Motors use electromagnetic induction to convert electrical energy into mechanical energy. AC motors have a stationary stator and rotating rotor that interact via magnetic fields generated by alternating currents. DC motors consist of an armature winding and stator winding, with the armature acting as the rotor. Motor starters are used to control motor speed and current during starting to prevent damage. Common motor starters include magnetic, full-voltage, reversing, reduced-voltage, and solid-state starters. Reduced-voltage starters gradually apply voltage during starting for smoother acceleration.
The single-phase motor, which are designed to operate from a single-phase supply, are manufactured in a large number of types to perform a wide variety of useful services in home, offices, factories, workshops and in a business establishments etc.
Small motors, particularly in the frictional kW sizes are better known than any other. In fact, most of the new products of the manufacturers of space vehicles, aircrafts, business machines and power tools etc. have been possible due to of the advances made in the design of frictional kW motors. Since the performance requirements of the various applications differ so widely, the motor manufacturing industry has developed many different types of such motors, each being designed to meet specific demands.
Single-phase motors may be classified as under, depending on their construction and method of starting:
1. Induction Motors (split-phase, capacitor and shaded-pole etc.)
2. Repulsion Motors (sometime called inductive-series motor)
3. AC Series Motor, and
4. Un-excited Synchronous Motors
The single-phase motor, which are designed to operate from a single-phase supply, are manufactured in a large number of types to perform a wide variety of useful services in home, offices, factories, workshops and in a business establishments etc.
Small motors, particularly in the frictional kW sizes are better known than any other. In fact, most of the new products of the manufacturers of space vehicles, aircrafts, business machines and power tools etc. have been possible due to of the advances made in the design of frictional kW motors. Since the performance requirements of the various applications differ so widely, the motor manufacturing industry has developed many different types of such motors, each being designed to meet specific demands.
Single-phase motors may be classified as under, depending on their construction and method of starting:
1. Induction Motors (split-phase, capacitor and shaded-pole etc.)
2. Repulsion Motors (sometime called inductive-series motor)
3. AC Series Motor, and
4. Un-excited Synchronous Motors
DC Compound motors are popular due do their characteristic of good starting torque and low speed regulation. The are used in pressure blowers, pumps, industrial fan, lathes etc.
Physical Description
Mathematical Model
Park's "dqo" transportation
Steady-state Analysis
phasor representation in d-q coordinates
link with network equations
Definition of "rotor angle"
Representation of Synchronous Machines in Stability Studies
neglect of stator transients
magnetic saturation
Simplified Models
Synchronous Machine Parameters
Reactive Capability Limits
Consists of two sets of windings:
3 phase armature winding on the stator distributed with centres 120° apart in space
field winding on the rotor supplied by DC
Two basic rotor structures used:
salient or projecting pole structure for hydraulic units (low speed)
round rotor structure for thermal units (high speed)
Salient poles have concentrated field windings; usually also carry damper windings on the pole face.Round rotors have solid steel rotors with distributed windings
Nearly sinusoidal space distribution of flux wave shape obtained by:
distributing stator windings and field windings in many slots (round rotor);
shaping pole faces (salient pole)
Advantages and Disadvatages of AC/DC MotorFika Khamis
Simple explanation on advantages and disadvantages of AC and DC motor. Focusing on main point only since the slides is for presentation. Originally design by me.
DC Compound motors are popular due do their characteristic of good starting torque and low speed regulation. The are used in pressure blowers, pumps, industrial fan, lathes etc.
Physical Description
Mathematical Model
Park's "dqo" transportation
Steady-state Analysis
phasor representation in d-q coordinates
link with network equations
Definition of "rotor angle"
Representation of Synchronous Machines in Stability Studies
neglect of stator transients
magnetic saturation
Simplified Models
Synchronous Machine Parameters
Reactive Capability Limits
Consists of two sets of windings:
3 phase armature winding on the stator distributed with centres 120° apart in space
field winding on the rotor supplied by DC
Two basic rotor structures used:
salient or projecting pole structure for hydraulic units (low speed)
round rotor structure for thermal units (high speed)
Salient poles have concentrated field windings; usually also carry damper windings on the pole face.Round rotors have solid steel rotors with distributed windings
Nearly sinusoidal space distribution of flux wave shape obtained by:
distributing stator windings and field windings in many slots (round rotor);
shaping pole faces (salient pole)
Advantages and Disadvatages of AC/DC MotorFika Khamis
Simple explanation on advantages and disadvantages of AC and DC motor. Focusing on main point only since the slides is for presentation. Originally design by me.
ENERGY EFFICIENT VARIABLE SPEED HIGH POWER FACTOR THREE PHASE INDUCTION MOTOR...Journal For Research
Paper presents a new energy efficient technique of three phase AC to AC voltage control using medium frequency pulse width modulation and extinction angle control. This technique is deployed to obtain independent control on speed and power factor of the three phase induction motor, using four semiconductor controllable switches. The technique has been realized using AC freewheeling switch. Power factor (PF) of induction motor reduces as it depends on the load parameters, thus induction motor draws more current, increase stator copper losses. Increased stator copper losses of induction motor causes depreciation of power factor and efficiency. Proposed drive maintains power factor of induction motor at unity for controllable speed of the motor. Thus reduces current consumption of the motor at low speeds. Stator copper losses also reduce and efficiency of the motor is improved. Advantage of proposed drive is its higher efficiency and unity power factor with simplicity of control. .If number of motors are driven using the proposed drive, plenty of power conservation is possible.
Speed control of Three phase Induction motor using AC voltage regulatorShivagee Raj
The role of AC Voltage Regulator in speed control of three phase Induction Motor is to vary the supply voltage which in turn, changes the speed of motor .
USE OF ARNO CONVERTER AND MOTOR-GENERATOR SET TO CONVERT A SINGLE-PHASE AC SU...IAEME Publication
This method is used to control the speed of a three-phase induction motor by using a three-phase to three-phase cycloconverter from a single-phase supply and to compare the use of ARNO converter and motor-generator set to convert a single-phase supply to a three-phase supply. ARNO converter is a rotating device which convert single-phase AC to three-phase AC. The three-phase supply needed for the three-phase induction motors which used in blowers, exhausters an oil pumps. A motor-generator set is a device for converting electrical power to another form. They are used to convert frequency, voltage or phase of power. Thus, both ARNO converter and motor-generator set have been used here one at a time to convert a single-phase AC supply to three-phase AC. Both have their own advantages and disadvantages
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/
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.
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.
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.
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.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
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.
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.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
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.
Planning Of Procurement o different goods and services
Motors and motor starters
1. Motors & Motor Starters
Prepared By:
Erik Redd
&
Jeremy Roberts
2. Motors
AC-Motors
Parts of an Electric Motor
A. Stator : Stationary Frame
B. Rotor : Revolving Part
The rotary motion in an ac-motor is caused by the
fundamental law of magnetism.
This law states that like poles repel and unlike poles attract.
3. Diagram of an ac-motor
This shows a three
phase, two pole stator.
Where A, B, and C are
the three phases
4. Diagram of the Three Phases
Fig. 13-2 Pg. 244
Poles 1 and 4 are at their greatest magnetic field at
time equal to one, because phase A (red line) is
connected to those poles, and the same for the
other poles when their corresponding phases are at
maximum current magnitude.
5. Synchronous Speed
Speed at which it takes the motor to go one cycle and
one revolution.
S=[120*frequency}]
(# poles)
Example:
For a three-phase, 60 Hertz, 2 pole motor:
S=[120*60]/2=3600 revolutions per minute
6. Polyphase Squirrel-Cage
Induction Motors
• The most common three-phase
motor
• Does not have solid poles
• Instead, it has laminations:
numerous flat sheets held together
in a package. They are insulated
from each other (this reduces Eddy
currents) making up the stator
• The difference between induction
and synchronous motors is that the
rotor for an induction motor can
travel at a different speed than the
stator. This is called Slip.
• slip= Syn. rpm – Motor rpm *100
Syn. rpm
7. Example.
A 2 pole, 60 Hz motor runs at a full-load
speed of 1760 rpm.
What is the slip?
9. Single-Phase Motors
Supplied by single source of ac voltage
Rotor must be spun by hand in either direction,
does not have a starting mechanism
Has no starting torque
Three different types of single-phase motors: split-
phase, capacitor start, permanent split-capacitor,
and shaded-pole motors
10. Resistance Split-Phase Motors
Has a start winding and a main
winding
Winding currents are out of
phase by 30 degrees, this
produces a flux field that starts
the motor
• Main winding current (IM) and
start winding current (IS) lags
supply voltage (VL)
Start (inrush) current is high
Needs centrifugal starting
switch or relay to disconnect
the start winding (protects it
from over heating)
Efficiency is between 50-60%
11. Capacitor-Start Motors
Has the same winding and
switch mechanism arrangement
as split-phase but adds a short
time-rated capacitor in series
with the start winding
The time shift phase between
the main and start winding is
close to 90 degrees
IS leads VL
Efficiency is between 50-65%
Capacitor controls the inrush
current
12. Permanent Split-Capacitor
Motors
Winding arrangement is the
same as the capacitor and split-
phase motors
Capacitor can run continuously,
rated in microfarads for high-
voltage ratings
No centrifugal switch is needed
IM lags VL, while IS leads VL
• Efficiency is between 50-70%
13. Shaded Pole Motors
Simple construction, least
expensive
Has a run winding only, shading
coils are used instead of the
start winding
Stator is made up of a salient
pole, one large coil per pole,
wound directly in a single large
slot
A small shift in the rotor causes
torque and starts the motor
Efficiency is between 20-40%
14. DC Motors
• Consists of an armature winding and a stator
winding
• Armature windings act as the rotor
• Has three different classifications: constant torque,
constant horsepower, or a combination of the two
• Standard industrial dc motors are shunt wounded
• Modifications of the dc motor are: shunt wound,
stabilized shunt exciting fields, compound wound
motors, and series wound motors
15. Armature Voltage Control
Is used for motor speeds below base speed
Output torque= T=k*ø*IA
k is machine constant
ø is the main pole flux
IA is the armature current
16. Shunt Field Control
Is used for motor speeds above base speed
Horsepower, (HP)= Torque*rpm
5252
Where torque is in lb-ft
18. Brushless DC Motors
Three phase ac power is converted into dc
by the input side of the motor to charge up a
bank of storage capacitors
These capacitors are called the Buss
The purpose of the buss is to store energy
and supply dc power to transistors in the
output side as the motor requires the power
to start up
19. Brushless DC Motors
Figure 13-21, page 264 shows the input power
section
It consists of three fuses, six diodes, a choke, and
two capacitors
The fuses protect the diodes
The choke protects against line transients
The motor control may run at very low speeds at
very high torques while drawing little current from
the ac line
20. Brushless DC Motors
This picture is a
representation of the
encoders (rotor part of
the motor) telling the
corresponding
transistors (stator) to
turn on in order to get
maximum torque from
the motor
22. Motor Control Starters
Motor will draw high inrush current while the
starter will slow current down
Starter reduces the amount of torque needed to
start the motor
23. Magnetic Motor Starter
Normally open contacts
Not always possible to control amount of
work applied to the motor
Has overloads
– Motor may be overloaded resulting in damage
to the motor
– Open due to excessive motor current, high
temperature, or a combination of both
25. Reversing Motor Starter
Contains two starters of equal size
Two starters connect to the motor
Interlocks are used to prevent both starters from
closing their line contacts at the same time
Figure 14-4A
26. Reduced-voltage Motor Starter
Applies a percentage of the total voltage to start
(50% - 80%)
After motor rotates, switching is provided to apply
full voltage
Torque will be reduced when starting
Four types:
1) Autotransformer
2) Primary Resistance
3) Wye – Delta
4) Part Winding
27. Autotransformer Starter
Two contactors are used:
1) Start contactor
- Closes first and connects motor to the line
through an autotransformer
- Deenergizes
2) Run contactor
- Motor switches to this contacter which has
full voltage
28. Primary Resistor Starter
Two contactor
1) Line contactor
- First to energize connecting motor to the
line voltage through a resistor
- After preset time, contactor opens
2) Accelerating contactor
- Energizes
- Causes smooth acceleration to full voltage
29. Wye – Delta Starter
Three contactors are used
1) Line contactor and start contactor
- Energizes first and connects motor in wye
putting about 58% of line voltage across
each motor phase
- Contacts open after preset time
2) Run contactor
- Energizes connecting motor in delta and
putting full voltage on the motor
30. Part Winding Starter
Starter supplies about 48% of normal starting torque
Not truly a reduced-voltage means
Two Types
1) Two-Step - one winding connected to
full voltage line and, after a preset time,
the other connects
2) Three-Step – one winding is connected in series
with a resistor to the voltage line; after interval, resistor
is shorted out and then second line is connected to
full voltage line
31. Solid-State Motor Starter
For lower starting
torque and smooth
acceleration
Used on conveyors,
pumps, compressors,
etc.
32. Standard Modes of Operation
Motor voltage gradually increases during
acceleration
Creates a kick start pulse of 500% of full
load amperage for high friction
Used when necessary to limit current
Used when motor requires a full voltage
start