1 Electric Machinery Chapter 1 Introduction to Machinery Principles Edit by Chi-Shan Yu.

1Electric Machinery

Chapter 1Introduction to Machinery

Principles

Edit by Chi-Shan Yu

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Instructor

• 俞齊山 (Chi-Shan Yu), • E-mail: [email protected]

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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