The principle of operation of electronic generators and their application. The invention and the first alternators
The first generator as well as modern alternators produce electricity. Electricity is one of the main components of the energy cycle in nature. To convert any energy into an electric generator is designed alternating current, in translation from the Latin - the manufacturer. The device, generating electricity, converts the mechanical or energy of nature into electrical. The most common use is the mechanical movement of steam, gas turbine, hydraulic or diesel engines.
Cylinders to which the ends of the anchor are attached are called "sliding rings" or contact rings that rotate simultaneously with the armature. The brushes are rubbed onto the contact rings to collect the electricity produced in the armor and transport it to the outer contour. Embossed parts of the reinforcing core. Small and medium units use segmented embedded elements, such as those shown in Figure 2, which also show the fingers that are used to form the ventilation ducts.
Embedded parts of the main pole and commutation. Usually this piece is made of a laminated soft steel plate, but in large generators with high demand, where rapid changes in load occur, layers can be used. The switch is made of high-strength copper rods in the form of a wedge-shaped carbon brush. These parts slide along the switch rods and carry the load current from the rotor coils to the external circuit. Carbon holders hold carbon atoms from the surface of the switch using.
History of the invention of an electric generator
The history of the invention of the power generator shows that the foundations of the first generator were laid by the invention of the battery by the Italian Alessandro Volta, the generation of a magnetic field from an electric current by the Dane Hans Christian Oersted and the electromagnet by the British William Sturgen. Practically discovering and investigating electromagnetic induction by scrolling a copper disk between the poles of a magnet, Faraday generated an electric current in a changing magnetic field, thus making the prototype of the first electric generator. From this moment, the first generators were started.
It produces free current and fixed voltage very accurately at any desired value from zero to the maximum rated value. According to this. Each motor must be formed with alternating poles in between. which are the areas where the magnetic lines of force are concentrated. Steel rolling mills, which are high-speed and multi-stage. to maintain a sufficiently constant pressure and smooth glide. respectively. These are machines that produce electrical energy by converting mechanical energy.
In 1833, a Russian scientist of German origin, Emil Khristianovich Lentz, published an article on the law of reciprocity of magneto-electrical phenomena, that is, on the interchangeability of a device that generates electricity and an engine. The first generators invented in the 19th century rotated a heavy permanent magnet near the wire coils gradually improving and finding practical application. Gradually, the power and consumer properties of the devices were refined over time. Now without electricity and its manufacturer can not do. Where electric power can not be connected from a power plant, mobile diesel power plants are offered by renting a generator.
What kind of energy producers do not exist at the present time, because the transformation from one type into another is the basis of life. Getting energy from the sun, wind, Earth, water movement, hydraulics, atomic, tidal, geothermal sources will surprise no one.
The engine for work uses the forces of attraction and repulsion that exist between the poles. The generator has an excellent response and is particularly suitable for precise output control by feedback regulators. This transformation is achieved by the action of the magnetic field on the electrical conductors located at the anchor. Secondary: they deliver some of the electrical energy that they previously received. This generator consists of two main parts. The electric motor works mainly on the basis of two principles: induction.
They are basically classified as: Primary: they convert the energy of another nature that they receive, or that they initially have electrical energy. And the principle: this means that if the current passes through a conductor located inside the magnetic field. And the generated voltage will depend on the strength of the magnets. Delta connection is carried out by connecting terminals 1 to the mechanical components of the generator: Housing. They are: Mechanical components. Star communication system. The poles of the rotor are located in pairs located or separated by 180º.
There are even generators receiving energy without fuel and external motion by means of the device by using the Earth's magnetic field.
Thus, the energy conversion generator is that small part of the eternal process of the energy cycle formed as a result of the Big Bang in the Universe, releasing energy and linking it in the process of its development.
There is a theory based on the generation of free energy dependent on gravity and time, but the research data goes beyond materialistic physics and science in general.
The grooves are mechanically and electrically separated by 180 °. This output voltage is obtained using a set of armature coils in the stator. then. A device that converts a particular form of energy into mechanical energy of rotation or torque. a stream returning to the south pole intercepts the A side of the pipeline.
When the rotor completes the revolution, it is said that it has completed the cycle. synchronous and protein cells. such as boats. From a constructive point of view. here will be discussed only three basic types: universal. Electricity generation is the process of generating electricity from other sources of primary energy. Its main method is still used today: electricity is generated by the movement of a wire loop or a copper disk between the poles of a magnet. For electricity companies, this is the first process of delivering electricity to consumers.
The first elementary source of electric power was invented in 1663 by a German scientist Otto von Guericke. He created an electrostatic generator that extracted from a rubble ball cast from sulfur, which was rotated by hand, considerable sparks, the noses of which could even be painful. As a result, an electric charge was accumulating on the ball - "electric fluid" as at that time called this electrical phenomenon. Guericke managed to notice the weak glow of the electrified ball in the dark and, most importantly, for the first time to find that the fluffs attracted by the ball later repel from it - this phenomenon neither Gerike nor many of his contemporaries could explain for a long time. The ball power was less than 1W. It would seem - a trifle, but with its help were discovered many important phenomena and properties of electricity.
Basic methods of power generation
We can achieve electrical energy in several ways, either by converting mechanical energy through a generator into electricity, by chemical reactions using photovoltaic cells, or by using thermal energy directly to generate small charges. The focus of the article will be on the basic methods of energy generation, processing methods that use other energy sources to generate mechanical energy and turn it into electrical in a unique way.
F. Hawkesbyin 1705 he created an electric generator, using a glass bowl instead of a sulfur ball. In 1744 a sliding contact was introduced into such a machine-a conductor-a metal tube suspended from silk threads, and later mounted on insulating supports. This contact served as a reservoir for the collection of electric charges, and the machine was able to continuously transmit electrical energy during rotation. After the invention of the Leyden jar (see below), these devices were also installed next to the machine.
Electrochemistry, which generates energy with chemical reactions
Electrochemistry is the separation of chemistry, which studies chemical reactions that arise in a solution at the interface between an electronic conductor and an ionic conductor. These reactions are associated with the transfer of electrons between the electrode and the electrolyte or species in solution.
An electrochemical cell is a device that generates an electric current from the energy released by a spontaneous oxidation-reduction reaction. This cell type includes a galvanic cell or a voltaic cell in honor of Luigi Galvani and Alessandro Volta, two scientists who conducted various experiments on chemical reactions and electric currents in the late 18th century, attributing Volta the invention of the first stack.
In 1799 the Italian scientist Alessandro Volta invented a more perfect source of electric current than Muslenbrook (see below), and most importantly almost continuous (determined by the humidity of the gasket) first electrochemical generator, so-called. "Volt post". His source of electricity, he named in honor of the Italian anatomist Luigi Galvani galvanic cell. It was a source of electricity more powerful than the generator of Gerike.
Electrochemical cells have two conducting electrodes. The anode is defined as an electrode where oxidation occurs, and the cathode is the electrode where the reduction is carried out. The electrodes can be made of any sufficiently conductive material, such as metals, semiconductors, graphite, and conductive polymers. One of these electrodes is an electrolyte that contains ions that can move freely.
The galvanic cell uses two different metal electrodes, each on an electrolyte, where positively charged ions are an oxidized form of a metal electrode. One electrode will undergo oxidation, while the other will suffer from a decrease. The anode metal will oxidize from the oxidation state from zero to the positive oxidation state and become an ion. At the cathode, the metal ion in the solution will take one or more electrons between the cathode and the oxidizing state of the ion, reduce to zero.
Studying the experiments of Galvani, who discovered the contraction of the muscles of the prepared frog when they came into contact with two dissimilar metals, Volta disagreed that this phenomenon was caused by a special "animal" electricity inherent in living organisms. He claimed that the frog in Galvani's experiments "is a sensitive electrometer," and the source of electricity is the contact of two dissimilar metals.
This forms a solid metal of electrodes on the cathode. The two electrodes must be electrically connected to each other, which allows the electron flow to leave the anode metal and flow through this connection with ions on the surface of the cathode. This electronic current is an electric current that can be used to perform work, for example, starting the engine or turning on the light source. We can create a bunch with a piece of zinc, copper and lemon.
At present, the batteries are made of plates with the help of reactive chemicals, which are separated by barriers. These barriers are polarized so that all electrons meet on one side. The side where they meet, becomes negatively charged, and the other side is charged positively. When the device is connected, an electric current is generated and the flow through the device to the positive side. At the same time, an electrochemical reaction occurs inside the cells, which leads to replenishment of the electrons.
However, numerous experiments have shown that simple contact of metals is not enough to obtain any appreciable current. A continuous electric current can arise only in a closed electrical circuit made up of different conductors: metals (which he called first class conductors) and liquids (called second-class conductors).
The result is a chemical process that generates electrical energy. These changes without a rechargeable battery are irreversible. However, a rechargeable battery can be effective to change the chemical changes that occur during the discharge process. Thus, it is completely restored and suitable for reuse.
Stream batteries store energy in chemical fluids contained in external tanks, such as external fuel cells, rather than inside the battery itself. The two main components - equipment for electrochemical conversion, through which liquids pass, and storage tanks for chemicals - can be independently calculated. Thus, the amount of energy that can be stored is limited only by the size of the tanks. The design allows you to store large amounts of energy at a lower price than with traditional batteries.
Between small disks of copper and zinc (electrodes), Volta placed a porous pad impregnated with acid or alkali (electrolyte).
As a result of the chemical reaction that occurs between the electrodes and the electrolyte, an excess of electrons is formed on the zinc electrode, and it acquires a negative electric charge, and on the copper one, on the contrary, there is a lack of electrons, and it acquires a positive charge. At the same time, an electric field arises between different electric charges of such a current source, the electromotive force (abbreviated EMF) or voltage acts. As soon as the conductor is connected to the poles of the cell or battery, an electric field will appear in it, under which the electrons will move to where their deficiency, that is, from the negative pole through the conductor to the positive pole of the source of electrical energy. This is the ordered motion of electrons in the conductor-the electric current. The current flows through the conductor because the electromotive force acts in the resulting circuit (the positive pole of the element, the conductors, the negative pole of the cell, the electrolyte).
When we talk about the thermoelectric effect, we are talking about a direct conversion of the thermal potential into electrical voltage or vice versa. Some thermoelectric devices create a voltage when there is a different temperature on each side. On the other hand, when voltage is applied to them, the result is the temperature difference. At an atomic scale, the temperature gradient causes the charge carriers in the material to divide from the hot side to the cold side.
This effect can be used to generate electricity, measure temperature or change the temperature of objects. Since the heating direction as cooling is determined by the polarity of the applied voltage, thermoelectric devices can be used as temperature controllers.
While the pad is wet, a chemical reaction occurs between the discs and the solution, creating a weak electric current in the conductor connecting the disks. Connecting pairs of disks in the battery, it was possible to receive already considerable electric current. Such batteries were called volt poles. They were the beginning of electrical engineering.
Thermocouples can be used to create tiny currents, which are analyzed by the controllers to determine the temperature of the object to be monitored. The Peltier effect is the presence of heating or cooling at the electrified crossing of two different conductors. When an electric current flows through the connection between two conductors A and B, heat can be generated at the junction.
This is due to the fact that the metals reacted differently to the temperature difference, creating a current circuit and a magnetic field. Seebeck did not recognize that an electric current was involved, so he called the phenomenon a thermomagnetic effect. The Danish physicist Hans Christian Oersted corrected the error and came up with the term "thermoelectricity".
By accumulating a large number of such elements, Volta received an electrochemical source of electricity with a voltage of up to 2 kV. It was already it is enough to study electricity, to obtain an electric arc, an electric arc candle, to weld metals, and so on.
Batteries, which we now use in watches, receivers, etc. - are the same, but improved, volt bars - galvanic cells.
The Seebeck effect is used in thermoelectric generators that function as heat engines, but are less cumbersome, do not have moving parts and are usually more expensive and less efficient. They use power plants to convert heat to additional electricity and in cars, such as automotive thermoelectric generators, to improve fuel efficiency. Space probes usually use radioisotope thermoelectric generators with the same mechanism, but using radioisotopes to obtain the required heat difference.
If a column is made of several pairs of various metals, for example zinc and silver (without gaskets), then each zinc plate charged with electricity of the same sign will be in contact with two identical silver plates charged with electricity of the opposite sign, and their common action will be mutually destroyed .
In order for the action of individual pairs to be summed up, it is necessary to ensure that each zinc plate touches only one silver one, that is, to eliminate the oncoming metal contact. This is done with the help of conductors of the second class (wet cloth circles); such circles separate metal pairs and at the same time do not interfere with the movement of electricity.
It is established that the electrons in the conductor move from the negative pole (where there is an excess of them) to the positive (where there is a defect in them), but even now, as in the last century, it is commonly assumed that the current flows from plus to minus, i.e. In the direction opposite to the motion of the electrons. The conditional direction of the current, in addition, is laid by scientists in the basis of a number of rules related to the determination of many electrical phenomena. At the same time, this convention does not create any special inconvenience if one firmly believes that the current in the conductors is opposite to the direction of the motion of the electrons. In the same cases, when the current is created by positive electric charges, for example in electrolytes of chemical sources of direct current, the current of holes in semiconductors, there are no such contradictions at all, because the direction of motion of positive charges coincides with the current direction. As long as the cell or battery is operating, the current flows in the same direction in the outer portion of the electrical circuit. Such a current is called permanent.
If the poles of the element are interchanged, only the direction of the electrons will change, but the current, in this case, will also be constant. And if the poles of the current source are interchanged very quickly and rhythmically? In this case, the electrons in the outer part of the chain will also alternately change their direction of motion. First they will flow in one direction, then when the poles are reversed - in the other, the reverse of the previous one, then again in the direct, again in the reverse, etc. In the chain, the leak will no longer be constant, but alternating current.
With alternating current, the electrons in the conductor seem to oscillate from side to side. Therefore, alternating current is also called electrical fluctuations. The alternating current advantageously differs from the constant in that it is easily convertible. So, for example, with the help of a transformer, you can increase the AC voltage or, conversely, lower it. Alternating current, in addition, can be rectified, that is, converted to direct current.
Within 2 - 3 years after the creation of the voltaic column a number of scientists developed several different modifications of batteries of galvanic cells. Among the various designs of the voltaic column, a galvanic battery built in 1802 deserves special attention. V.V. Petrov (see below).
Numerous experiments with a volt pole, conducted by scientists from different countries, already within 2 to 3 years after the creation of the column led to the discovery of chemical, thermal, light and magnetic actions of electric current.
In 1824 Arago described the phenomenon of " magnetism rotation", Satisfactorily to explain which neither he nor other physicists could. The essence of the phenomenon was as follows (Fig. 4.2) .
The horseshoe magnet could rotate around the vertical axis, and above its poles was an aluminum disk, which also could rotate on an axis coinciding in direction with the axis of rotation of the magnet. At rest, no interactions between the disk and the magnet were observed. But when you started to rotate the magnet, as the disk rushed after him and vice versa. To exclude the possibility of entrainment of the disk by air streams, the magnet and disk were separated by glass.
The discovery of electromagnetic induction (1831) helped Faraday explain the Arago phenomenon and at the very beginning of the research wrote: "I was hoping to make a new source of electricity from Mr Arago's experience." Faraday first introduced the notion of magnetic lines of force, the totality of which constitutes a magnetic field, as a physical reality. He was shown that the current is induced only when the conductor is moving across magnetic lines of force. Hence the possibility of generating an electric current when moving a closed conductor in the field of a magnet resulted.
From disk Arago Faraday really made a new source of electricity. As a result of numerous experiments, Faraday built first electromagnetic generator, the so-called "Faraday disk", by means of which it was possible to obtain an electric current.
Forcing an aluminum or copper disk to rotate between the poles of the magnet, Faraday placed brushes on the disk axis and on its periphery. Thus, an electric machine (a DC generator) was designed, which later was called a unipolar generator (Figure 4.4).
Further investigations of electromagnetic induction led to the establishment of laws on the direction of the induced current. This law was formulated in 1832. Emilie Lenz and allowed him to formulate the most important for electrical engineering principle - reversibility of the generator and motor modes of electrical machines.
