How does electricity get to us? Where does electricity come from in our house? presentation for a lesson on the world around (Grade 1) on the topic. Typical scheme for supplying electricity to a private house
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Tasks:
Learn how electricity is generated and supplied to the house;
Fix the rules safe handling with electrical appliances
Relevance of the topic: modern life is impossible without electricity.
Research methods:
Self-assembly of the simplest electrical circuit.
Excursions to the Museum entertaining sciences Einstein, to the People's Museum of Energy. L.N. Mishina (Noginsk)
Virtual tour of the Museum of PJSC "MOESK", (Moscow)
Interview with a veteran of the Eastern electrical networks.
Introduction
Dear Teachers, researchers, friends!
AT modern world We can't live without electricity.
And at a conference at the end of winter
We present to your attention
Project "Where does electricity come from to the house?"
You can't live long in a room without light,
You can't drink tea without an electric kettle,
We'll be lost without a washing machine,
We will come to school in a crumpled uniform.
After all, an iron, a computer and a doorbell
Yes, and school, which calls everyone to the lesson,
I couldn't work without electricity.
TV remote, like our flashlight,
They could not work if they appeared in old age.
What is it about electric current?
On the one hand, an assistant, a dangerous other?
How does electricity come about? Where?
And how does it come to the house to each family?
Here are the questions we are looking at
And we hope that we will become friendly with electricity!
Hypothesis A: Electricity comes into the house in many ways.
Chapter 1
Recently Ant-Question came to our lesson.
This is a very inquisitive hero of the textbook on the world around him, compiled by Andrei Anatolyevich Pleshakov.
He asked the Wise Turtle: “Where does electricity come from in our house?
To this question, many of our classmates answered that, of course, by wire. We learned this from the special educational cartoons of Aunt Owl,
Smesharikov
and Fixikov
An electric current is somewhat similar to a river, only water flows in the river, and small very small particles flow through the wires - electrons. Electric current is produced by large powerful power plants. To generate electricity at such stations, the power of water, sun and wind energy is used. Electric current first flows through thick high voltage wires, then flows through ordinary wires into our apartments, getting into switches and sockets.
We have studied the development of energy in the city of Noginsk.
To do this, we visited the Veteran of Labor, Honorary Power Engineer of the Noginsk Electric Networks Kosarev Yury Arsenyevich.
He told us that the first electrical substation of Istomkino was built in 1920, i.e. almost 100 years ago.
In 1955, the first electrical substation in Europe with a capacity of 500 kV was built in the village of Krasny Elektrik.
These substations distribute electricity that runs through wires.
from Shaturskaya and Kuibyshev hydroelectric power plants
to transformer substations, which are located in almost every yard.
For many years, the People's Museum of Energy named after Lev Nikolaevich Mishin has been operating in the Noginsk office of MOESK, long years head of the Noginsk electrical networks.
The museum is known far beyond the city limits. In December 2016, it was visited by the Governor of the Moscow Region Andrey Yuryevich Vorobyov.
“Where does the electricity come from to our school?” - we asked this question to Tatiana Andreevna Pismennaya, long time head of the museum.
She told us how electricity is generated by the Elektrogorsk GRES-3 power plant named after engineer R. E. Klasson
and runs along thick cables to the Zakharovo electrical substation.
Then he runs to the transformer station in Kadetsky Lane.
And from there to the school and residential buildings and school.
Chapter 3
We are surrounded great amount items that make life easier, powered by batteries. So the batteries have current?
This question was answered by an animator-guide of the Einstein Museum of Entertaining Sciences.
Since ancient times, many scientists have been surprised by the ability of the sea stingray to strike in the form of an electric discharge, but no one could explain how this creature manages to accumulate current for a discharge of such force and where the current comes from in this fish.
The Italian chemist and physicist Alessandro Volta drew attention to the repeating combination of plates on the back of the stingray and decided to create an accurate model of this design. It was the prototype of the modern battery.
The composition of modern batteries is more complex, but they work on the same principle. If a light bulb is connected to the battery using wires, then the negative particles will run to the positively charged particles of the rod and light the bulb.
We repeated this experiment in class. The light bulb actually lit up.
The next task of the heroes of the textbook puzzled us greatly. The ant suggested that we assemble an electrical circuit from the elements of an electrical constructor. What if there is no such constructor?
An older friend, a student of the 8th grade Pavel Yushkin, came to our aid. At home, he assembled an electrical circuit, and then explained its structure and purpose.
We bring to your attention this experience. (Demonstration)
In this way, our electric tri-che-chain has the following basic constituent elements:
current source (battery)
on-tre-bi-te-li current (LED)
key(switch)
connect-no-tel-nye pro-vo-yes
Draw a diagram of the electrical circuit we assembled with the use of conventional symbols:
Conclusion
Based on a study of the city's energy and experience in assembling an electrical circuit, we conclude that electricity enters our house in two ways: through wires and is contained in batteries, for example, in batteries.
And in conclusion, let me say
Don't forget about electrical safety.
Safety rules when getting acquainted with electricity were observed:
Baranov Ilya,
Romanov Ivan and
Temnenkova Daria.
Sources
1.A.A. Pleshakov. World around. Grade 1 (2014)
2.I. Leenson. Mysterious charges and magnets Entertaining electricity (2006)
3. Virtual Museum of Energy MOESK
4. National Museum of Energy named after Lev Mishin (Noginsk)
5. Museum of entertaining sciences of Einstein (Noginsk)
How does electricity get to our homes, what path does it travel before reaching our sockets, what transmission schemes exist and where is it generated? You will find answers to all these questions by reading this article to the end!
Figure 1. Transmission and distribution of electricity.
Types of power plants.
The main sources of electricity are power plants. Currently, the most popular and effective of them are:
- hydroelectric power plants (HPP),
- thermal power plants(CHP),
- nuclear power plants (NPP).
But geothermal, wind, solar power plants are also used to generate electricity. Recently, their popularity is growing every year, as these power plants are more environmentally friendly and safe for nature and humans.
In order to transfer electricity from the power plant to the consumer, it must go a long way through a large number of devices. What devices and why they are needed, we will now figure it out.
Figure 2. Nuclear power plant.
The most important problem of electric power transmission is that when it is transmitted over long distances, large current losses occur. The main reason for these losses is the resistance in the conductors through which electricity is transmitted. Hence the question arises, how to reduce the resistance in the wires?
To reduce the resistance in the wires, it is necessary to increase their cross-sectional area. But given the length to which the electricity must be transmitted, it is obvious that this is unprofitable. There is another way to transfer the same power through the wires, you can reduce the current flowing through the wires by increasing the voltage.
This process can be compared to water pipe where the water is electricity, a pipe is a conductor, the volume of water flowing through a pipe is power, water pressure is voltage.
Now everything is clear, increase the diameter of the pipe so that more water not profitable due to the long distance, you need to increase the pressure voltage so that more water flows through the same pipe diameter. True, you will have to increase the thickness of the pipe so that it does not break, in an electrician this will be an increase in the thickness of the insulators so that there is no breakdown. But it's still better!
Voltage of overhead power lines.
Step-up transformers are used to increase the voltage in power plants. From the power plant high voltage transmitted over power lines (TL). The voltage in the power line depends on the length over which the electricity must be transmitted.
The farther from the power plant are consumers, the higher the voltage in the power line must be in order to avoid losses. The magnitude of the voltage depending on the length of the line can be. The highest voltage transmission line in the world is located in Russia, its voltage is 1150 kV.
- Ultra-long power transmission lines with voltage from 500kV, 750kV, 1150kV.
- Main transmission lines with a voltage of 220 kV, 330 kV.
- Distribution transmission lines with a voltage of 35kV, 110kV, 150kV.
High voltage from power plants through power lines comes to the central distribution substations(PIU) which are located directly in the cities or close to them. There is a voltage drop, if necessary, and the distribution of electricity through the lines of a lower voltage of 220.110 kV. These lines feed the substations, respectively, 110.220 kV, which are distributed over the districts of the city, as a rule, these are several substations per district.
Figure 3. High voltage power line.
At 110.220 kV substations, the voltage is reduced to 6.10 kV and distributed to transformer points (TP) through cable lines that are laid in the ground. One transformer point (TP) can feed several multi-storey residential buildings. On average, it is 2, 3 or 4, depending on the number of storeys of residential buildings per one transformer substation.
The voltage of 6 or 10 kV coming to the transformer substation again decreases to the usual 0.4 kV (220, 380V) for all of us. From the transformer substation, voltage of 380V is supplied through cable lines to residential buildings. From switchboard residential buildings, electricity diverges through cable lines to floor shields, and from floor shields it is supplied to our apartments.
As everyone is well aware, electricity is delivered from the place of its production to a remote consumer via high-voltage power lines designed for voltages of 110 kV, 220 kV or 330 kV. After the electricity is delivered to your area through high-voltage wires, it must be converted into the familiar voltage of 220 volts. Therefore, first of all, it is transformed into more low voltages 6, 10 or 35 kV, and only then at local transformer substations (TS) it turns into three phase voltage 380/220 V.
Transformer substations can have various capacities and types of execution. Powerful city transformer substations are arranged, as a rule, in separate buildings, which house special step-down oil transformers and everything necessary for reliable operation substations switching and protective equipment.
High-voltage voltage supplied to urban transformer substations can be supplied to them through underground cable channels. A reduced three-phase voltage of 380/220 V is delivered directly to your house through the same underground cable channels. And only on the inlet panel of the entire building is this three-phase voltage disconnected into separate phase lines, taking into account the even distribution of loads on each of the phases.
For small rural and suburban transformer substations, a separate building, as a rule, is not provided. Rural substations are a perimeter-closed site with equipment installed directly in the open air, usually consisting of only one transformer.
At the same time, high voltage is supplied to such transformer substations via an overhead line (OHL), and the reduced voltage is distributed to linear consumers - garden houses or rural houses- along another overhead line fixed on poles (supports).
Both urban and rural transformer substations allow you to get a working three-phase voltage that enters your house through three phase wires, usually referred to as phases "A", "B" and "C". True, at the TP, one more wire N is added to these three phase wires, which is commonly called neutral. This wire appears as a result of the organization of local protective earth substation equipment, which is mounted in the immediate vicinity of it. In this case, the voltage between the pairs phase wires A-B, B-C and A-C is 380 V and is called line voltage.
The voltage between each of the phase wires and the neutral conductor is called phase and is 220 V. This is the same voltage from which all our Appliances, as well as apartment lighting devices are lit.
Such a domestic power supply scheme for residential buildings and structures is called "three-phase four-wire" and it is most often used in domestic power supply systems. The main task of the subsequent wiring of the system is to ensure that each of the three phase lines A-N, B-N and C-N has (if possible) the same load.
When connecting to a three-phase four-wire network of individual garden plots, for example, they try to distribute consumers by phases so that approximately the same number of houses are connected to each phase line and lighting fixtures installed on the territory of the garden cooperative.
In addition to distributing energy to consumers, substations of all types are also capable of solving another very important task. They are equipped with a special oil transformer winding switch, which will allow you to adjust the output voltage and set the operating voltage value of 380 V at the output of the transformer substation with a given accuracy. The operating phase voltage of 220 V supplied to the consumer will also be set with a certain accuracy, i.e. be within tolerances. And the magnitude of the deviation of the supply voltage from its nominal value and its changes during the day, as you know, largely determine the reliability of the electrical equipment and its durability.
Supply of electricity to multi-apartment and private houses.
How many of us think about how electricity gets into our home. Remembering school lessons in physics, you can draw something like the following diagram:
Electricity is generated at a power plant, then transmitted through high-voltage power lines (high-voltage power lines), then it enters city and district distribution zones.
After the RES, electricity enters the transformer substations (transformer substations), where it is reduced to the 380/220 Volts we need. And these same 380/220 volts we get as a result at home. Here we will consider the last step in more detail.
At the transformer substation, the voltage drops from 6kV or 10kV, depending on the transformer, to 380V/220V. In a transformer substation, as in an ordinary transformer, there are two parts - high and low.
Electricity supply in private sector happens in a slightly different way. If in urban conditions all communications (cables) are carried out underground, then countryside In most cases, transformer substations are powered by power lines.
A high voltage of 6 (10) kV is supplied to the transformers, then a low (relatively) -380 / 220V voltage leaves the transformer through the wires to the private sector.
This is how the electricity supply to our homes looks like.
Humanity is currently using many household electrical appliances not to mention production using electricity. Electricity has quickly become an integral part of our lives. But where does the energy we need so much come from? Even children know that it is produced by power plants. But how does it come from the power plant to our house?
The main types of power plants: nuclear power plants, hydroelectric power plants, thermal power plants. On construction sites, hospitals and sometimes in private homes use diesel plants and mini power plants. In Europe, wind and solar energy is used to generate electricity. Scientists around the world are also working on alternative species electricity, such as fusion reaction, biomass power plants. metatrader nordfx trader's office
In our country, the main sources of electricity are nuclear power plants, hydroelectric power plants and thermal power plants. More than half of the electricity produced by thermal power plants. Cities can also use combined heat and power plants, which provide the city not only with electricity, but also hot water and warmth. The cheapest electricity is produced by hydroelectric power plants.
Nuclear power plants- modern sources of electricity. They can be placed almost anywhere. Nuclear power plants do not pollute environment if all the requirements for their construction are met.
How does electricity get into our homes? What happens next? Electricity from electrically removable tires and cables is supplied to the electrical part of the power plant, which can be open, closed and combined type. In the electrical part there is a control room for the control of the power plant, an automated control system technological process(APCS), switching devices, relay protection, control and measuring instruments and signaling, high-voltage step-up and step-down transformers, high-voltage circuit breakers, busbars and autotransformers. After the conversion of energy, electricity is supplied to a high-voltage power line (VTL). Power lines that transmit electricity over long distances must have a large throughput and small losses. They consist of wires, fasteners, supports, lightning protection cables, as well as auxiliary devices. According to their purpose, power transmission lines are divided into ultra-long, trunk and distribution. Main elements overhead lines transmission lines are metal supports, which are installed at a certain distance from each other. They are anchor, intermediate and angular. Anchor supports are installed at the beginning and end of the power line, as well as at the crossing points of engineering structures or natural barriers. Intermediate supports are installed on straight sections and are designed to support wires with an allowable sag of 6-8 meters in populated areas, and 5-7 meters in non-populated areas. Corner supports are installed at the angles of rotation of the power line. Special transposition supports are installed to change the order of the wires on the supports, as well as to branch the wires from the main line of the overhead power transmission line. For the transmission of electricity in high-voltage power lines, no insulated wires made of aluminum and steel-aluminum of the following grades: AN, AZh, AKP (aluminum) and VL, AS, AKS, ASKP, ASK (steel-aluminum). Wires are attached to the poles using support or tension insulators, which are mounted on the pole. hanging way, and mounting fittings. Insulators are porcelain, glazed, glass, tempered glass, and polymeric, from special plastics. To protect the power line from lightning, lightning protection cables are pulled on the poles, arresters are installed, and the poles are grounded. Since the line usually runs for a long distance, intermediate substations with step-up transformers are used to avoid voltage losses.
For further distribution of electricity, distribution substations are connected to the main overhead transmission lines, which, in turn, distribute electricity to step-down substations. When distributing electricity from the substation to the PTS, 2 types of gaskets can be used : air and underground. In air laying, aluminum or steel-copper bare wires are usually used, which are suspended on supports. For laying underground, a power cable with copper or aluminum conductive conductors and armor that protects against mechanical influences is used. Cables of this type include brands designed for operation at voltages up to 35 kV, for example ASBl or SBL (6-10 kV), PvPBv. If the transformer substation is far away, then an air gasket is used.
From the step-down substation along the power lines, energy is distributed between the PTS, which are divided into mast and kiosk (through and dead-end). Complete transformer substations carry out voltage reduction from 10 (6) to 0.4 kV alternating current frequency of 50 Hz and are designed to supply electricity to private houses, separate settlements or small industrial facilities. In mast transformer substations, the input and output of the cable is carried out using overhead lines. KTP kiosk type are installed in the simplest concrete platform and allows for input and output by air and underground.
For the removal of overhead lines, self-supporting aluminum insulated wires SIP are used, which are suspended on wooden or concrete supports with mounting hardware. This method of laying a distribution line is used in private sectors, garage cooperatives or where it is necessary to supply a large number of consumers located at some distance from each other. Used for laying underground lineswith aluminum or copper conductors, insulated with various materials, shielded, armored, with or without protective cover. Depending on the laying method, different brands of cable can be used. For laying in special double-walled corrugated pipes can be used power cables without a protective cover and armor, such as or For laying in trenches, cables with armor and protective covers that have good protection from the physical and mechanical impact. These are cables such as AVBBSHV and (with armor and protective cover) or AVVBG and VVBG (with armor without protective cover). Depending on the nature of the stray currents, it is possible to use power cables with various types screens that are designed for laying, both in trenches and in protected pipes. These cables include the brands APvEgP or ApvASHv.
Electricity from the transformer substation is transmitted by wires to distribution points located in special rooms (panel rooms). In switchboards are installed switchgears, which not only ensure the transmission of electricity to apartments, but also supply floor and emergency lighting, elevators, ventilation, air conditioning and security systems. Distribution from the switchboard to floor boards is carried out by cables that should not spread combustion and have low smoke and gas emission rates. Such brands of cables include (aluminum conductors), (copper conductors).
For the main line, a ladder tray and special fastening brackets are used, which ensure the safety of the cable for the entire service life. To supply power from the switchboard to the floor boards, a busbar is used. The bus duct has a number of advantages in relation to the cable trunk line. One of the advantages is ease of installation (sections are easily assembled and mounted in a niche), in addition, it has smaller dimensions compared to cable line, ease of use. And, finally, from the floor boards, electricity is supplied to the meter or the metering and distribution board of the apartment.