Electric power transmission presentation. Electricity production and use. The largest hydropower plants in the world

Use of electricity The main consumer of electricity is industry, which accounts for about 70% of the electricity produced. Transport is also a major consumer. An increasing number of railway lines are being converted to electric traction.

About a third of the electricity consumed by industry is used for technological purposes (electric welding, electric heating and melting of metals, electrolysis, etc.). Modern civilization is inconceivable without the widespread use of electricity. A disruption in the supply of electricity to a large city in an accident paralyzes its life.

Electricity transmission Electricity consumers are everywhere. It is produced in relatively few places close to sources of fuel and water resources. Electricity cannot be conserved on a large scale. It must be consumed immediately upon receipt. Therefore, there is a need to transmit electricity over long distances.

Energy transfer is associated with noticeable losses. The fact is that electric current heats up the wires of power lines. In accordance with the Joule-Lenz law, the energy spent on heating the line wires is determined by the formula where R is the line resistance.

Since the power of the current is proportional to the product of the current strength and the voltage, in order to maintain the transmitted power, it is necessary to increase the voltage in the transmission line. The longer the transmission line, the more advantageous it is to use a higher voltage. So, in the high-voltage transmission line Volzhskaya HPP - Moscow and some others, a voltage of 500 kV is used. Meanwhile, alternators are built for voltages not exceeding kV.

Higher voltages would require sophisticated special measures to isolate the windings and other parts of the generators. Therefore, step-up transformers are installed at large power plants. For the direct use of electricity in the motors of the electric drive of machine tools, in the lighting network and for other purposes, the voltage at the ends of the line must be reduced. This is achieved using step-down transformers.

Recently, in connection with environmental issues, the shortage of fossil fuels and its uneven geographical distribution, it becomes expedient to generate electricity using wind power plants, solar panels, small gas generators

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Work of pupils of 11 B grade of School No. 288 in Zaozersk Erina Maria and Staritsyna Svetlana

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Electricity is a physical term that is widely used in technology and in everyday life to determine the amount of electrical energy supplied by the generator to the electrical network or received from the network by the consumer. Electricity is also a commodity purchased by participants in the wholesale market from generating companies and consumers of electricity in the retail market from energy sales companies.

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There are several ways to create electricity: Various power plants (hydroelectric power plants, nuclear power plants, thermal power plants, TPPs ...) As well as alternative sources (solar energy, wind energy, earth energy)

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Thermal power plant (TPP), a power plant that generates electrical energy as a result of the conversion of thermal energy released during the combustion of fossil fuel. The first thermal power plants appeared at the end of the 19th century and gained predominant distribution. In the mid-70s of the 20th century, thermal power plants were the main type of power plants. At thermal power plants, the chemical energy of the fuel is converted first into mechanical energy and then into electrical energy. The fuel for such a power plant can be coal, peat, gas, oil shale, fuel oil.

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Hydroelectric station (HPP), a complex of structures and equipment through which the energy of the flow of water is converted into electrical energy. A hydroelectric power station consists of a sequential chain of hydraulic structures that provide the necessary concentration of water flow and the creation of pressure, and power equipment that converts the energy of water moving under the pressure of water into mechanical energy of rotation, which, in turn, is converted into electrical energy.

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Nuclear power plant power plant in which atomic Energy converted to electrical. The power generator at a nuclear power plant is a nuclear reactor. The heat that is released in the reactor as a result of a chain reaction of fission of the nuclei of some heavy elements, then, just like in conventional thermal power plants, is converted into electricity. Unlike thermal power plants operating on fossil fuel, nuclear power plants operate on nuclear fuel.

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About 80% of the growth in GDP (gross domestic product) in developed countries is achieved through technical innovations, the bulk of which is associated with the use of electricity. Everything new to the industry, Agriculture and everyday life comes to us thanks to new developments in various industries science. Modern society impossible to imagine without electrification production activities... Already at the end of the 1980s, more than 1/3 of all energy consumption in the world was in the form of electrical energy. By the beginning of the next century, this proportion may increase to 1/2. Such an increase in electricity consumption is primarily associated with an increase in its consumption in industry.

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This raises the problem effective use this energy. When electricity is transmitted over long distances, from the producer to the consumer, heat losses along the transmission line increase in proportion to the square of the current, i.e. if the current doubles, then the heat loss increases by 4 times. Therefore, it is desirable that the current in the lines is small. For this, the voltage on the transmission line is increased. Electricity is transmitted through lines where the voltage reaches hundreds of thousands of volts. Near cities that receive energy from transmission lines, this voltage is brought to several thousand volts using a step-down transformer. In the city itself, at substations, the voltage drops to 220 volts.

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Our country covers a large territory, almost 12 time zones. This means that if in some regions the consumption of electricity is maximum, in others the working day has already ended and consumption is decreasing. For rational use of electricity generated by power plants, they are integrated into the power systems of separate regions: the European part, Siberia, the Urals, the Urals, the Far East, etc. Such a combination allows more efficient use of electricity by coordinating the work of individual power plants. Now various energy systems are united into a single energy system of Russia.

PRESENTATION ON THE TOPIC:
"PRODUCTION AND TRANSFER
ELECTRICITY "
Pupils of the 11th grade of the State Budgetary Educational Institution of Secondary School No. 1465 Startsova Tatyana.
Teacher: Kruglova Larisa Yurievna 1.Production of electricity from
power plants
a) NPP
b) hydroelectric power station
c) CHP
2.Power transmission, line types
power transmission
a) Air
b) Cable

Power generation

Electricity is produced at
power plants. There are three main
type of power plants:
o Nuclear power plants(NPP)
o Hydroelectric power plants (HPP)
o Thermal power plants, or
combined heat and power plants (CHP)

Nuclear power plants

Atomic
power plant (NPP) -
nuclear facility for
energy production in
given modes and conditions
applications,
located within
defined by the project
territory where for
achieving this
used nuclear
reactor (s) and
complex of necessary
systems, devices,
equipment and structures with
necessary workers

Principle of operation

.

The figure shows a diagram of the operation of the atomic
power plants with double-circuit water - water
power reactor. Energy released in
the reactor core, transferred to the coolant
the first circuit. Then the coolant enters
heat exchanger (steam generator), where it heats up to
boiling water of the second circuit. The resulting
steam enters turbines,
rotating power generators. Out of the turbines
steam enters the condenser, where it is cooled by a large
the amount of water coming from the reservoir.
The pressure compensator is quite
a complex and cumbersome structure that serves
to equalize pressure fluctuations in the circuit during
the operating time of the reactor arising from the thermal
expansion of the coolant. 1st circuit pressure
can reach up to 160 atm (VVER-1000).

.

In addition to water, in various reactors as
coolant can also be used melts
metals: sodium, lead, eutectic lead alloy with
bismuth, etc. The use of liquid metal
coolants allows you to simplify the design
the shell of the reactor core (as opposed to
water circuit, pressure in liquid metal
contour does not exceed atmospheric), get rid of
pressure compensator. Total number of contours
may vary for different reactors, the scheme for
The figure is for VVER type reactors (Water-to-Water Power Reactor). Reactors type
RBMK (High Power Channel Type Reactor)
uses one water circuit, reactors on fast
neutrons - two sodium and one water circuits,
promising designs of SVBR-100 reactor plants
and BREST suggest a two-circuit scheme, with a heavy
coolant in the first circuit and water in the second.

Power generation

World leaders in the production of nuclear
electricity are:
USA (836.63 billion kWh / year), 104 nuclear
reactor (20% of generated electricity)
France (439.73 billion kWh / year),
Japan (263.83 billion kWh / year),
Russia (177.39 billion kWh / year),
Korea (142.94 billion kWh / year)
Germany (140.53 billion kWh / year).
There are 436 nuclear power plants in the world
reactors with a total capacity of 371.923 GW,
Russian TVEL company supplies fuel
for 73 of them (17% of the world market)

Hydroelectric power plants

Hydroelectric power plant (HPP) - power plant, in
using energy as a source of energy
water flow. Hydroelectric power plants are usually built
on rivers, building dams and reservoirs.
For efficient production electricity at hydroelectric power plants
two main factors are needed: guaranteed
water supply all year round and possibly large
river slopes, favorable for hydro-construction
canyon-like landforms.

Principle of operation

.

The chain of hydraulic structures is
providing the necessary pressure of water entering
on the turbine blade, which drives
generators that generate electricity.
The required water pressure is formed by
dam construction, and as a result of concentration
rivers in a certain place, or by derivation -
natural flow of water. In some cases, for
to obtain the required water pressure, use
together both the dam and the derivation.
Directly in the building of the hydroelectric power station
all power equipment is located. V
depending on the purpose, it has its own
a certain division. The machine room contains
hydraulic units directly converting
energy from water flow into electrical energy.

.

Hydroelectric stations
are divided according to
from the generated power:
powerful - generate from 25 MW and above;
medium - up to 25 MW;
small hydroelectric power plants - up to 5 MW.
They are also divided depending on
maximum use of head
water:
high-pressure - more than 60 m;
medium-pressure - from 25 m;
low-pressure - from 3 to 25 m.

The largest hydropower plants in the world

Name
Power
GW
Average annual
working out
Owner
Geography
Three Gorges
22,5
100 billion kWh
R. Yangtze,
Sandouping, China
Itaipu
14
100 billion kWh
R. Caroni, Venezuela
Guri
10,3
40 billion kWh
R. Tocantins, Brazil
Churchill Falls
5,43
35 billion kWh
R. Churchill, Canada
Tucurui
8,3
21 billion kWh
R. Parana,
Brazil / Paraguay

Thermal power plants

Thermal power plant (or thermal
power station) -
power plant generating
electrical energy due
transformation of chemical
fuel energy into mechanical energy
rotation of the generator shaft.

Principle of operation

Types

Boiler and turbine power plants
Condensing power plants (IES, historically
received the name GRES - state district
power station)
Combined heat and power plants (cogeneration
power plants, CHP)
Gas turbine power plants
Power plants based on combined cycle plants
Reciprocating power plants
engines
Compression ignition (diesel)
Spark ignition
Combined cycle

Electricity transmission

Transfer of electrical energy from electrical
stations to consumers are carried out
on electrical networks. Power grid facilities -
natural monopoly sector of the electric power industry:
the consumer can choose from whom to buy
electricity (i.e. power supply company),
the power supply company can choose among
wholesale suppliers (manufacturers
electricity), but the network through which the
electricity, as a rule, is one, and the consumer
technically cannot choose the power grid
company. From a technical point of view, electrical
a network is a collection of lines
power transmission lines and transformers,
located at substations.

.

Power lines represent
metal conductor through which it passes
.
electric
current. Nowadays practically
alternating current is commonly used.
Power supply overwhelmingly
cases - three-phase, so the line
power transmission, as a rule, consists of three phases,
each of which may include several
wires.

Power lines are divided into 2 types:

Air
Cable

Air

Overhead transmission lines are suspended above the ground at a safe height at
special structures called piers. Typically, the wire on
the overhead line has no surface insulation; insulation is available in places
fastening to supports. The overhead lines have lightning protection systems.
The main advantage of overhead power transmission lines is their
relative cheapness in comparison with cable. Also much better
maintainability (especially in comparison with brushless CLs): not
it is required to carry out excavation work to replace the wire, nothing is difficult
visual inspection of the line condition. However, overhead power lines have a number of
disadvantages:
wide strip of alienation: in the vicinity of power lines it is forbidden to install any
constructions and planting trees; when the line passes through the forest, trees along
the entire width of the right-of-way is cut down;
insecurity from external influences, for example, falling trees on
line and wire theft; despite the lightning protection devices, air
lines also suffer from lightning strikes. Due to vulnerability, one
the overhead line is often equipped with two circuits: the main and the backup;
aesthetic unattractiveness; this is one of the reasons practically
widespread transition to cable power transmission in urban
line.

Cable

Cable lines (CL) are conducted underground. Electrical
cables are of various designs, but it is possible to identify
common elements. The core of the cable is three
conductors (according to the number of phases). The cables have both
external and inter-core insulation. Usually as
the insulator is liquid transformer oil,
or oiled paper. Conductive cable core,
usually protected by steel armor. From the outside
the cable is covered with bitumen. There are collector and
brushless cable lines. In the first case, the cable
is laid in underground concrete channels - collectors.
At certain intervals, the line is equipped with
exits to the surface in the form of hatches - for convenience
penetration of repair crews into the collector.
Brushless cable lines are laid
directly in the ground.

.

Brushless lines are significantly cheaper than collector lines when
construction, but their operation is more costly due to
inaccessibility of the cable. The main advantage of cable lines
power transmission (compared to overhead) is the lack of a wide
right of way. Provided that it is deep enough,
various structures (including residential) can be built
directly above the manifold line. In the case of a brushless
laying construction is possible in the immediate vicinity of the line.
Cable lines do not spoil the cityscape with their appearance, they are much
better air protection from external influences. To the disadvantages
cable power lines can be attributed to the high cost
construction and subsequent operation: even in the case of a brushless
laying the estimated cost of a running meter of a cable line is several times higher,
than the cost of an overhead line of the same voltage class. Cable
lines are less accessible for visual observation of their state (and in the case of
brushless styling - not available at all), which is also
a significant operational disadvantage.

Types of power plants Thermal (TPP) - 50% Thermal (TPP) - 50% Hydroelectric power plants (HPP)% Hydroelectric power plants (HPP)% Nuclear (NPP) - 15% Nuclear (NPP) - 15% Alternative sources Alternative energy sources - 2 - 5% (solar energy, fusion energy, tidal energy, wind energy) energy - 2 - 5% (solar energy, fusion energy, tidal energy, wind energy)

Electric current generator The generator converts mechanical energy into electrical energy The generator converts mechanical energy into electrical Action generator is based on the phenomenon of electromagnetic induction The action of the generator is based on the phenomenon of electromagnetic induction

The frame with the current is the main element of the generator The rotating part is called the ROTOR (magnet). The rotating part is called the ROTOR (magnet). The fixed part is called STATOR (frame) The fixed part is called STATOR (frame) When the frame rotates, penetrating the frame, the magnetic flux changes in time, as a result of which an induction current appears in the frame

Electricity transmission Power transmission lines (PTL) are used to transmit electricity to consumers. When electricity is transmitted over a distance, it is lost due to heating of the wires (Joule-Lenz law). Ways to reduce heat losses: 1) Reducing the resistance of wires, but increasing their diameter (heavy - difficult to hang, and expensive - copper). 2) Reducing the current by increasing the voltage.

Influence of thermal power plants on environment TPP - lead to thermal pollution of the air with fuel combustion products. Hydroelectric power plants - lead to the flooding of huge areas that are removed from land use. NPP - can lead to the release of radioactive substances.

The main stages of production, transmission and consumption of electricity 1. Mechanical energy is converted into electrical energy using generators in power plants. 1. Mechanical energy is converted into electrical energy using generators in power plants. 2. The voltage is increased to transmit electricity over long distances. 2. The voltage is increased to transmit electricity over long distances. 3. Electricity is transmitted at high voltage through high voltage power lines. 3. Electricity is transmitted at high voltage through high voltage power lines. 4. When distributing electricity to consumers, the voltage is lowered. 4. When distributing electricity to consumers, the voltage is lowered. 5. When electricity is consumed, it is converted into other types of energy - mechanical, light or internal. 5. When electricity is consumed, it is converted into other types of energy - mechanical, light or internal.

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The presentation on "Power generation and transmission" can be downloaded absolutely free of charge on our website. Project subject: Physics. Colorful slides and illustrations will help you engage your classmates or audience. To view the content, use the player, or if you want to download the report - click on the corresponding text under the player. The presentation contains 10 slide (s).

Presentation slides

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Electrical energy has undeniable advantages over all other types of energy. It can be transmitted via wires over great distances with relatively low losses and can be conveniently distributed among consumers. The main thing is that with the help of fairly simple devices it is easy to convert into any other types of energy: mechanical, internal, light energy, etc.

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The twentieth century has become a century when science invades all spheres of society: economy, politics, culture, education, etc. Naturally, science directly affects the development of energy and the scope of electricity. On the one hand, science contributes to the expansion of the scope of application of electric energy and thereby increases its consumption, but on the other hand, in an era when the unlimited use of non-renewable energy resources is dangerous for future generations, the tasks of developing energy-saving technologies and their implementation are becoming topical tasks of science.

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The use of electricity.

Electricity consumption doubles in 10 years

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Consider these questions at specific examples... About 80% of the growth in GDP (gross domestic product) in developed countries is achieved through technical innovations, the bulk of which is associated with the use of electricity. Most scientific research starts with theoretical calculations. All new theoretical developments are verified experimentally after calculations on a computer. And, as a rule, at this stage, research is carried out using physical measurements, chemical analyzes, etc. Here, the tools of scientific research are diverse - numerous measuring instruments, accelerators, electron microscopes, magnetic resonance tomographs, etc. Most of these experimental science tools run on electrical energy.

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But science not only uses electricity in its theoretical and experimental fields, scientific ideas constantly arise in the traditional field of physics related to the generation and transmission of electricity. Scientists, for example, are trying to create electrical generators without rotating parts. In conventional electric motors, a direct current must be applied to the rotor in order to create a "magnetic force". Modern society cannot be imagined without the electrification of production activities. Already at the end of the 1980s, more than 1/3 of all energy consumption in the world was in the form of electrical energy. By the beginning of the next century, this proportion may increase to 1/2. Such an increase in electricity consumption is primarily associated with an increase in its consumption in industry. Main part industrial enterprises runs on electrical energy. High energy consumption is typical for such energy-intensive industries as metallurgy, aluminum and mechanical engineering. Transport is also a major consumer. An increasing number of railway lines are being converted to electric traction. Almost all villages and villages receive electricity from state power plants for industrial and domestic needs.

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Electricity transmission and distribution

1% of electricity losses per day - 0.5 million rubles loss To reduce heat losses in power transmission lines (PTL), you can increase the cross-section of the conductors S, which is economically unprofitable, or reduce the current I. So that the transmitted power p = IU remains unchanged at decreasing the current strength, it is necessary to increase the voltage U in the transmission line (U-500 Kv.; 750 Kv.; 1150 Kv.; - transmission lines)