STUDENT KIT LAB MODULE
Program: EE242/CEEE242/CEEE223
Semester: 7
Ownership: Discipline of Power
Date
March 2022
Issued:
Course Name: ELECTRICAL ENGINEERING LABORATORY V
Version: 2.0
Course Code: EPO662
Mode of Delivery: !
Face to Face
Virtual
HIGH VOLTAGE AC GENERATION AND BREAKDOWN
Authors
Prepared by: Dr. Ngah Ramzi Hamzah
Dr. Dalina Johari
Faranadia Abdul Haris
Dr. Dalina Johari
2nd Revision :
Faranadia Abdul Haris
1st Revision :
Date : Dec 2010
Date : Feb 2019
Date : Mac 2022
ASSESSMENT DETAILS
Field/Module: High Voltage / HV1
Experiment Title: HIGH VOLTAGE AC GENERATION AND BREAKDOWN
At the end of the course, students should be able to:
CLO1: Work in a team effectively to perform laboratory works
(A3).
CLO2: Display proficiency using laboratory tools in
Course Learning
conducting experiment (P4).
Outcomes: CLO3: Determine a suitable technique in order to solve the
Complex engineering problem (C4).
CLO4: Present the findings observed from the experiment/case
Study clearly and effectively through a lab/PBL report
(A3).
Upon completion of this experiment, students should have the:
MO1: Ability to construct and setup high voltage AC test circuit
with safety measures.
Module Outcomes: MO2: Ability to apply the knowledge on AC breakdown knowledge
studied in previous semester.
MO3: Ability to perform analysis on the AC breakdown
phenomenon.
Instructions:
1. Perform the tasks as given/instructed in the lab module.
2. Submit the report in a group.
1. No food or drink is allowed in lab unless food or drinks are
provided as a part of the lab.
2. Shoes must be worn in lab.
Safety
3. Please ensure all the diagram connection is checked or
Instructions:
approved by instructor/assistance engineer before running the
experiment.
4. Always bring test pen during laboratory session.
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1.
THEORETICAL BACKGROUND
1.1 Introduction
In High Voltage Engineering applications, the dielectrics also known as electrical insulator can
be categorized either gas/vacuum, liquid and solid insulations. High pressure gas also provides
a flexible and reliable medium for high voltage insulation. The high-pressure gas suitable for
insulation are Sulphur hexafluoride (SF6), Nitrogen (N2), Carbon dioxide (CO2) and Freon
(CCl2F2). Vacuum is the best insulator with the dielectric strength up to 1012 V/cm limited by
emission from the electrode surfaces. Under high vacuum conditions, the breakdown cannot
occur due to collisional processes as in gases, and hence the breakdown strength is quite high.
Vacuum insulation is used in particle accelerators, x-ray and field emission tubes, electron
microscopes, capacitors, and circuit breakers.
5. PRE-LAB WORK
2.1.
Explain the function of switchgears in electrical system.
2.2.
Why it is important to quench the arc that occurs in the switchgears?
2.3.
List and briefly explain the medium used to quench the arc in switchgears.
2.4. State the type of switchgear that uses vacuum as medium to quench the arc and explain
the operation of this switchgear.
6. EXPERIMENTAL WORK
3.1 Preparing the Test Vessel DG100
Procedures
1.
Turn the cap B1 to counter clockwise until the cap B1 is detached from the portion B.
Refer Figure 1.1
2.
Turn the locking screw A counter clockwise until the portion B is able to be lifted away
from the test vessel assembly
3.
Properly place the portion B on a flat surface that will not cause scratch to the electrode
C1 or bending of the rod D as shown in Figure 1.2.
4.
Wipe the interior wall of the test cell E and the electrode C2 using the designated jig ;
to ensure no moisture and oil droplets inside the test cell E. Refer Figure 1.3 and Figure
1.4.
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5.
Wipe the portion B and the electronic rod C1 and D need to be clean and preventing it
from moisture and oil as shown in Figure 1.5 and Figure 1.6 using the designated jig.
6.
Carefully re-assemble all the detached parts of the test vessel DG100 as shown in
Figure 1.7.
7.
Adjust the portion F to ensure the electrode C1 is aligned with the electrode C2 as
shown in Figure 1.8.
8.
Measure the gap between the electrodes C1 and C2 as shown in Figure 1.8. The default
setting is 1.0 cm, and the gap adjustment can ONLY be carried out by the Lab
Instructor.
9.
Wipe the exterior part of the Test Vessel as shown in Figure 1.10
10.
By using three fingers, turn the valve G in clockwise direction. Do not close the valve
G too tightly.
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5
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3.2 Using the Vacuum Pump (BO78R04)
Procedures
1. The connection between Test Vessel and Vacuum Pump is shown in Figure 2.1.
2. Based on Figure 2.2, turn the valve G three rounds in counter clockwise direction to flush
out air inside the Vacuum Pump.
3. Wait for 10 seconds and turn the valve G at the Test Valve clockwise until fingers tight.
4. Turn the lever I on the side of the vacuum pump to ON position (Figure 2.3) and lever I
on top of the vacuum pump to ON position (Figure 2.4).
5.
Wait for 3 second to “flush out” air in the vacuum pump.
6.
Turn the lever I and the lever H in sequence to OFF position.
7.
Connect the Portable Vacuum Pump BO78R04 to the Test Vessel DG100 via the hose J.
Ensure a tight fitting at the hose ends.
8.
Plug the electrical socket K to wall outlet.
9.
Switch ON the power supply at the vacuum pump by pressing the toggle switch L.
10. Turn the lever I to OPEN position
11. From OFF position turn the lever H for 10 degrees only. At this moment, the pointer on
the meter M will turn the counter clockwise.
12. By using three fingers, turn the valve G in counter clockwise direction. The pointer on
the meter M will drop and stay at stable position for quite some time.
13. Adjust the lever H slowly so that the pointer on the vacuum meter M starts to increase
slowly.
14. When the pointer reaches -0.1 bar (which is 50% of the desired pressure), turn the valve
G 1 time in clockwise direction.
15. When the pointer reaches -0.15 bar (the desired pressure), turn the valve G1 time in
clockwise direction.
16. When the pointer reaches -0.2 bar (the desired pressure), turn the valve G1 time in
clockwise direction; to seal the valve G.
17. Turn OFF the Valve G at the Test Vessel in clockwise little by little as shown in Figure
2.6 and be alert to close it when the Pressure Meter shows the desired value.
18. Turn off the vacuum pump by pressing toggle switch L as shown in Figure 2.7.
19. Turn the lever I to OFF position.
20. Turn the lever I to OFF position.
21. Disconnect the hose J from the Test Vessel as shown in Figure 2.8.
22. Turn the lever H and lever I to ON position.
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23. Unplug the electrical socket K out from the wall socket outlet as shown in Figure 2.9.
24. Keep back the Vacuum Pump in the right way as shown in Figure 2.10.
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3.3. Discharging Using Discharge Rod
Procedures
1. The discharge rod for AC system is shown in Figure 3.
2. The operator shall hold the rod at the end without the hook.
3. The operator shall apply a safety Personal Protective Equipment (PPE) as
shown in Figure 3.1 and Figure 3.2.
4. The operator shall handle the discharging rod at the handle end.
5. Touch the hooked end to all live parts (surface by surface) of the test circuit for
discharging process as shown in Figure 3.3.
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6. After touching all the live parts, place the hook to attach to the component nearest to the
test transformer T100 as shown in Figure 3.4.
7. Before conducting an experiment, make sure the hooked is removed from the hanging
place and put it on the rubber mat.
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3.4. Experiment High Alternating Voltage Generation
Procedures
1. Setup the circuit as shown in Figure 4.1 The box indicated with A letter consists of
measuring circuit and the construction of the circuit is shown in Figure 4.2
2. Place the MCP 100 at the correct position as shown in Figure 4.3.
3. Remove the shorting wire for this experiment as shown in Figure 4.4. When not in use,
the MCP100 is shorted for maintaining its accuracy.
4. Use a metal rod as connector between MCP 100 and the capacitor as shown in Figure 4.4.
5. Ensure that the equipment and all metal parts in contact or slightly above the floor are
properly earthed in Figure 4.4.
6. After setting up the circuits of Figure 4 and 5, consult the instructor and check the circuits
for correct wiring of the testing circuit and earth circuit as shown in Figure 4.5. For safety
precaution, ensure that the discharge rod is connected to the earth circuit.
7. Remove the discharge rod upon completing procedure 6 as shown in Figure 4.6.
8. All personnel should leave the testing area.
9. Close the fence gate properly as shown in Figure 4.8.
10. Switch on the system by turning on the key 1 once to the right (position 1) and return
to vertical (position 0) as shown in Figure 5.3. Turn on the computer by pressing
power switch 2 (see Figure 6).
11. Select “EPO660” User Account WGMSWIN.
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13
14
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12. Once the Microsoft Windows is displayed on the monitor 3 , press on the Mode PC
button 4 and Display Test button 5 on the SIMATIC PANEL.
13. Switch on the ICM compact unit 6 . Observe and record the partial discharge
reading (in pC) on the ICM compact unit 6
14. The toggle asked for save previous work, immediately click for “NO”. If click
“SAVE”, it will corrupt the system.
15. Look for the WGMSWIN icon on the desktop and double click it. The monitor
screen will display the main panel as shown in Figure 7.
16. Click on the “File” menu and then click on “Open” sub-menu. A dialog box as shown in
Figure 8 will be displayed. You will be asked if you want to “Save changes to WgmsMan?”.
Select “No” to prevent the system from collapsing.
17. A directory will then appear Then go to “Local C Harddisk > Program Files
HIGHVOLT > Wgmswin > Templates > 02007 > V2.6 > Gradually Successive” as
shown in Figure 9.
18. Double click on the “Gradually Successive” file and then at the bottom of the simulation
have toggle button then press test result as shown in Figure 10 will be displayed.
19. Fill the Name of Operator, Date, Test Object, Number of experiment for reference and
also Remarks to labeled as a name of experiment.
20. Before running the experiment, setting the simulation and set the parameter is
mandatory refer table 1 for the value.
21. Click Test Setting tab at the bottom of the page and the page will come up as the
Figure 11
22. Click the “Settings” button on the left-hand side of the panel. A sub-panel as shown in
Figure 5.4 will be displayed.
23. Click on the “Limits” tab and the sub-panel will display as shown in Figure 5.5. Set the
“voltage limit”, i.e. the maximum voltage to be tested. The current limit and current
comparator limit are to be left as displayed
24. Click on the “WBG Settings” tab and the sub-panel will display as shown in
Figure 5.6. Set the parameters as instructed in Table 1.
25. Click on the “Climate Conditions” tab. Select the “AC” option as shown in Figure 5.7.
Keep the other data and parameters as displayed
26. Click on the “OK” button. The sub-panel will disappear, leaving only the main panel being
displayed. Observe that the parameters on the top side of the panel are automatically set.
Check that the “Switch on Ready” is displayed.
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27. Click on the “Ready ON” button (bottom left-hand side of the main panel). “Ready ON”
button and “Operate ON” button will illuminate. The warning beacons on the fence will be
flashing with red light as shown in Figure 5.8.
28. Click on the “Operate ON” button (bottom left-hand side of the main panel). “Operate
ON” button will illuminate
29. Observe and record the reading displayed on the ICM Compact unit 6 (Figure 6).
30. Give warning by sounding the horn (XXX) or call-out, “Attention! Switch on!”.
Ensure that there are no personnel in the testing area (within the fence).
31. Click on the “START” button (bottom right-hand side of the main panel.
32. The main panel will display the progress of test voltage. Observe that the Actual Voltage
may be slightly different from the Setting Voltage (on the top side of the panel). Record
both values.
33. Observe and record the reading displayed on the ICM compact unit 6 from time to time.
34. This step No. 35 and 36 may be repeated for several values of test voltage. At each value
of test voltage, record the Actual Voltage and Setting Voltage. Also, record the reading
displayed on the ICM compact unit 6.
35. After the test has been completed, click on the “Operate OFF” button and then the
“Ready OFF” button.
36. Open the gate of the fence as shown in Figure 5.9.
37. Contact the discharge rod to the circuit. Faithfully observe the method of discharging as
taught by the instructor. Leave the discharge rod in contact with the testing circuit as
shown in Figure 5.10.
38. After completing the experiment, remove the MCP100 from the circuit and re-attached
the shorting wire for safe keeping.
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18
19
Figure 5.6
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3.5. Experiment One Minute Power Frequency Test
Procedures
1. Setup the circuit as shown in Figure 12. The Test Vessel is to be placed as the Test
Object. The setup must be made within the testing (fenced) area.
2. Ensure that the discharge rod is connected to the earth circuit.
3. The measuring circuit is shown as crossed box in Figure 12. For details of the circuit,
refer to Figure 13.
4. Ensure that the equipment and all metal parts in contact and properly earthed.
5. After setting up the circuits of Figure 12 and 13, consult the instructor and together check
the circuits for correct wiring of the testing circuit and earth circuit.
6. Once the correct wiring is confirmed, remove the discharge rod.
7. Leave the testing area and head for the Control Measuring and Automatization System
(see Figure 14).
8. Ensure that there are no personnel in the testing area (within the fence).
9. Ensure that there is no discharge rod in contact (electrically or mechanically) with the test
circuit.
10. Close the fence gate properly.
11. Switch on the system by turning on the key 1 once to the right (position 1) and return to
vertical (position 0). Turn on the computer by pressing power switch 2 . (See Figure 14).
12. Once the Microsoft Windows is displayed on the monitor 3 ,press on the Mode PC button
4 and Display Test button 5 on the SIMATIC PANEL.
13. Look for the WGMSWIN icon on the desktop and double click it. The monitor screen
will display the main panel as shown in Figure 15.
14. Click on the “File” menu and then click on “Open” sub-menu. A dialog box as shown in
Figure 14 will be displayed. You will be asked if you want to “Save changes to
WgmsMan?”. Select “No”.
15. Then go to “Local C Hard disk > Program Files > HIGHVOLT >Wgmswin > Templates
> 02007 > V2.6 > Gradually Successive.xlsm”.
16. Double click on the “Gradually Successive.xlsm” file and the panel will be displayed as
shown in Figure 16.
17. Move the cursor onto the cell with dark borders (below the Disruptive voltage at gradually
successive voltage) and click the mouse’s left button. A sub-panel will appear as shown
in Figure 17.
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23
24
25
18. In this experiment, set the parameters according to the data in Table 3. After all the
parameters have been confirmed, click on the “OK” button.
Table 3: Parameters to be set.
Voltage
Limit voltage [kV]:
Final voltage [kV]:
Start voltage [kV]:
Step voltage [kV]:
Rate of voltage rise [kV/s]:
Stress
40
30
5
1
3
Tolerance of step voltage [%]:
No. of cycles:
Duration of step:
Break duration:
2
<5
00:01:00
00:00:05
19. Click on the “Test Results” tab of the Page menu (at the bottom of the panel).
The panel will appear as shown in Figure18.
20. Enter the operator’s name, date of experiment conducted, name of test object, test number
and remarks (if any) on the “Test Results” page.
21. Click on the “Ready ON” button (bottom left-hand side of the main panel). “Ready ON” button
and “Operate OFF” button will illuminate. The warning beacons on the fence will be turning
with red light. Check that the Indicator Bar displays “Switch on Operate”.
22. Click on the “Operate ON” button (bottom left-hand side of the main panel). “Operate
ON” button will illuminate. Check that the Indicator Bar displays “Ready”.
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23. Give warning by call-out, “Attention! Switch on!” Ensure that there is no personnel in
the testing area (within the fence).
24. Click on the “START” button (bottom right-hand side of the main panel).
25. The operator should give warning by call-out/countdown the Actual Test Time once the
main panel displayed the progress of test voltage.
26. Observe and record the Actual Voltage on the SIMATIC PANEL.
27. Observe and record the Partial Discharge on the ICM Compact unit.
28. Once the breakdown voltage is reached, the profile of the voltage will drop to zero. The
main panel will display Actual Time Test (on the top side of the panel) as “00:00:XX”.
29. Click on the “Operate OFF” button and then the “Ready OFF” button.
30. Repeat step 24 through 32 to complete the no. of cycles set in Table 3.
31. Click “File” on the menu bar and then click “Save As”. Then go to “Desktop” icon, click
on the “EPO660_TEST_RESULTS” folder. Name the fiIe as “Gradually Successive.xlsm
where XX is the operator’s group number and YY is the test number.
32. Click “File” on the menu bar and then click “Close”. You will be asked if you want to
“Save changes to “Gradually Successive?”. Select “No”.
33. Open the gate of the fence.
34. Perform discharging with the discharge rod and leave the discharge rod in contact with
the component nearest to the test transformer T100.
35. Setup the Test Vessel for a vacuum pressure of -0.4 bar.
36. Repeat steps 14 through 37 until the vacuum pressure of the test vessel reach -1.0 bar.
37. Copy all results in a folder and download to a pen drive.
7.
RESULTS
Student should include the findings such as completed the tables and presented the graphs of
Experiment 3.4 and 3.5
Experiment 3.4
1. Observe and record the Actual Voltage on the SIMATIC PANEL.
2. Observe and record the Partial Discharge on the ICM Compact unit.
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Setting Voltage
(kV)
10
11
12
13
14
15
16
17
18
19
20
Table 1.1
Actual Voltage
(kV)
Partial Discharge
(Coulomb)
Experiment 3.5
1. Observe and record the Actual Voltage on the SIMATIC PANEL.
2. Observe and record the Partial Discharge on the ICM Compact unit.
3. Observe and record item No.1 and 2 at different vacuum pressure (-0.2 bar, -0.4 bar, -0.6
bar, -0.8 bar and -1.0 bar)
Setting Voltage
(kV)
5
6
7
8
9
10
11
12
13
14
15
Table 1.2: (Pressure: -0.2 bar)
Actual Voltage
(kV)
Partial Discharge
(Coulomb)
4. Plot the graph of breakdown voltage versus vacuum pressure.
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8.
DISCUSSIONS
5.1
Based on Experiment 1, the maximum setting voltage has been set to 20kV with a test
object of MCP100 (Standard Capacitor). Why is the breakdown occurred at a setting
voltage of 20kV?
5.2
What types of ‘Law’ for breakdown in gases that involved in Experiment 2?
5.3
Explain the working principle of law stated in answer (4.2) with a necessary diagram
and equation.
5.4
Explain two methods that can been used in this experiment to generate High AC
Voltage.
5.5
Based on the experiment, the breakdown occurs in non-uniform electric field. Hence,
explain the form of the discharge occurs between the two electrodes with a necessary
diagram.
5.6
Explain the process of Electron Avalanche in gaseous insulator with a necessary diagram.
9.
QUIZ
6.1.
High voltage engineering is a requirement for electrical engineering students as it has
many practical applications. Give three (3) modes of high voltage applications.
(3 marks)
6.2.
Differentiate between an insulator and a conductor by showing their energy band
diagram.
(4 marks)
6.3.
Define the terms of dielectric strength and electric field stress.
(3 marks)
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10. CONCLUSION
Conclude in detail the findings and the outcomes of this experiment. This should include the
summary of knowledge gained, comments and discussion of the results, errors and their
possible sources and how this experiment can be improved.
11. REFERENCES
•
•
•
Naidu M.S. and Kamaraju V., High Voltage Engineering 2nd ed, Tata McGraw-Hill
Publ. Co., Ltd., New Delhi, 1996.
J. R. Lucas, High Voltage Engineering, 2001
E. Kuffel, W.S. Zaengl and J. Kuffel, High Voltage Engineering: Fundamentals, 2nd,
Newness, 2000, ISBN: 8181477367
END
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