PRINCIPLES OF ELECTRIC MACHINES WITH POWER ELECTRONIC APPLICATIONS PDF
DOWNLOAD PDF. PRINCIPLES OF ELECTRIC MACHINES WITH POWER ELECTRONIC APPLICATIONS BOOKS IN THE IEEE PRESS SERIES ON POWER. Principles of electric machines and power electronics / Dr. P.C. Sen, Fellow IEEE. . developments in the applications of, for example, permanent magnet motors. Principles of electric machines and power electronics /. —2nd ed. p. Committee for technical excellence at the Industry Application Society An- nual Meeting in.
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Principles of Electric Machines with Power Electronic Applications provides a thorough grounding in the principles of electric machines and the closely related . Request PDF on ResearchGate | Principle of Electric Machines with Power Electronic Applications | Up-to-date treatment of conventional electromechanical . PDF | This paper presents a review of different solutions for small wind turbines of the order kW, Electrical machines and power electronic drives for wind turbine applications .. that uses almost the same control principle as the one.
The first electromagnetic generator employing rotation was invented by M. Pixii of Paris in In this first generator, a permanent magnet of the horseshoe type was rotated about a vertical axis by means of a hand crank and gearing.
Immediately above the magnet were the poles of a wire-wound soft-iron core fixed in a suspending frame. The terminals of the winding were connected to a commutator.
The machine produced a rapid succession of sparks when cranked. An magnetoelectric machine made by Saxton was displayed in June The machine had a horizontal horseshoe magnet. The armature consisted of a four-armed soft-iron cross. A soft-iron core carrying a coil was attached to each arm. The fourpole armature rotated on a horizontal spindle opposite the end of the magnet.
The rotation was provided by a belt from a vertical pulley and hand crank.
By , the development of dynamos depended on their perceived application as a source of electricity for powering lighthouses. The most important designs of that era were due to Frederick Hale Holmes.
The first of his designs was a 2 -hp machine. The rotor consisted of six wheels, each carrying six compound permanent magnets, for a total of The frame consisted of five rings, each carrying 24 coils.
A direct-current output was obtained through a large commutator. The success of the trial resulted in Holmes receiving an order for two machines, with the stipulation that the driving speed must not exceed 90 rpm. Holmes complied by modifying the design so that the magnets were stationary.
He used 60 magnets that were carried in three vertical planes.
Two coil-carrying wheels, each with 80 coils, rotated at 90 rpm. On December 8, , at South Foreland High Lighthouse, the first electric-powered lighthouse illuminated the sea. The design ran at rpm and had fixed magnets and rotating coils. The idea of replacing permanent magnets by electromagnets in the design of electric machines dates to observations by the Abbes Moigno and Raillard in Starting with a small machine whose permanent magnet was capable of lifting only a few grams, the electricity generated enabled a larger electromagnet to lift a load of kg.
About the same time, Charles G. Page found that by adding a current-carrying coil around a permanent magnet, the effect of the original magnet was greatly increased. In February , William Siemens announced that permanent magnets were not necessary to convert mechanical into electrical energy. Within a few years, he developed a practical machine in which the field magnet was in two parts and the poles faced one another on opposite sides of the armature.
The design employed a fundamental invention made in by Werner Von Siemens William's brother in which a cylindrical armature was made to rotate in a closely encircling tunnel in the magnet pole pieces.
An experiment by Henry Wilde involved a small magneto whose electricity output was fed to the field magnet of a second machine. The output of the second machine was led to the field of a third and larger one. Using this cascading approach, Wilde observed the melting of pieces of iron rod.
He effected self-excitation in some machines in by diverting some of the armature current through the field winding. His machines were used in electroplating and as the first electric searchlights on battleships. Within a year, the principles of "shunt" and "series" field windings were well recognized.
The machines constructed in this era all suffered from current fluctuations. A solution was proposed by Antonio Pacinotti in , but unfortunately, this went unnoticed until it was reinvented by Zenobe Theophile Gramme in Improvements to design of dynamos continued, aided by theoretical foundations provided by the publication of James Clerk Maxwell's treatise on electricity and magnetism in It is worth noting here that Maxwell's work influenced Hopkinson of King's College, Cambridge, who established magnetic flux, and reluctance.
These advances had a significant impact on the design of more economical and advanced machines. Dal Negro demonstrated in that a rotary motion can be obtained "from current supplied by a voltaic battery. The experiment showed that a pivoted magnet could be kept in continuous oscillation by current in an adjacent coil. In , Joseph Henry in the United States discussed the principles of operation of one of the first proposed electromagnetic motors, the operation of which was based on a rocking energized iron bar.
The Vermont inventor Thomas Davenport experimented with some early motor designs, and by had a workable motor. Page replaced the steam cylinder of a beam engine by a solenoid and the piston by an iron core.
With the aid of a Congressional grant, he built a double-acting beam-type electric motor with a flywheel and connecting rods. The fact that a dynamo can be used as well as a motor had been discovered by Heinrich Lenz as early as This simple fact went unnoticed until , when Pacinnoti announced a motor concept that created magnetic poles in the armature that were controlled by the commutator such that they did not move with the armature rotation but remained stationary as the iron itself moved.
Thomas Alva Edison designed a miniature motor for use in his famous electric pen.
The pen motor may be claimed as the first electric motor in history to be produced and sold commercially in large quantities. A motor specially designed for traction purposes is due to Immisch It featured a double horizontal field magnet and a long Gramme armature.
In an attempt to reduce magneticfield distortion and consequent sparking, he employed a particular commutator design. The commutator had two sections side-by-side, with segments staggered to short-circuit the coils as they passed through the neutral positions. The Sprague motor design incorporated effective solutions to problems of speed control, housing, suspension, geared drive, and the proper form of trolley contact.
Principles of Electric Machines and Power Electronics Solutions Manual
The Sprague system can be argued to have innagurated the golden age of electric motors for traction purposes, for railroad electrification grew vigorously beginning in the early s. In that period, the field of electrical engineering experienced phenomenal growth following the introduction of the incandescent lamp. Alternating current was used for early arc lamps, as it ensured equal burning of the two carbon electrodes. Direct current de held the field for a number of years for a number of reasons.
One of the strongest arguments is that de permitted the use of standby batteries, thus ensuring reliability of customer service and providing a nighttime supply when generators were shut down.
Efficient and reliable de motors were developed out of the fundamental work related to the dynamo. However, the scales were tipped in favor of alternating current ac with the emergence of two inventions, the transformer and the induction motor. Both devices were developed in the last decade of the nineteenth century. Page's work on what he termed a "dynamic multiplier.
Principles of Electric Machines with Power Electronic Applications, 2nd Edition
From the prototype of the autotransformer, he evolved a design that featured a separate primary and a secondary. In , C. Varley devised a device in which the advantages of a subdivided iron core to secure minimum eddy-current loss were combined with a simple construction.
The core in Varley's construction was a bundle of iron wires. The primary and secondary windings were wound over the center one-third of the core length.
The ends of core wires were turned back over the windings to complete the magnetic circuit. Close to 30 years later, Lucien Gaulard and John D. Gibbs introduced a system of single-phase V ac distribution. The system's backbone is a transformer with a core of soft-iron wire with a primary of insulated wire coil that is surrounded by six equal coils.
The secondaries are brought out to separate terminals on the side, so that six sections can be used if required. In , George Westinghouse read of the use of ac in Europe in conjunction with transformers displayed in England by L. Gaulard and J. The transformer configuration patented by Gaulard and Gibbs utilized multiple oneto-one turns-ratio transformers with the primary windings connected in series across the high-voltage primary circuit.
The secondary circuit then supplied an individual low-voltage secondary. Westinghouse bought the American rights to Gaulard-Gibbs patents and authorized the development of equipment for an experimental power plant at Great Barrington, Massachusetts.
Under the direction of William Stanley, the Westinghouse transformers, which were designed in , had the primary windings for the individual units connected in parallel across the high-voltage primary circuit rather than in series.
Tests being successful, Westinghouse marketed the first commercial ac system at the end of In , W.
Principles of Electric Machines with Power Electronic Applications
Mordey invented the construction that has been used up to the present. The magnet core was made of soft-iron stampings. Mordey employed the shell-type construction, with the iron sheets assembled around the primary and secondary coils so that the windings were completely surrounded by iron.
The importance of the transformer to the advance of ac stems from the growing demand for electric power. With a large demand in major urban centers, it made obvious sense to produce cheap power at remote centers. The transformer used in a step-up configuration enabled the transmission of power at high voltages with lower transmission losses. Once there, a transformer is used to step-down the voltage so the electric power can be more widely used.
Parallel to the development of the transformer were advances in the production of efficient ac motors. We review this presently. Details were announced on May 16 of the same year. Tesla's paper described three forms of his invention.
The common factor between the three forms is the ring-wound stator with four salient poles. The first form had a rotor with four salient poles, forming a reluctance motor that ran at synchronous speed. This form is not self-starting. The second form had a wound rotor and ran at slightly less than synchronous speed. The third form was a synchronous motor, as de was supplied to the rotor windings.
Tesla's motors were designed for two-phase current taken from a dynamo with a drum armature through two coils at right angles connected to two pairs of slip rings instead of the normal commutator. George Westinghouse bought Tesla's patents and employed him to develop them. The Westinghouse organization produced a practical induction motor in The power supply consisted of two single-phase Hz hp alternators on the same engine shaft, but displaced 90 degrees.
The motor had 12 poles with a distributed two-phase primary winding of cable threaded through rotor slots. The Thomson-Houston Company entered the field of designing and producing induction motors, and soon both they and Westinghouse adopted three-phase induction motors for commercial purposes.
The invention of the T-connection of two transformers to provide a three-phase supply from two-phase systems is due to C. Scott at Westinghouse. The T or Scott connection was a determining factor in the transition from two-phase to three-phase designs. Single-phase motors require a rotating magnetic field.
Tesla invented the splitphase winding to achieve this from a single-phase supply. Two coils displaced by 90 degrees were used, one winding having a much higher resistance than the other, so that the currents were displaced in phase. The high-resistance winding had to be opened when the motor approached full speed.
Since , this type of motor has been largely replaced by the capacitor motor. While these developments were taking place in North America, parallel developments in Britain and on the Continent added to the rapid progress in motor technology.
Galileo Ferrari of Turin produced a prototype two-phase induction motor that used high inductance in one coil to produce the necessary phase shift in Langdon Davies produced an experimental single-phase induction motor in , and a more advanced version in The Davies design featured slotted laminated sheets for stator construction and squirrel-cage conductors in the rotor.
At the Frankfurt Exhibition in , a three-phase lhp induction motor was displayed. We begin by looking at the scope of the area, and then we look back briefly at the history of electrical engineering to identify some of the major events that have shaped the growth of power electronics into the major industry it is today.
Power electronics is the technology associated with efficient conversion, control, and conditioning of electric power by static means, from its available input form into the desired electrical output form. This technology involves the efficient use of electrical and electronic components, the application of linear and nonlinear circuit and control theory, the use of skillful design practices, and the development of sophisticated analytical tools toward achieving the following objective: The goal of power electronics is to control the flow of energy from an electrical source to an electrical load with high efficiency, high availability, high reliability, small size, light weight, and low cost.
All power electronic systems control and regulate the flow of electric energy between an ac or de source and one or more electrical loads that need alternating or direct current. The object is to meet the requirements of the load s , and is achieved by changing the electrical impedance of one or more elements internal to the power converter that is placed between the source and the load s.
Achieving high reliability requires avoiding the use of parts that have known or unpredictable short life-expectancy limitations such as tubes using heaters and filaments, or certain types of electrolytic capacitors. Avoiding moving parts that require periodic maintenance or replacement is motivated by the requirement that they be readily available. This is true when components are in the path of the main power flow and involved in the regular establishment and interruption of CUfrent as an essential part of the power conversion process.
In fact, this is the reason for including the word "static" in the definition of power electronics. Most power electronic circuits can be satisfactorily modeled by an electrical network consisting of controlled sources and lumped purely passive resistive, capacitive, and inductive elements in which the current that enters one terminal of any two-terminal element appears instantaneously at the other terminal. For a static power converter to operate efficiently, the variable impedance in the main power path between the source and load should change as rapidly as possible between as high a value and as Iowa value as possible.
In other words, it is desirable that the impedance varies between values that are orders of magnitude apart. We now tum our attention to the roots of power electronics, which some argue dates back to when Lee DeForest invented the three-element thermionic vacuum tube. The natural power source for this device is a de voltage. The nonlinear switching element is resistive and changes from a large value of resistance to a small value under the control of voltage applied to one of its terminals called the grid.
Many authors suggest that the dawn of the power electronics era took place in , five years after Deforest's invention of the vacuum tube. This is when E. The Alexanderson patent for the magnetic amplifier is considered to be the first device to meet all the requirements of the definition for power electronics, and most of the goals for power electronic equipment. Being essentially an ac-to-ac power converter, the circuit is a very effective power electronic circuit.
The magnetic amplifier differs from the three-element thermionic vacuum tube in significant ways.
The natural power source for the former is a de voltage, not an ac one, as is the case for magnetic amplifiers. Because vacuum tubes can use batteries for their power source, they are far more attractive than magnetic amplifiers for portable applications. Moreover, magnetic amplifiers are incapable of self-oscillation. By , Alexanderson's magnetic amplifier had been used to modulate as much as 70 kW of power, while DeForest's three-element thermionic vacuum tube was able to handle only a few tens of watts.
It was during that year that Alexanderson achieved a major triumph by using magnetic amplifiers to establish the first radio link between the United States and Europe. Although restricted largely to low-power applications, vacuum tubes with truly phenomenal performance soon overshadowed the solid virtues of magnetic amplifiers for most low-power applications and were rapidly developed during the years from to The history of power electronics can be divided into three overlapping periods: those when magnetic amplifiers, gas-tube and vapor-tube controlled rectifiers, and power transistors and semiconductor controlled rectifier were developed.
The period between and saw the development of gas- and vapor-filled controlled rectifiers, which were designed specifically for higher-power applications. Prominent among the new devices were two controlled rectifiers: the gas-filled thyratron and the mercury-arc ignitron. In both cases, a unidirectional current with a relatively low voltage drop flows after an enabling signal is applied to a third electrode, allowing the gas discharge to start. In the case of the thyratron, the function of the grid is to prevent the initiation of an arc from anode to cathode until after a preselected time in the cycle.
In the case of the ignitron, announced in by Slepian and Ludwig, a pulse of current through the third electrode, called an igniter, initiates a cathode spot on the pool of mercury at the beginning of each conduction period. During the s, Frank G. Logan, an engineer at Vickers Electric in St. Louis, Missouri, patented nineteen improvements to magnetic amplifiers in which the nonlinear switching effect in the magnetic cores were coordinated with the change in the resistance of the rectifiers between forward conducting and reverse blocking states.
The result was a considerably higher power gain with simpler circuit configurations. Such circuits are called self-saturating magnetic amplifiers. Numerous applications combined tube controlled rectifiers and magnetic amplifiers.
One such application was the stepless variation of theater-stage and auditorium lighting. A few watts expended in the grid circuit of two thyratrons in a push-pull connection provided the variable de current to control the much larger magneticamplifier-output current to lighting loads.
During that period, the term industrial electronics became popular to describe the high power applications of electronics for purposes other than communication. By the time of World War II a rotating amplifier called the amplidyne or Rototrol saw a great deal of service.
This was a power amplifier that was effectively a combination motor-generator, with no rotating shaft brought to the outside. Because of its nonstatic electromechanical nature, however, such a device does not qualify under the definition of an electronic power conditioner. Unlike static PDF Principles of Electric Machines and Power Electronics solution manuals or printed answer keys, our experts show you how to solve each problem step-by-step.
No need to wait for office hours or assignments to be graded to find out where you took a wrong turn. You can check your reasoning as you tackle a problem using our interactive solutions viewer. Plus, we regularly update and improve textbook solutions based on student ratings and feedback, so you can be sure you're getting the latest information available.
How is Chegg Study better than a printed Principles of Electric Machines and Power Electronics student solution manual from the bookstore? Our interactive player makes it easy to find solutions to Principles of Electric Machines and Power Electronics problems you're working on - just go to the chapter for your book.
Hit a particularly tricky question? Bookmark it to easily review again before an exam. The best part? As a Chegg Study subscriber, you can view available interactive solutions manuals for each of your classes for one low monthly price.In a generating plant, several generators are operated in parallel in the power grid to provide the total power needed.
In such a case, as the load current increases, the series field m. In Chapter 2, the basic laws, definitions, and relevant phenomena of electromagnetism are discussed. It may be noted that separately excited d. Present systems use ac generators with rotating rectifiers, known as brushless excitation systems. We discuss the evolution of the B-H hysteresis loop in the following intervals. The brush width is equal to the width of one commutator segment and one mica insulation.
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