Generation, transmission and distribution, as well as power supplied to industrial and commercial customers uses a 3 phase system.
|
|
- Mavis Holland
- 5 years ago
- Views:
Transcription
1 Three-phase Circuits Generation, transmission and distribution, as well as power supplied to industrial and commercial customers uses a 3 phase system. Where 3 voltages are supplied of equal magnitude, but 120 out of phase. an 0 an bn cn cn I c ab cn bn bn 120 I b θ I a an bn Why? fewer conductors, less loss a) Economic advantages (at higher power, lower $ / kw than single-phase) b) Operational advantages (rotating machinery; constant instantaneous power, constant torque developed at shaft and less vibration) 77
2 (For s.s. analysis) We will mostly be dealing with balanced 3-phase systems (quantities of equal magnitude but displaced by 120 with balanced loads). Loads can be naturally balanced, like 3 phase machinery / loads or designed to be balanced (all large loads 3 balanced, 1 are averaged to balance out). Distribution to an office building is 3-phase, while the individual loads (outlets, lights, PC s etc) are 1-phase. In this case, during the design phase, care is taken to balance the load (e.g. one phase per floor/ branch circuit). 78
3 Generation of 3-phase voltages (Only scratch the surface, more details in ECE 331, 432, 433 ). 3 synchronous generators are commonly used for power generation (see next page). The rotor with dc current excitation is moved by the prime mover (steam or hydro turbine etc). The dc current creates a magnetic field, which is now rotating by the force of the prime mover, thus establishing a time-varying magnetic field. This magnetic field flux (magnetic field lines) links the stationary stator windings, and a voltage is induced according to Faraday s law: e dλ dt N d dt λ flux linkage associated with a winding N number of turns total winding flux 79
4 The generator is designed to ensure sinusoidal induced voltages. Since the three stator winding axes are 120 displaced ( in space) the resulting three voltage waveforms are also displaced by 120 (in time). The 3 windings can be connected in either wye ( Υ ) or delta ( Δ ). Of course the 3 voltages are of the same frequencies, We represent them as phasors where the reference of time zero is chosen for convenience. 80
5 81
6 82
7 83
8 84
9 an, bn, cn Have equal magnitudes Displaced by 120deg Source Imp. Z ga Z gb Z gc an cn n Z ga bn I a I b Z gb Z la a line impedance b Z lb B Z B Z In a balanced system I a + I b + I c 0 I n n and N are at the N same potential Z la Z lb Z lc Z Z B Z C Z gc I n Z C I c c Z lc C 85
10 Typical Building Power Distribution Scheme Delta/Wye Distribution Transformer For Top Floor 3 Distribution Panel Load N G N G Power Feeder Branch Circuit Three Phase Bus Delta/Wye Distribution Transformer For First Floor 3 Distribution Panel Load N N G G Power Feeder Branch Circuit Three Phase Supply From Utility Mains Three Phase Stepdown Transformer In Building Basement B C 86
11 Note that the phase sequence a c, b, is also possible (negative sequence). lso note that: an + bn + cn 0, which also implies for the instantaneous voltages: van ( t) + vbn ( t) + vcn ( t) 0. (i.e. 3 sinusoids of the same magnitude and frequency, but displaced 120, add up to zero.) This also means that a balanced 3-phase set can be described by 2 quantities since c a b oltage sources and loads can be connected in wye or delta, i.e. we have the following combinations: Source Load Line 87
12 Let s consider a Υ / Υ system in more detail a Z la I a Z ga Z I b an bn cn n Z gb b Z lb B Z B N Z gc I n Z C I c c Z lc C 88
13 For a balanced 3 circuit: 1. an by, bn, cn are a set of balanced 120 ). 2. Z ga Z gb Z gc (Source impedance is same) 3 voltages (equal magnitude displaced 3. Z la Zlb Zlc (Line impedance is same) 4. Z Z B ZC (Load impedance is same) 5. I a, I b, Ic are a set of balanced 3 currents. I a + Ib + Ic 0 In neutral current 0 and the neutral can be omitted. Balanced 3-phase circuits are more easily analyzed by considering only one phase. ( if Δ load converted to a Υ ) to get neutral point N In analyzing 3 circuits, first construct 1 equivalent, converting all Δ ' s to Υ ' s ( Δ Z ). Υ Z 3 89
14 Per phase equiv. a' Z ga a Zla Δ Z Z Υ 3 cn I c a'n I a Z I b θ I a an n N bn Now it is easier to see that I a ' a n I Z + + a ga Z la Z Z p θ, and I Z most likely lagging Other two currents are ' I θ 120 ± 120 displaced ' I θ b n c n I b, I c Z Z p Z p Z 90
15 With this Υ circuit, we have worked with phase voltages (referred to the neutral) and line currents (equal to the phase currents in a wye configration) However, oftentimes the wye neutral point is not accessible. We can t use the phase voltages. This of course is true for Δ circuits as well. So we need to define quantities, which are accessible from the terminals. The line (or line-to-line) voltage,, ab bc ca cn ab Where ab an bn L 30 bc L ( ) L ca L ( ) L Summarize line vs. phase. phase notation or p line voltage, or line-to-line voltage bn an B N bn 91
16 Wye: line Delta line I C B C I I I B B N phase phase N C I I N B I B B phase voltage θ line voltage 3 ( ) L (0 line current phase current I I θ I L θ θ + 30 phase voltage line voltage Δ 30 L 30 phase current I I Δ θ Δ B θ Δ θ Δ line current Δ Δ Δ 3I ( θ 30 ) I ( θ 30 ) I Note Z y Z Δ /3 L Z Δ ) 30 I B I C I I B + I C I BC I 92
17 Example: The magnitude of the phase voltage of an ideal balanced threephase Y-connected source is The source is connected to a balanced Y-connected load by a distribution line that has an impedance of 1+j8Ω/. The load impedance is 119+j27Ω/. The phase sequence of the source is abc. Use the a-phase voltage of the source as the reference. Specify the magnitude and phase angle of the following quantities: (a) the three line currents, (b) the three line voltages at the source, (c) the three phase voltages at the load, and (d) the three line voltages at the load ref. Υ a n I a 1Ω j8ω all per phase N Υ 119Ω j27ω 93
18 Polar form of a) The 3 line currents, Υ connected, line current phase current I I I a b c j35 (sum of Z s) 32 ( ) ( ) b) the 3 line voltages at the source L ab bc ca 3 ( (4000) ) ( ) ( ) c) the 3 phase voltages at the load I ( j27) (or 4000 (1 + j8) N BN CN a d) the 3 line voltages at the load B BC C ( ) a I ) 94
19 Power in Balanced 3 Circuits (So far we have discussed only voltage and current in 3 systems.) Start with Balanced Υ load - will be using all rms quantities. I a I bb I cc B + C Z B BN Z Z C + N + N CN We can calculate the average power associated with each phase by using the same techniques as used for 1. I B N a line to line, or just line phase, or line to neutral voltage phase and line current 95
20 The average power associated with phase- is: P P P B C (if not rms, have 2 1 here) ( θ Z L phase angle of the phase quantities, angle of the load impedance per phase) I cos( θ θ ) (see power summary) N, rms a, rms v i (only magnitude, since we are only after a real number) θ Z L BN I bb cos( θ vb θ ib ), θ Z L I cos( θ θ ) CN cc vc ic Where N BN CN, voltage magnitudes same ( I I I I a bb cc current magnitudes same ( 120 apart) 120 apart) θ θ Z L θ v θ i θ vb θ ib θ vc θ ic 96
21 Thus power delivered to each phase of the load is the same. P P P P I cosθ θ θ ) B C ( v i The total average power delivered to the balanced Υ connected load P T (not a function of time) P 3 I cosθ constant 3 ve power per phase Important in motors where the shaft power is a constant and there are no torque pulsations. It is very useful to express in terms of rms line quantities (accessible!) 97
22 Where L rms line voltage( B in diagram) I rms linecurrent phasecurrent L P T 3 L 3 I L cosθ 3 LI L cosθ phase angle between the phase voltage and current NOT between L and I L The same holds true for Reactive Power Q. The reactive power Q associated with each phase is: Q I sinθ Q T 3Q 3 L I L sineθ The complex power S associated with each phase is: S I * P + jq ST 3 S 3L I L magnitude θ 98
Three Phase Circuits
Amin Electronics and Electrical Communications Engineering Department (EECE) Cairo University elc.n102.eng@gmail.com http://scholar.cu.edu.eg/refky/ OUTLINE Previously on ELCN102 Three Phase Circuits Balanced
More informationLO 1: Three Phase Circuits
Course: EEL 2043 Principles of Electric Machines Class Instructor: Dr. Haris M. Khalid Email: hkhalid@hct.ac.ae Webpage: www.harismkhalid.com LO 1: Three Phase Circuits Three Phase AC System Three phase
More informationChapter 2-3 Transformers
Principles of Electric Machines and Power Electronics Chapter 2-3 Transformers Third Edition P. C. Sen Auto transformer Per unit system S b = S rate V b1 = V rate1 V b2 = V rate2 S b I b1 = = S rate =
More informationTHREE-PHASE CIRCUITS
THR-HAS CIRCUITS 4.1 Introduction Generation, Transmission and distribution of electricity via the National Grid system is accomplished by three-phase alternating currents. The voltage induced by a single
More informationECE 420. Review of Three Phase Circuits. Copyright by Chanan Singh, Panida Jirutitijaroen, and Hangtian Lei, For educational use only-not for sale.
ECE 40 Review of Three Phase Circuits Outline Phasor Complex power Power factor Balanced 3Ф circuit Read Appendix A Phasors and in steady state are sinusoidal functions with constant frequency 5 0 15 10
More informationTHREE PHASE SYSTEMS Part 1
ERT105: ELECTRCAL TECHNOLOGY CHAPTER 3 THREE PHASE SYSTEMS Part 1 1 Objectives Become familiar with the operation of a three phase generator and the magnitude and phase relationship. Be able to calculate
More informationIntroduction to Synchronous. Machines. Kevin Gaughan
Introduction to Synchronous Machines Kevin Gaughan The Synchronous Machine An AC machine (generator or motor) with a stator winding (usually 3 phase) generating a rotating magnetic field and a rotor carrying
More informationChapter 12: Three-Phase Circuits
Chater 1: Three-Phase Circuits 1.1 ntroduction 1. Balanced Three-Phase oltages 1.3 Balanced Wye-Wye connection 1.4 Balanced Wye-Delta Connection 1.7 Power in a Balanced System 1.1 NTRODUCTON A single-hase
More informationEKT103 ELECTRICAL ENGINEERING
EKT13 EECTRCA ENGNEERNG Chater 1 Three-Phase System 1 COURSE OUTCOME (CO) CO1: Ability to define and exlain the concet of single-hase and threehase system. 2 Revision A sinusoid is a signal that has the
More informationLecture (5) Power Factor,threephase circuits, and Per Unit Calculations
Lecture (5) Power Factor,threephase circuits, and Per Unit Calculations 5-1 Repeating the Example on Power Factor Correction (Given last Class) P? Q? S? Light Motor From source 1000 volts @ 60 Htz 10kW
More informationBasics of Electric Circuits
António Dente Célia de Jesus February 2014 1 Alternating Current Circuits 1.1 Using Phasors There are practical and economic reasons justifying that electrical generators produce emf with alternating and
More informationConsider Figure What is the horizontal axis grid increment?
Chapter Outline CHAPER 14 hree-phase Circuits and Power 14.1 What Is hree-phase? Why Is hree-phase Used? 14.2 hree-phase Circuits: Configurations, Conversions, Analysis 14.2.1 Delta Configuration Analysis
More informationLesson 17: Synchronous Machines
Lesson 17: Synchronous Machines ET 332b Ac Motors, Generators and Power Systems Lesson 17_et332b.pptx 1 Learning Objectives After this presentation you will be able to: Explain how synchronous machines
More informationSynchronous Machines
Synchronous machine 1. Construction Generator Exciter View of a twopole round rotor generator and exciter. A Stator with laminated iron core C Slots with phase winding B A B Rotor with dc winding B N S
More informationCh 8. Three-phase systems
Ch 8. Three-ase systems Lecture outcomes (what you are supposed to learn): Generation of three-ase voltages Connection of three-ase circuits Wye-Delta transformation Power of three-ase connected loads
More informationECE 421/521 Electric Energy Systems Power Systems Analysis I 2 Basic Principles. Instructor: Kai Sun Fall 2013
ECE 41/51 Electric Energy Systems Power Systems Analysis I Basic Principles Instructor: Kai Sun Fall 013 1 Outline Power in a 1-phase AC circuit Complex power Balanced 3-phase circuit Single Phase AC System
More informationSSC-JE EE POWER SYSTEMS: GENERATION, TRANSMISSION & DISTRIBUTION SSC-JE STAFF SELECTION COMMISSION ELECTRICAL ENGINEERING STUDY MATERIAL
1 SSC-JE STAFF SELECTION COMMISSION ELECTRICAL ENGINEERING STUDY MATERIAL Power Systems: Generation, Transmission and Distribution Power Systems: Generation, Transmission and Distribution Power Systems:
More informationLecture 3: Three-phase power circuits
1/24/28 Lecture : Three-phase power circuits 1 nstructor: Dr. Gleb. Tcheslavski Contact: gleb@ee.lamar.edu Office Hours: TBD; Room 2 Class web site: MyLamar ntroduction 2 Almost all electric power generation
More informationSynchronous Machines
Synchronous Machines Synchronous generators or alternators are used to convert mechanical power derived from steam, gas, or hydraulic-turbine to ac electric power Synchronous generators are the primary
More informationTHREE-PHASE CIRCUITS. Historical Profiles
C H A P T E R THREE-PHASE CIRCUITS 1 2 Society is never prepared to receive any invention. Every new thing is resisted, and it takes years for the inventor to get people to listen to him and years more
More informationEE 742 Chapter 3: Power System in the Steady State. Y. Baghzouz
EE 742 Chapter 3: Power System in the Steady State Y. Baghzouz Transmission Line Model Distributed Parameter Model: Terminal Voltage/Current Relations: Characteristic impedance: Propagation constant: π
More informationLecture 9: Space-Vector Models
1 / 30 Lecture 9: Space-Vector Models ELEC-E8405 Electric Drives (5 ECTS) Marko Hinkkanen Autumn 2017 2 / 30 Learning Outcomes After this lecture and exercises you will be able to: Include the number of
More informationLESSON 20 ALTERNATOR OPERATION OF SYNCHRONOUS MACHINES
ET 332b Ac Motors, Generators and Power Systems LESSON 20 ALTERNATOR OPERATION OF SYNCHRONOUS MACHINES 1 LEARNING OBJECTIVES After this presentation you will be able to: Interpret alternator phasor diagrams
More informationELECTRIC POWER CIRCUITS BASIC CONCEPTS AND ANALYSIS
Contents ELEC46 Power ystem Analysis Lecture ELECTRC POWER CRCUT BAC CONCEPT AND ANALY. Circuit analysis. Phasors. Power in single phase circuits 4. Three phase () circuits 5. Power in circuits 6. ingle
More informationChapter 5 Steady-State Sinusoidal Analysis
Chapter 5 Steady-State Sinusoidal Analysis Chapter 5 Steady-State Sinusoidal Analysis 1. Identify the frequency, angular frequency, peak value, rms value, and phase of a sinusoidal signal. 2. Solve steady-state
More informationThe synchronous machine (detailed model)
ELEC0029 - Electric Power System Analysis The synchronous machine (detailed model) Thierry Van Cutsem t.vancutsem@ulg.ac.be www.montefiore.ulg.ac.be/~vct February 2018 1 / 6 Objectives The synchronous
More informationLecture 1: Induction Motor
1 / 22 Lecture 1: Induction Motor ELEC-E8402 Control of Electric Drives and Power Converters (5 ECTS) Marko Hinkkanen Aalto University School of Electrical Engineering Spring 2016 2 / 22 Learning Outcomes
More informationElectrical Machines and Energy Systems: Operating Principles (Part 2) SYED A Rizvi
Electrical Machines and Energy Systems: Operating Principles (Part 2) SYED A Rizvi AC Machines Operating Principles: Synchronous Motor In synchronous motors, the stator of the motor has a rotating magnetic
More informationPower Systems - Basic Concepts and Applications - Part I
PDHonline Course E104 (1 PDH) Power ystems Basic Concepts and Applications Part I Instructor: hihmin Hsu PhD PE 01 PDH Online PDH Center 57 Meadow Estates Drive Fairfax A 006658 Phone & Fax: 709880088
More informationExercise Dr.-Ing. Abdalkarim Awad. Informatik 7 Rechnernetze und Kommunikationssysteme
Exercise1 1.10.015 Informatik 7 Rechnernetze und Kommunikationssysteme Review of Phasors Goal of phasor analysis is to simplify the analysis of constant frequency ac systems v(t) = max cos(wt + q v ) i(t)
More informationUniversity of Jordan Faculty of Engineering & Technology Electric Power Engineering Department
University of Jordan Faculty of Engineering & Technology Electric Power Engineering Department EE471: Electrical Machines-II Tutorial # 2: 3-ph Induction Motor/Generator Question #1 A 100 hp, 60-Hz, three-phase
More information11. AC Circuit Power Analysis
. AC Circuit Power Analysis Often an integral part of circuit analysis is the determination of either power delivered or power absorbed (or both). In this chapter First, we begin by considering instantaneous
More informationReview of Basic Electrical and Magnetic Circuit Concepts EE
Review of Basic Electrical and Magnetic Circuit Concepts EE 442-642 Sinusoidal Linear Circuits: Instantaneous voltage, current and power, rms values Average (real) power, reactive power, apparent power,
More informationMassachusetts Institute of Technology Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science 6.685 Electric Machines Class Notes 4: Elementary Synchronous Machine Models September 14, 2005 c 2005 James
More informationRevised October 6, EEL , Henry Zmuda. 2. Three-Phase Circuits 1
Three Phase Circuitsit Revised October 6, 008. Three-Phase Circuits 1 Preliminary Comments and a quick review of phasors. We live in the time domain. We also assume a causal (nonpredictive) world. Real-world
More informationControl of Wind Turbine Generators. James Cale Guest Lecturer EE 566, Fall Semester 2014 Colorado State University
Control of Wind Turbine Generators James Cale Guest Lecturer EE 566, Fall Semester 2014 Colorado State University Review from Day 1 Review Last time, we started with basic concepts from physics such as
More informationAn Introduction to Electrical Machines. P. Di Barba, University of Pavia, Italy
An Introduction to Electrical Machines P. Di Barba, University of Pavia, Italy Academic year 0-0 Contents Transformer. An overview of the device. Principle of operation of a single-phase transformer 3.
More informationUNIT- I Phase Sequence:
UNIT- I Phase Sequence: Phase sequence refers to the relation between voltages (or currents, as well) in a three-phase system. The common representation of this relation is in terms of a phasor diagram,
More informationAC Electric Machines. Objectives. Introduction. 1. To understand what the meant by the term ac circuit. 2. To understand how to analyze ac circuits.
AC Electric Machines Objectives 1. To understand what the meant by the term ac circuit.. To understand how to analyze ac circuits. 3. To understand the basic construction and operation of an ac machine.
More informationGenerators. What its all about
Generators What its all about How do we make a generator? Synchronous Operation Rotor Magnetic Field Stator Magnetic Field Forces and Magnetic Fields Force Between Fields Motoring Generators & motors are
More informationECE 421/521 Electric Energy Systems Power Systems Analysis I 3 Generators, Transformers and the Per-Unit System. Instructor: Kai Sun Fall 2013
ECE 41/51 Electric Energy Systems Power Systems Analysis I 3 Generators, Transformers and the Per-Unit System Instructor: Kai Sun Fall 013 1 Outline Synchronous Generators Power Transformers The Per-Unit
More informationJRE SCHOOL OF Engineering
JRE SCHOOL OF Engineering Class Test-1 Examinations September 2014 Subject Name Electromechanical Energy Conversion-II Subject Code EEE -501 Roll No. of Student Max Marks 30 Marks Max Duration 1 hour Date
More informationElectrical Machines and Energy Systems: Operating Principles (Part 1) SYED A Rizvi
Electrical Machines and Energy Systems: Operating Principles (Part 1) SYED A Rizvi AC Machines Operating Principles: Rotating Magnetic Field The key to the functioning of AC machines is the rotating magnetic
More informationLecture 11 - AC Power
- AC Power 11/17/2015 Reading: Chapter 11 1 Outline Instantaneous power Complex power Average (real) power Reactive power Apparent power Maximum power transfer Power factor correction 2 Power in AC Circuits
More informationBalanced three-phase systems and operation
ELEC0014 - Introduction to power and energy systems Balanced three-phase systems and operation Thierry Van Cutsem t.vancutsem@ulg.ac.be www.montefiore.ulg.ac.be/~vct October 2017 1 / 17 system used for
More informationElectric Circuits II Power Measurement. Dr. Firas Obeidat
Electric Circuits II Power Measurement Dr. Firas Obeidat 1 Table of contents 1 Single-Phase Power Measurement 2 Three-Phase Power Measurement 2 Single-Phase Power Measurement The wattmeter is the instrument
More informationBASIC PRINCIPLES. Power In Single-Phase AC Circuit
BASIC PRINCIPLES Power In Single-Phase AC Circuit Let instantaneous voltage be v(t)=v m cos(ωt+θ v ) Let instantaneous current be i(t)=i m cos(ωt+θ i ) The instantaneous p(t) delivered to the load is p(t)=v(t)i(t)=v
More informationROEVER COLLEGE OF ENGINEERING & TECHNOLOGY ELAMBALUR, PERAMBALUR DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING ELECTRICAL MACHINES I
ROEVER COLLEGE OF ENGINEERING & TECHNOLOGY ELAMBALUR, PERAMBALUR-621220 DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING ELECTRICAL MACHINES I Unit I Introduction 1. What are the three basic types
More informationTHE UNIVERSITY OF NEW SOUTH WALES. School of Electrical Engineering & Telecommunications FINALEXAMINATION. Session
Name: Student ID: Signature: THE UNIVERSITY OF NEW SOUTH WALES School of Electrical Engineering & Telecommunications FINALEXAMINATION Session 00 ELEC46 Power System Analysis TIME ALLOWED: 3 hours TOTAL
More informationFinite Element Based Transformer Operational Model for Dynamic Simulations
496 Progress In Electromagnetics Research Symposium 2005, Hangzhou, China, August 22-26 Finite Element Based Transformer Operational Model for Dynamic Simulations O. A. Mohammed 1, Z. Liu 1, S. Liu 1,
More informationThree-phase AC Circuits. Measurement of Power in a Three-phase Circuit
Three-phase AC Circuits Lesson Measurement of Power in a Three-phase Circuit In the previous lesson, the phase and line currents for balanced delta-connected load fed from a three-phase supply, along with
More informationENE 104 Electric Circuit Theory
Electric Circuit Theory Lecture 11: : Dejwoot KHAWPARSUTH http://webstaff.kmutt.ac.th/~dejwoot.kha/ Objectives : Ch12 Page 2 single-phase and polyphase systems Y- and Δ- connected three-phase system per-phase
More informationChapter 4. Synchronous Generators. Basic Topology
Basic Topology Chapter 4 ynchronous Generators In stator, a three-phase winding similar to the one described in chapter 4. ince the main voltage is induced in this winding, it is also called armature winding.
More information3 d Calculate the product of the motor constant and the pole flux KΦ in this operating point. 2 e Calculate the torque.
Exam Electrical Machines and Drives (ET4117) 11 November 011 from 14.00 to 17.00. This exam consists of 5 problems on 4 pages. Page 5 can be used to answer problem 4 question b. The number before a question
More informationDynamics of the synchronous machine
ELEC0047 - Power system dynamics, control and stability Dynamics of the synchronous machine Thierry Van Cutsem t.vancutsem@ulg.ac.be www.montefiore.ulg.ac.be/~vct October 2018 1 / 38 Time constants and
More informationModeling Free Acceleration of a Salient Synchronous Machine Using Two-Axis Theory
1 Modeling ree Acceleration of a Salient Synchronous Machine Using Two-Axis Theory Abdullah H. Akca and Lingling an, Senior Member, IEEE Abstract This paper investigates a nonlinear simulation model of
More informationECE 421/521 Electric Energy Systems Power Systems Analysis I 2 Basic Principles. Instructor: Kai Sun Fall 2014
ECE 41/51 Electric Energy Systems Power Systems Analysis I Basic Princiles Instructor: Kai Sun Fall 014 1 Outline Power in a 1-hase AC circuit Comlex ower Balanced 3-hase circuit Single Phase AC System
More informationChapter 5 Three phase induction machine (1) Shengnan Li
Chapter 5 Three phase induction machine (1) Shengnan Li Main content Structure of three phase induction motor Operating principle of three phase induction motor Rotating magnetic field Graphical representation
More informationHomework 2 SJTU233. Part A. Part B. Problem 2. Part A. Problem 1. Find the impedance Zab in the circuit seen in the figure. Suppose that R = 5 Ω.
Homework 2 SJTU233 Problem 1 Find the impedance Zab in the circuit seen in the figure. Suppose that R = 5 Ω. Express Zab in polar form. Enter your answer using polar notation. Express argument in degrees.
More informationEEE3405 ELECTRICAL ENGINEERING PRINCIPLES 2 - TEST
ATTEMPT ALL QUESTIONS (EACH QUESTION 20 Marks, FULL MAKS = 60) Given v 1 = 100 sin(100πt+π/6) (i) Find the MS, period and the frequency of v 1 (ii) If v 2 =75sin(100πt-π/10) find V 1, V 2, 2V 1 -V 2 (phasor)
More informationMassachusetts Institute of Technology Department of Electrical Engineering and Computer Science Electric Machines
Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science 6.685 Electric Machines Problem Set 10 Issued November 11, 2013 Due November 20, 2013 Problem 1: Permanent
More informationTransformer. Transformer comprises two or more windings coupled by a common magnetic circuit (M.C.).
. Transformers Transformer Transformer comprises two or more windings coupled by a common magnetic circuit (M.C.). f the primary side is connected to an AC voltage source v (t), an AC flux (t) will be
More informationInduction Motors. The single-phase induction motor is the most frequently used motor in the world
Induction Motor The single-phase induction motor is the most frequently used motor in the world Most appliances, such as washing machines and refrigerators, use a single-phase induction machine Highly
More informationEl-Hawary, M.E. Basics of Electric Energy System Theory Electrical Energy Systems. Series Ed. Leo Grigsby Boca Raton: CRC Press LLC, 2000
El-Hawary, M.E. Basics of Electric Energy System Theory Electrical Energy Systems. Series Ed. Leo Grigsby Boca Raton: CRC Press LLC, 9 Chapter BASICS OF ELECTRIC ENERGY SYSTEM THEORY.1 INTRODUCTION This
More informationThe synchronous machine (SM) in the power system (2) (Where does the electricity come from)?
1 The synchronous machine (SM) in the power system (2) (Where does the electricity come from)? 2 Lecture overview Synchronous machines with more than 2 magnetic poles The relation between the number of
More informationRefresher course on Electrical fundamentals (Basics of A.C. Circuits) by B.M.Vyas
Refresher course on Electrical fundamentals (Basics of A.C. Circuits) by B.M.Vyas A specifically designed programme for Da Afghanistan Breshna Sherkat (DABS) Afghanistan 1 Areas Covered Under this Module
More informationREACTANCE. By: Enzo Paterno Date: 03/2013
REACTANCE REACTANCE By: Enzo Paterno Date: 03/2013 5/2007 Enzo Paterno 1 RESISTANCE - R i R (t R A resistor for all practical purposes is unaffected by the frequency of the applied sinusoidal voltage or
More informationEE 451 Power System Stability
EE 451 Power System Stability Power system operates in synchronous mode Power system is subjected to a wide range of disturbances (small and large) - Loads and generation changes - Network changes - Faults
More informationDefinition Application of electrical machines Electromagnetism: review Analogies between electric and magnetic circuits Faraday s Law Electromagnetic
Definition Application of electrical machines Electromagnetism: review Analogies between electric and magnetic circuits Faraday s Law Electromagnetic Force Motor action Generator action Types and parts
More informationPower and Energy Measurement
Power and Energy Measurement ENE 240 Electrical and Electronic Measurement Class 11, February 4, 2009 werapon.chi@kmutt.ac.th 1 Work, Energy and Power Work is an activity of force and movement in the direction
More informationYou know for EE 303 that electrical speed for a generator equals the mechanical speed times the number of poles, per eq. (1).
Stability 1 1. Introduction We now begin Chapter 14.1 in your text. Our previous work in this course has focused on analysis of currents during faulted conditions in order to design protective systems
More informationSinusoidal Steady State Analysis (AC Analysis) Part II
Sinusoidal Steady State Analysis (AC Analysis) Part II Amin Electronics and Electrical Communications Engineering Department (EECE) Cairo University elc.n102.eng@gmail.com http://scholar.cu.edu.eg/refky/
More informationPower System Stability and Control. Dr. B. Kalyan Kumar, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, India
Power System Stability and Control Dr. B. Kalyan Kumar, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, India Contents Chapter 1 Introduction to Power System Stability
More informationElectric Machines I Three Phase Induction Motor. Dr. Firas Obeidat
Electric Machines I Three Phase Induction Motor Dr. Firas Obeidat 1 Table of contents 1 General Principles 2 Construction 3 Production of Rotating Field 4 Why Does the Rotor Rotate 5 The Slip and Rotor
More informationSteady State Modeling of Doubly Fed Induction Generator
Steady State Modeling of Douly Fed Induction Generator Bhola Jha 1, Dr. K. R. M Rao 2 1 Dept. of Electrical Engg., G. B. Pant Engg. College, Pauri-Garhwal, India 2 Dept. of Electrical Engg., M. J. College
More informationECE 325 Electric Energy System Components 7- Synchronous Machines. Instructor: Kai Sun Fall 2015
ECE 325 Electric Energy System Components 7- Synchronous Machines Instructor: Kai Sun Fall 2015 1 Content (Materials are from Chapters 16-17) Synchronous Generators Synchronous Motors 2 Synchronous Generators
More informationChapter 3 AUTOMATIC VOLTAGE CONTROL
Chapter 3 AUTOMATIC VOLTAGE CONTROL . INTRODUCTION TO EXCITATION SYSTEM The basic function of an excitation system is to provide direct current to the field winding of the synchronous generator. The excitation
More informationCHAPTER 5 SIMULATION AND TEST SETUP FOR FAULT ANALYSIS
47 CHAPTER 5 SIMULATION AND TEST SETUP FOR FAULT ANALYSIS 5.1 INTRODUCTION This chapter describes the simulation model and experimental set up used for the fault analysis. For the simulation set up, the
More informationECE 422/522 Power System Operations & Planning/ Power Systems Analysis II 2 Synchronous Machine Modeling
ECE 422/522 Power System Operations & Planning/ Power Systems Analysis II 2 Synchronous achine odeling Spring 214 Instructor: Kai Sun 1 Outline Synchronous achine odeling Per Unit Representation Simplified
More informationPrince Sattam bin Abdulaziz University College of Engineering. Electrical Engineering Department EE 3360 Electrical Machines (II)
Chapter # 4 Three-Phase Induction Machines 1- Introduction (General Principles) Generally, conversion of electrical power into mechanical power takes place in the rotating part of an electric motor. In
More informationSpeed Sensorless Control of a Long-Stator Linear Synchronous-Motor arranged by Multiple Sections
Speed Sensorless Control of a Long-Stator Linear Synchronous-Motor arranged by Multiple Sections Roberto Leidhold Peter Mutschler Department of Power Electronics and Control of Drives Darmsta University
More informationModule 4. Single-phase AC Circuits
Module 4 Single-phase AC Circuits Lesson 14 Solution of Current in R-L-C Series Circuits In the last lesson, two points were described: 1. How to represent a sinusoidal (ac) quantity, i.e. voltage/current
More informationChapter 15 Power And Harmonics in Nonsinusoidal Systems
Chapter 15 Power And Harmonics in Nonsinusoidal Systems 15.1. Average power in terms of Fourier series 15.2. RMS value of a waveform 15.3. Power factor THD Distortion and Displacement factors 15.4. Power
More informationChapter 15 Magnetic Circuits and Transformers
Chapter 15 Magnetic Circuits and Transformers Chapter 15 Magnetic Circuits and Transformers 1. Understand magnetic fields and their interactio with moving charges. 2. Use the right-hand rule to determine
More informationVTU E-LEARNING NOTES ON:
VTU E-LEARNING NOTES ON: 10EE35 ELECTRICAL AND ELECTRONIC MEASUREMENTS AND INSTRUMENTATION BY DR. M.S. RAVIPRAKASHA PROFESSOR & HEAD DEPT. OF E&E ENGG. MALNAD COLLEGE OF ENGG. HASSAN 573 201. SUBJECT CODE
More informationDynamic Modeling of Surface Mounted Permanent Synchronous Motor for Servo motor application
797 Dynamic Modeling of Surface Mounted Permanent Synchronous Motor for Servo motor application Ritu Tak 1, Sudhir Y Kumar 2, B.S.Rajpurohit 3 1,2 Electrical Engineering, Mody University of Science & Technology,
More informationStep Motor Modeling. Step Motor Modeling K. Craig 1
Step Motor Modeling Step Motor Modeling K. Craig 1 Stepper Motor Models Under steady operation at low speeds, we usually do not need to differentiate between VR motors and PM motors (a hybrid motor is
More information1 Unified Power Flow Controller (UPFC)
Power flow control with UPFC Rusejla Sadikovic Internal report 1 Unified Power Flow Controller (UPFC) The UPFC can provide simultaneous control of all basic power system parameters ( transmission voltage,
More informationEE 212 PASSIVE AC CIRCUITS
EE 212 PASSIVE AC CIRCUITS Condensed Text Prepared by: Rajesh Karki, Ph.D., P.Eng. Dept. of Electrical Engineering University of Saskatchewan About the EE 212 Condensed Text The major topics in the course
More informationMATLAB SIMULINK Based DQ Modeling and Dynamic Characteristics of Three Phase Self Excited Induction Generator
628 Progress In Electromagnetics Research Symposium 2006, Cambridge, USA, March 26-29 MATLAB SIMULINK Based DQ Modeling and Dynamic Characteristics of Three Phase Self Excited Induction Generator A. Kishore,
More informationELEC Introduction to power and energy systems. The per unit system. Thierry Van Cutsem
ELEC0014 - Introduction to power and energy systems The per unit system Thierry Van Cutsem t.vancutsem@ulg.ac.be www.montefiore.ulg.ac.be/~vct October 2018 1 / 12 Principle The per unit system Principle
More informationSimulations and Control of Direct Driven Permanent Magnet Synchronous Generator
Simulations and Control of Direct Driven Permanent Magnet Synchronous Generator Project Work Dmitry Svechkarenko Royal Institute of Technology Department of Electrical Engineering Electrical Machines and
More informationExamples of Applications of Potential Functions in Problem Solving (Web Appendix to the Paper)
Examples of Applications of otential Functions in roblem Solving (Web Appendix to the aper) Ali Mehrizi-Sani and Reza Iravani May 5, 2010 1 Introduction otential functions may be exploited to formulate
More informationChapter 33. Alternating Current Circuits
Chapter 33 Alternating Current Circuits 1 Capacitor Resistor + Q = C V = I R R I + + Inductance d I Vab = L dt AC power source The AC power source provides an alternative voltage, Notation - Lower case
More informationControl of an Induction Motor Drive
Control of an Induction Motor Drive 1 Introduction This assignment deals with control of an induction motor drive. First, scalar control (or Volts-per-Hertz control) is studied in Section 2, where also
More informationMathematical Modeling and Dynamic Simulation of a Class of Drive Systems with Permanent Magnet Synchronous Motors
Applied and Computational Mechanics 3 (2009) 331 338 Mathematical Modeling and Dynamic Simulation of a Class of Drive Systems with Permanent Magnet Synchronous Motors M. Mikhov a, a Faculty of Automatics,
More informationMutual Inductance. The field lines flow from a + charge to a - change
Capacitors Mutual Inductance Since electrical charges do exist, electric field lines have a starting point and an ending point. For example, if you have a + and a - change, the field lines would look something
More informationINDUCTION MOTOR MODEL AND PARAMETERS
APPENDIX C INDUCTION MOTOR MODEL AND PARAMETERS C.1 Dynamic Model of the Induction Motor in Stationary Reference Frame A three phase induction machine can be represented by an equivalent two phase machine
More informationA simple model based control of self excited induction generators over a wide speed range
ISSN 1 746-7233, England, UK World Journal of Modelling and Simulation Vol. 10 (2014) No. 3, pp. 206-213 A simple model based control of self excited induction generators over a wide speed range Krishna
More informationPHASOR DIAGRAMS HANDS-ON RELAY SCHOOL WSU PULLMAN, WA.
PHASOR DIAGRAMS HANDS-ON RELAY SCHOOL WSU PULLMAN, WA. RON ALEXANDER - BPA What are phasors??? In normal practice, the phasor represents the rms maximum value of the positive half cycle of the sinusoid
More information