Principles of assembling an electric generator at home. How to make a homemade generator from an asynchronous motor Do it yourself generator

Constant and uninterrupted supply of electricity in the house is the key to a pleasant and comfortable pastime at any time of the year. To organize autonomous power supply suburban area, we will have to resort to mobile installations - electric generators, which in last years especially popular due to the large range of different capacities.

Scope of application

Many people are interested in how to make an electric generator for a summer cottage? We will talk about this below. In most cases we use an asynchronous generator alternating current, which will produce energy to operate electrical appliances. In an asynchronous generator, the speed of rotation of the rotors than in a synchronous one and the efficiency will be higher.

However, power plants have found their application in a wider range, such as excellent remedy for energy production, namely:

• They are used in wind power plants.
• Used as welding units.
• They provide autonomous support for electricity in the house on a par with a miniature hydroelectric power station.

The unit is turned on using the incoming voltage. Often, the device is connected to power to start up, but this is not entirely logical and rational decision for a mini-station, which itself must generate electricity, and not consume it to run. Therefore, in recent years, generators with self-excitation or series switching of capacitors have been actively produced.

How does an electric generator work?

An asynchronous power generator produces a resource if the speed of rotation of the motor is faster than synchronous. The most common generator operates at parameters starting from 1500 rpm.

It produces power if the rotor at start is running faster than the synchronous speed. The difference between these figures is called slip and is calculated as a percentage of the synchronous speed. However, the stator speed is even higher than the rotor speed. Due to this, a stream of charged particles is formed that change polarities.

Watch the video, how it works:

When energized, the connected power generator device takes control of the synchronous speed by independently controlling the slip. The energy leaving the stator passes through the rotor, however, active nutrition has already moved into the stator coils.

The basic principle of operation of an electric generator is the conversion of mechanical energy into electrical energy. Strong torque is required to start the rotor to produce power. The most adequate option, according to electricians, is “perpetual idling,” which maintains one rotation speed while the generator is operating.

Why is an asynchronous generator used?

Unlike a synchronous generator, an asynchronous one has a huge number of advantages and disadvantages. The main factor in choosing the asynchronous option was the low clear factor. A high clear factor characterizes the quantitative presence of higher harmonics in the output voltage. They cause unnecessary heating of the motor and uneven rotation. Synchronous generators have a clear factor value of 5-15%; in asynchronous ones it does not exceed 2%. It follows from this that an asynchronous energy generator produces only useful energy.

A little about the asynchronous generator and its connection:

An equally significant advantage of this type of electric generator is the complete absence of rotating windings and electronic parts that are sensitive to damage and external factors. Consequently, this type of device is not subject to active wear and will last longer.

How to make a generator with your own hands

Device asynchronous alternating current generator

Purchasing an asynchronous electric generator is quite an expensive pleasure for the average resident of our country. Therefore, many craftsmen resort to solving the issue of self-assembly apparatus. The principle of operation, as well as the design, is quite simple. If you have all the tools, assembly will not take more than 1-2 hours.

According to the above-defined principle of operation of the electric generator, all equipment should be configured so that the rotations are faster than the engine speed. To do this, you need to connect the engine to the network and start it. To calculate the number of revolutions per minute, use a tachometer or tachogenerator.

Having determined the value of the engine rotation speed, add 10% to it. If the rotation speed is 1500 rpm, then the generator should run at 1650 rpm.

Now you need to remake the asynchronous generator “for yourself”, using capacitors of the required capacities. Use the following label to determine the type and capacity:

We hope it is already clear how to assemble an electric generator with your own hands, but please note: the capacitor capacity should not be very high, otherwise the generator running on diesel fuel will get very hot.

Install capacitors according to calculations. Installation requires a fair amount of attention. Ensure good insulation and use special coverings if necessary.

At the engine base, the generator assembly process is completed. Now it can already be used as a necessary source of energy. Remember that in the case where the device has a squirrel-cage rotor and produces a fairly serious voltage that exceeds 220 volts, it is necessary to install a step-down transformer that stabilizes the voltage at the required level. Remember, in order for all appliances in the house to work, there must be strict control of the homemade 220-volt electric generator.

Watch the video, stages of work:

For a generator that will operate at low power, in order to save money, you can use single-phase asynchronous motors from old or unnecessary household electrical appliances, for example, washing machines, drainage pumps, lawn mowers, chainsaws, etc. Motors from such household appliances should be connected in parallel to the winding. Alternatively, phase shifting capacitors can be used. They rarely differ in required power, so it will need to be increased to the required levels.

Such generators perform very well when it is necessary to power light bulbs, modems and other small devices with a stable active voltage. With certain knowledge, you can connect an electric generator to an electric stove or heater.

The generator, ready for operation, should be installed so that it is not affected by precipitation and environment. Take care of an additional casing that will protect the installation from adverse conditions.

Almost every asynchronous generator, be it a brushless, electric, gasoline or diesel generator, is considered a device with a fairly high level of danger. Handle such equipment very carefully and always keep it protected from external weather and mechanical influences or make a casing for it.

Let's watch the video, good advice specialist:

Any autonomous unit should be equipped with special measuring instruments that will record and display data on operating efficiency. To do this, you can use a tachometer, voltmeter and frequency meter.

• Equip the generator with an on/off button whenever possible. To start, you can use manual start.
• Some electric generators require grounding before use, carefully assess the area and select a location for installation.
• When converting mechanical energy into electricity, sometimes the efficiency can drop by up to 30%.
• If you are not confident in your abilities or are afraid of doing something wrong, we advise you to purchase a generator at the appropriate store. Sometimes risks can turn out extremely bad...
• Monitor the temperature asynchronous generator and its thermal regime.

Results

Despite their ease of implementation, homemade electric generators are a very painstaking work that requires complete concentration on the design and correct connection. Assembly is only advisable from a financial point of view if you already have a working and unnecessary engine. Otherwise, you will pay more than half of its cost for the main element of the installation, and the total costs may significantly exceed the market value of the generator.

It is difficult not to notice how the stability of electricity supplies to suburban facilities differs from the provision of urban buildings and enterprises with electricity. Admit that you, as the owner of a private home or cottage, have more than once encountered interruptions, associated inconveniences and damage to equipment.

The listed negative situations, along with the consequences, will no longer complicate the lives of lovers of natural spaces. Moreover, with minimal labor and financial costs. To do this, you just need to make a wind power generator, which we describe in detail in the article.

We have described in detail the options for manufacturing a system that is useful in the household and eliminates energy dependence. According to our advice, an inexperienced home craftsman can build a wind generator with his own hands. This practical device will help to significantly reduce your daily expenses.

Alternative energy sources are the dream of any summer resident or homeowner whose plot is located far from central networks. However, when we receive bills for electricity consumed in a city apartment and look at the increased tariffs, we realize that a wind generator created for domestic needs would not hurt us.

After reading this article, perhaps you will make your dream come true.

Wind generator – perfect solution to provide a suburban facility with electricity. Moreover, in some cases, installing it is the only possible solution.

In order not to waste money, effort and time, let's decide: are there any external circumstances that will create obstacles for us during the operation of the wind generator?

To provide electricity to a summer house or small cottage, it is enough, the power of which will not exceed 1 kW. Such devices in Russia are equated to household products. Their installation does not require certificates, permits or any additional approvals.

The principle of operation of a wind turbine

A wind generator or wind power plant (WPP) is a device that is used to convert the kinetic energy of wind flow into mechanical energy. The resulting mechanical energy rotates the rotor and is converted into the electrical form we need.

The principle of operation and device are described in detail in the article, which we recommend that you read.

The wind turbine includes:

• blades forming a propeller,
• rotating turbine rotor,
• the generator axis and the generator itself,
• an inverter that converts alternating current into direct current, which is used to charge batteries,
• battery.

The essence of wind turbines is simple. As the rotor rotates, a three-phase alternating current is generated, which then passes through the controller and charges battery direct current. The inverter then converts the current so that it can be consumed to power lights, radios, TVs, microwaves, and so on.

The detailed design of a wind generator with a horizontal axis of rotation allows you to clearly imagine which elements contribute to the conversion of kinetic energy into mechanical, and then into electrical

In general, the operating principle of a wind generator of any type and design is as follows: during the rotation process, three types of force effects occur on the blades: braking, impulse and lifting.

This diagram of the operation of a wind turbine allows you to understand what happens to the electricity produced by the operation of the wind generator: part of it is accumulated, and the other is consumed

The last two forces overcome the braking force and set the flywheel in motion. On the stationary part of the generator, the rotor generates a magnetic field to electricity followed the wires.

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Classification of types of energy generators

There are several criteria by which wind power plants are classified. How to choose the best device option for a country property is described in detail in one of our websites.

So, windmills differ in:

• number of blades in the propeller;
• blade manufacturing materials;
• the location of the axis of rotation relative to the surface of the earth;
• pitch feature of the screw.

There are models with one, two, three blades and multi-blades.

Products with a large number The blades begin to rotate even in light winds. They are usually used in work where the rotation process itself is more important than generating electricity. For example, to extract water from deep wells.

It turns out that wind turbine blades can be made not only from hard materials but also from affordable fabric

The blades can be sail or rigid. Sailing products are much cheaper than rigid ones, which are made from metal or fiberglass. But they have to be repaired very often: they are fragile.

Regarding the location of the axis of rotation relative to the earth's surface, horizontal models are also distinguished. And in this case, each variety has its own advantages: vertical ones react more sensitively to every breath of wind, but horizontal ones are more powerful.

Wind generators are divided according to step characteristics into models with fixed and variable pitch. The variable pitch allows you to significantly increase the rotation speed, but this installation has a complex and massive design. Fixed-pitch wind turbines are simpler and more reliable.

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Rotary wind turbine

Let's figure out how to make a simple windmill with a vertical axis of rotation of the rotor type with your own hands. Such a model may well provide the electricity needs of a garden house, various outbuildings, and also provide illumination in the dark. local area and garden paths.

The blades of this rotor-type installation with a vertical axis of rotation are clearly made from elements cut from a metal barrel

Our goal is to produce a wind turbine with a maximum power of 1.5 kW.

To do this we will need the following elements and materials:

• 12 V car generator;
• 12 V gel or acid battery;
• semi-hermetic switch of the “button” variety for 12 V;
• converter 700 W – 1500 W and 12V – 220V;
• a bucket, large-capacity pan or other capacious container made of stainless steel or aluminum;
• car charge or battery charging warning lamp relay;
• car voltmeter (you can use any one);
• bolts with nuts and washers;
• wires with a cross section of 4 square mm and 2.5 square mm;
• two clamps for securing the generator to the mast.

In the process of completing the work, we will need a grinder or metal scissors, a construction pencil or marker, a tape measure, wire cutters, a drill, a drill, keys and a screwdriver.

You can also assemble a controller for a system that generates electricity yourself. The article will introduce you to the rules and manufacturing schemes, the contents of which we recommend that you familiarize yourself with.

Starting stage of the plant manufacturing

We start making a homemade windmill by taking a large metal container cylindrical. Usually, an old boiling pot, bucket or pan is used for this purpose. It will be the basis for our future WPP.

Using a tape measure and a construction pencil (marker), apply markings: divide our container into four equal parts.

When making cuts in accordance with the instructions contained in the text, under no circumstances cut through the metal all the way through.

The metal will have to be cut. To do this, you can use the grinder. It is not used for cutting containers made of galvanized steel or painted sheet metal, because this type of metal will certainly overheat. For such cases, it is better to use scissors. We cut out the blades, but do not cut them through to the very end.

Simultaneously with the continuation of work on the tank, we will remodel the generator pulley. In the bottom of the former pan and in the pulley you need to mark and drill holes for the bolts. The work at this stage must be treated with the utmost care: all holes must be located symmetrically so that no imbalance occurs during the rotation of the installation.

This is how the blades of another design with a vertical axis of rotation look like. Each blade is manufactured separately and then mounted into a common device

We bend the blades so that they do not stick out too much. When we perform this part of the work, we be sure to take into account which direction the generator will rotate.

Usually the direction of its rotation is clockwise. The bending angle of the blades affects the area of ​​influence of air flows and the speed of rotation of the propeller.

Now you need to attach a bucket with blades prepared for work to the pulley. We install the generator on the mast, securing it with clamps. All that remains is to connect the wires and assemble the circuit. Be prepared to write down the wiring diagram, wire colors, and pin markings. You will certainly need it later. We fix the wires on the mast of the device.

To connect the battery, you need to use wires with a cross section of 4 mm². It is enough to take a segment of 1 meter in length. That's enough.

And in order to connect a load to the network, which includes, for example, lighting and electrical devices, wires with a cross-section of 2.5 mm² are sufficient. Install the inverter (converter). For this you will also need a 4 mm² wire.

Advantages and disadvantages of the rotary windmill model

If you did everything carefully and consistently, then this wind generator will work successfully. In this case, no problems will arise during its operation.

If you use a 1000 W converter and a 75A battery, this installation will provide electricity to both video surveillance devices and burglar alarm and even street lighting.

The advantages of this model are:

• economical;
• elements can be easily replaced with new ones or repaired;
• no special conditions are required for operation;
• reliable in operation;
• provides complete acoustic comfort.

There are also disadvantages, but not too many: the performance of this device is not very high, and it has a significant dependence on sudden gusts of wind. Air currents can simply disrupt an improvised propeller.

In order to accurately select the model of wind generator of the required power before starting work, we recommend using the formulas given in the recommended article.

Assembly of an axial wind turbine on neodymium magnets

Since neodymium magnets appeared in Russia relatively recently, axial wind generators with iron-free stators began to be made not so long ago.

The appearance of magnets caused a rush of demand, but gradually the market became saturated, and the cost of this product began to decline. It became available to craftsmen, who immediately adapted it to their various needs.

Axial wind turbine on neodymium magnets with a horizontal axis of rotation – more complex design, requiring not only skill, but also certain knowledge

If you have a hub from an old car with brake discs, then we will take it as the basis for the future axial generator.

It is assumed that this part is not new, but has already been used. In this case, it is necessary to disassemble it, check and lubricate the bearings, thoroughly clean away sedimentary deposits and all rust. Don't forget to paint the finished generator.

The hub with brake discs, as a rule, goes to craftsmen as one of the components of an old car that has been scrapped, and therefore needs thorough cleaning

Distributing and securing magnets

Neodymium magnets must be glued to the rotor disks. For our work, we will take 20 magnets 25x8mm.

Of course, a different number of poles can be used, but it is necessary to observe following rules: the number of magnets and poles in a single-phase generator should be the same, but if we are talking about a three-phase model, then the ratio of poles to coils should be 2/3 or 4/3.

When placing magnets, the poles alternate. It's important not to make a mistake. If you are not sure that you will place the elements correctly, make a hint template or apply the sectors directly to the disk itself.

If you have a choice, buy better not round, but rectangular magnets. In rectangular models, the magnetic field is concentrated along the entire length, and in round ones - in the center.

The opposing magnets must have different poles. You won't confuse anything if you use a marker to mark them with minus or plus signs. To determine the poles, take magnets and bring them close to each other.

If the surfaces attract, put a plus on them, if they repel, then mark them with minuses. When placing magnets on disks, alternate poles.

The magnets are installed in compliance with the rule of alternating policies, plasticine sides are located along the outer and inner perimeters: the product is ready to be filled with epoxy resin

To securely fasten the magnet, you need to use high-quality and as strong glue as possible.

To enhance the reliability of fixation, you can use epoxy resin. It should be diluted as indicated in the instructions and filled with it on the disc. The resin should cover the entire disc, but not run off it. You can prevent the possibility of dripping if you wrap the disk with tape or make temporary plasticine barriers made of a polymer strip around its perimeter.

Single-phase and three-phase generators

If we compare single-phase and three-phase stators, the latter will be better. A single-phase generator vibrates when loaded. The cause of vibration is the difference in the amplitude of the current, which arises due to its inconsistent output at a time.

The three-phase model does not have such a disadvantage. It is characterized by constant power due to phases that compensate each other: when the current increases in one, it decreases in the other.

According to the testing results, the output of the three-phase model is almost 50% greater than that of the single-phase model. Another advantage of this model is that in the absence of unnecessary vibration, acoustic comfort increases when the device operates under load.

That is, a three-phase generator practically does not hum during its operation. When vibration is reduced, the service life of the device logically increases.

In the fight between three-phase and single-phase devices, three-phase invariably wins, because it does not hum so much during operation and lasts longer than single-phase

Rules for winding a reel

If you ask a specialist, he will say that before winding the coils, you need to perform a careful calculation. A practitioner in this matter will rely on his intuition.

We chose a generator that was not very fast. Our charging procedure for a twelve-volt battery should begin at 100-150 rpm. Such initial data require that the total number of turns of all coils be 1000-1200 pieces. We just have to divide this figure between all the coils and determine how many turns there will be on each.

A windmill at low speeds can be more powerful if the number of poles increases. The frequency of current oscillations in the coils will increase. If you use a larger cross-sectional wire to wind the coils, the resistance will decrease and the current will increase. Don't lose sight of the fact that higher voltage can "eat up" current due to winding resistance.

The winding process can be made easier and more efficient if you use a special machine for this purpose.

It is not at all necessary to do such a routine process as winding coils by hand. A little ingenuity and an excellent machine that can easily cope with winding are already there

The performance characteristics of homemade generators are greatly influenced by the thickness and number of magnets that are located on the disks. The total total power can be calculated by winding one coil and then spinning it in a generator. The future power of the generator is determined by measuring the voltage at specific speeds without load.

Let's take an example. With a resistance of 3 ohms and 200 rpm, 30 volts comes out. If you subtract 12 volts of battery voltage from this result, you get 18 volts. Divide this result by 3 ohms and get 6 amperes. The volume is 6 amperes and will go to the battery. Of course, in the calculation we did not take into account the losses in the wires and on the diode bridge: the actual result will be less than the calculated one.

Usually the coils are made round. But, if you stretch them out a little, you will get more copper in the sector and the turns will be straighter. If you compare the size of the magnet and the diameter of the inner hole of the coils, then they should match each other or the size of the magnet may be slightly smaller.

Ready-made coils should correspond in size to the magnets: they should be slightly larger than the magnets or equal in size to them

The thickness of the stator we make must be correctly related to the thickness of the magnets. If the stator is made larger by increasing the number of turns in the coils, the interdisk space will increase and the magnetic flux will decrease. The result may turn out to be this: the same voltage is generated, but due to the increased resistance of the coils, we will receive less current.

Plywood is used to make the stator mold. However, sectors for coils can be marked on paper using plasticine as borders.

If you place fiberglass fabric on top of the coils at the bottom of the mold, the strength of the product will increase. Before application epoxy resin You need to lubricate the mold with Vaseline or wax, then the resin will not stick to the mold. Some people use tape or film instead of lubricant.

The coils are fixed to each other. In this case, the ends of the phases are brought out. The six wires brought out should be connected in a star or triangle. By rotating the assembled generator by hand, it is tested. If the voltage is 40 V, then the current will be approximately 10 amperes.

Final assembly of the device

The length of the finished mast should be approximately 6-12 meters. With such parameters, its base must be concreted. The windmill itself will be fixed to the top of the mast.

In order to be able to reach it in the event of a breakdown, it is necessary to provide a special mount at the base of the mast, which will allow the pipe to be raised and lowered using a hand winch.

The mast with the wind generator attached to it rises high, but the prudent master made special device, which allows, if necessary, to lower the structure to the ground

To make a screw, you can use a pipe PVC diameter 160 mm. It will be used to cut a two-meter propeller consisting of six blades from its surface. It is better to develop the shape of the blades yourself experimentally. The goal is to increase torque at low rpm.

The propeller should be protected from excessive wind. To solve this problem, use a folding tail. The generated energy is stored in batteries.

We have provided our readers with two options for self-made 220 V wind generators, which enjoy increased attention not only from country property owners, but also from ordinary summer residents.

Both wind turbine models are effective in their own way. Especially good results These devices can be demonstrated in steppe areas with frequent and strong winds. They are efficient enough to be used in organizing and supplying electricity. And they are not so difficult to build with your own hands.

Conclusions and useful video on the topic

This video shows an example of a wind turbine with a horizontal axis of rotation. The author of the device explains in detail the nuances of the design of the installation, made by hand, draws the audience's attention to mistakes that may be made in the process self-made wind generator, gives practical advice.

Please note that getting to the device, raised to a decent height, is not so easy. Reinstalling such a wind turbine will most likely be problematic. Therefore, the folding design of the mast in this case will not be superfluous at all.

This video shows a rotary windmill with a vertical axis of rotation. This installation is located low, made in an original way and is highly sensitive: even a slight wind sets the blades of the device in motion.

If you live in an area where winds are not considered a rare phenomenon, using this particular source of alternative energy may be the most effective for you. The above examples of self-made windmills prove that making them with your own hands is not so difficult. Wind energy is a publicly accessible and renewable resource that can and should be used.

We invite site visitors interested in the topic of the article to express their opinions in the comments and ask questions that arose while reading the material.

For the needs of constructing a private residential building or cottage home handyman You may need an autonomous source of electrical energy, which you can buy in a store or assemble with your own hands from available parts.

A homemade generator can operate on the energy of gasoline, gas or diesel fuel. To do this, it must be connected to the engine through a shock-absorbing coupling, which ensures smooth rotation of the rotor.

If local natural conditions allow, for example, frequent winds blow or a source is located nearby running water, then you can create a wind or hydraulic turbine and connect it to an asynchronous three-phase motor to generate electricity.

Thanks to such a device, you will have a constantly working alternative source electricity. It will reduce energy consumption from public networks and allow you to save on its payment.

In some cases, it is permissible to use single-phase voltage to rotate an electric motor and transmit torque to it. homemade generator to create your own three-phase symmetrical network.

How to choose an asynchronous motor for a generator based on design and characteristics

Technological features

The basis of a homemade generator is asynchronous electric motor three-phase current with:

• phase;
• or a squirrel-cage rotor.

Stator device

The magnetic cores of the stator and rotor are made of insulated electrical steel plates, in which grooves are created to accommodate the winding wires.

Three separate stator windings can be connected at the factory according to the following diagram:

• stars;
• or triangle.

Their terminals are connected inside the terminal box and connected by jumpers. The power cable is also installed here.

In some cases, wires and cables may be connected in other ways.

Symmetrical voltages are supplied to each phase of the asynchronous motor, shifted along the angle by a third of the circle. They generate currents in the windings.

It is convenient to express these quantities in vector form.

Rotor design features

Wound rotor motors

They are equipped with a winding made like a stator winding, and the leads from each are connected to slip rings, which provide electrical contact with a launch and adjustment circuit through pressure brushes.

This design is quite difficult to manufacture and expensive. It requires periodic monitoring of operation and qualified maintenance. For these reasons, it makes no sense to use it in this design for a homemade generator.

However, if there is a similar motor and it has no other application, then the conclusions of each winding (those ends that are connected to the rings) can be shorted to each other. In this way, the wound rotor will turn into a short-circuited one. It can be connected according to any scheme discussed below.

Squirrel-cage motors

Aluminum is poured inside the grooves of the rotor magnetic circuit. The winding is made in the form of a rotating squirrel cage (for which it received such an additional name) with jumper rings short-circuited at the ends.

This is the most simple circuit engine, which is devoid of moving contacts. Due to this, it operates for a long time without the intervention of electricians and is characterized by increased reliability. It is recommended to use it to create a homemade generator.

Markings on the motor housing

In order for a homemade generator to work reliably, you need to pay attention to:

• , characterizing the quality of protection of the housing from environmental influences;
• power consumption;
• speed;
• winding connection diagram;
• permissible load currents;
• Efficiency and cosine φ.

The principle of operation of an asynchronous motor as a generator

Its implementation is based on the method of reversibility of an electric machine. If the motor, disconnected from the mains voltage, begins to forcibly rotate the rotor at the design speed, then an EMF will be induced in the stator winding due to the presence of residual magnetic field energy.

All that remains is to connect a capacitor bank of the appropriate rating to the windings and a capacitive leading current will flow through them, which has a magnetizing character.

In order for the self-excitation of the generator to occur, and a symmetrical system of three-phase voltages to form on the windings, it is necessary to select a capacitance of capacitors greater than a certain critical value. In addition to its value, the output power is naturally influenced by the design of the engine.

For normal generation of three-phase energy with a frequency of 50 Hz, it is necessary to maintain a rotor speed that exceeds the asynchronous component by the slip value S, which lies within the range S=2÷10%. It must be maintained at the synchronous frequency level.

A sinusoid's deviation from the standard frequency value will negatively affect the operation of equipment with electric motors: saws, planes, various machines and transformers. This has virtually no effect on resistive loads with heating elements and incandescent lamps.

Electrical connection diagrams

In practice, all common methods of connecting the stator windings of an asynchronous motor are used. By choosing one of them they create various conditions for equipment operation and generate voltage of certain values.

Star circuits

Popular option for connecting capacitors

Wiring diagram for an induction motor with star-connected windings for operation as a generator three-phase network has a standard appearance.

Scheme of an asynchronous generator with capacitors connected to two windings

This option is quite popular. It allows you to power three groups of consumers from two windings:

• two voltage 220 volts;
• one - 380.

The working and starting capacitors are connected to the circuit using separate switches.

Based on the same circuit, you can create a homemade generator by connecting capacitors to one winding of an asynchronous motor.

Triangle diagram

When assembling the stator windings in a star configuration, the generator will produce a three-phase voltage of 380 volts. If you switch them to a triangle, then - 220.

The three schemes shown in the pictures above are basic, but not the only ones. Based on them, other connection methods can be created.

How to calculate generator characteristics based on engine power and capacitor capacity

To create normal operating conditions for an electric machine, it is necessary to maintain equality between its rated voltage and power in generator and electric motor modes.

For this purpose, the capacitance of the capacitors is selected taking into account the reactive power Q they generate at various loads. Its value is calculated by the expression:

Q=2π∙f∙C∙U 2

From this formula, knowing the engine power, to ensure full load, you can calculate the capacity of the capacitor bank:

С=Q/2π∙f∙U 2

However, the mode of operation of the generator should be taken into account. On Idling capacitors will unnecessarily load the windings and heat them up. This leads to large energy losses, overheating of the structure.

To eliminate this phenomenon, capacitors are connected in stages, determining their number depending on the applied load. To simplify the selection of capacitors for starting an asynchronous motor in generator mode, a special table has been created.

Starting capacitors of the K78-17 series and similar ones with an operating voltage of 400 volts or more are well suited for use as part of a capacitive battery. It is entirely acceptable to replace them with metal-paper counterparts with the appropriate denominations. They will have to be assembled in parallel.

It is not worth using models of electrolytic capacitors to operate in the circuits of an asynchronous homemade generator. They are designed for direct current circuits, and when passing through a sinusoid changing in direction, they quickly fail.

There is a special scheme for connecting them for such purposes, when each half-wave is directed by diodes to its assembly. But it's quite complicated.

Design

The autonomous device of the power plant must fully support the operating equipment and be carried out as a single module, including a hinged electrical panel with devices:

• measurements - with a voltmeter up to 500 volts and a frequency meter;
• switching loads - three switches (one general supplies voltage from the generator to the consumer circuit, and the other two connect capacitors);
• protection - eliminating the consequences of short circuits or overloads and) saving workers from insulation breakdown and phase potential reaching the housing.

Main power supply redundancy

When creating a homemade generator, it is necessary to ensure its compatibility with the grounding circuit of the working equipment, and when operating autonomously, it must be reliably connected to.

If the power plant is created for backup power supply of devices operating from the state network, then it should be used when the voltage is turned off from the line, and when it is restored, it should be stopped. For this purpose, it is enough to install a switch that controls all phases simultaneously or connect complex system automatic switching on of backup power.

Voltage selection

The 380 volt circuit has an increased risk of injury to humans. It is used in extreme cases, when it is not possible to get by with a phase value of 220.

Generator overload

Such modes create excessive heating of the windings with subsequent destruction of the insulation. They occur when the currents passing through the windings are exceeded due to:

1. incorrect selection of capacitor capacity;
2. connecting high power consumers.

In the first case, it is necessary to carefully monitor the thermal regime during idling. If excessive heating occurs, the capacitance of the capacitors must be adjusted.

Features of connecting consumers

The total power of a three-phase generator consists of three parts generated in each phase, which is 1/3 of the total. The current passing through one winding should not exceed the rated value. This must be taken into account when connecting consumers, distribute them evenly over the phases.

When a homemade generator is designed to operate on two phases, it cannot safely generate more than 2/3 of the electricity. total value, and if only one phase is involved, then only 1/3.

Frequency control

A frequency meter allows you to monitor this indicator. When it is not installed in the design of a homemade generator, you can use the indirect method: at idle, the output voltage exceeds the nominal 380/220 by 4–6% at a frequency of 50 Hz.

One of the options for making a homemade generator from an asynchronous motor and its capabilities are shown in their video by channel owners Maria and Alexander Kostenko.

Goods

Electric generator source of alternative energy

It is worth clarifying the definition “ electric generator". Most have associations with gasoline or diesel generators built on the basis of an internal combustion engine. Of course, a do-it-yourself electric generator, an essential component of a car, and household power plants based on internal combustion engines are the most common of industrial designs. A-priory electric generator- a device that converts different kinds energy into electrical energy.

It is impossible to use atomic energy at home (not on the same scale). Energy from the sun, wind, moving water and thermal energy(ICE) use within your capabilities.

Electric generator and solar energy

Solar battery- alternative energy source, no different high power, but as an auxiliary (backup) system is already quite widespread.

It directly generates electricity, which is used to charge the battery. Of course, the power plant operates during the day and the power depends on the length of daylight hours. If you look at the insolation map of Russia, you can see that the duration of “sunshine” in half of the territory ranges from 1700 to 2000 hours per year, and in the southern regions (surprisingly, in Yakutsk) more than 2000 hours.

The efficiency of such batteries ranges from 9% to 25% of the declared power (depending on the type of element), the most common models are with an efficiency of 14-19%. Without going into distinctive features batteries, then in most cases, to get 1 kW of electricity you need a panel with an area of ​​7 to 10 square meters. m. Now you can multiply by the quantity sundial and get a good amount of annual savings...

Another good thing about solar panels is their ease of installation. If you do not install the system according to the “sunflower” principle, with a rotation relative to the position of the sun, then the diagram solar generator very simple.

Electric generator and solar battery

Do-it-yourself electric generator: location of a stationary battery

for year-round operation it should be +15° to the latitude, for the summer months it is necessary to subtract 15° from the latitude. Although for small systems it is possible to increase the power up to 50% by tracking the azimuth of the sun, since the deviation of the battery from perpendicular sunbeam no more than 15° gives 99% helioradiation. The height of the sun does not need to be tracked, since it mainly falls within a 30° spread. The main thing is to take all this into account when installing the battery, for example, on a pitched roof.

Solar panels

In addition to stationary systems, you can buy or make your own portable solar power station, the power of which will be enough to recharge a phone or tablet somewhere in nature.

Mobile electric generator

Electric generator and wind power

Wind is another environmentally friendly form of energy. But if solar energy is converted into electric power using photocells simply (from the point of view of the end user), then a wind power generator is a complex engineering structure that requires a whole range of work. In fact, at home it is necessary to repeat the industrial installation.

Wind power generator

Main components: engine - multiplier (gearbox) - DC generator - battery charge controller - battery - voltage converter.

A wind engine, or wind wheel, can have a horizontally oriented axis or a vertical one. In the first case, this is the familiar (and most common) propeller design.

Wind generator horizontal

The vertical axis is wind turbines based on a Darrieus or Savonius rotor. Of the two, making an electric generator with your own hands is easier using the second option.

Vertical wind generator

Do-it-yourself electric generator: each scheme has its own advantages.

Vertical-axial ones have an efficiency of no more than 15%, but they also have a much lower noise level, and the Savonius rotor is quite simple from the point of view of a wind engine. In addition, this type is less dependent on wind strength and does not require orientation relative to the direction of the air flow.

Horizontal-axial modifications have higher efficiency, but require orientation relative to the direction of the air flow (with a weather vane or shovel) and protection from strong winds. In addition, they are quite noisy, not only due to aerodynamic noise, but also mechanical noise (after all, the support bearing is “noisy”). Plus, to generate decent power you need a rather large screw size. But nevertheless, this particular type is used in almost all industrial designs.

Now about the propeller, its dimensions and the number of blades. There is already a strictly verified, including experimentally, table of the dependence of the installation’s power on the wind speed, the size of the blade and their number.

In order not to get confused with fractions, it is worth giving a simple layout for a wind speed of 4 m (the efficiency of a horizontal “windmill” is 0.35, the efficiency of the generator is 0.9, the gearbox is 0.8):

• diameter 2 m: 2 blades - 10 Watt, 3 blades - 15 Watt, 4 blades - 20 Watt, 6 blades - 30 Watt, 8 blades - 40 Watt;
• diameter 4 m: 2 blades - 40 Watt, 3 blades - 60 Watt, 4 blades - 80 Watt, 6 blades - about 120 Watt.

In principle, as the diameter increases, the dependence is not entirely linear, but it gives a general idea. To get 500 Watts at a wind speed of 4 m per second, the diameter of the wind wheel for 2 blades is 14 m, 3 blades - 11.48 m, 4 blades - 9.94.

• Why is 4 meters per second chosen for the calculation?

As a rule, for middle zone In Russia, this indicator is the ceiling for average monthly values. For example, for Moscow and the region, the average monthly wind speed during 2012 generally fluctuates around 2.5 m/sec. So when choosing a wind power generator, you should first take an interest in the statistics in the region, and then calculate whether it’s worth the effort, but if there is available materials and nodes, then why not make such a device.

Now about the blades - the most crucial moment. Sail blades (like those of ancient windmills) have low efficiency, so they need aerodynamic ones, like an airplane wing.

You can even carve them out of wood, although many craftsmen cut plastic pipe. But here there are nuances.
With a small number of blades, it is more difficult to balance them and vibrations are also possible. A wind wheel with 2-3 blades is a high-speed one, the linear speed in strong winds at the end of the blade can reach up to 200 m/sec (a Makarov pistol bullet is 400 m/sec, and the bullet speed of a Saint-Etienne dueling pistol of the 1835 model is 168 m/sec ).

Plastic is a fragile material and can break at high speed if vibration occurs. Therefore, it is best to use slower wind wheels with 6 blades and a diameter of 2-3 meters to make a wind generator with your own hands.

Wind generator

And to make them take PVC pipe for pressure water supply with a wall thickness of 4 mm. We cut out the blades, grind their edges and grind them to obtain the required aerodynamic characteristics.

• Then a “star” is made from sheet steel to assemble the propeller.

After installing the blades, the wind wheel must be balanced. To do this, install it indoors on a vertical support with the axis level strictly horizontal and ensure that the wheel does not rotate arbitrarily at any position of the blades, otherwise vibrations will occur.

Simultaneously with balancing, the position of the blades in space relative to the vertical is checked. For this, a fixed reference point is used at the lower (or upper) point, determining the distance from this point to each blade when it is opposite it.

Unfortunately, without using a factory-made electric generator or a DC motor, it will not be possible to make a wind generator.

Theoretically, it can be manufactured, but why... You can always find and buy a low-speed DC electric motor with permanent magnets and a voltage of up to 100 V. You can also install a car one, but it requires high speeds, and therefore a gearbox. You can choose a bicycle motor whose speed at 200 rpm maximum power 250 Watt, at 24 V (enough with a margin).

After the propeller and generator selection, you need to make a frame with reliable design(after all, the “airplane” is on a leash).
Then make a rotary unit attached to the frame and carrying the wind wheel and generator, with a brush current collector (if it is possible to pick up a factory one, then it is better to use it).

And to protect against hurricane winds, install a movable side shovel with a spring tie on a hinge. In strong winds, the spring force will not be enough to align the shovel perpendicular to the blades. And the force of the wind will simply turn the blades along the direction of the wind. At normal flow speed, the spring will rotate the blades perpendicular to the shovel.

All that remains is to assemble the structure: the propeller to the generator, the generator to the frame, the frame to the frame, a shovel is attached to it on a stretcher, the frame to rotary mechanism, the generator to the current collector, and from it wires go to the electrical part.

This entire structure is installed on a mast.

Electrical part wind generator the simplest: the diode bridge through the fuses and the voltage controller is connected to the battery, and the voltage is distributed further from it. Constant - for powering devices with the appropriate type of power supply. And to obtain alternating current, a voltage converter is used.

IN country houses and on summer cottages often there is no stationary electricity, so electric generators are quite popular. Since it is far from a cheap pleasure, many craftsmen are trying to make this device with their own hands. But in order for it to fully cope with the task assigned to it - providing the house with electricity, it is necessary to clearly understand the scheme of the device. Your attention is an instruction for creating an electric generator with your own hands at home (a video instruction is attached).

Electric generator: areas of application, principle of operation

Today we will talk about an asynchronous electric generator, since it has a number of advantages that distinguish it from the classic synchronous one. The most important of them is a low clear factor. The fact is that synchronous generators have a rather high clear factor, which is characterized by a large number of high harmonics in the output voltage. This, in turn, leads to unnecessary heating of the device and uneven rotation of the motor.

A do-it-yourself asynchronous electric generator is quite suitable for use in a summer cottage, but if we talk about industrial applications similar devices, then they are used to extract energy at wind farms, as welding units or as an autonomous means of supporting electricity in the house along with a stationary thermal power plant.

Engine device

The principle of operation of the device is quite simple, if you do not consider each process occurring inside it separately. The generator operates due to the phenomenon of magnetic induction. The conductor passes through an electric field (artificially created) and in doing so creates an impulse that is converted into direct current.

A motor is located inside the generator, which generates electricity according to the following scheme: fuel is burned in the combustion chambers of the engine, while gas is released that sets the crankshaft in motion. That, in turn, transmits an impulse to the driven shaft, which gives a certain amount of energy at the output.

DIY generator assembly process

Assembling an asynchronous electric generator, in principle, is not difficult if you approach the process with full responsibility. First you need to collect all structural elements, which will be needed to assemble the device:

• Engine. This generator element can be made independently, but the process is so long and painstaking that it is easier to use a used motor from some old household appliance (or is ideal).
• Stator. It is better to buy a fully assembled stator (already with a winding).
• Electrical wires, in addition to which you will also need electrical tape.
• Transformer. An optional element that is needed only when the output energy has different powers.

used motor

Before assembling, we calculate the power of the future generator. To do this, you just need to connect the engine to the network and use a tachometer to determine its rotation speed. We add 10% to the resulting value (a compensatory value that will prevent the device from overheating).

Advice. Since the generator is directly connected to the production of electricity, it is necessary to ground it. The absence of this can lead not only to rapid wear of the device, but also to its transformation into a life-threatening device.

Having calculated the power, we select suitable capacitors and connect them in a certain sequence according to one of the diagrams that can be found freely available on the Internet.

When creating an electric generator at home, be prepared for the fact that it (in most cases) will not be able to compete with factory models in terms of performance. Trying to bring an idea to life is worth it only in cases where:

• have relevant skills and knowledge in the field of electronics and mechanics;
• there have already been successful attempts to create such devices;
• everything is on hand necessary equipment and instruments for precise calculations;
• have experience in reading electrical diagrams, as well as the ability to carry out calculations when designing electrical appliances.

Homemade generators certainly have certain advantages, among which are cost savings and the ability to create a device that fully meets the requirements.

A homemade generator will not be as powerful as a store bought one.

But such devices also have their drawbacks:

• Great chance frequent breakdowns due to the lack of sealed fastenings between the structural elements of the device;
• possible inaccuracy in calculating the power of the device, which will lead to low productivity during the operation of the device;
• To create an effective and reliable device, certain knowledge and skills are required.

Advice. To increase the protection of your device from exposure external factors(which, in turn, will maintain its productivity over a long period), it is advisable to build a special protective casing for it.

And finally a few useful tips relatively competent operation asynchronous generator. Firstly, it is better to equip the generator device with an “on/off” button. (if possible). Secondly, the temperature of the device should be periodically monitored to prevent overheating. Thirdly, since the device being created does not have automatic elements, during its operation it will be necessary to periodically use a tachometer, voltmeter and ammeter.

As you can see, in principle, creating a generator at home is not so difficult, especially if its basic structural elements are available. The question is the feasibility of such devices. From a financial point of view, this can only be beneficial in one case: if you have a used working engine on hand. In any case, it's worth a try. Good luck!