U.S.NRC imag e of a modern steamturbine gen erator Early Ganz Generator in Zwevegem, West F landers, Belgium Early 20th centu ry altern ator made in Budapest, Hungary, in the power gener atinghall of a hydr oelect ric station Farad ay disk, the first elect ric generator. The horseshoe-shaped magnet (A) create d a magn eticfield throug h the disk(D). When the di skwas turned, this induced an el ectric current radial ly outwa rd from the center toward the ri m. The current flowed out throught he sli ding spring contact m, throug h the externa l circuit, and back into the center of the diskthroug h the axle. Dyna mos are no longer used for powe r gener ation due to the size and complex ity of the commutator Electric generator From Wikipedia, the free encyclopedia In el ectricity generation, an electric generator is a device that converts mechanical energy to electrical energy . A generator forces electric current to flow through an external circuit. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air, or any other source of mechanical energy. Generators provi de nearly all ofthe power for electric power grids. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities . Many motors can be mechanically driven to generate electricity and frequently make acceptable generators. Contents 1 History 2 Electromagnetic generators 2.1 Dynamo 2.2 Alternator 2.3 Induction generator 2.4 MHD generator 2.5 Other rotating electromagnetic generators 2.6 Homopolar generator 2.7 Excitation 3 Electrostatic generator 3.1 Wimshurst machine 3.2 Van de Graaff generator 4 Te rminolo gy 5 Equivalent circuit 6 Vehicle-mounted generators 7 Engine-generator 8 Human powered electrical generators 9 Linear electric generator 10 Tachogenerator 11 See also 12 References 13 External links History Before the connection between magnetism and electricit y was discovered, electrostati c generators were used. They operated on electrostatic principles. Such generators generated very high voltage and low current. They operated by using moving el ectrically charged belt s, plates, and disks that carried charge to a high potential electrode. The charge was generated using either of two mechanisms: Electrostatic induction The triboelectric effect, where the contact between two insulators leaves them charged. Because of their inefficiency and the difficulty of insulating machines that produced very high voltages, electrostati c generators had low power ratings, and were never used for generation of commerciall y significant quantiti es of electric power. The Wimshurst machine and Van de Graaff generator are examples of these machines that have survived. In 1827, Hungarian Anyos Jedlik started experimenting with the electromagnetic rotating devices which he ca lled electromagnetic self-rotors , now called the Jedlik's dynamo. In the prototy pe of the single-pole electric starter (finished between 1852 a nd 1854) both the stationary and the revolving parts were electromagnetic. He formulated the concept of the dynamo at least 6 years before Siemens and Wheatstone but didn't patent it as he thought he wasn't the first to realize this. In essence the concept is that instead of permanent magnets, two electromagnets opp osite to each other induce the magnetic field around the rotor. It was also the discovery of the principle of self-excitatio n. [1] In the years of 1831–1832, Michael Faraday discovered the operating principle of electromagnetic generators. The principle, later c alled Faraday' s law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux . He also built the first electromagnetic generator, called the Faraday disk, a type of homopo lar generator, using a copper disc rotating between the poles of a horseshoe magnet. It produced a small DC voltage. This design was inefficient, due to self-cancelling co unterflows of current in regions that were not under the influence of the magnetic field. While current was induced directly underneath the magnet, the current would circulate backwards in regions that were outside the influence of the magnetic field. This counterflow limited the power output to the pickup wires, a nd induced waste heating of the copper disc. Later homopolar generators would solv e this prob lem by using an array of magnets arranged aro und the disc perimeter to maintain a steady field effect in one current-flow direction. Another disadvantage was that the output voltage was very low, due to the single current path through the magnetic flux. Experimenters found that using multiple t urns of wire in a coil could produce higher, more useful voltages. Since the output voltage is proportional to the number of turns, generators could be easily designed to produce any desired voltage by varying the number of turns. Wire windings became a basic feature of all subsequent generator designs. The dynamo was the first electrical generator capable of delivering power for industry . The dynamo uses electromagnetic induction to convert mechanical rotation into direct current through the use of a commutator. The first dynamo was built by Hippoly te Pixii in 1832. A dynamo machine consists of a stationary structure, which provides a constant magnetic field, and a set of rotating windings which turn within that field. On small machines the constant magnetic field may be provided by one or more permanent magnets; larger machines have the constant magnetic fiel d provided by one or more electromag nets, which are usually called field coils. Through a series of accidental discoveries, the dynamo became the source of many later inventions, including the DC electric motor, the AC alternator, the AC synchronous motor, and the rotary converter. Alternating current generating systems were known in simple forms from the discovery of the magnetic induction of electric current. The early machines were developed by pioneers such as Michael Faraday and Hippo lyte Pixi i.
Transcript
7/28/2019 Electric Generator - Wikipedia, The Free Encyclopedia
lectric generatorm Wikipedia, the free encyclopedia
electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A
erator forces electric current to flow through an external circuit. The source of mechanical energy may be a
procating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a
d turbine, a hand crank, compressed air, or any other source of mechanical energy. Generators provide nearly all of
power for electric power grids.
e reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and
erators have many similarities. Many motors can be mechanically driven to generate electricity and frequently make
eptable generators.
Contents
1 History
2 Electromagnetic generators
2.1 Dynamo
2.2 Alternator
2.3 Induction generator
2.4 MHD generator
2.5 Other rotating electromagnetic generators
2.6 Homopolar generator
2.7 Excitation
3 Electrostatic generator
3.1 Wimshurst machine
3.2 Van de Graaff generator
4 Terminology
5 Equivalent circuit
6 Vehicle-mounted generators7 Engine-generator
8 Human powered electrical generators
9 Linear electric generator
10 Tachogenerator
11 See also
12 References
13 External links
istory
ore the connection between magnetism and electricity was discovered, electrostatic generators were used. They operated on electrostatic
nciples. Such generators generated very high voltage and low current. They operated by using moving electrically charged belts, plates, and
ks that carried charge to a high potential electrode. The charge was generated using either of two mechanisms:
Electrostatic induction
The triboelectric effect, where the contact between two insulators leaves them charged.
ause of their inefficiency and the difficulty of insulating machines that produced very high voltages, electrostatic generators had low power ratings, and were never used for generation
ommercially significant quantities of electric power. The Wimshurst machine and Van de Graaff generator are examples of these machines that have survived.
827, Hungarian Anyos Jedlik started experimenting with the electromagnetic rotating devices which he called electromagnetic self-rotors, now called the Jedlik's dynamo. In the
totype of the single-pole electric starter (finished between 1852 and 1854) both the stationary and the revolving parts were electromagnetic. He formulated the concept of the dynamo at
t 6 years before Siemens and Wheatstone but didn't patent it as he thought he wasn't the first to realize this. In essence the concept is that instead of permanent magnets, two
ctromagnets opposite to each other induce the magnetic field around the rotor. It was also the discovery of the principle of self-excitation.[1]
In the years of 1831–1832, Michael Faraday discovered the operating principle of electromagnetic generators. The principle, later called Faraday's
law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux. He also built the first
electromagnetic generator, called the Faraday disk, a type of homopolar generator, using a copper disc rotating between the poles of a horseshoe
magnet. It produced a small DC voltage.
This design was inefficient, due to self-cancelling counterflows of current in regions that were not under the influence of the magnetic field. Whilecurrent was induced directly underneath the magnet, the current would circulate backwards in regions that were outside the influence of the
magnetic field. This counterflow limited the power output to the pickup wires, and induced waste heating of the copper disc. Later homopolar
generators would solve this problem by using an array of magnets arranged around the disc perimeter to maintain a steady field effect in one
current-flow direction.
Another disadvantage was that the output voltage was very low, due to the single current path through the magnetic flux. Experimenters found that
using multiple turns of wire in a coil could produce higher, more useful voltages. Since the output voltage is proportional to the number of turns,
generators could be easily designed to produce any desired voltage by varying the number of turns. Wire windings became a basic feature of all
subsequent generator designs.
The dynamo was the first electrical generator capable of delivering power for industry. The
dynamo uses electromagnetic induction to convert mechanical rotation into direct current
through the use of a commutator. The first dynamo was built by Hippolyte Pixii in 1832.
A dynamo machine consists of a stationary structure, which provides a constant magnetic field,
and a set of rotating windings which turn within that field. On small machines the constantmagnetic field may be provided by one or more permanent magnets; larger machines have the
constant magnetic field provided by one or more electromagnets, which are usually called field
s.
ough a series of accidental discoveries, the dynamo became the source of many later inventions, including the DC electric motor,
AC alternator, the AC synchronous motor, and the rotary converter.
ernating current generating systems were known in simple forms from the discovery of the magnetic induction of electric current.
e early machines were developed by pioneers such as Michael Faraday and Hippolyte Pixii.
7/28/2019 Electric Generator - Wikipedia, The Free Encyclopedia
needed for highpower applications. This large belt-
driven high-current dynamo produced 310 amperes at
7 volts, or 2,170watts, when spinning at 1400 RPM.
"Dynamo Electric Machine" (end
view, partly section,U.S. Patent
284,110 (http ://www.google.com/
patents/US284110))
aday developed the "rotating rectangle", whose operation was heteropolar - each active conductor passed successively through
ions where the magnetic field was in opposite directions.[2] The first public demonstration of a more robust "alternator system" took
ce in 1886.[3] Large two-phase alternating current generators were built bya British electrician, J.E.H. Gordon, in 1882. Lord
vin and Sebastian Ferranti also developed early alternators, producing frequencies between 100 and 300 Hz. In 1891, Nikola Tesla
ented a practical "high-frequency" alternator (which operated around 15 kHz).[4] After 1891, polyphase alternators were introduced to supply currents of multiple differing phases.[5]
er alternators were designed for varying alternating-current frequencies between sixteen and about one hundred hertz, for use with arc lighting, incandescent lighting and electric
ors.[6]
ge power generation dynamos are now rarely seen due to the now nearly universal use of alternating current for power distribution. Before the adoption of AC, very large direct-
rent dynamos were the only means of power generation and distribution. AC has come to dominate due to the ability of AC to be easily transformed to and from very high voltages to
mit low losses over large distances.
ectromagnetic generators
namo
Main arti cle: Dynamo
ynamo is an electrical generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable
delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the
ctric motor, the alternating-current alternator, and the rotary converter. Today, the simpler alternator dominates large scale power generation, for
ciency, reliability and cost reasons. A dynamo has the disadvantages of a mechanical commutator. Also, converting alternating to direct current
ng power rectification devices (vacuum tube or more recently solid state) is effective and usuallyeconomic.
ternator
Main arti cle: Alternator
hout a commutator, a dynamo becomes an alternator, which is a synchronous singly fed generator. Alternators produce alternating current with
equency that is based on the rotational speed of the rotor and the number of magnetic poles.
omotive alternators produce a varying frequency that changes with engine speed, which is then converted by a rectifier to DC. By comparison,
rnators used to feed an electric power grid are generally operated at a speed very close to a specific frequency, for the benefit of AC devices that
ulate their speed and performance based on grid frequency. Some devices such as incandescent lamps and ballast-operated fluorescent lamps do not require a constant frequency, but
chronous motors such as in electric wall clocks do require a constant grid frequency.
en attached to a larger electric grid with other alternators, an alternator will dynamically interact with the frequency already present on the grid, and operate at a speed that matches the
d frequency. If no driving power is applied, the alternator will continue to spin at a constant speed anyway, driven as a synchronous motor by the grid frequency. It is usually necessary
an alternator to be accelerated up to the correct speed and phase alignment before connecting to the grid, as any mismatch in frequency will cause the alternator to act as a synchronous
tor, and suddenly leap to the correct phase alignment as it absorbs a large inrush current from the grid, which may damage the rotor and other equipment.
pical alternators use a rotating field winding excited with direct current, and a stationary (stator) winding that produces alternating current. Since the rotor field only requires a tiny
tion of the power generated by the machine, the brushes for the field contact can be relatively small. In the case of a brushless exciter, no brushes are used at all and the rotor shaft
ries rectifiers to excite the main field winding.
duction generator
Main arti cle: induction generator
induction generator or asynchronous generator is a type of AC electrical generator that uses the principles of induction motors to produce power. Induction generators operate by
chanically turning their rotor faster than the synchronous speed, giving negative slip. A regular AC asynchronous motor usually can be used as a generator, without any internal
difications. Induction generators are useful in applications such as minihydro power plants, wind turbines, or in reducing high-pressure gas streams to lower pressure, because they can
over energy with relatively simple controls.
operate an induction generator must be excited with a leading voltage; this is usually done by connection to an electrical grid, or sometimes they are self excited by using phase
recting capacitors.
HD generator
Main arti cle: MHD gene rator
magnetohydrodynamic generator directly extracts electric power from moving hot gases through a magnetic field, without the use of rotating electromagnetic machinery. MHD
erators were originally developed because the output of a plasma MHD generator is a flame, well able to heat the boilers of a steam power plant. The first practical design was the
CO Mk. 25, developed in 1965. The U.S. government funded substantial development, culminating in a 25 MW demonstration plant in 1987. In the Soviet Union from 1972 until the1980s, the MHD plant U 25 was in regular commercial operation on the Moscow power system with a rating of 25 MW, the largest MHD plant rating in the world at that time.[7]
HD generators operated as a topping cycle are currently (2007) less efficient than combined cycle gas turbines.
her rotating electromagnetic generators
er types of generators, such as the asynchronous or induction singly fed generator, the doubly fed generator, or the brushless wound-rotor doubly fed generator, do not incorporate
manent magnets or field windings that establish a constant magnetic field, and as a result, are seeing success in variable speed constant frequency applications, such as wind turbines or
er renewable energy technologies.
e full output performance of any generator can be optimized with electronic control but only the doubly fed generators or the brushless wound-rotor doubly fed generator incorporate
ctronic control with power ratings that are substantially less than the power output of the generator under control, a feature which, by itself, offers cost, reliability and efficiency
efits.
mopolar generator
Main arti cle: Homopolar generator
omopolar generator is a DC electrical generator comprising an electrically conductive disc or cylinder rotating in a plane perpendicular to a
form static magnetic field. A potential difference is created between the center of the disc and the rim (or ends of the cylinder), the electrical
arity depending on the direction of rotation and the orientation of the field. It is also known as a unipolar generator, acyclic generator, disk
namo, or Faraday disc. The voltage is typically low, on the order of a few volts in the case of small demonstration models, but large research
erators can produce hundreds of volts, and some systems have multiple generators in series to produce an even larger voltage.[8] Theyare
sual in that they can source tremendous electric current, some more than a million amperes, because the homopolar generator can be made to
e very low internal resistance.
7/28/2019 Electric Generator - Wikipedia, The Free Encyclopedia
A small early 1900s 75 kVA direct-driven powerstation ACalternator,
with a separate belt-driven exciter generator.
A Van de Graaff generator,for class
room demonstrations
ppose that the conditions are as in
figure, with the segment A1
sitive and the segment B1 negative.
w, as A1 moves to the leftand B1 to
right, their potentials will rise on
count of the work done in separating
m against attraction. When A1 and
ghboring sectors comesopposite segment B2 of the B plate, which is
w in contactwith the brush Y,they
l cause adisplacement of electricity
ng the conductor between Y and Y1
nging a negative charge, larger than
positive charge in A1 alone, on Y
d sending a positive charge to the
gment touchingY1. As A1 moves
it passes near the brush Zand is
rtially discharged into the external
cuit. It then passes on until, on
uching the brush X,has a new
arge, this time negative,driven into
y inductionfrom B2 and
ghboring sectors. As the machinens, the process causes exponential
reases in the voltages on all
sitions,until sparking occurs
miting the increase.
citation
Main arti cle: Excitat ion (magnetic)
electric generator or electric motor that uses field coils rather than permanent magnets requires a current to be present in the field coils for the
ice to be able to work. If the field coils are not powered, the rotor in a generator can spin without producing any usable electrical energy, while
rotor of a motor may not spin at all.
aller generators are sometimes self-excited , which means the field coils are powered by the current produced by the generator itself. The field
s are connected in series or parallel with the armature winding. When the generator first starts to turn, the small amount of remanent magnetism
sent in the iron core provides a magnetic field to get it started, generating a small current in the armature. This flows through the field coils,
ating a larger magnetic field which generates a larger armature current. This "bootstrap" process continues until the magnetic field in the core
els off due to saturation and the generator reaches a steady state power output.
y large power station generators often utilize a separate smaller generator to excite the field coils of the larger. In
event of a severe widespread power outage where islanding of power stations has occurred, the stations may neederform a black start to excite the fields of their largest generators, in order to restore customer power service.[9]
ectrostatic generator
Main arti cle: electrostat ic generator
electrostatic generator, or electrostatic machine, is a mechanical device that produces static electricity, or
ctricity at high voltage and low continuous current. The knowledge of static electricity dates back to the earliest
lizations, but for millennia it remained merely an interesting and mystifying phenomenon, without a theory to
lain its behavior and often confused with magnetism. By the end of the 17th Century, researchers had developed
practical means of generating electricity by friction, but the development of
electrostatic machines did not begin in earnest until the 18th century, when they became fundamental
instruments in the studies about the new science of electricity. Electrostatic generators operate by using
manual (or other) power to transform mechanical work into electric energy. Electrostatic generators develop
electrostatic charges of opposite signs rendered to two conductors, using only electric forces, and work by
using moving plates, drums, or belts to carryelectric charge to a high potential electrode. The charge isgenerated by one of two methods: either the triboelectric effect (friction) or electrostatic induction.
Wimshurst machine
Main artic le: Wimshurst machine
The Wimshurst influence machine is an electrostatic generator, a machine for generating high voltages
developed between 1880 and 1883 by British inventor James Wimshurst (1832–1903). It has a distinctive
appearance with two large contra-rotating discs mounted in a vertical plane, two crossed bars with metallic
brushes, and a spark gap formed by two metal spheres.
Van de Graaff generator
Main artic le: Van de Graaff generator
A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate very highvoltages on a hollow metal globe on the top of the stand. It was invented by American physicist Robert J.
Van de Graaff in 1929. The potential difference achieved in modern Van de Graaff generators can reach 5
megavolts. The Van de Graaff generator can be thought of as a constant-current source connected in parallel
with a capacitor and a very large electrical resistance, so it can produce a visible electrical discharge to a
nearby grounding surface which can potentially cause a "spark" depending on the voltage.
Wimshurst machine with two Leyden
jars.
Terminology
e two main parts of a generator or motor can be described in either mechanical or electrical terms.
chanical:
Rotor: The rotating part of an electrical machine
Stator: The stationary part of an electrical machine
ctrical:
Armature: The power-producing component of an electrical machine. In a generator, alternator, or dynamo the armature windings generate the electric current. The armature can be
on either the rotor or the stator.Field: The magnetic field component of an electrical machine. The magnetic field of the dynamo or alternator can be provided by either electromagnets or permanent magnets
mounted on either the rotor or the stator.
ause power transferred into the field circuit is much less than in the armature circuit, AC generators nearly always have the field winding on the rotor and the stator as the armature
ding. Only a small amount of field current must be transferred to the moving rotor, using slip rings. Direct current machines (dynamos) require a commutator on the rotating shaft to
vert the alternating current produced by the armature to direct current, so the armature winding is on the rotor of the machine.
7/28/2019 Electric Generator - Wikipedia, The Free Encyclopedia
The Caterpillar 3512CGenset is anexample of the engine-generator
package.This unit produces 1225
kilowatts of electric power.
Protesters at Occupy Wall Street using
bicycles connected to a motor and one-waydiode to charge batteries for their
electronics[12]
quivalent circuit
e equivalent circuit of a generator and load is shown in the diagram to the right. The generator's and parameters can be determined by
asuring the winding resistance (corrected to operating temperature), and measuring the open-circuit and loaded voltage for a defined current
d.
ehicle-mounted generators
ly motor vehicles until about the 1960s tended to use DC generators with electromechanical regulators. These have now been replaced by
rnators with built-in rectifier circuits, which are less costly and lighter for equivalent output. Moreover, the power output of a DC generator is
portional to rotational speed, whereas the power output of an alternator is independent of rotational speed. As a result, the charging output of an
rnator at engine idle speed can be much greater than that of a DC generator. Automotive alternators power the electrical systems on the vehicle
recharge the battery after starting. Rated output will typically be in the range 50-100 A at 12 V, depending on the designed electrical load
hin the vehicle. Some cars now have electrically powered steering assistance and air conditioning, which places a high load on the electrical
tem. Large commercial vehicles are more likely to use 24 V to give sufficient power at the starter motor to turn over a large diesel engine.hicle alternators do not use permanent magnets and are typically only 50-60% efficient over a wide speed range. [10] Motorcycle alternators often
permanent magnet stators made with rare earth magnets, since they can be made smaller and lighter than other types. See also hybrid vehicle.
magneto, like a dynamo, uses permanent magnets but generates alternating current like an alternator. Because of the limited field strength of
manent magnets, magnetos are not used for high-power production applications, but are very reliable. This reliability is part of why they are used in aviation piston engines.
me of the smallest generators commonly found power bicycle lights. Called a bottle dynamo these tend to be 0.5 ampere, permanent-magnet alternators supplying 3-6 W at 6 V or 12 V.
ng powered by the rider, efficiency is at a premium, so these may incorporate rare-earth magnets and are designed and manufactured with great precision. The maximum efficiency is
und 80% for the best of these generators—60% is more typical—due in part to the rolling friction at the tire–generator interface, imperfect alignment, the small size of the generator,
bearing losses. Cheaper designs tend to be less efficient. Due to the use of permanent magnets, efficiency falls at high speeds because the magnetic field strength cannot be controlled
ny way. Hub dynamos remedy many of these flaws since they are internal to the bicycle hub and do not require an interface between the generator and tire. The increasing use of LED
hts, more efficient than incandescent bulbs, reduces the power needed for cycle lighting.
ling boats may use a water- or wind-powered generator to trickle-charge the batteries. A small propeller, wind turbine or impeller is connected to a low-power alternator and rectifier to
ply currents of up to 12 A at typical cruising speeds.
l smaller generators are used in micropower applications.
ngine-generator
Main arti cle: Engine -generator
engine-generator is the combination of an electrical generator and an engine (prime mover) mounted together to form a single piece of self-
tained equipment. The engines used are usually piston engines, but gas turbines can also be used. And there are even hybrid diesel-gas units,
ed dual-fuel units. Many different versions of engine-generators are available - ranging from very small portable petrol powered sets to large
bine installations. The primary advantage of engine-generators is the ability to independently supply electricity, allowing the units to serve as
kup power solutions.[11]
uman powered electrical generators
Main arti cle: Self-powered e quipment
enerator can also be driven by human muscle power (for instance, in field radio station equipment).
man powered direct current generators are commercially available, and have been the project of some DIY enthusiasts. Typically operated by
ans of pedal power, a converted bicycle trainer, or a foot pump, such generators can be practically used to charge batteries, and in some cases are
igned with an integral inverter. The average adult could generate about 125-200 watts on a pedal powered generator, but at a power of 200 W, a
ical healthy human will reach complete exhaustion and fail to produce any more power after approximately 1.3 hours.[13] Portable radio
eivers with a crank are made to reduce battery purchase requirements, see clockwork radio. During the mid 20th century, pedal powered radios
e used throughout the Australian outback, to provide schooling (School of the Air), medical and other needs in remote stations and towns.
near electric generator
Main arti cle: Linear alternator
he simplest form of linear electric generator, a sliding magnet moves back and forth through a solenoid - a spool of copper wire. An alternating
rent is induced in the loops of wire by Faraday's law of induction each time the magnet slides through. This type of generator is used in the
aday flashlight. Larger linear electricity generators are used in wave power schemes.
achogenerator
hogenerators are frequently used to power tachometers to measure the speeds of electric motors, engines, and the equipment they power. Generators generate voltage roughly
portional to shaft speed. With precise construction and design, generators can be built to produce very precise voltages for certain ranges of shaft speeds.
e also
Diesel generator
Electric motor
Faraday's law of induction
Goodness factor
Hybrid vehicle
Induction motor
Radioisotope thermoelectric generator
Thermogenerator
Tidal generator
Tidal power
Turbine hall
Solar cell
Superconducting electric machine
Wave power
Wind turbine
achogenerator is an electromechanical device which produce an output voltage proportional to its shaft speed. it can be employed as an analogue speed indicator, velocity feedback
ice or a signal integrator. Two commonly used tachogenerators are DC and AC tachogenerators.
3. ^ Blalock,Thomas J., " Alternating Current Electrification, 1886 (http://www.ieee.org/organizations/history_center/stanley.html)". IEEE History Center, IEEE Milestone.( ed . first practical demonstration of a
dc generator - ac transformer system.)
7/28/2019 Electric Generator - Wikipedia, The Free Encyclopedia
7. ^ Langdon Crane, Magnetohydrodynamic (MHD) Power Generator: More Energy from Less Fuel, Issue Brief Number IB74057 , Library of Congress Congressional Research Service, 1981, retrieved from
Digital.library.unt.edu (http://digital.library.unt.edu/govdocs/crs/permalink/meta-crs-8402:1) July 18, 2008
8. ^ Losty, H.H.W & Lewis,D.L.(1973) Homopolar Machines.Philosophical Transactions for the Royal Society of London.Series A, Mathematical and Physical Sciences.275 (1248), 69-75
9. ^ SpecSizer: Generator Set Sizing (http://www.youtube.com/watch?v=zduGlpGZrkk&feature=related)
0. ^ Horst Bauer Bosch Automotive Handbook 4th Edition Robert Bosch GmbH, Stuttgart 1996 ISBN 0-8376-0333-1, page 813
1. ^ "Hurricane Preparedness: Protection Provided by Power Generators |Power On with Mark Lum" (http://www.wpowerproducts.com/blog/2011/05/hurricane-preparedness-protection-provided-by-power-
2. ^ With Generators Gone,Wall Street Protesters Try Bicycle Power( http://cityroom.blogs.nytimes.com/2011/10/30/with-generators-gone-wall-street-protesters-try-bicycle-power/), Colin Moynihan, New York
Times, October 30, 2011; accessed November 2, 2011
Simple generator (http://amasci.com/amateur/coilgen.html)Demonstration of an electrical generator (http://www.vega.org.uk/video/programme/224)
Short video of a simple generator (http://www.vega.org.uk/video/programme/309)
rieved from "http://en.wikipedia.org/w/index.php?title=Electric_generator&oldid=556735703"
egories: Electrical generators English inventions
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