The principle of operation of the generator presentation. Alternating electric current
"Alternator"Alternator (alternator)
is an electromechanical device
which converts mechanical energy into
AC electrical energy.
Most alternators
use a rotating magnetic field.
Story:
Systems producing alternating current wereknown in simple forms since the discovery
magnetic induction of electric current.
Early machines were designed by Michael
Faraday and Hippolyte Pixie.
Faraday developed a "rotating
triangle", the action of which was
multipolar - each active conductor
passed sequentially through the region,
where the magnetic field was in opposite directions
directions. First public demonstration
the most powerful “alternator system”
took place in 1886. Large two-phase
The alternator was built
British electrician James Edward
Henry Gordon in 1882. Lord Kelvin and
Sebastian Ferranti also designed an early
alternator producing frequencies between 100
and 300 hertz. In 1891 Nikola Tesla
patented a practical "high-frequency"
alternator (which operated at a frequency
about 15000 hertz). After 1891, there were
multiphase alternators were introduced.
The operating principle of the generator is based on
action of electromagnetic induction -
occurrence of electrical voltage in
stator winding located in AC
magnetic field. It is created using
rotating electromagnet - rotor at
passing through its winding of direct current.
AC voltage is converted to
constant semiconductor
rectifier
General view of an alternating current generator with internal poles. The rotor is an inductor and the stator is an armature
Rotor - core,rotating around
horizontal or
vertical axis
along with his
winding
The stator is a stationary core with its winding.
Generator design diagram: 1 - fixed armature, 2 - rotating inductor, 3 - contact rings, 4 - brushes sliding along them
Rotatinginductor
generator I
(rotor) and armature
(stator) 2, in
winding of which Rotor
(inductor)
generator
variable
current
With
internal
poles. On the rotor shaft
on right
shown
rotor
auxiliary
cars,
Types of generators:
A turbogenerator is a generatorwhich is put into action
steam or gas turbine. Diesel unit
-
Generate
op,
rotor
which
O
rotates
from
move Hydroge
nerator
rotates
hydra
rbina. Early 20th century alternator made in Budapest,
Hungary, in the hall of electricity production of a hydroelectric power station
(photo by Prokudin-Gorsky, 1905-1915). Automotive
generator
variable
current Driven
the belt is removed.
Wide application of alternators:
It will come as no surprise to anyone that these days the popularity,relevance and demand for devices such as power plants and alternating generators
current are quite high. This is explained, first of all, by the fact that modern
Generating equipment is of great importance to our population. Besides
it is necessary to add that alternating current generators have found their wide range
application in a wide variety of fields and areas.
Industrial generators can be installed in places such as clinics and
kindergartens, hospitals and catering establishments, freezer warehouses and
many other places that require a continuous supply of electrical current. Pay your
Please note that lack of electricity in a hospital can lead directly to
to the death of a person. That is why there should be generators in such places
must be installed.
Also quite common is the use of generators
alternating current and power plants at construction sites. This
allows builders to use the equipment they need even in those areas
where there is no electrification at all. However, the matter did not stop there.
Power plants and generator sets have been further improved. IN
As a result, we were offered household alternating current generators that
could be quite successfully installed for the electrification of cottages and country houses
houses.
Thus, we can conclude that modern alternating generators
current have a fairly wide range of applications. In addition, they are able to solve
a large number of important problems associated with incorrect operation of electrical
network, or lack thereof.
Definition Alternating current is an electric current that periodically changes in magnitude and direction. Symbol or. The modulus of the maximum current value over a period is called the amplitude of current fluctuations. Currently, electrical networks use alternating current. Many laws that were derived for direct current also apply to alternating current.
Alternating current has a number of advantages over direct current: - an alternating current generator is much simpler and cheaper than a direct current generator; - alternating current can be transformed; - alternating current is easily converted into direct current; - AC motors are much simpler and cheaper than DC motors; - the problem of transmitting electricity over long distances was solved only by using high voltage alternating current and transformers. A sinusoidal voltage is used to produce alternating current.
An alternator is an electromechanical device that converts mechanical energy into alternating current electrical energy. Systems producing alternating current have been known in simple forms since the discovery of magnetic induction of electric current. The operating principle of the generator is based on the phenomenon of electromagnetic induction, the occurrence of electrical voltage in the stator winding located in an alternating magnetic field. It is created using a rotating electromagnet of the rotor when direct current passes through its winding.
"AC electrical circuits"- Application of electrical resonance. Vector diagram of voltages in an alternating current network. Ohm's law. Current fluctuations. AC electrical circuits. Electrical resonance. Diagram. Three types of resistance. Vector diagram. Diagram with only inductive reactance in the AC circuit.
"Alternating current"- Alternating current. Alternator. Alternating current is an electric current that changes over time in magnitude and direction. Definition. EZ 25.1 Producing alternating current by rotating a coil in a magnetic field.
""Alternating current" physics"- Capacitor resistance. Capacitor in an alternating current circuit. Current fluctuations on the capacitor. R,C,L in an AC circuit. How does a capacitor behave in an alternating current circuit? How does inductance behave? Let's analyze the formula for inductive reactance. Using the frequency properties of a capacitor and inductor.
“Resistance in an alternating current circuit” - Inductive reactance is a quantity characterizing the resistance provided to alternating current by the inductance of the circuit. Capacitance is a value that characterizes the resistance provided to alternating current by electrical capacitance. Are the shapes the same color? Active resistance in an alternating current circuit.
"Alternating electric current"- Let's consider the processes occurring in a conductor connected to an alternating current circuit. Active resistance. Im= Um / R. i=Im cos ?t. Free electromagnetic oscillations in the circuit quickly fade and are therefore practically not used. Conversely, undamped forced oscillations are of great practical importance.
"Transformer"- If the answer is “yes,” then to what current source should the coil be connected and why? Write a summary for paragraph 35 Physical processes in a transformer. Task 2. AC power supply. Induction emf. K – transformation coefficient. Write the formula. Is it possible to convert a step-up transformer into a step-down transformer?
1 slide
Presentation on the topic: “Three-phase current generator” Municipal Atypical General Educational Institution “Gymnasium No. 1 of the city of Belovo” Head: Popova Irina Aleksandrovna Completed by: students of class 11 “B” Ponomarev Kirill Malakhov Alexander Glushchenko Anatoly Belovo 2011 BRAIN 2.0
2 slide
3 slide
Objectives: 1) understand the principle of operation of a three-phase generator 2) find out the advantages of three-phase systems 3) consider connections in three-phase circuits 4) compare phase (Uph) and linear (Ul) voltages 5) consider diagrams, graphs to study and consolidate knowledge of the topic. 6) carry out the experiment, applying the acquired knowledge 7) draw practical conclusions
4 slide
History of the origin... Mikhail O Sipovich Doli Vo-Dobrovolsky is a Russian electrical engineer of Polish origin, one of the creators of three-phase alternating current technology, a German entrepreneur. The creative and engineering activities of M. O. Dolivo-Dobrovolsky were aimed at solving problems that would inevitably be encountered with the widespread use of electricity. Work in this direction, based on the three-phase current obtained by Nikola Tesla, in an unusually short time led to the development of a three-phase electrical system and a perfect, in principle, unchanged design of an asynchronous electric motor. Thus, currents with a phase difference of 120 degrees were obtained, a connected three-phase system was found, the distinctive feature of which was the use of only three wires for the transmission and distribution of electricity.
5 slide
Design of a three-phase current generator The operating principle of the generator is based on the phenomenon of electromagnetic induction - the occurrence of electrical voltage in the stator winding located in an alternating magnetic field. It is created using a rotating electromagnet - the rotor - when direct current passes through its winding. Main elements: The inductor in a three-phase current generator is an electromagnet, the winding of which is powered by direct current. The inductor is the rotor, the generator armature is the stator. Three independent electrical circuits are located in the stator slots. windings shifted in space by 120 degrees. When the rotor rotates at angular speed, an induced emf occurs, changing. according to the harmonic law with frequency ω Due to the shift of the windings in space, the oscillation phases are shifted by 2p/3 and 4p/3.
6 slide
7 slide
Connections in three-phase circuits Phase voltage is the voltage between the beginning and end of each phase winding of the generator. Line voltage is the voltage between the beginnings of any two phase windings.
8 slide
Experiment Three coils with cores are placed around a circle at an angle of 120° with respect to each other. Each coil is connected to a galvanometer. A straight magnet is attached to the axis in the center of the circle. If you rotate the magnet, an alternating current appears in each of the three circuits. When the magnet rotates slowly, you can notice that the highest and lowest values of currents and their directions will be different at each moment in all three circuits.
Slide 9
Advantages of three-phase systems: 1) economical production and transmission of electricity 2) the ability to obtain a relatively simple circular rotating magnetic field 3) the ability to obtain two operating voltages in one installation: phase and linear 4) the use of fewer wires in production Conclusion: Thanks to these advantages, three-phase systems are the most common in modern power engineering.
10 slide
List of used literature: Bessonov L.A. Theoretical foundations of electrical engineering: Electric circuits. Textbook for students of electrical engineering, energy and instrument engineering specialties of universities. –7th ed., revised. and additional –M.: Higher. school, 1978. –528 p.; Glazunov A.T., Kabardin O.F., Malinin A.N., Orlov V.A., Pinsky A.A., S.I. Kabardina “Physics. Grade 11". – M.: Education, 2009. Fundamentals of circuit theory: Textbook. for universities / G.V. Zeveke, P.A. Ionkin, A.V. Netushil, S.V. Strakhov. –5th ed., revised. –M.: Energoatomizdat, 1989. -528 p.
