The document discusses interpoles, also known as commutating poles, in direct current (DC) machines. Interpoles are narrow poles placed between the main poles of a DC machine that carry windings connected in series with the armature. Their purpose is to counter the distorting and weakening effects of armature reaction on the magnetic flux. Specifically, the magnetomotive force produced by the interpole windings is designed to be equal and opposite to the magnetomotive force of the armature reaction, thereby nullifying its effects and allowing commutation to occur without shifting the brushes. While interpoles only neutralize armature reaction in the narrow brush zone, their use significantly improves machine performance and allows for higher voltage,
Effect of non sinusoidal waveform of a.c. machine performancevishalgohel12195
Effect of Non sinusoidal waveform of A.C. Machine performance
Nonsinusoidal Waveforms
Key Similarities and Differences between Sinusoidal and Nonsinusoidal Waveforms
Effect of harmonics in motor drives
Square wave inverter with 180° mode
Effect of leakage reactance on the harmonic content of current
Parasitic torques due to non-sinusoidal voltages
The project focuses on the harmonic analysis of transformer during the switching transient period. Measuring fundamental and second harmonics of differential current, an algorithm based on the Discrete Fourier Transform and an amplitude estimator are used to simulate and list various harmonic components of current and flux. Generalized functions for describing the relationships between resultant flux and harmonic components are derived. This is important to find these relations for further use in detecting non-linearity and elimination of harmonic components.
This report gives an overview of patenting activity around Doubly-fed Induction Generators (DFIG) used in the horizontal axis wind turbines for efficient power generation. Patents were categorized as per key DFIG technologies and analyzed for generating different trends within PatSeer Project.
Effect of non sinusoidal waveform of a.c. machine performancevishalgohel12195
Effect of Non sinusoidal waveform of A.C. Machine performance
Nonsinusoidal Waveforms
Key Similarities and Differences between Sinusoidal and Nonsinusoidal Waveforms
Effect of harmonics in motor drives
Square wave inverter with 180° mode
Effect of leakage reactance on the harmonic content of current
Parasitic torques due to non-sinusoidal voltages
The project focuses on the harmonic analysis of transformer during the switching transient period. Measuring fundamental and second harmonics of differential current, an algorithm based on the Discrete Fourier Transform and an amplitude estimator are used to simulate and list various harmonic components of current and flux. Generalized functions for describing the relationships between resultant flux and harmonic components are derived. This is important to find these relations for further use in detecting non-linearity and elimination of harmonic components.
This report gives an overview of patenting activity around Doubly-fed Induction Generators (DFIG) used in the horizontal axis wind turbines for efficient power generation. Patents were categorized as per key DFIG technologies and analyzed for generating different trends within PatSeer Project.
Objectives: This course will provide a comprehensive overview of power system stability and control problems. This includes the basic concepts, physical aspects of the phenomena, methods of analysis, the integration of MATLAB and SINULINK in the analysis of power system .
Course Content: 1. Power System Stability: Introduction
2. Stability Analysis: Swing Equation
3. Models for Stability Studies
4. Steady State Stability
5. Transient Stability
6. Multimachine Transient Stability
7. Power System Control: Introduction
8. Load Frequency Control
9. Automatic generation Control
10. Reactive Power Control
A synchronous motor is electrically identical with an alternator or AC generator.
A given alternator ( or synchronous machine) can be used as a motor, when driven electrically.
Some characteristic features of a synchronous motor are as follows:
1. It runs either at synchronous speed or not at all i.e. while running it maintains a constant speed. The only way to change its speed is to vary the supply frequency (because NS=120f/P).
2. It is not inherently self-starting. It has to be run up to synchronous (or near synchronous) speed by some means, before it can be synchronized to the supply.
3. It is capable of being operated under a wide range of power factors, both lagging and leading. Hence, it can be used for power correction purposes, in addition to supplying torque to drive loads.
Thank you very much for checking out my presentation.
If you are a student or a faculty of an engineering college and need to create a presentation, you can contact me. Check out my profile to know how.
This presentation explains about the parallel operation of transformers, along with sym. and unsym. voltage ratios, in brief.
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Current Transformer and Potential TransformerRidwanul Hoque
One of the major difference between them is that the current transformer converts the high value of current into low value whereas the potential or voltage transformer converts the high value of voltages into low voltage.
Winding
What is Armature winding?
Terms related to armature winding.
Single layer and double layer windings.
Comparison between closed and open windings.
Types of DC armature winding.
Types of AC armature winding.
Objectives: This course will provide a comprehensive overview of power system stability and control problems. This includes the basic concepts, physical aspects of the phenomena, methods of analysis, the integration of MATLAB and SINULINK in the analysis of power system .
Course Content: 1. Power System Stability: Introduction
2. Stability Analysis: Swing Equation
3. Models for Stability Studies
4. Steady State Stability
5. Transient Stability
6. Multimachine Transient Stability
7. Power System Control: Introduction
8. Load Frequency Control
9. Automatic generation Control
10. Reactive Power Control
A synchronous motor is electrically identical with an alternator or AC generator.
A given alternator ( or synchronous machine) can be used as a motor, when driven electrically.
Some characteristic features of a synchronous motor are as follows:
1. It runs either at synchronous speed or not at all i.e. while running it maintains a constant speed. The only way to change its speed is to vary the supply frequency (because NS=120f/P).
2. It is not inherently self-starting. It has to be run up to synchronous (or near synchronous) speed by some means, before it can be synchronized to the supply.
3. It is capable of being operated under a wide range of power factors, both lagging and leading. Hence, it can be used for power correction purposes, in addition to supplying torque to drive loads.
Thank you very much for checking out my presentation.
If you are a student or a faculty of an engineering college and need to create a presentation, you can contact me. Check out my profile to know how.
This presentation explains about the parallel operation of transformers, along with sym. and unsym. voltage ratios, in brief.
What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing What is Power Swing | Power Swing
Current Transformer and Potential TransformerRidwanul Hoque
One of the major difference between them is that the current transformer converts the high value of current into low value whereas the potential or voltage transformer converts the high value of voltages into low voltage.
Winding
What is Armature winding?
Terms related to armature winding.
Single layer and double layer windings.
Comparison between closed and open windings.
Types of DC armature winding.
Types of AC armature winding.
CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
It consists of cw radar and fmcw radar ,range measurement,if amplifier and fmcw altimeterThe CW radar operates using continuous wave transmission, while the FMCW radar employs frequency-modulated continuous wave technology. Range measurement is a crucial aspect of radar systems, providing information about the distance to a target. The IF amplifier plays a key role in signal processing, amplifying intermediate frequency signals for further analysis. The FMCW altimeter utilizes frequency-modulated continuous wave technology to accurately measure altitude above a reference point.
Water billing management system project report.pdfKamal Acharya
Our project entitled “Water Billing Management System” aims is to generate Water bill with all the charges and penalty. Manual system that is employed is extremely laborious and quite inadequate. It only makes the process more difficult and hard.
The aim of our project is to develop a system that is meant to partially computerize the work performed in the Water Board like generating monthly Water bill, record of consuming unit of water, store record of the customer and previous unpaid record.
We used HTML/PHP as front end and MYSQL as back end for developing our project. HTML is primarily a visual design environment. We can create a android application by designing the form and that make up the user interface. Adding android application code to the form and the objects such as buttons and text boxes on them and adding any required support code in additional modular.
MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software. It is a stable ,reliable and the powerful solution with the advanced features and advantages which are as follows: Data Security.MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software.
The Internet of Things (IoT) is a revolutionary concept that connects everyday objects and devices to the internet, enabling them to communicate, collect, and exchange data. Imagine a world where your refrigerator notifies you when you’re running low on groceries, or streetlights adjust their brightness based on traffic patterns – that’s the power of IoT. In essence, IoT transforms ordinary objects into smart, interconnected devices, creating a network of endless possibilities.
Here is a blog on the role of electrical and electronics engineers in IOT. Let's dig in!!!!
For more such content visit: https://nttftrg.com/
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
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.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
2. Concept of armature reaction
• In dc machine, unloaded condition magneto
motive force (mmf) acting in a dc generator is
that due to the field. However, when it loaded
the current flowing in the armature coils also
creates a powerful magnetomotive force that
distorts and weakens the flux coming from the
poles. This distortion and field weakening
takes place in both motors and generators.
The effect produced by the armature mmf is
called armature reaction.
3.
4.
5. Interpoles or Commutating poles
• To counter the effect of
armature reaction in
medium and large-
power dc machines, we
always place a set of
commutating
poles/Inter poles
between the main poles
6. Interpoles (continued)
• These narrow poles carry windings that are connected
in series with the armature.
• The number of turns on the windings is designed so
that the poles develop a magnetomotive force (mmfc)
equal and opposite to the magnetomotive force
(mmfa), of the armature.
• As the load current varies, the two magnetomotive
forces rise and fall together, exactly bucking each other
at all times. By nullifying the armature mmf in this way,
the flux in the LpaCe between the main poles is always
zero and so we no longer have to shift the brushes.
7. Interpoles (continued)
• In practice, the mmf of the commutating poles is
made slightly greater than the armature mmf.
• This creates a small flux in the neutral zone,
which aids the commutation process.
• In the figure 1 shows how the commutating
poles of a 2-pole machine are connected. Clearly,
the direction of the current flowing through the
windings indicates that the mmf of the
commutating poles acts opposite to the mmf of
the armature and, therefore, neutralizes its
effect.
8. Why not other methods
• Other methods to compensates Armature
reaction are
1. High reluctance pole tips
2. Reduction of armatures flux
3. Compensating windings/pole face windings/
Thompson Ryan windings
9. Advantages of Interpoles (continued)
• Both high reluctance pole tips & reduction in
armature flux are mechanical techniques have
major disadvantages in that they do not inter act
the effects of high armature currents and MMF
due to heavy loads.
• Compensating Winding Disadvantages is winding
neutralizes the cross magnetizing effect due to
armature conductors only but not due to
interpolar region. This winding is used in large
machine in which load is fluctuating.
10. Advantages of Interpoles (continued)
• Compensating winding and interpoles are
used for same purpose but the difference
between them is, interpoles produce e.m.f for
neutralizing reactance e.m.f whereas
compensating winding produces an m.m.f
which opposes the m.m.f produced by
conductors.
11. Disadvantages of interpoles
• However, the neutralization is restricted to the
narrow brush zone where commutation takes
place. The distorted flux distribution under
the main poles, unfortunately, remains the
same.
12. Discussion
• Another method of providing the necessary “reversing
field" is to fit special commutation poles to the frame
of the machine. These poles are placed midway
between the main poles, and are excited in such a
manner as to produce a commutation field of the
required polarity and strength.
• For a generator, to assist the reversal of the current
the polarity of the interpole must obviously be the
same as that of the main pole in advance
• For a motor, on the other hand the converse will be
true.
13. Discussion
• Again, since the reactance e.m.f. increases in
direct proportion to the current, the reversing
field must increase in the same pro portion.
This involves the interpole windings being
connected in series with the armature.
14. Discussion
• It will be noted that the reversing field required is of
opposite polarity to that which armature reaction tends to
establish. If, in fact, the interpoles were not excited,
commutation would be seriously impaired.
• By arranging that the m.m.f. developed by the interpole is
exactly equal and opposite to that of armature reaction,
commutation would take place in the magnetic neutral
position, and there would be no reversing field. In short, to
establish a reversing field under the interpole shoe, it is
essential that the m.m.f. developed by the interpole
winding shall overpower that due to armature reaction, the
flux established being determined by the difference of the
magnitude of these two m.m.f.
15. Discussion
• The interpole winding is local in its action. That is
to say, the winding develops an m.m.f. which
overcomes armature reaction in the commutating
zone only.
• Thus the distortion of the main field under the
pole shoes is not affected by the use of
interpoles. This is illustrated by Figure, which
gives the resulting field form for a loaded
interpole machine and indicates that, in a
generator, the interpoles act as outposts of the
main poles.
16.
17. More discussion on interpoles
• By the use of these series-wound interpoles it then become
possible to obtain satisfactory commutation with brushes in
a fixed position—the geometric neutral—under all
conditions of load.
• Further, in motors, satisfactory commutation becomes
possible with fixed brushes for both directions of rotation,
and over a considerable range of speed obtained by field
control.
• More important still, with interpole it has been made
possible to construct machines, such as relatively high
voltage and high speed machines, which could not possibly
be built to operate satisfactorily without interpoles.
18. More discussion on interpoles
(continued)
• In fact, until interpoles were used, the rated
output of d.e. machinery was quite often
proscribed solely from sparking Con siderations.
• With interpoles, temperature rise practically
alway determines the rated output, so that it has
become possible to increase very considerably
the rated output of machines of gjven
dimensions, and to take full advantage of the
more intensive methods of ventilation now
commonly employed.
19. More discussion on interpoles
(continued)
• This vastly improved performance and, often, vastly
increased rating, is then obtained at the expense of
building, assembling, and fitting the interpoles and
their relatively powerful coils. The extra expense
moreover, is partly compensated by the fact that it is
not necessary with interpole machines to work with
such strong field windings on the main poles as in non-
interpole machines. In fact, the air gap can be reduced
to a figure not much in excess of the minimum
necessitated by mechanical reasons. The advantages
gained bv the use of interpoles are so great that it is
standard practice always in employ interpoles except
for very small machines.