Tap changers are devices fitted to power transformers that allow for regulation of the output voltage. Voltage regulation is achieved by altering the number of turns in one winding of the transformer, which changes the transformer ratios. Tap changers offer variable control to keep the supply voltage within limits. They can be on load or off load tap changers. On load tap changers consist of a diverter switch and selector switch to transfer current between taps without interruption.
On Load Tap Changer (OLTC) is used in "High Power Transformers" to control output voltage, when electric load on transformers get increase the output voltage get decrease due to internal voltage drop inside winding, change in tap is required to maintain output voltage. OLTC is a device which perform tap changing in High Power Transformers during On Load conditions and is powered by a motor.
On Load Tap Changer (OLTC) is used in "High Power Transformers" to control output voltage, when electric load on transformers get increase the output voltage get decrease due to internal voltage drop inside winding, change in tap is required to maintain output voltage. OLTC is a device which perform tap changing in High Power Transformers during On Load conditions and is powered by a motor.
Presentation on 132/33 KVSubstation Training Sakshi Rastogi
This is a presentation based on the 132/33 KV substation. At which I have done my vocational Training. this presentation uncovers all the aspects related to the substation.
A brief about 33kv Substation........
like and share.................
want some help in your ppt or in any project visit..
https://www.fiverr.com/dawachya
This ppt describes the function of Power Transformer in a Power Generation plant. Here DPL(Durgapur Projects Limited) was our VT venue, so chose it as the Base.
The following topics are covered: components of power distribution systems, fuses, padmounted transformers, pole mounted transformers, vault installed transformers, transformer stations protection, transformer connections, thermometers, pressure relief devices, restricted ground faults, differential protection current transformers connections, overexcitation, inrush current, percentage differential relays, gas relays, characteristics of CTs.
Presentation on 132/33 KVSubstation Training Sakshi Rastogi
This is a presentation based on the 132/33 KV substation. At which I have done my vocational Training. this presentation uncovers all the aspects related to the substation.
A brief about 33kv Substation........
like and share.................
want some help in your ppt or in any project visit..
https://www.fiverr.com/dawachya
This ppt describes the function of Power Transformer in a Power Generation plant. Here DPL(Durgapur Projects Limited) was our VT venue, so chose it as the Base.
The following topics are covered: components of power distribution systems, fuses, padmounted transformers, pole mounted transformers, vault installed transformers, transformer stations protection, transformer connections, thermometers, pressure relief devices, restricted ground faults, differential protection current transformers connections, overexcitation, inrush current, percentage differential relays, gas relays, characteristics of CTs.
The use of conventional devices as control mechanism for system voltage profile enhancement
and loss reduction is still predominantly prevalent in most third world nations and Nigeria is never an
exemption. This study seeks to compare efficiency of Load Tap-Changing Transformer and Shunt Capacitors
using system voltage profile enhancement and real power loss minimization as performance matrix on
Nigerian 330kV, 24-Bus grid system as a test case. In this work, the Newton Raphson iterative algorithm was
adopted due to its superior features over other iterative techniques. Load flow analysis was performed on the
test case with and without incorporation of LTCT and Shunt Capacitors, the result of the analysis shows that
with shunt capacitors injection at the weak buses identified, the algorithm converged in 5 iterations but with
LTC transformer convergence was achieved in 4 iterations. Also, the total system losses with shunt capacitor
injection was found to be 82.2826MW which is about 4.1% reduction while with LTC transformer, the total
system losses reduced appreciably to 81.9865MW which is about 4.8% reduction. Incorporation of LTCT
gives a better improvement on system voltage profile compared with the improvement observed with shunt
capacitor injection at the defective buses identified.
Measurement of Motion, Force
and Torque - Displacement and speed measurement for translational and rotation systems using
potentiometers, LVDT and RVDT, Encoders, accelerometers and gyroscopes. Force and Torque
measurements using strain gauges and piezoelectric pickups.
Review of Step down Converter with Efficient ZVS OperationIJRST Journal
This paper presents the review of step down converter with efficient ZVS operation. The designed buck converter uses ZCS technique and the function is realized so that the power form is converted from 12V DC 5V DC (1A). A detailed analysis of zero current switching buck converters is performed and a mathematical analysis of the mode of operation is also presented. In order to reduce the switching losses in associated with conventional converters; resonant inductor and resonant capacitor (LC resonant circuit) is applied which helps to turn on-off the switch at zero current. The dc-dc buck converter receives the energy from the input source, when the switch is turned-on. The buck–buck converters have characteristics that warrant a more detailed study. The buck converters under discontinuous conduction mode /continuous conduction mode boundary.
Chokeless welding transformer with load series motoreSAT Journals
Abstract
Welding is a materials-joining process that produces coalescence of materials by heating them to the welding temperature with or
without the application of pressure or by the application of pressure alone, and with or without filler metal. It is used to make
welds. It is observed that the welding transformer with choke or movable core is having large size, so to reduce the size we are
replacing the choke with one coil. This coil functions same as the choke. This coil helps to reduce the size as well as the cost of the
welding transformer. The forced air cooled transformer consists of an exhaust fan which rotates at a constant speed whether the
welding work is going or not. So, the more energy will be wasted there. To avoid this, the load series motor is used. The load
series motor as the name suggests is a motor, which is to be connected in series with a load. The load series motor, which shaded
pole motor but designed in such a way that if connected in series with load, it will run and speed of such motor will be
proportional to the load current. The ordinary exhaust fan motor can be, easily replaced by the load series motor.
Keywords: Rotary Switch, and Load Series Motor.
The use of distributed generation (DG) within distribution systems has increased for the last two decades due to worldwide increase in demand for electricity and governmental policy change from “conventional” energy to “green” energy. High levels of penetration of DG have many significant benefits but also come with many drawbacks such as voltage drop and power losses. This study presents the impact of DG at different locations in a distribution feeder in terms of the feeder voltage profile. A radial distribution system is simulated using PSCAD/EMTDC simulation software while changing the size and location of DG in the system. The obtained results are used for better understanding on the impact of DG on voltage profile in radial distribution feeder.
Industrial Training in 2×3.14MVA 33/11 KV substation.rohitkashiv2020
### Overview of a 33/11KV Substation
A 33/11KV substation is a critical infrastructure in electrical power distribution systems, acting as a node where voltage levels are transformed from high to medium levels to facilitate safe and efficient distribution of electricity to residential, commercial, and industrial consumers. These substations are strategically located to optimize the distribution network and ensure reliable and stable power supply.
### Function and Importance
The primary function of a 33/11KV substation is to step down the voltage from 33KV to 11KV using transformers. This voltage transformation is essential because high voltage (33KV) is more efficient for transmitting power over long distances due to reduced losses, while lower voltage (11KV) is safer and more practical for local distribution.
#### Key Roles:
1. **Voltage Transformation**: The core function involves stepping down the voltage from 33KV to 11KV.
2. **Protection and Control**: It ensures the safe operation of the electrical network by incorporating various protection and control mechanisms.
3. **Power Distribution**: It serves as a distribution point to various feeders that supply power to different areas.
### Components of a 33/11KV Substation
A 33/11KV substation comprises several key components, each playing a vital role in the substation's operation:
#### Transformers
The main component of a substation is the transformer. A 33/11KV transformer typically has a capacity ranging from 5MVA to 40MVA, depending on the load requirements. These transformers are designed to handle the high voltage input and step it down to a manageable level.
#### Circuit Breakers
Circuit breakers are essential for protecting the substation and connected circuits from faults and overloads. At a 33/11KV substation, both 33KV and 11KV circuit breakers are used. These devices can quickly interrupt current flow in case of an abnormal condition, preventing damage to equipment and ensuring safety.
#### Isolators
Isolators are used to disconnect parts of the substation for maintenance and repair. They are not intended to interrupt load current but to ensure a section is de-energized for safe access.
#### Busbars
Busbars are conductors that serve as a central point for electricity distribution within the substation. They collect power from incoming lines and distribute it to outgoing feeders. The design and construction of busbars are crucial for maintaining the reliability and efficiency of the power distribution system.
#### Switchgear
Switchgear in a substation includes various switches, fuses, and relays that control and protect the electrical equipment. High voltage switchgear handles the 33KV input, while medium voltage switchgear manages the 11KV output. Modern substations use metal-clad or gas-insulated switchgear for enhanced safety and compact design.
#### Protective Relays
Protective relays monitor electrical parameters and trigger circuit breakers in case of faults
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
Tap changer
1. A tap changer is a device fitted
to power transformers for
regulation of the output voltage
to required levels. This is
normally achieved by changing
the ratios of the transformers
on the system by altering the
number of turns in one winding
of the appropriate
transformer/s. Tap changers
offer variable control to keep
the supply voltage within the
limits. The 2 ½% step can be
2. Voltage regulation is normally achieved by changing
the ratios of the transformers on the system by altering
the number of turns in one winding of the appropriate
transformer/s. Tap changers offer variable control to
keep the supply voltage within these limits. Tap
changers can be on load or off load. On load tap
changers generally consist of a diverter switch and a
selector switch operating as a unit to effect transfer
current from one voltage tap to the next. Tap changers
can be adjusted to fit the application needs.
3. To supply a desired voltage to the load.
To counter the voltage drops due to loads.
To counter the input supply voltage changes on load.
Additionally required to perform the task of regulation of
active and reactive power flows.
4. Some form of impedance is present to
prevent short circuiting of the tapped
section.
A duplicate circuit is provided so that
the
load current can be carried by one circuit
whilst switching is being carried out on the
other.
5. Nominal Voltage set point.
Bandwidth (the amount of variation allowed before a
tap change
occurs).
Time delay (The amount of time the voltage must be
outside the
bandwidth before a tap change occurs) .
Line drop compensation ( a way vary the set point
voltage to
compensate for heavy loads)
6. Tap point is placed
In star connected winding, near the star point.
In delta connected winding, at the center of the windin
In autotransformer, between the series and common
7. Tap changers connected to the primary or
secondary side windings of the transformer
depending on:
Current rating of the transformer.
Insulation levels present.
Type of winding within the transformer (eg. Star, delta or
autotransformer).
Position of tap changer in the winding.
Losses associated with different tap changer configurations eg.
Coarse tap or
reverse winding.
Step voltage and circulating currents.
Cost.
Physical size.
8. No-Load Tap Changer (NLTC or
DETC)
On Load Tap Changer (OLTC
Mechanical tap changers
Thyristor-assisted tap changers
Solid state (thyristor) tap
changers
9. No-Load Tap Changer (NLTC or
DETC)In low power, low voltage transformers, the tap point can
take the form of a connection terminal, requiring a power lead to
be disconnected by hand and connected to the new terminal.
Since the different tap points are at different voltages, the two
connections can not be made simultaneously, as this would
short-circuit a number of turns in the winding and produce
excessive circulating current.
Mechanical tap
changers
A mechanical tap changer
physically makes the new
connection before releasing the
old using multiple tap selector
switches, but avoids creating
high circulating currents by
using a diverter switch to
10. Solid state (thyristor) tap changer
Recently developed which uses thyristors both to
switch the load current and to pass the load current in the
steady state. Their disadvantage is that all of the non-
conducting thyristors connected to the unselected taps still
dissipate power due to their leakage current.
Thyristor-assisted tap changers
Thyristor-assisted tap changers use thyristors to
take the on-load current while the main contacts change
over from one tap to the previous. This prevents arcing on
the main contacts and can lead to a longer service life.
11. On Load Tap Changer (OLTC)
OLTCs enable voltage regulation and/or phase shifting by
varying the transformer ratio under load without interruption. On
load tap changers generally consist of a diverter switch and a
selector switch operating as a unit to effect transfer current from
one voltage tap to the next. The selector selects the taps and is
operating in the transformer oil. The diverter is the actual switch
with high current contacts that balances the load from one tap to
the other. The divertor is inside a separate compartment inside the
transformer tank. The diverter and selector are positionned above
each-other and driven by the same axe. The voltage between the
taps is known as the step voltage, which normally lies between
0.8 % and 2.5 % of the rated voltage of the transformer.
Two switching principles have been used for load
transfer
operation :
1.the high-speed resistor-type OLTCs
2.the reactor-type OLTCs.
12. The resistor-type OLTCs are installed inside the transformer
tank (in-tank OLTCs)
The reactor-type OLTCs are in a separate compartment which
is normally welded to the transformer tank
13.
14. The OLTC changes the ratio of a transformer by adding or
subtracting to and turns from either the primary or the secondary
winding.
15. The “make before break contact concept”, is used. The transition
impedance in the form of a resistor or reactor consists of one or
more units that bridge adjacent taps for the purpose of transferring
load from one tap to the other without interruption or appreciable
change in the load current. At the same time they limit the
circulating current (IC ) for the period when both taps are used.
16.
17. Examples of commonly used winding
schemes
In star/wye connection, windings have
regulation applied to the neutral end.
18. Regulation of delta-connected windings requires a three-
phase OLTC whose three phases are insulated according
to the highest system voltage applied.
Today, the design limit for three-phase OLTCs with phase-
to-phase insulation is the highest voltage for equipment of
145 kV.
To reduce the phase-to-phase stresses on the delta-
OLTC the three pole mid-winding arrangement (fig. 7 c)
can be used.
19. For regulated autotransformers, the most appropriate
scheme is chosen with
regard to regulating range, system conditions and/or
requirements, as well as weight and size restrictions during
transportation. Autotransformers are always wye-connected.
20. The switching capacity itself is primarily a function of the
contact design, contact speed and arc-quenching agent.
Based on that OLTC are of two type:
1. Oil-type OLTCs
2. Vacuum-type OLTCs
Resistor oil-type OLTCs
In an oil-type OLTC, the OLTC is immersed in
transformer oil and switching contacts make and break
current under oil.
For higher ratings and higher voltages comprises a
diverter switch (arcing switch) and a tap selector.
For lower ratings, OLTC designs in which the functions of
the diverter switch (arcing switch) and the tap selector are
21. 1. With a diverter switch & a tap selector operation takes place in t
a. The next is preselected by the tap selector at no load.
b. The diverter switch then transfers the load current from the tap
operation to the preselected tap.
The OLTC is operated by means of a drive mechanism.
Switching time of a divertor switch is b/w 40 &60 ms.
Transition resistor are inserted which are loaded for 20-30 ms.
Total operation time 3-1o sec.
2. A selector switch(arcing tap switch) carries out the tap in one ste
tap in service to the adjacent tap
22.
23. Reactor oil-type OLTCs
The following types of switching are used for reactor oil-
type OLTCs:
1. Selector switch (arcing tap switch)
2. Diverter switch (arcing switch) with tap selector
24.
25.
26.
27. Technical features
The vacuum interrupter is a hermetically-sealed system.
There is no interaction with the surrounding medium, despite the arc.
The switching characteristics do not depend on the surrounding medium.
Low energy consumption.
Reduced contact wear.
Elimination of the insulating medium as the arc quenching agent.
Elimination of by-products e. g. carbon when using transformer oil.
On-line filter is unnecessary.
Easy disposal.
No aging of the quenching medium.
Constant or even improving switching characteristics throughout the entire
lifespan of the
vacuum interrupters (getter effect).
No interaction/oxidation during switching.
High rate of recondensation of metal vapour on contacts extends contact
life.
Constantly low contact resistance.
Extraordinary fast dielectric recovery of up to 10 kV/µs.
Ensures short arcing times (maximum one halfcycle) even in the case of
28.
29.
30. To select the appropriate OLTC, the following key data
of the corresponding transformer windings should be
known:
MVA rating.
Connection of tap winding (for wye, delta or singlephase
connection).
Rated voltage and regulating range.
Number of service tap positions.
Insulation level to ground.
Lightning impulse and power frequency voltage of internal
insulation.
The following OLTC operating data may be derived
from this information:
Rated through-current: Iu
31. The appropriate tap-changer can be
determined:
OLTC type
Number of poles
Nominal voltage level of OLTC
Tap selector size/insulation level
Basic connection diagram
32. During the operation of the diverter switch (arcing switch)
from the end of the tap winding to the end of the coarse
winding and vice versa, all turns of the whole tap winding and
coarse winding are inserted in the circuit.
This results in a leakage impedance value which is
substantially higher than during operation within the tap
winding where only negligible leakage impedance of one step
is relevant. The higher impedance value in series with the
transition resistors has an effect on the circulating current
which is flowing in the opposite direction through coarse
winding and tap winding during diverter switch operation.
Consequently a phase shift between switched current and
recovery voltage takes place at the transition contacts of the
diverter switch and may result in an extended arcing time.
In order to ensure optimal selection, it is necessary to
33.
34.
35.
36.
37.
38. Reduction of power losses
Voltage profile enhancement
Voltage stability
The tap changing transformer is connected at the load terminal, its
tap ratio is ‘t’. Transformer reactance at unity off-nominal tap ratio
The approximate voltage drop formula is
System voltages and impedance referred to the system load side a
respectively
39.
40. Voltage value of sec. terminal of transformer can be
regulated using tap changer. This regulation also affects
the calculation of the thevenin equivalent parameters.
Changes of equivalent parameters cause a change of
voltage stability conditions.
41. In the radial distribution system, each radial feeder is
divided into load sections with a tap changing transformer at
the beginning of the distribution network. However, there is the
need to find the tap setting of the substation transformer that
would give minimum distribution loss while satisfying the
operating constraints under a certain load pattern. These
operating constraints are voltage drop, current capacity and
radial operating structure of the system. The mathematical
formulation for the minimization of power loss tap changer
problems is