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1Electric Machinery
Chapter 1Introduction to Machinery
Principles
Edit by Chi-Shan Yu
3Electric Machinery
Text book and supplementary materials of this course
• Stephen J. Chapman• , PH PTR , 5th edition
(Feb. 18, 2011), 東華書局代理
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Reference book
• A. E. Fitzgerald, Electric Machinery, McGraw-Hill , 6th edition (July 25, 2002)
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Electric Machinery
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Introduction to Electric machinery Fundamental
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Introduction to Electric machinery Fundamental
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What to learn in this course ?
• Energy Conversion schemes are the key ideas introduced in this course
• Which types of energy conversion are concerned?• Electric energy to electric energy
– Transformer
• Electric energy to mechanical energy– Motor
• Mechanical energy to electric energy– Generator
• Magnetic energy is essential !
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Course Outlines - Overview of relative electromagnetic theories
(3wks)
• Magnetic field: Ampere’s law• Magnetic flux: magnetic material, hysteresis
characteristics• Transformer: Faraday’s law, Len’s law
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Course Outlines - Overview of relative electromagnetic theories
(conti)
• Magnetic circuit• Motor/generator: Induced voltage, induced
force
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Course Outlines - Transformer (3wks)
• Ideal/non-ideal transformer• Equivalent transformer circuit• Voltage regulation, efficiency
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Course Outlines - Basic electric machine (motor/generator) theories
(3wks)
• AC machine : induction machine, synchronous machine
• DC machine : separated excited, shunt excited, series excited, compound excited
• How the motor rotates ?– Torque/speed
• How the generator to build output voltage ?– Voltage/current
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Course Outline - induction (asynchronous) machine (3wks)
• Induction motor (IM) – the most widely used ac motor in the world– Structure and operation theories of IM– Equivalent circuit of IM– Torque/speed characteristics– Basic motor control
• Induction generator (seldom used)– Output voltage control– Voltage/current characteristics
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Course Outline - synchronous machine (3wks)
• Synchronous generator (SG) – the most widely used generator in the world– Structure and operation theories of SG– Equivalent circuit of SG– Voltage/current characteristics– Parallel operation
• Synchronous motor– Operation principles– Starting of synchronous motor– Torque/speed characteristics
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History of Electric Machinery
1882Thomas A. Edison opens Pearl St. Station, NYC
DC generator, driven by steam engines
Waterwheel-driven DC generator installed in Appleton, Wisconsin
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History of Electric Machinery
1884Frank J. Sprague
produces DC motor for Edison systems
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History of Electric Machinery
1885William Stanley
develops commercially practical transformer
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History of Electric Machinery
1888
Nikola Tesla presents paper on two-phase ac
induction and synchronous motors
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Today’s development
• DC Machine– Motor– Generator
• Transformer– Single phase– Three phases
• AC Machine– Synchronous machine – motor, generator– Asynchronous machine (induction machine) – motor,
generator
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Today’s development and future trends
• Micro-step stepping motor• Permanent magnet synchronous motor
(PMSM)– Brushless dc motor (BLDCM)
• Linear motor• Reluctance motor
– Synchronous reluctance– Switched reluctance
• Ultrasonic motor• Bionic robotics• MEMS motor
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Course relation
• 碩 /博班入學與高考科目• It is the fundamental course of the electrical
engineering• Future courses
– Power electronics– Motor control– Electric motor drive– Power systems– Renewable energy– Electrical vehicle
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Chapter 1. Introduction to machinery principles
1. Rotation motion, Newton’s law and power relationships
2. The magnetic field3. Faraday’s law4. Produce an induced force on a wire5. Produce an induced voltage on a conductor6. Linear dc machine examples7. Real, reactive and apparatus power in AC
circuits
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Rotation motion, Newton’s law and power relationships
• Clockwise (CW) and Counterclockwise (CCW)– CCW is assumed as the positive direction, CW is
assumed as the negative direction.
• Linear and rotation motion– Position and angular (meter) (degree or radian)– Speed and angular speed
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Rotation motion, Newton’s law and power relationships
– relationships
– Acceleration and angular acceleration
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Torque
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Torque
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Newton’s law of rotation
1. Force
2. Torque
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Torque and Work
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Power (rate of doing work)
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Conversion between watts and horsepower
1. Watts and horsepower
2. Conversion between two units5252 / 7.04 = 746.021hp = 746W = 0.746kW
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The magnetic field
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Produce a magnetic field – Ampere’s law
1. The magnetic field is produced by ampere’s law
2. The core is a ferromagnetic material
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From the magnetic field to magnetic flux density
1. When the magnetic field is applied on a ferromagnetic material, the magnetic flux density B will be produced
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Magnetic flux density and magnetic flux
1. Magnetic flux density
2. Magnetic flux
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Magnetic Circuit – magnetomotive force
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Magnetic circuit
1. Magnetic circuit
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Electric circuit and magnetic circuit
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Reluctance in magnetic circuit
1. Series connection
2. Parallel connection
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The errors in magnetic circuit computation
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The errors in magnetic circuit computation
4. Air gap “fringing effect”
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Example 1-1
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Magnetic circuit
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MATLAB Programs
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Example 1-2
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Example 1-2
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Example 1-3
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Magnetic behavior of ferromagnetic material - Saturation
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Magnetic curve for a typical steel
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A plot of relative permeability r
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Example 1-4
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Example 1-5
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Energy loss in ferromagnetic core – hysteresis loss
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Hysteresis loop – residual flux
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The effect of magnetomotive force on the hysteresis loop
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Magnetization curve
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Hysteresis loss
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Hysteresis loss
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Faraday’s law – induce voltage from a time-varying magnetic field
1. Induced voltage magnitude and polarity
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The induced voltage polarity – Lenz’s law
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Flux and flux linkage
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Example 1-6
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Produce an induced force on a wire
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Example 1-7
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Example 1-7
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Relationship between electric-magnetic variables
• Magnetic field: Ampere’s law• Magnetic flux: magnetic material, hysteresis
characteristics• Transformer: Faraday’s law, Len’s law
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Induced voltage on a conductor
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Example 1-8
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Example 1-9
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The linear DC machine – a simple example
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Starting a linear DC machine
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Starting a linear DC machine
1. Current
2. Induced force
3. Induced voltage
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Starting a linear DC machine
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Summarize of a dc machine starting
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DC linear machine operates at no-load condition
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Linear dc motor
• While the load is applied
• The conversion power between mechanical and electrical
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Summarize of a dc motor operation
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Linear dc generator
• While the external force is applied on the moving direction
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Summarize of a dc generator operation
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Starting problem of dc linear machine
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Example 1-10
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Example 1-10
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Matlab/Simulink simulation
• Equations:– F = ilB– e = vBl– i = (Vb-e) / R– dv/dt = (F-Fload)/m
• Simulation parameters:– Vb=120V, R=0.3, l = 1m– B=0.6T, m=0.1kg– Fload=10(u-1)-20(u-2) nt
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Matlab/Simulink simulation
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Real, reactive and apparatus power in AC circuits
• Power in DC circuit
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Real, reactive and apparatus power in AC circuits
• AC source applies power to an impedance Z
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Instantaneous power
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Instantaneous power
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Average power and reactive power
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Reactive power Q and apparatus power S
1. Reactive power Q (var) is defined from instantaneous power
2. Apparatus power S (VA) is defined to represent the product of voltage and current magnitudes
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Complex power representation
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Complex power representation
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Power direction
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Power factor
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Example 1-11
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Three phase concepts
• The three phase concepts are also introduced in Appendix