Speed control in 3 phase induction motorKakul Gupta
Speed control in induction motors is required for efficient operation
Various methods of speed control through semiconductor devices:
1. Stator voltage control
2. Stator frequency control
3. Stator voltage control
4. Stator current control
5. Static Rotor Resistance Control
6. Slip Energy Recovery Control
Speed control in 3 phase induction motorKakul Gupta
Speed control in induction motors is required for efficient operation
Various methods of speed control through semiconductor devices:
1. Stator voltage control
2. Stator frequency control
3. Stator voltage control
4. Stator current control
5. Static Rotor Resistance Control
6. Slip Energy Recovery Control
Everywhere DC motors are used in large applications, the use of drives are very necessary for the smooth running and operating of these motors. The DC motor drives are used mainly for good speed regulation, frequent starting, braking and reversing.
Design factors; Limitations; Modern trends; Electrical
Engineering Materials; Space factor; Choice of Specific
Electric and Magnetic loadings; Thermal Considerations;
Heat flow; Temperature rise; Insulating Materials; Properties;
Rating of Machines; Various Standard Specifications ;
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.
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 .
Electrical drives are integral part of industrial and automation processes, particularly where precise control of speed of the motor is the prime requirement. In addition, all modern electric trains or locomotive systems have been powered by electrical drives. Robotics is another major area where adjustable speed drives offer precise speed and position control.
Breaking,Types of Electrical Braking system, Regenerative Braking, Plugging ...Waqas Afzal
Why Breaking?
Requirements for Braking
Types of Electrical Braking system
Regenerative Braking.
Plugging type braking.
Dynamic braking.
Breaking implementations at DC Motor and AC Motor
Electric Drives and Controls Unit 1 IntroductionDr.Raja R
Electric Drives and Controls
Unit 1 Introduction
Block Diagram of Electric Drive
Power Source
Power Modulator
Load
Control Unit
Sensing Unit
Motor
Classification of Electrical Drives
Advantages of Electrical Drives
Disadvantages of Electrical Drive
Applications of Electrical Drives
Everywhere DC motors are used in large applications, the use of drives are very necessary for the smooth running and operating of these motors. The DC motor drives are used mainly for good speed regulation, frequent starting, braking and reversing.
Design factors; Limitations; Modern trends; Electrical
Engineering Materials; Space factor; Choice of Specific
Electric and Magnetic loadings; Thermal Considerations;
Heat flow; Temperature rise; Insulating Materials; Properties;
Rating of Machines; Various Standard Specifications ;
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.
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 .
Electrical drives are integral part of industrial and automation processes, particularly where precise control of speed of the motor is the prime requirement. In addition, all modern electric trains or locomotive systems have been powered by electrical drives. Robotics is another major area where adjustable speed drives offer precise speed and position control.
Breaking,Types of Electrical Braking system, Regenerative Braking, Plugging ...Waqas Afzal
Why Breaking?
Requirements for Braking
Types of Electrical Braking system
Regenerative Braking.
Plugging type braking.
Dynamic braking.
Breaking implementations at DC Motor and AC Motor
Electric Drives and Controls Unit 1 IntroductionDr.Raja R
Electric Drives and Controls
Unit 1 Introduction
Block Diagram of Electric Drive
Power Source
Power Modulator
Load
Control Unit
Sensing Unit
Motor
Classification of Electrical Drives
Advantages of Electrical Drives
Disadvantages of Electrical Drive
Applications of Electrical Drives
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
5. ADVANTAGES
• FEASIBLE CONTROL CHARACTERISTICS
• AVAILABLE IN WIDE RANGE OF SPEED TORQUE
AND POWER
• HIGHER EFFICIENCY
• LOWER NOISE
• CLEANER OPERATION
• LOW MAINTENANCE REQUIREMENTS
• ELECTRIC ENERGY IS EASY TO TRANSPORT
12. GROUP DRIVE
DRIVE CONSISTS OF ONLY ONE ELECTRIC MOTOR
WHICH DRIVES SEVERAL MACHINES
ADVANTAGE
• RATING OF AN ELECTRICAL DRIVE CAN BE SMALLER
DISADVANTAGE
• IF ELECTRIC MOTOR IS SUBJECTED TO ANY FAULT ALL
THE EQUIPMENTS BECOME IDLE
• APPEARANCE IS NOT GOOD
• LAYOUT IS COMPLICATED
• ALL SYSTEM HAS LOWER EFFICIENCY
• CAUSES OF ACCIDENT
13. Individual Drives
• Most common drive. A single motor is
dedicated to each load. Applications include
hard disk drives, washers, dryers, fans.
14. INDIVIDUAL DRIVE
Advantages
• IF A SINGLE MOTOR IS USED TO DRIVE A SINGLE MACHINE AND ALL
THE MECHANISMS BELONGING TO THE SAME MACHINE.
• LAYOUT IS GOOD
• IMPROVED A POWER FACTOR
• AUTOMATIC CONTROL
• CONTROLING A SPEED IS EASY
• USER FRINDLY
• RELAIBLE DRIVE
DISADVANTAGE
• DUE TO POWER LOSS ,THE EFFICIENCY OF SUCH DRIVE IS ALSO
POOR
15. MULTIMOTOR DRIVE
• A SEPARATE MOTOR IS PROVIDED FOR
DRIVING THE SEPARATE MECHANISM
• ADVANTAGES
• INCREASE THE OVERALL PRODUCTIVITY
16. Compression of Group Drives and
Individual Drives
Sr
NO.
Points Group Drives Individual Drives
1 Capital Cost Low High
2 Efficiency Low High
3 Flexibility Low High
4 Reliability Low High
5 Speed Not Constant Constant
6 Power factor Low Good
7 Space High Low
8 Heavy load Difficult Easy
19. Components of Torque
• Frictional Torque(Tf):- When any drives rotate
then friction is produces so it oppose torque
• Windage Torque(Tw) :- When motor rotate
then it oppose a wind force
• Useful Torque :Tu= Tf - Tw
20. Different Load Characteristic
• 1. Constant torque type load.
• 2. Torque proportional to speed (generator
type load)
• 3. Torque proportional to square of the speed
(fan type load)
• 4. Torque inversely proportional to speed
(constant power type load)
33. Elevator
• A machine consisting of an endless belt with
scoops attached, used for raising grain to an
upper side for storage.
34. Types of Elevator
Elevator
Hydraulic
With Hole
Elevator
Without Hole
Elevator
With Rope
Elevator
Rope or
Traction
Elevator
With machine
elevator
Geared
Elevator
Geared
Elevator
Without
machine
Elevator
41. Advantages & Disadvantages
• Low power consumption
• Speed is good
• Cost is low
Disadvantages
• Big space
• Maintained is complex
42. Comparison
Sr no Description Hydraulic Traction
1 Capital Cost Low High
2 Maintance Cost Low High
3 Speed Low High
4 Travel Distance Very Short Very Long
5 Consumption of
energy
High Low
6 Application Only For 4 to 5
floor
High rise building
43. FACTORS AFFECTING THE SELECTION
OF DRIVE
• LIMIT OF SPEED RANGE
• EFFICIENCY
• BRAKING
• STARTING REQUIREMENTS
• POWER FACTOR
• LOAD FACTOR
• AVAILABILITY OF SUPPLY
• ECONOMICAL ASPECTS
44. SELECTION OF MOTOR BASED ON
LOAD VARIATION
• CONTINOUS LOAD
• CONTINOUS VARIABLE LOAD
• PULSATING LOAD
• IMPACT LOADS
• SHORT TIME INTERMITTENT LOAD
• SHORT TIME LOAD
45. CLASSES OF DUTY AND SELECTION OF
RATING OF MOTOR
• ONCE CYCLE OF VARIATION OF LOAD IS DUTY
• CONTINOUS DUTY
• CONTINOUS DUTY,VARIABLE LOAD
• SHORT TIME DUTY
• INTERMITTENT PERIODIC DUTY
• INTERMITTENT PERIODIC DUTY WITH STARTING
• INTERMITTENT PERIODIC DUTY WITH STARTING
AND BRAKING
46. POWER LOSSES AND HEATING OF
MOTOR
• COPPER LOSS
• CORE LOSS
• POWER LOSSES CAUSE LOCALISED HEATING
AND RESPONSIBLE FOR TEMPERATURE RISE
OF THE MOTOR
47. STEADY STATE CONDITION
• FINAL TEMPERATURE RISE IS REACHED WHEN
THE RATE OF PRODUCTION OF HEAT AND
RATE OF HEAT DISSIPATION ARE EQUAL
48. CONTINOUS RATING
• CONTINOUS RATING OF A MACHINE IS THAT
RATING FOR WHICH THE TEMPERATURE RISE
IS JUST BELOW THE PERMISSIBLE VALUE OF
TEMPERATURE RISE
49. HEATING AND COOLING CURVES
• A SMALLER TIME CONSTANT IS OBTAINED FOR
GOOD VENTILATION
• THE TIME CONSTANT IS INVERSELY
PROPORTIONAL TO SPECIFIC HEAT
DISSIPATION
• COOLING TIME CONSTANT IS THE TIME
REQUIRED TO COOL THE MACHINE
50. SELECTION OF POWER RATING FOR
DRIVE MOTORS
• CONTINOUS LOAD
• CONTINOUS RATING SPECIFIES THE
MAXIMUM LOAD THAT THE MOTOR CAN TAKE
OVER A PERIOD FOR TIME
• CONTINOUS VARIABLE LOAD
• CLASS OF DUTY IS SELECTED ON BASED ON
AVERAGE POWER OR CURRENT
51. SELECTION OF MOTOR FOR
INDUSTRIAL APPLICATIONS
• STEEL ROLLING MILLS
• DC MOTOR WITH WARD LEONARD SYSTEM
• AC COMMUTATOR MOTORS
• ACCURATE TORQUE AND SPEED CONTROL
52. CRANES AND HOISTS
• SERIES MOTORS
• GOOD STARTING TORQUE
• ELECTRIC BRAKING AT LOW SPEED IS POSSIBLE
53. TEXTILE INDUSTRY
• MODERATE STARTING TORQUE
• CONSTANT SPEED
• HIGH TORQUE SQUIRREL CAGE INDUCTION
MOTOR IS PREFFERED
54. COAL AND MINNING INDUSTRY
• COAL CUTTING OR DRILLING REQUIRES
COSTANT SPEED AND HIGH STARTING TORQUE
• SQUIRREL CAGE MOTORS ARE PREFFERED
• CENTRIFUGAL PUMPS ARE USED IN MINNING
FOR PUMPING WATER.
• HIGH TORQUE SQUIRREL CAGE ARE SELECTED
55. IMPORTANT QUESTIONS -TWO MARKS
• DRAW THE FUNCTIONAL FUNCTIONAL
DIAGRAM OF AN ELECTRICAL DRIVE SYSTEM
• GIVE ANY TWO FACTORS THAT INFLUENCE THE
CHOICE OF ELECTRICAL DRIVES
• MENTION THE USAGE OF DIFFERENT TYPES OF
MOTORS WITH APPLICATION IN TEXTILE MILL
• WHAT IS MEANT INTERMITTENT DUTY
• LIST ANY FOUR ADVANTAGES OF ELECTRIC
DRIVES
56. IMPORTANT QUESTIONS -TWO MARKS
• WHAT IS MEANT BY ELECTRIC DRIVE
• DEFINE CONTINOUS RATING OF A MOTOR
• WHAT IS OVERLOAD CURRENT CAPABILITY OF
MOTOR
• DEFINE COOLING TIME CONSTANT OF A
MACHINE
• NAME ANY FOUR CLASSES OF DUTY
57. IMPORTANT QUESTIONS -SIXTEEN
MARKS
• DERIVE AN EXPRESSION FOR A THERMAL
MODEL OF MOTOR FOR HEATING AND
COOLING.ALSO DRAW THE HEATING AND
COOLING CURVE
• EXPLAIN THE DIFFERENT CLASSES OF MOTOR
DUTY WITH NEAT SKETCH
• EXPLAIN THE VARIOUS FACTORS INFLUENCING
THE CHOICE OF ELECTRICAL DRIVE
59. COMPARISON BETWEEN AC AND DC
DRIVE
S.NO D.C.DRIVE A.C DRIVE
1 SPEED TORQUE CAN BE ACHIEVED EASILY IT IS NOT EASTY TO ADJUST
SPEED TORQUE CURVES
2 SELF STARTING NOT SELF STARTING
3 FREQUENT MAINTENANCE IS REQUIRED LESS MAINTENANCE
4 COSTLY CHEAPER
5 RECTIFYING CIRCUIT IS NECESSARY NO NEED
60. FOUR QUADRANT OPERATION
QUADRAN
T
POLARITY OF
VOLTAGE
POLARITY OF
CURRENT
NATURE OF OPERATION
I POSITIVE POSITIVE FORWARD MOTORING
II POSITIVE NEGATIVE FORWARD REGENERATION
III NEGATIVE NEGATIVE REVERSE MOTORING
IV NEGATIVE POSITIVE REVERSE REGENERATION
