Republic of the Philippines
SOUTHERN LEYTE STATE UNIVERSITY
Main Campus, Sogod, Southern Leyte
website: www.slsuonline.edu.ph
email: slsumaincampus@gmail.com /
op@slsuonline.edu.ph telefax: (053) 577-8299
Name: __________________________
Course, Yr. & Sec.: _______________
Group no.: ______________________
Score: __________________________
Date Performed: __________________
Date Submitted: __________________
Instructor: Engr. Marvin Arsel R. Cabalo
Experiment #1
Parts of a transformer
I. OBJECTIVE:
To be able to know the different parts of a transformer specifically oil immersed transformer.
II. CONCEPTUAL BACKGROUND:
A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to
another, or multiple circuits. A varying current in any one coil of the transformer produces a varying magnetic
flux in the transformer's core, which induces a varying electromotive force across any other coils wound
around the same core. Electrical energy can be transferred between separate coils without a metallic
(conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the
induced voltage effect in any coil due to a changing magnetic flux encircled by the coil.
Ideal Transformer
An ideal transformer is a theoretical linear transformer that is lossless and perfectly coupled.
Practical / Real Transformer
The ideal transformer model neglects the following basic linear aspects of real transformers:
•
•
•
Core losses, collectively called magnetizing current losses, consisting of Hysteresis and Eddy current.
Unlike the ideal model, the windings in a real transformer have non-zero resistances and inductances
associated with Joule losses and Leakage flux.
similar to an inductor, parasitic capacitance and self-resonance phenomenon due to the electric field
distribution. Three kinds of parasitic capacitance are usually considered, and the closed-loop equations
are provided
1. Capacitance between adjacent turns in any one layer
2. Capacitance between adjacent layers
3. Capacitance between the core and the layer(s) adjacent to the core
Real Transformer Equivalent Circuit refereed to Primary side
III. Procedure
1. Draw an oil immersed transformer (range 10kva – 50kva).
2. Identify the different parts of an oil immersed transformer.
3. Enumerate the purpose of the different parts of a transformer.
Requirements on answering:
1. Fill up all the needed data in this experiment.
In the occurrence of extra paper:
1. On the upper left of the bond paper, write your full name and under it is your course.
Ex. JUAN DELA CRUZ, JR.
BSEE
2. On the upper center, write the Experiment number and title
Ex. Simulation Experiment #1 – Total Resistance
3. On the upper right, write the date you have started the exercises and affix your signature
right next to it.
Methods on sending your answers (Online)
4. Bottom center, write the page number (applicable to two or more pages only)
1. Take a clear picture of your output per page.
(For clearer results, use “CamScanner” app available on Google Play/App Store)
2. If you have many pages, please organize on sending your outputs.
(Page 2 should be sent after page 1)
3. Send (via email) to “mrcabalo@gmail.com”.
3. Leave a message “My Outputs – Title of the Module – Full name – Time sent”
Ex. My Outputs
Simulation Experiment #1 – Total Resistance
Juan Dela Cruz, Jr.
7:59 pm
4. Deadline: 1st Week of November
Methods on sending your answers (Offline)
1. Place this experiment on a brown envelop.
2. Write your full name, course and section, and instructor’s name at the back.
Ex. Juan Dela Cruz, Jr.
BSEE 1-A
Engr. Marvin Arsel R. Cabalo
3. Send your outputs thru LBC or JRS Express address to SLSU-Main, Brgy. San Roque, Sogod,
Southern Leyte.
4. Deadline: 1st Week of November
Annex A.
RUBRIC IN PROJECTS/OUTPUTS
Projects/Outputs Level
Exemplary
Points
6
5
Indicators
Work/project is exceptional and impressive.
A distinctive sophisticated application of
knowledge and skills are evident.
Work/project exceeds the standard;
thorough and effective application of
knowledge and skills are evident
Strong
Proficient
Developing
4
3
Emerging
2
Learning
1
*DepEd, 2007
Rating Scale:
6
1.0 – 1.5
5
1.6 – 2.0
4
2.1 – 2.5
3
2.6 – 3.0
2
3.1 – 3.5
1
3.6 & above Failed
Conditional
Work/project
meets
the
standard;
acceptable and it displays the application of
essential knowledge and skills
Work/project does not yet meet the
standard; show basic but inconsistent
application of knowledge and skills; work
needs further development
Work/project shows partial application of
knowledge and skills; lacks depth or
incomplete
and
needs
considerable
development errors and omissions are
present
No work presented
Republic of the Philippines
SOUTHERN LEYTE STATE UNIVERSITY
Main Campus, Sogod, Southern Leyte
website: www.slsuonline.edu.ph
email: slsumaincampus@gmail.com /
op@slsuonline.edu.ph telefax: (053) 577-8299
Name: __________________________
Course, Yr. & Sec.: _______________
Group no.: ______________________
Score: __________________________
Date Performed: __________________
Date Submitted: __________________
Instructor: Engr. Marvin Arsel R. Cabalo
Experiment #2
Characteristic of a Practical Transformer
I. OBJECTIVE:
To be able to know the characteristics of a practical transformer.
To be able to know the relationship between voltage output and
different values of inductance (primary & secondary windings).
II. CONCEPTUAL BACKGROUND:
A practical transformer will differ from an ideal transformer in many ways. For example, the core material will
have finite permeability, there will be eddy current and hysteresis losses taking place in the core, there will be
leakage fluxes, and finite winding resistances.
We first draw the φ max phasor. Since the core is not ideal, a finite magnetizing current l m will be drawn from
supply and it will be in phase with the flux phasor as shown in figure below. The induced voltages in primary
E1 and secondary E2 are drawn 90º ahead (as explained earlier following convention 2). Since winding
resistances and the leakage flux are still neglected, terminal voltages V1 and V2 will be same as E1 and E2
respectively
If you compare this no load phasor diagram with the no load phasor diagram of the ideal transformer, the only
difference is the absence of lm in the ideal transformer. Noting that lm lags V1 by 90º and the magnetizing
current has to supplied for all loading conditions, common sense prompts us to connect a reactance Xm, called
the magnetizing reactance across the primary of an ideal transformer as shown in figure 24.3(a). Thus the
transformer having a finite magnetizing current can be modeled or represented by an ideal transformer with a
fixed magnetizing reactance Xm connected across the primary. With S opened in figure 24.3(a), the current
drawn from the supply is I1 = lm since there is no reflected current in the primary of the ideal transformer.
However, with S closed there will be I2 , hence reflected current I’2 = I2/ a will appear in the primary of the ideal
transformer. So current drawn from the supply will be I 1 = Im + I’2
The exact equivalent circuit can now be drawn with respective to various sides taking all the realities into
account. Resistance and leakage reactance drops will be present on both the sides and represented as shown in
the figures below. The drops in the leakage impedances will make the terminal voltages different from the
induced voltages.
Note: I1 = I’2 = I0 in a no-load state
Re1 = R1 + R2 (N1/N2)2
Re2 = R2 + R1 (N2/N1)2
Xe1 = X1 + X2 (N1/N2)2
Xe2 = X2 + X1 (N2/N1)2
Ze1 = √[(Re1)2 + (Xe1)2]
Ze2 = √[(Re2)2 + (Xe2)2]
Note: turn
ratio is
a = N1
N2
III. APPARATUS AND MATERIALS: (APPLICATION: ELECTRIC CIRCUIT STUDIO)
Supply voltage = 7200V
Inductance= 1H, 10H, 100H, 1kH, 10kH, 100kH
Voltmeter
IV. PROCEDURE:
1. Make a simple circuit of a practical or real transformer using “Electric Circuit Studio” shown below
2. Select a voltage source (AC Source) and set the voltage input(amplitude) to 7200Volts at 60hz.
3. Select a transformer and adjust the inductance value, Primary and Secondary, base on the Table 1.1.
4. Record the output voltage.
Voltage Input
Primary Inductance
Secondary Inductance
7200V
100kH
1H
7200V
10kH
1H
7200V
1kH
1H
7200V
100H
1H
7200V
10H
1H
7200V
1H
1H
7200V
1H
100kH
7200V
1H
10kH
7200V
1H
1kH
7200V
1H
100H
7200V
1H
10H
7200V
1H
1H
Table 1.1
V. Conclusion
Voltage Output
Requirements on answering:
1. Fill up all the needed data in this experiment.
In the occurrence of extra paper:
1. On the upper left of the bond paper, write your full name and under it is your course.
Ex. JUAN DELA CRUZ, JR.
BSEE
2. On the upper center, write the Experiment number and title
Ex. Simulation Experiment #1 – Total Resistance
3. On the upper right, write the date you have started the exercises and affix your signature
right next to it.
4. Bottom center, write the page number (applicable to two or more pages only)
Methods on sending your answers (Online)
1. Take a clear picture of your output per page.
(For clearer results, use “CamScanner” app available on Google Play/App Store)
2. If you have many pages, please organize on sending your outputs.
(Page 2 should be sent after page 1)
3. Send (via email) to “mrcabalo@gmail.com”.
3. Leave a message “My Outputs – Title of the Module – Full name – Time sent”
Ex. My Outputs
Simulation Experiment #1 – Total Resistance
Juan Dela Cruz, Jr.
7:59 pm
4. Deadline: 4th Week of November
Methods on sending your answers (Offline)
1. Place this experiment on a brown envelop.
2. Write your full name, course and section, and instructor’s name at the back.
Ex. Juan Dela Cruz, Jr.
BSEE 1-A
Engr. Marvin Arsel R. Cabalo
3. Send your outputs thru LBC or JRS Express address to SLSU-Main, Brgy. San Roque, Sogod,
Southern Leyte.
4. Deadline: 4th Week of November
Annex A.
RUBRIC IN PROJECTS/OUTPUTS
Projects/Outputs Level
Exemplary
Points
6
5
Indicators
Work/project is exceptional and impressive.
A distinctive sophisticated application of
knowledge and skills are evident.
Work/project exceeds the standard;
thorough and effective application of
knowledge and skills are evident
Strong
Proficient
Developing
4
3
Emerging
2
Learning
1
*DepEd, 2007
Rating Scale:
6
1.0 – 1.5
5
1.6 – 2.0
4
2.1 – 2.5
3
2.6 – 3.0
2
3.1 – 3.5
1
3.6 & above Failed
Conditional
Work/project
meets
the
standard;
acceptable and it displays the application of
essential knowledge and skills
Work/project does not yet meet the
standard; show basic but inconsistent
application of knowledge and skills; work
needs further development
Work/project shows partial application of
knowledge and skills; lacks depth or
incomplete
and
needs
considerable
development errors and omissions are
present
No work presented