EE 350: Electric Machinery Fundamentals Lecture Schedule See Time Table Course Type, Semester Fundamental Engineering, Fifth Credit Hours Three + One Pre-requisite Physics Instructor Dr. Muhammad Asghar Saqib Mr. Arsalan A Rahim Contact saqib@uet.edu.pk arsalanarahim@uet.edu.pk Office Room # 214, First Floor, Department of Electrical Engineering Office Hours Tuesday and Thursday 12:00 pm 03:00 pm Lab Instructors Mr. Habib Wajid Mr. Arsalan A Rahim Lab Schedule See Time Table Course Description This course is intended to provide a basic introduction to the theory of magnetic circuits linked with transformers and rotating electrical machines. The principles of electromechanical energy conversion will be discussed in the context of three-phase induction motors, synchronous and DC machines. In depth analysis of DC & Induction Motors will be carried out for different characteristics. Special-purpose fractional-horsepower motors will also be covered in the course with introduction of BLDC & SR Motors. Introduction of MATLAB will also be done to represent different loading capability curves of different machines. Measurable Learning Outcomes CLOs Description Apply the concepts of magnetic circuits for the performance evaluation of electrical machines. Evaluate the operation and characteristics of DC machines. Analyze the performance of transformers and three phase machines. Assess the operation of synchronous machines in a power system. Domain Taxonom y Level PLO Cognitive 3 PLO1, Medium Cognitive 5 PLO3, Cognitive 4 PLO2, Medium Cognitive 5 PLO4, Textbooks REQUIRED: Electric Machinery Fundamental, 5th Edition, Stephen J., McGraw-Hill International Edition Electric Machinery, 6th Edition, A.E. Fitzgerald, McGraw-Hill International Edition OPTIONAL: Electric Machines: Theory, Operating Applications, and Controls by Charles I. HUBERT, Prentice Hall, 2nd Edition, 2001. Grading Policy vis-àvis CLO Mapping Quizzes ( 4) + Assignments: 30% - Midterm: 30% & Final: 40% &
Lecture Plan Lecture No. 1 2 3 4 5 6 7 8 9&10 Topics Readings Introduction to magnetic circuits Chapter 1 & Fitzgerald Introduction to magnetic circuits Chapter 1 DC motors: Working principle, construction and operation, seven important parts of DC motor, different types of DC motors, equivalent circuits and terminal equations, magnetic characteristics of DC machines, terminal characteristics of separately excited and shunt type DC motor. Speed Control: Base speed, constant power and torque regions, speed control of DC motors especially shunt type and separately excited machine, voltage control method, field current control method, effects of open field, permanent magnet machines DC series motor, expression for torque, applications, terminal characteristics, six methods for speed control Armature Reaction: Concept of magnetic and magnetic neutral axis, placement of carbon brushes, armature reaction and its causes, components of armature reaction, effects of armature reaction, remedies for armature reaction, compensating winding, flux enhancement and brush shifting Commutation: Commutation process, commutation time, ideal commutation, poor commutation, effects of poor commutation, practical difficulties, Ldi/dt effect, interpoles, function of interpoles. Losses: Different types of losses and their formulation, power flow diagram of motor and generator, calculation of maximum efficiency, calculation of losses at different loads Design of Armature Winding: Pole pitch, coil pitch, front pitch, commutator pitch, multiplex windings, lap winding, wave winding, design examples of lap winding, developed diagram, sequence diagram, parallel path diagram, characteristics of lap winding, derivation of induced EMF Design of Armature Winding 1. Design example of simplex wave winding with 18 and 30 slots for four pole machine 2. Design example of double layer lap winding with 18 slots and 6 poles 3. Design example of single layer simplex lap winding with 20 slots and 6 poles 8.1 to 8.4 And 8.6 9.4 and 9.5 9.6 8.4 and Notes Notes and 8.4 and 8.7 8.3 and 8.5 8.3 and 8.4 + Notes of windings
11 12 13 14 15* 16* 17 18 19 DC Generator: Types of DC generators, equivalent circuit and characteristic equations, separately excited generator, shunt generator, voltage build-up phenomenon, series generator, compounded generator and its type; under compounded, over compounded and flat compounded generator, voltage control in all generators and terminal characteristics of all the generators Transformers: Basic principal and operation, types and construction, applications, ideal and practical transformer and their comparison; voltage and current transformation, impedance matching, dot convention, calculation of hysteresis loss and BH curve, volt second product, E/f ratio of transformer. Equivalent circuit and phasor diagrams: Equivalent circuit of practical transformers, approximate equivalent circuit, and equivalent circuit referred to primary and secondary sides, phasor diagram of ideal and practical transformer without load, phasor diagram of secondary side of practical transformer with unity, lagging and leading power factor, complete phasor diagram of practical transformer. Transformer Tests: Open circuit Test and calculations of magnetizing branch parameters, short circuit test and calculation of impedance, efficiency calculations, calculation of maximum efficiency, output for maximum efficiency Voltage regulation: Voltage regulation, reasons of voltage drops, voltage regulation under different load conditions, transformer phasor diagrams Auto Transformers: Basic principle, construction and working, voltage and current relationship, apparent power rating advantage of auto transformers. Three phase transformers: Types, ratings, different type of connections Mid Term Examination Introduction to AC Machines: Introduction to single phase, two phase and three phase systems, waveforms and equations, phasor and polar representation, balanced and un balanced poly phase systems, Types of AC motors, Main parts, Stator windings, concentrated winding, distributed winding, full pitched winding, fractional pitched winding, pole formation in AC machines, revolving magnetic field in three phase machines Introduction to AC Machines: Nature of magnetic field, properties of DC, single phase, two phase and three phase fields, phase sequence, Reversal of magnetic field in three phase machines, Speed of revolving magnetic field, conditions to produce RMF, Phase splitting in single phase machines. Analytical proof of revolving magnetic field, and basic mathematical expression for machines. Induction motor: Construction, working and principle of IM, development of induced torque in induction motor, types of induction motor, squirrel cage and slip ring induction motor and their merits, demerits and comparison, concept of rotor slip and its 8.11 to end of chapter 2.1 to 2.4 2.5 and 2.6 2.7 and 2.8 2.9 And 2.10 Chapter 4 and Chapter 4 and 7.1 to 7.3
20 21 22 23 24 25 26 expression, concept of rotor frequency and its relation with slip, example 7.1, equivalent circuit of induction motor, rotor circuit and slip effects, final equivalent circuit. Power and Torque Calculations: Power flow diagram of induction motor, calculation of different losses in an induction motor. Modification of equivalent circuit including R conv, thevenin voltage and impedance calculation, calculation of current in rotor circuit, expression of induced torque, torque speed characteristics, variation of torque speed characteristics with rotor resistance and stator frequency. Speed Control of Induction motor Pole changing method, Line frequency method, voltage control method, V/f control for controlling the speed, Rotor resistance control method and torque speed characteristics for each method, Load torque curves Tests on Induction motor No load test, blocked rotor test, resistance test and calculation of R1, R2, Xm, X1 and X2 using the data of tests Starting of IM Wye-delta starter, auto transformer starter, resistance starting, soft starting, rotor resistance starting control, power slip control and conditions for synchronization of rotor power with main supply/grid and use of PLCs in starting of induction motor Induction Generator: Basic principle, working and construction, Voltage build up phenomenon in stand-alone system, working in a network and its applications Synchronous Generator Basic principal and working, different types of prime movers, salient pole and cylindrical rotors and their comparison, brushless exciters, pilot exciters, application of synchronous generators, Synchronous speed expression, DC excitation and use of permanent magnets Equivalent circuit of synchronous generator, armature resistance, armature leakage inductance, armature reaction loss and its reactance, armature reaction at different power factors and explanation with phasor diagram, Power expression including, phasor diagrams at different power factor loads, derivation of power expressions (with and without armature reaction resistance) Throttle, control of active power, power frequency characteristics, Modes of operation of synchronous generator, working alone, working in parallel with same SG, and connected to infinite bus bar, house diagram and sharing of power, effect of excitation keeping throttle constant, effect of throttle keeping excitation constant, effect of throttle keeping excitation and power factor constant Salient pole synchronous generator, q and d axis and reactance and their calculations, phasor diagram of salient pole machines, derivation of power and torque expressions, comparison of cylindrical and salient pole synchronous generator, calculation of equivalent circuit parameters and synchronization of alternator with infinite bus bar 7.4 & 7.5 7.9 to 7.11 7.8 & 7.12 and Chapter 5 5.1 to 5.3 and Chapter 5 and Chapter 5 and Chapter 5 and Appendix C 27 Synchronous motor: Chapter 6 and
28 29 30& 31* * - Tentative Construction, working, principle, types, windings, voltage and power equation, phasor diagram for unity, lagging and leading power factor, over excited, normally excited and under excited states of machine, torque speed characteristics, effect of change of excitation, v-curves of synchronous motor, effect of change of load, application in power factor improvement Pulsating torque, synchronous Motor starting issues, starting with reduced frequency, starting as synchronous generator, damper winding, comparison of induction motor and synchronous motor and pop up quiz Single phase Machines: Introduction, concept of two phase revolving magnetic field, main winding and auxiliary winding, calculation of capacitor in auxiliary winding, and different types of capacitor motors and non-capacitor motors, double revolving magnetic field theory and equivalent circuit of single phase machines. Introduction of Fractional Horse Power Machines (Pole Shaded, Reactance), BLDC, SR Motor & Servo Motors Laboratory Plan Chapter 6 and Chapter 10 Notes and Students Presentation Measurable Learning Outcomes CLOs Description Demonstrate the operation of different configurations of electrical machines. Develop the characteristics of three phase machines in different loading conditions. Integrate software skills for the performance evaluation of electrical machines. Domain Taxonomy Level PLO 3 PLO1, Mediu m 4 PLO3, 4 PLO5, Perform experiments in the laboratory environment as an individual and team. 2 PLO9, Low Laboratories Topics CLOs 1 * Introduction to lab equipment Running a DC machine in different configurations under no load and loaded condition 1- Separately Excited DC motor 1* 2- Shunt configuration 3- Series Motor 4- Compound machine in long shunt and short shunt configuration 1 Magnetic Characteristics of DC Shunt and separately excited DC generator 1 Load Characteristics of DC Shunt Generator 1 Load Test of DC series motor 1 Speed Control of DC shunt and separately excited motor 1 Calculation of Voltage drop components in DC shunt generator Voltage regulation for capacitive, inductive and resistive load for Single Phase 1 Transformer 1* Develop an equivalent circuit of transformer Calculation of losses and efficiency &
of transformer 1 Load test of a DC series generator 1 Load Test of a three phase induction motor 1 Synchronization of a synchronous Generator with the WAPDA Supply 1 Equivalent circuit of a three phase induction motor & Running induction motor as an induction generator and speed control of induction 1 motor * - Tentative