Production, transmission and distribution of electrical energy. Electricity production and distribution

I Introduction
II Electricity production and use
1. Electricity generation
1.1 Generator
2. Electricity use
III Transformers
1. Purpose
2. Classification
3. Device
4. Characteristics
5. Modes
5.1 Idling
5.2 Short circuit mode
5.3 Load mode
IV Electricity transmission
V GOELRO
1. History
2. Results
VI List of references

I. Introduction

Electricity, one of the most important types of energy, plays a huge role in the modern world. It is the core of the economies of states, determining their position in the international arena and level of development. Huge sums of money are invested annually in the development of scientific industries related to electricity.
Electricity is an integral part of everyday life, so it is important to have information about the features of its production and use.

II. Electricity production and use

1. Electricity generation

Electricity generation is the production of electricity by converting it from other types of energy using special technical devices.
To generate electricity use:
An electric generator is an electrical machine in which mechanical work is converted into electrical energy.
A solar battery or photocell is an electronic device that converts the energy of electromagnetic radiation, mainly in the light range, into electrical energy.
Chemical current sources - the conversion of part of the chemical energy into electrical energy through a chemical reaction.
Radioisotope sources of electricity are devices that use the energy released during radioactive decay to heat a coolant or convert it into electricity.
Electricity is generated at power plants: thermal, hydraulic, nuclear, solar, geothermal, wind and others.
Almost all power plants of industrial importance use the following scheme: the energy of the primary energy carrier, using a special device, is first converted into mechanical energy of rotational motion, which is transferred to a special electrical machine - a generator, where electric current is generated.
The main three types of power plants: TPP, HPP, NPP
Thermal power plants (TPPs) play a leading role in the electric power industry of many countries.
Thermal power plants require huge amounts of organic fuel, but its reserves are decreasing, and the cost is constantly increasing due to increasingly complex production conditions and transportation distances. Their fuel utilization rate is quite low (no more than 40%), and the volume of waste that pollutes the environment is large.
Economic, technical, economic and environmental factors do not allow thermal power plants to be considered a promising way to generate electricity.
Hydroelectric power plants (HPP) are the most economical. Their efficiency reaches 93%, and the cost of one kWh is 5 times cheaper than other methods of generating electricity. They use an inexhaustible source of energy, are serviced by a minimum number of workers, and are well regulated. In terms of the size and power of individual hydroelectric power stations and units, our country occupies a leading position in the world.
But the pace of development is hampered by significant costs and construction time due to the remoteness of hydroelectric power station construction sites from large cities, lack of roads, difficult construction conditions, subject to the influence of seasonality of river regimes, large areas of valuable riverine lands are flooded by reservoirs, large reservoirs negatively impact the environmental situation, powerful hydroelectric power stations can only be built in places where appropriate resources are available.
Nuclear power plants (NPPs) operate on the same principle as thermal power plants, i.e., the thermal energy of steam is converted into mechanical energy of rotation of the turbine shaft, which drives the generator, where mechanical energy is converted into electrical energy.
The main advantage of nuclear power plants is the small amount of fuel used (1 kg of enriched uranium replaces 2.5 thousand tons of coal), as a result of which nuclear power plants can be built in any energy-deficient areas. In addition, the reserves of uranium on Earth exceed the reserves of traditional mineral fuel, and during trouble-free operation of nuclear power plants they have little impact on the environment.
The main disadvantage of nuclear power plants is the possibility of accidents with catastrophic consequences, the prevention of which requires serious safety measures. In addition, nuclear power plants are poorly regulated (it takes several weeks to completely shut them down or start them up), and technologies for processing radioactive waste have not been developed.
Nuclear energy has grown into one of the leading sectors of the national economy and continues to develop rapidly, ensuring safety and environmental cleanliness.

1.1 Generator

An electric generator is a device in which non-electrical types of energy (mechanical, chemical, thermal) are converted into electrical energy.
The principle of operation of the generator is based on the phenomenon of electromagnetic induction, when an EMF is induced in a conductor moving in a magnetic field and crossing its magnetic lines of force. Therefore, such a conductor can be considered by us as a source of electrical energy.
The method of obtaining induced EMF, in which the conductor moves in a magnetic field, moving up or down, is very inconvenient for practical use. Therefore, generators use not linear, but rotational movement of the conductor.
The main parts of any generator are: a system of magnets or, most often, electromagnets that create a magnetic field, and a system of conductors that cross this magnetic field.
An alternator is an electrical machine that converts mechanical energy into alternating current electrical energy. Most alternators use a rotating magnetic field.

When the frame rotates, the magnetic flux through it changes, so an emf is induced in it. Since the frame is connected to an external electrical circuit using a current collector (rings and brushes), an electric current arises in the frame and the external circuit.
With uniform rotation of the frame, the angle of rotation changes according to the law:

The magnetic flux through the frame also changes over time, its dependence is determined by the function:

Where S− frame area.
According to Faraday's law of electromagnetic induction, the induced emf arising in the frame is equal to:

where is the amplitude of the induced emf.
Another quantity that characterizes the generator is the current strength, expressed by the formula:

Where i- current strength at any time, I m- current amplitude (maximum modulus current value), φ c- phase shift between current and voltage fluctuations.
The electrical voltage at the generator terminals changes according to a sinusoidal or cosine law:

Almost all generators installed in our power plants are three-phase current generators. Essentially, each such generator is a connection in one electric machine of three alternating current generators, designed in such a way that the emfs induced in them are shifted relative to each other by one third of the period:

2. Electricity use

Power supply for industrial enterprises. Industrial enterprises consume 30-70% of the electricity generated as part of the electrical power system. The significant variation in industrial consumption is determined by the industrial development and climatic conditions of different countries.
Power supply for electrified transport. Rectifier substations of electric transport on direct current (urban, industrial, intercity) and step-down substations of intercity electric transport on alternating current are powered by electricity from the electrical networks of the EPS.
Electricity supply for municipal and household consumers. This group of buildings includes a wide range of buildings located in residential areas of cities and towns. These are residential buildings, administrative buildings, educational and scientific institutions, shops, healthcare buildings, cultural buildings, public catering, etc.

III. Transformers

Transformer - a static electromagnetic device having two or more inductively coupled windings and designed to transform, through electromagnetic induction, one (primary) alternating current system into another (secondary) alternating current system.

Transformer device diagram

1 - primary winding of the transformer
2 - magnetic circuit
3 - secondary winding of the transformer
F- direction of magnetic flux
U 1- voltage on the primary winding
U 2- voltage on the secondary winding

The first transformers with an open magnetic circuit were proposed in 1876 by P.N. Yablochkov, who used them to power an electric “candle”. In 1885, Hungarian scientists M. Dery, O. Blati, K. Tsipernovsky developed single-phase industrial transformers with a closed magnetic circuit. In 1889-1891. M.O. Dolivo-Dobrovolsky proposed a three-phase transformer.

1. Purpose

Transformers are widely used in various fields:
For transmission and distribution of electrical energy
Typically, in power plants, alternating current generators produce electrical energy at a voltage of 6-24 kV, and it is profitable to transmit electricity over long distances at much higher voltages (110, 220, 330, 400, 500, and 750 kV). Therefore, transformers are installed at each power plant to increase the voltage.
The distribution of electrical energy between industrial enterprises, populated areas, in cities and rural areas, as well as within industrial enterprises, is carried out via overhead and cable lines, at voltages of 220, 110, 35, 20, 10 and 6 kV. Consequently, transformers must be installed in all distribution nodes, reducing the voltage to 220, 380 and 660 V.
To provide the required circuit for switching on valves in converter devices and matching the voltage at the output and input of the converter (converter transformers).
For various technological purposes: welding (welding transformers), power supply of electrothermal installations (electric furnace transformers), etc.
For powering various circuits of radio equipment, electronic equipment, communication and automation devices, electrical household appliances, for separating electrical circuits of various elements of these devices, for matching voltage, etc.
To include electrical measuring instruments and some devices (relays, etc.) in high-voltage electrical circuits or in circuits through which large currents pass, in order to expand the measurement limits and ensure electrical safety. (instrument transformers)

2. Classification

Transformer classification:

• By purpose: general power (used in power transmission and distribution lines) and special applications (furnaces, rectifiers, welding, radio transformers).
• By type of cooling: with air (dry transformers) and oil (oil transformers) cooling.
• According to the number of phases on the primary side: single-phase and three-phase.
• According to the shape of the magnetic circuit: rod, armored, toroidal.
• According to the number of windings per phase: two-winding, three-winding, multi-winding (more than three windings).
• According to the winding design: with concentric and alternating (disc) windings.

3. Device

The simplest transformer (single-phase transformer) is a device consisting of a steel core and two windings.

The principle of a single-phase two-winding transformer
The magnetic core is the magnetic system of the transformer, through which the main magnetic flux is closed.
When an alternating voltage is supplied to the primary winding, an emf of the same frequency is induced in the secondary winding. If you connect some electrical receiver to the secondary winding, then an electric current arises in it and a voltage is established at the secondary terminals of the transformer, which is somewhat less than the EMF and depends to some relatively small extent on the load.

Transformer symbol:
a) - transformer with a steel core, b) - transformer with a ferrite core

4. Transformer characteristics

• The rated power of a transformer is the power for which it is designed.
• Rated primary voltage is the voltage for which the primary winding of the transformer is designed.
• Rated secondary voltage - the voltage at the terminals of the secondary winding, resulting from the no-load condition of the transformer and the rated voltage at the terminals of the primary winding.
• Rated currents are determined by the corresponding rated power and voltage values.
• The highest rated voltage of a transformer is the highest of the rated voltages of the transformer windings.
• The lowest rated voltage is the smallest of the rated voltages of the transformer windings.
• Average rated voltage is a rated voltage that is intermediate between the highest and lowest rated voltage of the transformer windings.

5. Modes

5.1 Idling

No-load mode is the operating mode of the transformer in which the secondary winding of the transformer is open and alternating voltage is applied to the terminals of the primary winding.

A current flows in the primary winding of a transformer connected to an alternating current source, resulting in an alternating magnetic flux appearing in the core. Φ , penetrating both windings. Since Φ is the same in both windings of the transformer, then the change Φ leads to the appearance of the same induced emf in each turn of the primary and secondary windings. Instantaneous value of induced emf e in any turn of the windings is the same and is determined by the formula:

where is the amplitude of the EMF in one turn.
The amplitude of the induced emf in the primary and secondary windings will be proportional to the number of turns in the corresponding winding:

Where N 1 And N 2- the number of turns in them.
The voltage drop across the primary winding, like a resistor, is very small compared to ε 1, and therefore for effective voltage values ​​in the primary U 1 and secondary U 2 windings the following expression will be valid:

K- transformation coefficient. At K>1 step-down transformer, and when K<1 - повышающий.

5.2 Short circuit mode

Short circuit mode - a mode when the terminals of the secondary winding are closed by a current conductor with a resistance equal to zero ( Z=0).

A short circuit of a transformer under operating conditions creates an emergency mode, since the secondary current, and therefore the primary one, increases several tens of times compared to the rated one. Therefore, in circuits with transformers, protection is provided that, in the event of a short circuit, automatically turns off the transformer.

It is necessary to distinguish between two short circuit modes:

Emergency mode - when the secondary winding is closed at the rated primary voltage. With such a short circuit, the currents increase by 15¸ 20 times. The winding is deformed and the insulation becomes charred. Iron also burns. This is hard mode. Maximum and gas protection disconnects the transformer from the network in the event of an emergency short circuit.

The experimental short circuit mode is a mode when the secondary winding is short-circuited, and such a reduced voltage is supplied to the primary winding when the rated current flows through the windings - this is U K- short circuit voltage.

In laboratory conditions, a test short circuit of the transformer can be carried out. In this case, the voltage expressed as a percentage U K, at I 1 =I 1nom denote uK and is called the transformer short circuit voltage:

Where U 1nom- rated primary voltage.

This is a characteristic of the transformer indicated in the passport.

5.3 Load mode

Load mode of a transformer - operating mode of a transformer in the presence of currents in at least two of its main windings, each of which is closed to an external circuit, and currents flowing in two or more windings in no-load mode are not taken into account:

If voltage is connected to the primary winding of the transformer U 1, and connect the secondary winding to the load, currents will appear in the windings I 1 And I 2. These currents will create magnetic fluxes Φ 1 And Φ 2, directed towards each other. The total magnetic flux in the magnetic circuit decreases. As a result, the EMF induced by the total flow ε 1 And ε 2 are decreasing. RMS voltage U 1 remains unchanged. Decrease ε 1 causes an increase in current I 1:

With increasing current I 1 flow Φ 1 increases just enough to compensate for the demagnetizing effect of the flow Φ 2. Equilibrium is restored again at almost the same value of the total flow.

IV. Electricity transmission

Transferring electricity from power plants to consumers is one of the most important tasks in the energy sector.
Electricity is transmitted primarily through overhead AC power lines (OLTs), although there is a trend towards increasing use of cable and DC lines.

The need to transmit electricity over a distance is due to the fact that electricity is generated by large power plants with powerful units, and is consumed by relatively low-power electrical receivers distributed over a large area. The trend towards concentration of generating capacity is explained by the fact that with their growth, the relative costs of constructing power plants decrease and the cost of generated electricity decreases.
The placement of powerful power plants is carried out taking into account a number of factors, such as the availability of energy resources, their type, reserves and transportation capabilities, natural conditions, the ability to operate as part of a unified energy system, etc. Often such power plants turn out to be significantly remote from the main centers of electricity consumption. The operation of unified electrical power systems covering vast territories depends on the efficiency of transmitting electricity over distances.
It is necessary to transfer electricity from the places of its production to consumers with minimal losses. The main reason for these losses is the conversion of part of the electricity into the internal energy of the wires, their heating.

According to the Joule-Lenz law, the amount of heat Q, released during time t in the conductor by resistance R when current passes I, equals:

From the formula it follows that to reduce the heating of the wires it is necessary to reduce the current in them and their resistance. To reduce the resistance of the wires, increase their diameter; however, very thick wires hanging between power line supports can break under the influence of gravity, especially during snowfall. In addition, as the thickness of the wires increases, their cost increases, and they are made of a relatively expensive metal - copper. Therefore, a more effective way to minimize energy losses during electricity transmission is to reduce the current in the wires.
Thus, in order to reduce the heating of wires when transmitting electricity over long distances, it is necessary to make the current in them as small as possible.
Current power is equal to the product of current and voltage:

Consequently, to maintain the power transmitted over long distances, it is necessary to increase the voltage by the same amount as the current in the wires was reduced:

It follows from the formula that at constant values ​​of transmitted current power and wire resistance, heating losses in the wires are inversely proportional to the square of the network voltage. Therefore, to transmit electricity over distances of several hundred kilometers, high-voltage power lines (power lines) are used, the voltage between the wires of which is tens and sometimes hundreds of thousands of volts.
With the help of power lines, neighboring power plants are combined into a single network called a power grid. The Unified Energy System of Russia includes a huge number of power plants controlled from a single center and ensures an uninterrupted supply of electricity to consumers.

V. GOELRO

1. History

GOELRO (State Commission for Electrification of Russia) is a body created on February 21, 1920 to develop a project for the electrification of Russia after the October Revolution of 1917.

Over 200 scientists and technicians were involved in the work of the commission. The commission was headed by G.M. Krzhizhanovsky. The Central Committee of the Communist Party and V.I. Lenin personally daily directed the work of the GOELRO commission and determined the main fundamental provisions of the country’s electrification plan.

By the end of 1920, the commission had done a lot of work and prepared the “Electrification Plan of the RSFSR” - a volume of 650 pages of text with maps and diagrams of electrification of areas.
The GOELRO plan, designed for 10-15 years, implemented Lenin’s ideas of electrifying the entire country and creating a large industry.
In the field of the electric power industry, the plan consisted of a program designed for the restoration and reconstruction of the pre-war electric power industry, the construction of 30 regional power stations, and the construction of powerful regional thermal power plants. The power plants were planned to be equipped with boilers and turbines that were large for that time.
One of the main ideas of the plan was the widespread use of the country's enormous hydropower resources. A radical reconstruction based on the electrification of all sectors of the country's national economy and mainly the growth of heavy industry and the rational distribution of industry throughout the country were envisaged.
The implementation of the GOELRO plan began in difficult conditions of the Civil War and economic ruin.

Since 1947, the USSR has ranked 1st in Europe and 2nd in the world in electricity production.

The GOELRO plan played a huge role in the life of our country: without it, it would not have been possible to bring the USSR into the ranks of the most industrially developed countries in the world in such a short time. The implementation of this plan shaped the entire domestic economy and still largely determines it.

The drawing up and implementation of the GOELRO plan became possible solely due to a combination of many objective and subjective factors: the considerable industrial and economic potential of pre-revolutionary Russia, the high level of the Russian scientific and technical school, the concentration in one hand of all economic and political power, its strength and will, as well as the traditional conciliar-communal mentality of the people and their obedient and trusting attitude towards the supreme rulers.
The GOELRO plan and its implementation proved the high efficiency of the state planning system in conditions of strictly centralized government and predetermined the development of this system for many decades.

2. Results

By the end of 1935, the electrical construction program was exceeded several times.

Instead of 30, 40 regional power plants were built, at which, together with other large industrial stations, 6,914 thousand kW of capacity were commissioned (of which 4,540 thousand kW were regional - almost three times more than according to the GOELRO plan).
In 1935, among the regional power plants there were 13 power plants with 100 thousand kW each.

Before the revolution, the capacity of the largest power plant in Russia (1st Moscow) was only 75 thousand kW; there was not a single large hydroelectric power station. By the beginning of 1935, the total installed capacity of hydroelectric power stations reached almost 700 thousand kW.
The largest hydroelectric power station in the world at that time, the Dnieper hydroelectric station, Svirskaya 3rd, Volkhovskaya, etc., were built. At the highest point of its development, the Unified Energy System of the USSR was superior in many respects to the energy systems of developed countries in Europe and America.

Electricity was virtually unknown in villages before the revolution. Large landowners installed small power plants, but their numbers were few.

Electricity began to be used in agriculture: in mills, feed cutters, grain cleaning machines, and sawmills; in industry, and later in everyday life.

List of used literature

Venikov V.A., Long-distance power transmission, M.-L., 1960;
Sovalov S. A., Power transmission modes 400-500 sq. EES, M., 1967;
Bessonov, L.A. Theoretical foundations of electrical engineering. Electric circuits: textbook / L.A. Bessonov. — 10th ed. - M.: Gardariki, 2002.
Electrical engineering: Educational and methodological complex. /AND. M. Kogol, G. P. Dubovitsky, V. N. Borodyanko, V. S. Gun, N. V. Klinachev, V. V. Krymsky, A. Ya. Ergard, V. A. Yakovlev; Edited by N.V. Klinachev. - Chelyabinsk, 2006-2008.
Electrical systems, vol. 3 - Energy transmission by alternating and direct current of high voltage, M., 1972.

Sorry, nothing found.

It is difficult to overestimate the importance of electricity. Rather, we subconsciously underestimate it. After all, almost all the equipment around us runs on electricity. There is no need to talk about basic lighting. But we are practically not interested in electricity production. Where does electricity come from and how is it stored (and in general, is it possible to save)? How much does it actually cost to generate electricity? And how safe is it for the environment?

Economic significance

We know from school that power supply is one of the main factors in achieving high labor productivity. Electric power is the core of all human activity. There is not a single industry that can do without it.

The development of this industry indicates the high competitiveness of the state, characterizes the growth rate of production of goods and services, and almost always turns out to be a problematic sector of the economy. The cost of generating electricity often involves a significant initial investment that will pay for itself over many years. Despite all its resources, Russia is no exception. After all, energy-intensive industries make up a significant share of the economy.

Statistics tell us that in 2014, Russia's electricity production has not yet reached the Soviet level of 1990. Compared to China and the USA, the Russian Federation produces - respectively - 5 and 4 times less electricity. Why is this happening? Experts say that this is obvious: the highest non-production costs.

Who consumes electricity

Of course, the answer is obvious: every person. But now we are interested in industrial scales, which means those industries that primarily need electricity. The main share falls on industry - about 36%; Fuel and energy complex (18%) and the residential sector (slightly more than 15%). The remaining 31% of electricity generated comes from non-manufacturing sectors, railway transport and network losses.

It should be taken into account that the consumption structure varies significantly depending on the region. Thus, in Siberia, more than 60% of electricity is actually used by industry and the fuel and energy complex. But in the European part of the country, where a larger number of settlements are located, the most powerful consumer is the residential sector.

Power plants are the backbone of the industry

Electricity production in Russia is provided by almost 600 power plants. The power of each exceeds 5 MW. The total capacity of all power plants is 218 GW. How do we get electricity? The following types of power plants are used in Russia:

• thermal (their share in total production is about 68.5%);
• hydraulic (20.3%);
• atomic (almost 11%);
• alternative (0.2%).

When it comes to alternative sources of electricity, romantic pictures of wind turbines and solar panels come to mind. However, in certain conditions and locations these are the most profitable types of electricity generation.

Thermal power plants

Historically, thermal power plants (TPPs) have occupied a major place in the production process. On the territory of Russia, thermal power plants providing electricity production are classified according to the following criteria:

• energy source – fossil fuel, geothermal or solar energy;
• type of generated energy – heating, condensation.

Another important indicator is the degree of participation in covering the electrical load schedule. Here we highlight basic thermal power plants with a minimum operating time of 5000 hours per year; semi-peak (they are also called maneuverable) - 3000-4000 hours per year; peak (used only during peak load hours) – 1500-2000 hours per year.

Technology for producing energy from fuel

Of course, mainly the production, transmission and use of electricity by consumers occurs through thermal power plants running on fossil fuels. They are distinguished by production technology:

• steam turbine;
• diesel;
• gas turbine;
• steam-gas.

Steam turbine units are the most common. They operate on all types of fuel, including not only coal and gas, but also fuel oil, peat, shale, firewood and wood waste, as well as processed products.

Organic fuel

The largest volume of electricity production occurs at Surgut State District Power Plant-2, the most powerful not only in the Russian Federation, but also on the entire Eurasian continent. Running on natural gas, it produces up to 5,600 MW of electricity. And of the coal-fired ones, the Reftinskaya GRES has the largest power – 3800 MW. More than 3000 MW can also be provided by Kostroma and Surgutskaya GRES-1. It should be noted that the abbreviation GRES has not changed since the times of the Soviet Union. It stands for State District Power Plant.

During the reform of the industry, the production and distribution of electricity at thermal power plants must be accompanied by the technical re-equipment of existing stations and their reconstruction. Also among the priority tasks is the construction of new energy generating capacities.

Electricity from renewable resources

Electricity obtained with the help of hydroelectric power stations is an essential element of the stability of the unified energy system of the state. It is hydroelectric power plants that can increase the volume of electricity production in a matter of hours.

The great potential of Russian hydropower lies in the fact that almost 9% of the world's water reserves are located on the country's territory. This is the second place in the world in terms of the availability of hydro resources. Countries such as Brazil, Canada and the United States have been left behind. The production of electricity in the world through hydroelectric power plants is somewhat complicated by the fact that the most favorable places for their construction are significantly removed from populated areas or industrial enterprises.

Nevertheless, thanks to the electricity produced at hydroelectric power stations, the country manages to save about 50 million tons of fuel. If it were possible to harness the full potential of hydropower, Russia could save up to 250 million tons. And this is already a serious investment in the country’s ecology and the flexible capacity of the energy system.

Hydroelectric power stations

The construction of hydroelectric power stations solves many issues not related to energy production. This includes the creation of water supply and sanitation systems for entire regions, and the construction of irrigation networks, which are so necessary for agriculture, and flood control, etc. The latter, by the way, is of no small importance for the safety of people.

The production, transmission and distribution of electricity is currently carried out by 102 hydroelectric power stations, the unit capacity of which exceeds 100 MW. The total capacity of Russian hydraulic installations is approaching 46 GW.

Electricity producing countries regularly compile their rankings. So, Russia now ranks 5th in the world in generating electricity from renewable resources. The most significant objects should be considered the Zeya hydroelectric power station (it is not only the first of those built in the Far East, but also quite powerful - 1330 MW), the Volga-Kama cascade of power plants (the total production and transmission of electricity is more than 10.5 GW), the Bureyskaya hydroelectric power station ( 2010 MW), etc. I would also like to mention the Caucasian hydroelectric power stations. Of the several dozen operating in this region, the new (already commissioned) Kashkhatau hydroelectric power station with a capacity of more than 65 MW stands out the most.

The geothermal hydroelectric power stations of Kamchatka also deserve special attention. These are very powerful and mobile stations.

The most powerful hydroelectric power stations

As already noted, the production and use of electricity is hampered by the remoteness of the main consumers. However, the state is busy developing this industry. Not only are existing hydroelectric power stations being reconstructed, but new ones are also being built. They must master the mountain rivers of the Caucasus, the high-water Ural rivers, as well as the resources of the Kola Peninsula and Kamchatka. Among the most powerful, we note several hydroelectric power stations.

Sayano-Shushenskaya named after. PS Neporozhniy was built in 1985 on the Yenisei River. Its current capacity has not yet reached the estimated 6000 MW due to reconstruction and repairs after the 2009 accident.

The production and consumption of electricity at the Krasnoyarsk hydroelectric power station is designed for the Krasnoyarsk aluminum smelter. This is the only “client” of the hydroelectric power station, which was commissioned in 1972. Its design capacity is 6000 MW. The Krasnoyarsk hydroelectric power station is the only one on which a ship lift is installed. It ensures regular navigation on the Yenisei River.

The Bratsk hydroelectric power station was put into operation back in 1967. Its dam blocks the Angara River near the city of Bratsk. Like the Krasnoyarsk hydroelectric power station, the Bratsk hydroelectric station serves the needs of the Bratsk aluminum smelter. All 4,500 MW of electricity goes to him. And the poet Yevtushenko dedicated a poem to this hydroelectric station.

Another hydroelectric power station is located on the Angara River - Ust-Ilimskaya (with a capacity of just over 3800 MW). Its construction began in 1963 and ended in 1979. At the same time, the production of cheap electricity began for the main consumers: the Irkutsk and Bratsk aluminum smelters, the Irkutsk aircraft building plant.

The Volzhskaya hydroelectric power station is located north of Volgograd. Its capacity is almost 2600 MW. This largest hydroelectric power station in Europe has been in operation since 1961. Not far from Tolyatti, the oldest of the large hydroelectric power stations, Zhigulevskaya, operates. It was put into operation back in 1957. The power of the hydroelectric power station is 2330 MW and covers the electricity needs of the Central part of Russia, the Urals and the Middle Volga.

But the production of electricity necessary for the needs of the Far East is provided by the Bureyskaya HPP. We can say that it is still very “young” - commissioning took place only in 2002. The installed capacity of this hydroelectric power station is 2010 MW of electricity.

Experimental offshore hydropower plants

Numerous oceanic and sea bays also have hydroelectric potential. After all, the height difference during high tide in most of them exceeds 10 meters. This means that huge amounts of energy can be generated. In 1968, the Kislogubskaya experimental tidal station was opened. Its power is 1.7 MW.

Peaceful atom

Russian nuclear energy is a full cycle technology: from the extraction of uranium ores to the production of electricity. Today, the country has 33 power units at 10 nuclear power plants. The total installed capacity is just over 23 MW.

The maximum amount of electricity generated by the nuclear power plant was in 2011. The figure was 173 billion kWh. Per capita electricity production from nuclear power plants increased by 1.5% compared to the previous year.

Of course, the priority direction in the development of nuclear energy is operational safety. But nuclear power plants also play a significant role in the fight against global warming. Environmentalists constantly talk about this, emphasizing that only in Russia it is possible to reduce carbon dioxide emissions into the atmosphere by 210 million tons per year.

Nuclear energy developed mainly in the North-West and in the European part of Russia. In 2012, all nuclear power plants generated about 17% of all electricity produced.

Nuclear power plants in Russia

The largest nuclear power plant in Russia is located in the Saratov region. The annual capacity of the Balakovo NPP is 30 billion kW/h of electricity. At the Beloyarsk NPP (Sverdlovsk region), only the 3rd unit is currently operating. But this allows us to call it one of the most powerful. 600 MW of electricity is obtained thanks to a fast neutron reactor. It is worth noting that this was the world's first fast neutron power unit installed to produce electricity on an industrial scale.

The Bilibino Nuclear Power Plant is installed in Chukotka, which produces 12 MW of electricity. And the Kalinin NPP can be considered recently built. Its first unit was put into operation in 1984, and the last (fourth) only in 2010. The total capacity of all power units is 1000 MW. In 2001, the Rostov NPP was built and put into operation. Since the connection of the second power unit - in 2010 - its installed capacity has exceeded 1000 MW, and the capacity utilization factor was 92.4%.

Wind energy

The economic potential of Russian wind energy is estimated at 260 billion kWh per year. This is almost 30% of all electricity produced today. The capacity of all wind turbines operating in the country is 16.5 MW of energy.

Particularly favorable for the development of this industry are such regions as the ocean coasts, foothills and mountainous regions of the Urals and the Caucasus.

Electrical energy has undeniable advantages over all other types of energy. It can be transmitted by wire over vast distances with relatively low losses and conveniently distributed among consumers. The main thing is that this energy, with the help of fairly simple devices, can easily be converted into any other forms: mechanical, internal (heating of bodies), light energy. Electrical energy has undeniable advantages over all other types of energy. It can be transmitted by wire over vast distances with relatively low losses and conveniently distributed among consumers. The main thing is that this energy, with the help of fairly simple devices, can easily be converted into any other forms: mechanical, internal (heating of bodies), light energy.

Advantage of electrical energy Can be transmitted through wires Can be transmitted through wires Can be transformed Can be transformed Easily converted into other types of energy Easily converted into other types of energy Easily obtained from other types of energy Easily obtained from other types of energy

Generator - A device that converts energy of one kind or another into electrical energy. A device that converts energy of one kind or another into electrical energy. Generators include galvanic cells, electrostatic machines, thermopiles, solar batteries Generators include galvanic cells, electrostatic machines, thermopiles, solar batteries

Operation of the generator Energy can be generated either by rotating a coil in the field of a permanent magnet, or by placing the coil in a changing magnetic field (rotating the magnet while leaving the coil stationary). Energy can be generated either by rotating a coil in the field of a permanent magnet, or by placing the coil in a changing magnetic field (rotating the magnet while leaving the coil stationary).

Importance of Generator in Electrical Energy Generation The most important parts of a generator are manufactured with great precision. Nowhere in nature is there such a combination of moving parts that can generate electrical energy so continuously and economically. The most important parts of the generator are manufactured with great precision. Nowhere in nature is there such a combination of moving parts that can generate electrical energy so continuously and economically

How does a transformer work? It consists of a closed steel core assembled from plates, on which two coils with wire windings are placed. The primary winding is connected to an alternating voltage source. A load is connected to the secondary winding.

Nuclear power plants produce 17% of global output. At the beginning of the 21st century, 250 nuclear power plants are in operation, 440 power units are in operation. Most of all the USA, France, Japan, Germany, Russia, Canada. Uranium concentrate (U3O8) is concentrated in the following countries: Canada, Australia, Namibia, USA, Russia. Nuclear power plants

Comparison of types of power plants Types of power plants Emission of harmful substances into the atmosphere, kg Area occupied Clean water consumption m 3 Dirty water discharge, m 3 Environmental protection costs % CHP: coal 251.5600.530 CHP: fuel oil 150.8350 ,210 HPP NPP--900,550 WPP10--1 SPP-2---BES10-200,210

Technological schemes and environmental indicators of electricity production at thermal and nuclear power plants, heating plants and wind power plants. Modern trends in the development of the electric power industry.

Electric power industry- the energy sector, which includes the production, transmission and sale of electricity. Electric power is the most important branch of energy, which is explained by the advantages of electricity over other types of energy, such as the relative ease of transmission over long distances, distribution between consumers, as well as conversion into other types of energy (mechanical, thermal, chemical, light, etc.). A distinctive feature of electrical energy is the practical simultaneity of its generation and consumption, since electric current spreads through networks at a speed close to the speed of light.

Historical excursion: Electric energy for a long time was only an object of experimentation and had no practical application. The first attempts at the beneficial use of electricity were made in the second half of the 19th century, the main areas of use were the recently invented telegraph, electroplating, and the military. At first, galvanic cells served as sources of electricity. A significant breakthrough in the mass distribution of electricity was the invention of electric machine sources of electrical energy - generators. Compared to galvanic cells, generators had greater power and useful life, were significantly cheaper and made it possible to arbitrarily set the parameters of the generated current. It was with the advent of generators that the first power stations and networks began to appear - the electric power industry became a separate industry. The first power transmission line in history (in the modern sense) was the Laufen - Frankfurt line, which began operating in 1891. The length of the line was 170 km, voltage 28.3 kV, transmitted power 220 kW. An important stage was the invention of the electric tram: tram systems were large consumers of electrical energy and stimulated the increase in the capacity of electrical stations. In many cities, the first electrical stations were built along with tram systems.

The beginning of the 20th century was marked by the so-called “war of currents” - a confrontation between industrial manufacturers of direct and alternating currents. Direct and alternating current had both advantages and disadvantages in use. The decisive factor was the possibility of transmission over long distances - the transmission of alternating current was implemented more easily and cheaper, which determined its victory in this “war”: at present, alternating current is used almost everywhere. However, there are currently prospects for the widespread use of direct current for long-distance transmission of high power.

Electrical energy transmission and distribution

The transmission of electrical energy from power plants to consumers is carried out via electrical networks. From a technical point of view, the electrical network is a collection of power transmission lines (PTLs) and transformers located at substations.

Power lines They are a metal conductor through which electric current passes. Electricity supply in the vast majority of cases is three-phase, so a power line usually consists of three phases, each of which may include several wires. Structurally, power lines are divided into air And cable.

o Overhead power lines suspended above the ground at a safe height on special structures called supports. The main advantage of overhead power lines is their relative cheapness compared to cable lines. Maintainability is also much better (especially in comparison with brushless cable lines): there is no need to carry out excavation work to replace the wire, and visual inspection of the condition of the line is not difficult. However, overhead power lines have a number of disadvantages: a wide right-of-way - it is prohibited to erect any structures or plant trees in the vicinity of the power lines; insecurity from external influences, for example, trees falling on the line and wire theft. Due to vulnerability, one overhead line is often equipped with two circuits: the main one and the backup one. Aesthetic unattractiveness; This is one of the reasons for the almost universal transition to cable power transmission in the city.

For overhead AC lines, the following scale of voltage classes is adopted: alternating - 0.4, 6, 10, 20, 35, 110, 150, 220, 330, 400, 500, 750, 1150 kV; constant – 400, 800 kV

o Cable lines (CL) are carried out underground. Electrical cables vary in design, but common elements can be identified. The core of the cable is three conductive cores (according to the number of phases). The cables have both external and intercore insulation. Typically, liquid transformer oil or oiled paper acts as an insulator. The conductive core of the cable is usually protected by steel armor. The outside of the cable is coated with bitumen. The main advantage of cable power lines (compared to overhead lines) is the absence of a wide right-of-way. The disadvantages of cable power lines include the high cost of construction and subsequent operation. Cable lines are less accessible for visual observation.

AC lines.

Most energy is transmitted through alternating current power lines.

AC power lines have a very important advantage: anywhere on the line, a step-down transformer connected to the line transmits energy to consumers.

Disadvantages of AC lines: the presence of inductive resistance of the line, which is associated with the phenomenon of electromagnetic induction. Inductive reactance significantly impairs the transmission of electricity in the line, since it leads to a decrease in voltage along the path from the source to the consumer. Line inductance causes a phase shift between current and voltage fluctuations. To reduce inductive reactance, various methods are used: a) for example, they include capacitors in the battery line; b) splitting one wire into several, which leads to a decrease in the inductive reactance of the line.

B) Electricity can be transmitted and via DC power lines.

DC power lines have advantages over AC lines. First of all, when direct current passes, there is no inductive reactance. In addition, lower metal consumption of wires (two wires are used instead of three in three-phase current lines); less losses due to corona discharge, hence less radio interference. Finally, the main thing is that the use of direct current in power lines makes it possible to unusually increase the stability of the power system, which in the case of alternating current requires strict synchronization, constant frequency of all generators included in the overall system. For direct current there is no such problem.

Nuclear power plant (NPP)

Nuclear power plant (NPP)- a set of technical structures designed to generate electrical energy by using the energy released during a controlled nuclear reaction.

Nuclear power plants are classified according to the reactors installed on them:

· Thermal neutron reactors, which use special moderators to increase the likelihood of neutron absorption by the nuclei of fuel atoms

ü Light water reactors

ü Heavy water reactors

• Fast reactors
• Subcritical reactors using external neutron sources
• Fusion reactors

Nuclear power plants can be divided into:

• Nuclear power plants (NPPs) designed to generate only electricity
• Nuclear combined heat and power plants (CHPs), generating both electricity and thermal energy

The figure shows a diagram of the operation of a nuclear power plant with a double-circuit pressurized water power reactor. The energy released in the reactor core is transferred to the primary coolant. Next, the coolant enters the heat exchanger (steam generator), where it heats the secondary circuit water to a boil. The resulting steam enters turbines that rotate electric generators. At the exit of the turbines, the steam enters the condenser, where it is cooled by a large amount of water coming from the reservoir. Or in simpler words, nuclear fuel decays in the reactor; during its decay, thermal energy is released, which boils water, in turn, the resulting steam turns the turbine, and it rotates the electric generator, which then produces electricity.

The pressure compensator is a rather complex and cumbersome structure that serves to equalize pressure fluctuations in the circuit during reactor operation that arise due to thermal expansion of the coolant. The pressure in the 1st circuit can reach up to 160 atmospheres (VVER-1000).

In addition to water, molten sodium or gas can also be used as a coolant in various reactors. The use of sodium makes it possible to simplify the design of the reactor core shell (unlike the water circuit, the pressure in the sodium circuit does not exceed atmospheric pressure), and to get rid of the pressure compensator, but it creates its own difficulties associated with the increased chemical activity of this metal.

The total number of circuits may vary for different reactors, the diagram in the figure is shown for reactors of the VVER type (Water-Water Energy Reactor). Reactors of the RBMK type (High Power Channel Type Reactor) use one water circuit, and BN reactors (Fast Neutron Reactor) use two sodium and one water circuits.

If it is not possible to use a large amount of water for steam condensation, instead of using a reservoir, the water can be cooled in special cooling towers, which due to their size are usually the most visible part of a nuclear power plant.

Advantages of nuclear power plants:

Small volume of fuel used and the possibility of its reuse after processing;

• High power: 1000-1600 MW per power unit;
• Low cost of energy, especially thermal energy.
• Possibility of placement in regions located far from large water-energy resources, large coal deposits, in places where opportunities for the use of solar or wind power are limited.
• When a nuclear power plant operates, a certain amount of ionized gas is released into the atmosphere, but a conventional thermal power plant, along with smoke, releases an even larger amount of radiation emissions, due to the natural content of radioactive elements in coal.

Disadvantages of nuclear power plants:

· Irradiated fuel is dangerous and requires complex and expensive reprocessing and storage measures;

· Variable power operation mode is undesirable for reactors operating on thermal neutrons;

· Large capital investments, both specific, per 1 MW of installed capacity for units with a capacity of less than 700-800 MW, and general, necessary for the construction of the station, its infrastructure, as well as in the event of possible liquidation.

Wind power plants

Wind generator(wind-electric installation or abbreviated as wind turbine) is a device for converting kinetic wind energy into electrical energy.

Wind generators can be divided into two categories: industrial and domestic (for private use). Industrial ones are installed by the state or large energy corporations. As a rule, they are combined into a network, resulting in a wind power plant. Its main difference from traditional ones (thermal, nuclear) is the complete absence of both raw materials and waste. The only important requirement for a wind farm is a high average annual wind level. The power of modern wind generators reaches 6 MW.

1. Foundation

2. Power cabinet including power contactors and control circuits

4. Ladder

5. Rotating mechanism

6. Gondola

7. Electric generator

8. Wind direction and speed tracking system (anemometer)

9. Brake system

10. Transmission

11. Blades

12. System for changing the angle of attack of the blade

13. Rotor cap.

The principle of operation of wind power plants is simple: the wind turns the blades of the windmill, driving the shaft of the electric generator. That, in turn, generates electrical energy. It turns out that wind power plants work like battery-powered toy cars, only the principle of their operation is the opposite. Instead of converting electrical energy into mechanical energy, wind energy is converted into electrical current.

What are the disadvantages of wind power plants?

First of all, their work adversely affects the operation of the television network. Here is an interesting example that can be given in this regard. Several years ago, unusual complaints began to be received from residents of the Orkney Islands (UK). It turned out that during the operation of a wind farm built on one of the hills, such strong interference occurs in the operation of the television network that the image disappears on the television screens. A solution was found in the construction of a powerful television repeater next to the wind turbine, which made it possible to amplify television signals. According to reports, a 0.1 MW wind power plant can cause distortion of television signals up to 0.5 km away.

Another unexpected feature of wind turbines was that they turned out to be a source of fairly intense infrasonic noise, which has an adverse effect on the human body, causing constant depression, severe unreasonable anxiety and discomfort in life. As the experience of operating a large number of wind turbines in the USA has shown, neither animals nor birds can withstand this noise when leaving the area where the station is located, i.e. The territories of the wind station itself and those adjacent to it become unsuitable for human life, animals and birds.

However, the main disadvantage of this type of energy, along with the variability of wind speed, is its low intensity, which requires a large area to accommodate a wind installation. From the calculations carried out by specialists, it follows that the optimal diameter for a wind wheel is 100 m. With such geometric dimensions and energy density per unit area of ​​the wind wheel of 500 W/m2 (wind speed 9.2 m/s), electrical power can be obtained from the wind flow , close to 1 MW. On an area of ​​1 km 2, 2-3 installations of the specified power can be placed, taking into account the fact that they should be located one from the other at a distance equal to three of their heights, so as not to interfere with each other and not reduce the efficiency of their work.

Let us assume for assessment that there are 3 installations located on an area of ​​1 km 2, i.e. from 1 km 2 you can remove 3 MW of electrical power. This means that to accommodate a wind station with an electrical capacity of 1000 MW, an area of ​​330 km 2 is needed. If we compare wind and thermal power plants in terms of energy production throughout the year, the resulting value should be increased by at least 2-3 times. For comparison, we point out that the area of ​​the Kursk NPP with a capacity of 4000 MW, together with auxiliary structures, a cooling pond and a residential village, is 30 km2, i.e. per 1000 MW of electrical power there are 7.5 km2. In other words, the size of the territory of a wind station per 1000 MW is 2 orders of magnitude larger than the area occupied by a modern nuclear power plant.

Despite this, some scientists believe that large-scale wind energy should be developed. Before the war, more than 8,000 wind turbines operated in our country on collective and state farms alone. In 1930 On the basis of the TsAGI wind engine department, the Central Wind Energy Institute was created, and in 1938 a design bureau for wind energy installations was organized. In the pre-war years and after the war, a fairly large number (approximately 10 thousand units) of various wind turbines were developed and produced. Intensive work on the use of wind energy is being carried out in a number of foreign countries.

So, we can indicate the following advantages and disadvantages of wind energy: no influence on the thermal balance of the Earth’s atmosphere, oxygen consumption, emissions of carbon dioxide and other pollutants, the ability to be converted into various types of energy (mechanical, thermal, electrical), but at the same time low energy density, per unit area of ​​the wind wheel; unpredictable changes in wind speed during the day and season, requiring backup of a wind station or accumulation of generated energy; negative impact on the habitat of humans and animals, on television communications and seasonal bird migration routes. Domestic and foreign experience demonstrates the technical feasibility and feasibility of constructing and operating low-power wind power plants for remote villages and distant pastures, as well as in the agricultural sector.

Thermal power plants

The most common are thermal power plants (TPPs), which use thermal energy released by burning organic fuel (solid, liquid and gaseous).

Thermal power plants generate about 76% of the electricity produced on our planet. This is due to the presence of fossil fuels in almost all areas of our planet; the possibility of transporting organic fuel from the extraction site to a power plant located near energy consumers; technical progress at thermal power plants, ensuring the construction of thermal power plants with high power; the possibility of using waste heat from the working fluid and supplying it to consumers, in addition to electrical energy, also thermal energy (with steam or hot water), etc.

The diagram shows the classification of thermal power plants using fossil fuels.

A thermal power plant is a complex of equipment and devices that convert fuel energy into electrical and (in general) thermal energy.

Thermal power plants are characterized by great diversity and can be classified according to various criteria.

Based on their purpose and type of energy supplied, power plants are divided into regional and industrial.

District power plants are independent public power plants that serve all types of consumers in the region (industrial enterprises, transport, population, etc.). District condensing power plants, which generate mainly electricity, often retain their historical name - GRES (state district power plants). District power plants that produce electrical and thermal energy (in the form of steam or hot water) are called combined heat and power plants (CHP). As a rule, state district power plants and district thermal power plants have a capacity of more than 1 million kW.

Industrial power plants are power plants that supply thermal and electrical energy to specific production enterprises or their complex, for example a chemical production plant. Often industrial power plants operate on the general electrical network, but are not subordinate to the power system dispatcher.

Based on the type of fuel used, thermal power plants are divided into power plants operating on fossil fuels and nuclear fuel.

Condensing power plants operating on fossil fuels, at a time when there were no nuclear power plants (NPPs), were historically called thermal power plants (TES - thermal power plant). It is in this sense that this term will be used below, although thermal power plants, nuclear power plants, gas turbine power plants (GTPP), and combined cycle power plants (CGPP) are also thermal power plants operating on the principle of converting thermal energy into electrical energy.

Gaseous, liquid and solid fuels are used as organic fuel for thermal power plants. Most thermal power plants in Russia, especially in the European part, consume natural gas as the main fuel, and fuel oil as a backup fuel, using the latter due to its high cost only in extreme cases; Such thermal power plants are called gas-oil power plants.

Based on the type of thermal power plants used at thermal power plants to convert thermal energy into mechanical energy of rotation of the rotors of turbine units, steam turbine, gas turbine and combined cycle power plants are distinguished.

The basis of steam turbine power plants are steam turbine units (STU), which use the most complex, most powerful and extremely advanced energy machine - a steam turbine - to convert thermal energy into mechanical energy. PTU is the main element of thermal power plants, combined heat and power plants and nuclear power plants.

STPs that have condensing turbines as a drive for electric generators and do not use the heat of exhaust steam to supply thermal energy to external consumers are called condensing power plants. STUs equipped with heating turbines and releasing the heat of exhaust steam to industrial or municipal consumers are called combined heat and power plants (CHP).

Gas turbine thermal power plants (GTPPs) are equipped with gas turbine units (GTUs) running on gaseous or, in extreme cases, liquid (diesel) fuel. Currently, in Russia there is one gas turbine power plant (GRES-3 named after Klasson, Elektrogorsk, Moscow region) with a capacity of 600 MW and one gas turbine cogeneration plant (in the city of Elektrostal, Moscow region).

Thermal power plant diagram (coal-fired)

Thermal power plants operate on the following principle: fuel is burned in the furnace of a steam boiler. The heat released during combustion evaporates the water circulating inside the pipes located in the boiler and overheats the resulting steam. The steam, expanding, rotates the turbine, which, in turn, rotates the shaft of the electric generator. The exhaust steam is then condensed; water from the condenser is returned to the boiler through the heater system.

Advantages of TPP:
1. The fuel used is quite cheap.
2. Require less capital investment compared to other power plants.
3. Can be built anywhere regardless of fuel availability. Fuel can be transported to the power plant location by rail or road transport.
4. Occupy a smaller area compared to hydroelectric power plants.
5. The cost of generating electricity is less than that of diesel power plants.

Flaws:
1. They pollute the atmosphere, releasing large amounts of smoke and soot into the air.
2. Higher operating costs compared to hydroelectric power plants.

QUESTIONS:

1. Define the electric power industry.

2. What advantages does electricity have over other types of energy?

3. The invention of what device is associated with the appearance of the first power stations?

4. What, from a technical point of view, is an electrical network?

5. Name the types of power lines in terms of their design features. List their advantages and disadvantages.

6. Draw a diagram of energy transmission along alternating current lines. Advantages and disadvantages of this method of transmission.

7. Draw a diagram of energy transmission along DC lines. What is their advantage over AC lines?

8. Fill out the table:

9. What causes the widespread use of thermal power plants

Related information.

Production (generation), distribution and consumption of electrical and thermal energy: a power plant produces (or generates) electrical energy, and a heating power plant produces electrical and thermal energy. Based on the type of primary energy source converted into electrical or thermal energy, power plants are divided into thermal (CHP), nuclear (NPP) and hydraulic (HPP). At thermal power plants, the primary source of energy is organic fuel (coal, gas, oil), at nuclear power plants - uranium concentrate, at hydroelectric power plants - water (hydraulic resources). Thermal power plants are divided into condensing thermal power plants (condensing power stations - CES or state district power plants - GRES), which generate only electricity, and heating plants (CHP), which generate both electricity and heat.

In addition to thermal power plants, nuclear power plants and hydroelectric power plants, there are other types of power plants (pumped storage, diesel, solar, geothermal, tidal and wind power plants). However, their power is low.

The electrical part of the power plant includes a variety of main and auxiliary equipment. The main equipment intended for the production and distribution of electricity includes: synchronous generators that generate electricity (at thermal power plants - turbogenerators); busbars designed to receive electricity from generators and distribute it to consumers; switching devices - switches designed to turn on and off circuits in normal and emergency conditions, and disconnectors designed to remove voltage from de-energized parts of electrical installations and to create a visible break in the circuit (disconnectors, as a rule, are not designed to break the operating current of the installation); electrical receivers for own needs (pumps, fans, emergency electric lighting, etc.). Auxiliary equipment is designed to perform measurement, alarm, protection and automation functions, etc.

Energy system (power system) consists of power plants, electrical networks and electricity consumers, interconnected and connected by a common mode in the continuous process of production, distribution and consumption of electrical and thermal energy, with general management of this mode.

Electrical power (electrical) system- this is a set of electrical parts of power plants, electrical networks and electricity consumers, connected by the commonality of the regime and the continuity of the process of production, distribution and consumption of electricity. The electrical system is part of the energy system, with the exception of heating networks and heat consumers. An electrical network is a set of electrical installations for the distribution of electrical energy, consisting of substations, switchgears, overhead and cable power lines. The electrical network distributes electricity from power plants to consumers. Power transmission line (overhead or cable) is an electrical installation designed to transmit electricity.

In our country, we use standard rated (phase-to-phase) voltages of three-phase current with a frequency of 50 Hz in the range of 6-1150 kV, as well as voltages of 0.66; 0.38 (0.22) kV.

The transmission of electricity from power plants via power lines is carried out at voltages of 110-1150 kV, i.e. significantly exceeding the voltage of generators. Electrical substations are used to convert electricity of one voltage into electricity of another voltage. An electrical substation is an electrical installation designed to convert and distribute electrical energy. Substations consist of transformers, busbars and switching devices, as well as auxiliary equipment: relay protection and automation devices, measuring instruments. Substations are designed to connect generators and consumers with power lines (step-up and step-down substations P1 and P2), as well as to connect individual parts of the electrical system.