This portable document format pdf file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. The phase relation between the rotor and stator magnetic field i. Eighth edition contains information on single phase and threephase transformers. Coates 2007 2010 introduction transformers have been an essential component in electrical and electronic circuits since the 1830s and although new technologies in some electronic circuits have reduced the need for transformers, they are still essential in many. This module describes the basic concepts of alternating current ac electrical circuits and discusses the associated terminology. Single phase midpoint and bridge types of stepup and stepdown cycloconverters. We can find the following quantities by using below formulas chart electrical formulas in dc full load current in amperes alternating current ac motors alternating current ac single. Introduction to three phase ac and three phase ac transformers. In the case of a circuit having only resistances, the voltages and currents are in phase, meaning the angle between them equals zero. Apart from providing a conventional introduction to ac theory however, there is a subtext.
Nevertheless, singlephase rectifiers are still in use both as lowpower standalone converters up to some kilowatts and as output stage in switched mode power supplies smps. To understand how these motors operate, a knowledge of the basic theory of operation of ac motors is necessary. This ebook covers alternating current ac circuit theory as well as a brief introduction of electronics. Schematic representation of a sinusoidal voltage of magnitude e applied on a circuit with a resistive load r. As the capacitor charges and discharges at each t, there is i in each plate, and equal displacement current between the plates, as though charge was conducted through c. Lecture notes on power electronics subject code bee1602 6th semester b. Module 8 ac reactive components this module describes inductance and capacitance and their effects on ac circuits.
Phasors are to ac circuit quantities as polarity is to dc circuit quantities. In most cases, the considerations can be extended to the other types. To avoid confusion, in this book the angle between the current and the voltage in the circuit will therefore be identi. Discuss and determine the phase relationship between two sinusoidal. Dc motors depend either on mechanical or electronic commutation to create rotating magnetic fields. The desired output of a system is called the reference. Here you can download the free lecture notes of electric circuits pdf notes ec notes pdf materials with multiple file links to download.
We start with a simple single phase ac generator and then add in a second. Finding motor hp horse power, kva kilovolt ampere kw input, when motor hp is known kw kilowatts amperes, when kva is known. Langsdorf, theory of alternating current machinery, 2nd. Things start to get complicated when we need to relate two or more ac voltages or currents that are out of. As such, it is difficult to analyze ac circuits in depth without using this form of mathematical expression.
Splitphase motors i resistancestart motor ii capacitorstart motor iii permanentsplit singlevalue capacitor motor iv twovalue capacitor motor. Since only dc sources are used in the first ebook, details of ac signals such as sinusoidal waveforms or sine waves, square waves, and triangle waves are provided. The threephase induction motor is the extensively used for various kinds of industrial drives. Module 2, titled ac circuits math background, covers the mathematics background needed for solving ac circuit problems.
The electric circuits notes pdf ec pdf notes book starts with the topics covering voltage and current sources, network reduction techniques, r. A substantial number of different ac dc and dcdc topologies appropriate for dc motor drives are presented. Single phase induction motor the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. With regard to the currents, the space vector can be defined as follows. The treatment throughout the handbook is practical with very little emphasis on theory. Suppose an induction motor were built to run on singlephase ac power rather than polyphase ac power. Module 7 basic ac theory this module describes the basic concepts of alternating current ac electrical circuits and discusses the associated terminology. Moduleiv 10 hours single phase half and full bridge inverter, pulse width modulated pwm technique for voltage.
Sep 29, 2019 the 11th edition of electronic devices and circuit theory by robert boylestad and louis nashelsky offers students complete, comprehensive coverage of the subject, focusing on all the essentials they will need to succeed on the job. Application of i single phase transformer ii single phase induction motor iii dc. Basic ac theory movement to measure ac voltage or current. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Single phase ac voltage regulators and its basic analysis. Phasors, phase shift and phasor algebra basic alternating. The three coils are equally spaced 120 apart around the inside of the stator. The single phase motors may be of the following types. Feb 18, 2018 in this video we learn how three phase electricity works from the basics. Basic transformer operation can be described by two formulae relating the transformation ratio to the turns ratio of the transformer windings.
To explain the details of why this is so, a bit of background knowledge about ac. The 11th edition of electronic devices and circuit theory by robert boylestad and louis nashelsky offers students complete, comprehensive coverage of the subject, focusing on all the essentials they will need to succeed on the job. The most popular type is the 3 phase, squirrelcage ac induction motor. From the above considerations it is easily deduced how threephase asynchronous motors can be considered the most widespread electric machine for industrial applications the power consumption of electrical motors. Typically the multimeter has different sockets for the probes to connect to. Phasors are based on the concept of complex numbers. How three phase electricity works the basics explained. Instead of multiple sets of windings, it only has one set of windings. An introduction to electric motors stmicroelectronics. As it says in every school physics textbook, an ampere is a. The handbook includes information on alternating current ac and direct current dc theory, circuits, motors, and generators. When applying ohms law and kirchhoffs laws, quantities of ac voltage and current must reflect phase shift as well as amplitude. The armature coils are wired so that the generator has three separate output voltages that differ in phase by 1200.
When ac theory is introduced, and especially when there is a bias towards radio frequencies, the very first new idea required by many people at least is a correct understanding of the word electricity. This course will cover ohms law, single and three phase power and general electrical. Nowadays, the three phase system serves as the basis of most electrical systems, which consist of energy generation, transmission and consumption. The schematics shows the resultant current i in phase with the voltage v. Simr oc k desy,hamb urg, german y abstract in engineering and mathematics, control theory deals with the beha viour of dynamical systems. An understanding of alternating current theory is an absolute must for anyone. Any other ac voltage or current in that circuit will have its phase shift expressed in terms relative to that source voltage. Three phase ac motor theory motors have been described as a transformer with a rotating secondary. A good meter measures ohms, ac volts, dc volts, and ac and dc amperes at least up to 300 milliamperes, as well as provides a continuity tester audible that measures continuity within a component such as a fuse. Generators, dc motors, ac theory, ac power, ac generators, voltage. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. Electric circuits pdf notes ec notes pdf smartzworld. Motors, generators, and transformers are similar in that their basic principle of operation involves induction. The singlephase motor stator has a laminated iron core with two windings arranged perpendicularly.
Although most mains power sockets are single phase, electrical ac power stations generate. When one or more output variables of a system need to follo w a certain ref. A three phase ac induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. There are many types of ac motors, but this course focuses on threephase ac induction motors, the most common type of motor used in industrial applications.
Module 9 ac power this module presents power calculations for single phase and three phase ac. Basic ac theory i i direct current dc alternating current ac i i figure 1. Electrical science module 7 basic ac theory ntc sites. The ac induction motor is the most used electrical motor in industrial applications worldwide.
Introduction to single phase ac, differences between ac and dc, ac applications. Electrical engineering ac fundamentals and ac power, rauf table of contents segment 1 alternating current introduction to single phase ac, differences between ac and dc, ac applications, complex math based representation of ac circuits and associated circuit analysis. Ac motors are widely used to drive machinery for a wide variety of applications. Alternating current fundamentals eighth edition by stephen l. Things start to get complicated when we need to relate two or more ac voltages or currents that are out of step with.
The premise for motor operation is that if you can create a. In this video we learn how three phase electricity works from the basics. The most popular type is the 3phase, squirrelcage ac induction motor. A threephase ac induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. Direct vs alternating current distribution systemsthat are far more ef. Phase theory is the latest empirical and conceptual innovation in syntactic theory within the chomskyan generative tradition. Ac induction motors are also the most common motors used in main powered home appliances. This property forces a 90 phase difference between the voltage and current waveforms. Ac waveform and ac circuit theory ac sinusoidal waveforms are created by rotating a coil within a magnetic field and alternating voltages and currents form the basis of ac theory direct current or d.
Circuit analysis ii lecture 6 three phase circuits. Pdf electronic devices and circuit theory by robert. This is what makes ac circuit calculations more complicated than dc. The armature coils are wired so that the generator has three separate output voltages that. The single phase motor stator has a laminated iron core with two windings arranged perpendicularly. Setting the standard for nearly 30 years, this highly accurate text is supported by strong pedagogy and content that is ideal for new students of this rapidly. A 3 phase induction motor can be used for different applications with various speed and load requirements. Other motors that are included are 1 phase induction motors, permanent synchronous motors and synchronous reluctance motors. Dc to ac converters converts dc to ac power by switching the dc input voltage or current in a predetermined sequence so as to generate ac voltage or current output. Assuming that i a, i b, i c are the instantaneous currents in the. Note that the rotor is actually a shortcircuited electromagnet.
The induction motor is made up of the stator, or stationary windings, and the rotor. However, polyphase generators are generally used to deliver power in threephase distribution system and the current is converted to. Explain what will happen to the unmagnetized rotor when 3phase ac power is applied to the stationary electromagnet coils. A substantial number of different acdc and dcdc topologies appropriate for dc motor drives are presented. The success of the dcdc book of knowledge has been part ly due to the lack of other text books. In the case of symmetrical three phase systems, the current does not flow through a common neutral line. There are many types of ac motors, but this course focuses on three phase ac induction motors, the most common type of motor used in industrial applications. Phasors phase and phasor diagrams what youll learn in module 5. Single phase induction motor the singlephase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth.
According to the statement in the book of boylestad. An ac gen erator alternator does not require brushes and commutators to work, and so is immune to these problems experienced by dc generators. Things start to get complicated when we need to relate two or more ac voltages or currents that are out of step with each other. Read about phasors, phase shift and phasor algebra basic alternating current ac theory in our free automation textbook. An introduction research surveys in linguistics barbara citko on. Ac phase basic ac theory electronics textbook all about circuits. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. Lecture notes on power electronics veer surendra sai. The 3phase set of currents, each of equal magnitude and with a phase difference of 120o, flow in the stator windings and generate a rotating. Tlc recommends that you download and save this pdf document and. When exported from japan, this manual does not require application to the ministry of economy, trade and industry for service transaction permission. Inverters are used in pv systems to produce ac power from a dc source, such as a pv array or batteries. The theory used in the work was collected by studying literature on how.
The handbook of electric power calculationsprovides detailed stepbystep calculation procedures commonly encountered in electrical engineering. This ebook was written as the sequel to the ebook titled dc circuits, which was written in 2016 by chad davis. Basic electrical theory overview of ac motors, transformers and measuring instruments instructor. Ac motors are used worldwide in many applications to transform electrical energy into mechanical energy. The 3phase set of currents, each of equal magnitude and with a phase difference of 120 o, flow in the stator windings and generate a rotating field will constant magnitude. S and average values and form factor for different periodic wave forms, series rl, rc, rlc and. A threephase ac generator is designed to produce threephase ac power by building more coils in the stator around the rotor. Pdf circuit analysis ii lecture 6 three phase circuits. Pdf on nov 28, 2016, hamza kaouach and others published circuit analysis ii. Singlephase generators can be used to generate power in singlephase electric power systems. Inverter school text inverter beginner course inverter school text inverter beginner course model model code specifications subject to change without notice. Singlephase generator also known as singlephase alternator is an alternating current electrical generator that produces a single, continuously alternating voltage. In general, the induction motor is cheaper and easier to maintain compared to other alternatives.
The potential across resistor r will cause a current to flow from y to x through the resistor. Basic ac theory vapors, the practical problems of sparkproducing brush contacts are even greater. The handbook contains a wide array of topics and each topic is written by an authority on the subject. Singlephase twophase threephase the presentation will describe the basics of the threephase brushless motor because it is the most common version. This booklecture is intended for a college freshman level class in problem. In particular, if a coil rotates in the presence of a magnetic field, the induced emf varies sinusoidally with time and leads to an alternating current ac, and provides a source of ac. The premise for motor operation is that if you can create a rotating magnetic field in the stator of the motor, it. Considering the voltage deviations from average shown in the tables, do you think the laboratory supply is adequate for 3 phase circuit experiments.
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