Figure 2.0
5
© 2010 Universiti Teknologi Malaysia – All Rights Reserved
CONNECT TO LOAD UNIT
1A
SECONDARY
±
W2