To make a wind generator with a power of up to 1 kW with your own hands, there is no need to purchase special equipment. This problem can be easily solved if you have an asynchronous motor. Moreover, the indicated power will be quite sufficient to create conditions for the operation of individual household appliances and connect street lighting in the garden at the dacha.
If you make a windmill with your own hands, then you will have a free source of energy that you can use at your discretion. Any home handyman able to manufacture independently a wind generator based on asynchronous motor.
What does the generator consist of?
The generating set, which will generate electricity, includes the following main elements:
Operating principle
Operation of homemade wind turbines carried out by analogy with wind generators which are used in industry. The main purpose is to generate alternating voltage, for which kinetic energy is transformed into electrical energy. The wind drives a rotor-type wind wheel, as a result of which the resulting energy flows from it to the generator. Moreover, usually the role of the latter is performed by an asynchronous motor.
As a result of the current generated by the generator, the latter enters the battery, which is equipped with a module and a charge controller. From there it is sent to a DC inverter, the source of which is the power grid. As a result it is possible to create an alternating voltage, the characteristics of which are suitable for use for domestic purposes (220 V 50 Hz).
A controller is used to transform AC voltage into DC voltage. It is with its help that the batteries are charged. In some cases, inverters are capable of performing the functions of a source uninterruptible power supply. In other words, in case of problems with the power supply, they can be used as a power source household devices batteries or generators.
Materials and tools
To make a wind generator, it is enough to have an asynchronous motor, which will have to be redone. At the same time, you will have to stock up on a number of materials:
Generator characteristics and installation
The generator has the following characteristics:
Installation features
Most often, do-it-yourself generator installation is done using a three-blade wind wheel, reaching a diameter of about 2 m. The decision to increase the number of blades or their length does not lead to improved performance. Regardless of the chosen option regarding the configuration, dimensions and shape of the blades, preliminary calculations should first be performed.
During self-installation you need to pay attention to such a parameter as the condition of the soil of the area where the support and guy wires will be placed. The mast is installed by digging a hole no more than 0.5 m deep, which must be filled with concrete mortar.
Network connection carried out in a strictly defined order: the batteries are connected first, followed by the wind generator itself.
The rotation of the wind generator can be carried out in a horizontal or vertical plane. In this case, the choice is usually made on the vertical plane, which is related to the structural design. It is permissible to use Darrieus and Savonius models as rotors.
The installation design must use sealing gaskets or a cap. Thanks to this solution, moisture will not harm the generator.
The location of the mast and support must be selected open place. A suitable height for the mast is 15 m. In this case masts are the most widely used, whose height does not exceed 5-7 m.
It is optimal if a self-made wind generator functions as a backup power source.
These installations have restrictions on their use, since their operation is only possible in those regions where the wind speed reaches about 7-8 m/s.
Before you start creating a windmill with your own hands, make accurate calculations. In some cases, difficulties arise with processing asynchronous motor components;
A windmill cannot be created without electrical modules, as well as a series of experiments.
How to make an asynchronous generator with your own hands?
Although, always you can buy ready-made asynchronous generator
, you can go the other way and save money by making it yourself. There will be no difficulties here. The only thing you need to do is prepare the necessary tools.
- One of the features of the generator is that it should rotate at a higher speed, rather than the engine. This can be achieved in the following way. After starting, you need to find out the engine rotation speed. A tachometer or tachometer will help us solve this problem.
- Having determined the above parameter, 10% should be added to the value. If, for example, its torque is 1200 rpm, then for a generator it will be 1320 rpm.
- To make an electric generator based on an asynchronous motor, you will need to find a suitable capacitance for the capacitors. Moreover, it should be remembered that everything capacitors should not differ in their phases from each other.
- It is recommended to use a medium-sized container. If it turns out to be too large, it will lead to heating of the asynchronous motor.
- For assembly capacitors should be used, which can guarantee the desired rotation speed. Their installation must be taken very seriously. It is recommended to protect them using special insulating materials.
These are all the operations that must be performed when installing an engine-based generator. Then you can proceed to its installation. Please be aware that if you use a device equipped with a squirrel-cage rotor, you will receive high voltage current. For this reason, to achieve a value of 220 V, you will need a step-down transformer.
All household appliances that are used today for household purposes are powered by electricity. That is, it turns out that electric current becomes the main one mechanical work devices. But this addiction has reverse side– it is possible to obtain electrical energy from mechanical energy. And many craftsmen take advantage of this by creating a generator from an asynchronous motor with their own hands.
Everyone who has a house outside the city is faced with the problem of inconsistent power supply. Let's face it, this is the number one problem of holiday villages. Generators running on gasoline or diesel fuel help get out of this situation. True, such energy devices are not a cheap pleasure, so many summer residents assemble generators with their own hands, using an asynchronous motor.
How does an asynchronous generator work?
So, as mentioned above, an asynchronous motor can operate in generator mode only if it is provided with rotor torque and the capacitor group is correctly selected and connected.
As for torque, there are a huge number of designs and devices that can create this torque. Here are just a few examples.
- It can be any low-power gasoline or diesel engine. Many craftsmen use chainsaws or walk-behind tractors for this. To increase the rotation speed of the electric motor rotor, it is necessary to calculate the ratio of the diameter of the pulleys installed on the rotor and the gas engine shaft. Rotation is transmitted using a belt; a chain is not used in this case due to the high rotation speed.
- You can create mechanical energy using water by installing a blade structure under its flow, similar to the propeller of a ship or boat.
- There is an option using a windmill. Typically, such devices are installed in steppe zones where wind is always present.
These are the three main ways to produce electric current through an induction motor.
Attention! All experts assure that ideal option the use of an engine for mechanical energy is one with a so-called perpetual idling. That is, the rotation speed does not change and is a constant value. In addition, you will have to increase the rotation speed of the electric motor shaft, which will differ from the nominal one by an increase of 10%.
You can find out the nominal rotation speed on the tag or in the device passport. Its unit of measurement is rpm. If you have not found this indicator, then you can determine it by turning on the motor to the power supply electrical network, having previously installed a tachometer on the shaft.
Now regarding the capacitors and the electric motor connection diagram. Firstly, there is a certain dependence of the capacitor capacity on the generator power. Here it is in the table below.
Secondly, the capacitance of the capacitors on each engine trim is the same. Thirdly, consider the point that high capacity may cause the motor to overheat. Therefore, strictly adhere to the ratio according to the table. Fourthly, installation and assembly of the capacitor group is a responsible matter, so be careful. Isolation is very important in this case.
Advice! The capacitors must be connected to each other according to a triangle diagram. And the windings are star circuit.
By the way, here is a diagram below for switching on an electric motor as a generator.
And one more thing. The generator from a squirrel-cage asynchronous motor produces a very high voltage. Therefore, if you need 220V voltage, it is recommended to install a step-down transformer after it. It is also possible to convert single-phase electric motors of low power, which are used in household appliances. Of course, they will also be low-power, but using them to turn on a light bulb or connect a modem will not be a problem. By the way, novice home craftsmen begin their activities as an electrician with such small devices. Their design is simple, the parts are accessible, and the assembled device itself is practically safe.
- A generator made from an asynchronous motor is a high-risk device. And it doesn’t matter what kind of motor it has that transmits mechanical energy. In any case, care must be taken to ensure safe operation. The easiest way is to properly insulate the device.
- If an asynchronous generator will be used periodically as a source of electricity, then it must be equipped with measuring instruments. Typically a tachometer and a voltmeter are used for this.
- Of course, there should be two buttons in the unit circuit: “ON” and “OFF”.
- A prerequisite is grounding.
- Please also take into account the fact that the power of an asynchronous generator usually differs from the power of the electric motor itself by 30-50%. This is due to losses during the conversion of mechanical energy into electrical energy.
- Pay attention also to temperature regime operation. Just like an internal combustion engine, the generator will heat up.
Conclusion on the topic
Making a generator from a regular asynchronous motor with your own hands is not a problem. Here it is important to comply with all the requirements that we described above. A small inaccuracy and everything can go wrong. In any case, it will no longer be possible to obtain a current of 220 volts, and even if it does, the unit itself will not work for long.
An asynchronous or induction type generator is a special type of device that uses alternating current and has the ability to generate electricity. The main feature is the relatively fast turns that the rotor makes; in terms of the rotation speed of this element, it is significantly superior to the synchronous variety.
One of the main advantages is the ability to use this device without significant circuit modifications or lengthy setup.
A single-phase type of induction generator can be connected by applying the required voltage to it, this will require connecting it to a power source. However, a number of models produce self-excitation; this ability allows them to function in a mode independent of any external sources.
This is accomplished by sequentially bringing the capacitors into working condition.
Generator circuit from an asynchronous motor
generator circuit based on an asynchronous motor In virtually any electric-type machine, designed as a generator, there are 2 different active windings, without which the operation of the device is impossible:
- Field winding, which is located on a special anchor.
- Stator winding, which is responsible for the formation of electric current, this process occurs inside it.
In order to visualize and more accurately understand all the processes occurring during the operation of the generator, the most the best option Let's take a closer look at how it works:
- Voltage, which is supplied from a battery or any other source, creates a magnetic field in the armature winding.
- Rotating device elements together with a magnetic field it is possible to realize in different ways, including manually.
- Magnetic field, rotating at a certain speed, generates electromagnetic induction, due to which an electric current appears in the winding.
- The vast majority of schemes used today does not have the ability to provide voltage to the armature winding, this is due to the presence of a squirrel-cage rotor in the design. Therefore, regardless of the speed and time of rotation of the shaft, the power supply devices will still be de-energized.
When converting an engine into a generator, self-creation moving magnetic field is one of the basic and mandatory conditions.
Generator device
Before taking any action to remodelinto the generator, you need to understand the structure of this machine, which looks like this:
- Stator, which is equipped with a 3-phase network winding located on its working surface.
- Winding organized in such a way that it resembles a star in shape: 3 initial elements are connected to each other, and 3 opposite sides are connected to slip rings that do not have any points of contact with each other.
- Slip rings have reliable fastening to the rotor shaft.
- In design There are special brushes that do not make any independent movements, but help turn on the rheostat with three phases. This allows you to change the resistance parameters of the winding located on the rotor.
- Often, in internal structure There is such an element as an automatic short-circuiter, which is necessary to short-circuit the winding and stop the rheostat, which is in working condition.
- Another additional element of the generator device may be a special device that spreads the brushes and slip rings at the moment when they pass the stage of closure. This measure helps to significantly reduce friction losses.
Making a generator from an engine
In fact, any asynchronous electric motor can be with my own hands converted into a device that functions like a generator, which can then be used in everyday life. Even an engine taken from washing machine old model or any other household equipment.
In order for this process to be successfully implemented, it is recommended to adhere to the following algorithm of actions:
- Remove the engine core layer, due to which a depression will be formed in its structure. This can be done at lathe, it is recommended to remove 2 mm. throughout the core and make additional holes with a depth of about 5 mm.
- Take dimensions from the resulting rotor, after which a template in the form of a strip is made from tin material, which will correspond to the dimensions of the device.
- Install in the resulting free space there are neodymium magnets, which must be purchased in advance. Each pole will require at least 8 magnetic elements.
- Fixation of magnets can be done using universal superglue, but it must be taken into account that when approaching the surface of the rotor they will change their position, so they must be held firmly with your hands until each element is glued. Additionally, it is recommended to use safety glasses during this process to avoid any glue splashing into your eyes.
- Wrap the rotor plain paper and tape, which will be needed to secure it.
- The end part of the rotor cover with plasticine, which will ensure sealing of the device.
- After completed actions it is necessary to process the free cavities between the magnetic elements. To do this, the remaining free space between the magnets must be filled epoxy resin. The most convenient way would be to cut a special hole in the shell, transform it into a neck and seal the borders with plasticine. You can pour resin inside.
- Wait until it hardens completely filled with resin, after which the protective paper shell can be removed.
- The rotor must be fixed using a machine or a vice so that it can be processed, which consists of grinding the surface. For these purposes, you can use sandpaper with a medium grit setting.
- Determine state and the purpose of the wires coming out of the engine. Two should lead to the working winding, the rest can be cut off so as not to get confused in the future.
- Sometimes the rotation process is quite poor, most often the cause is old worn out and tight bearings, in which case they can be replaced with new ones.
- Rectifier for generator can be assembled from special silicon, which are designed specifically for these purposes. You also don’t need a controller for charging; virtually all modern models are suitable.
After all the above steps have been completed, the process can be considered complete; the asynchronous motor has been converted into a generator of the same type.
Assessing the level of efficiency - is it profitable?
The generation of electric current by an electric motor is quite real and feasible in practice, the main question is how profitable is it?
The comparison is made primarily with a synchronous version of a similar device, which is missing electrical circuit excitation, but despite this fact, its structure and design are not simpler.
This is due to the presence of a capacitor bank, which is an extremely technically complex element that is absent in an asynchronous generator.
The main advantage of an asynchronous device is that the available capacitors do not require any maintenance, since all the energy is transferred from the magnetic field of the rotor and the current that is generated during the operation of the generator.
The electric current created during operation virtually does not have higher harmonics, which is another significant advantage.
Asynchronous devices do not have any other advantages besides those mentioned, but they do have a number of significant disadvantages:
- During their operation there is no possibility of ensuring the nominal industrial parameters of the electric current generated by the generator.
- High degree of sensitivity even to the slightest changes in workload parameters.
- If the permissible load parameters on the generator are exceeded, a lack of electricity will be detected, after which recharging will become impossible and the generation process will be stopped. To eliminate this drawback, batteries with significant capacity are often used, which have the ability to change their volume depending on the magnitude of the loads applied.
The electric current produced by an asynchronous generator is subject to frequent changes, the nature of which is unknown, it is random and cannot be explained in any way by scientific arguments.
The impossibility of accounting for and appropriate compensation for such changes explains the fact that similar devices did not gain popularity and were not particularly widespread in the most serious industries or household affairs.
Functioning of an asynchronous motor as a generator
In accordance with the principles on which all such machines operate, the operation of an induction motor after conversion to a generator occurs as follows:
- After connecting the capacitors to the terminals, a number of processes occur on the stator windings. In particular, a leading current begins to move in the winding, which creates a magnetization effect.
- Only if the capacitors match parameters of the required capacity, the device self-excites. This promotes a symmetrical 3-phase voltage system on the stator winding.
- Final voltage value will depend on the technical capabilities of the machine used, as well as on the capabilities of the capacitors used.
Thanks to the described actions, the process of converting a squirrel-cage asynchronous motor into a generator with similar characteristics occurs.
Application
In everyday life and in production, such generators are widely used in various fields and areas, but they are most in demand to perform the following functions:
- Use as engines for , this is one of the most popular features. Many people make their own asynchronous generators to use them for these purposes.
- Work as a hydroelectric power station with little output.
- Providing food and electricity in a city apartment, private country house or separate household equipment.
- Perform basic functions welding generator.
- Uninterrupted equipment alternating current of individual consumers.
It is necessary to have certain skills and knowledge not only in the manufacture, but also in the operation of such machines; the following tips can help with this:
- Any type of asynchronous generators regardless of the area in which they are applied, is dangerous device, for this reason it is recommended to isolate it.
- During the manufacturing process of the device installation needs to be considered measuring instruments, since it will be necessary to obtain data on its functioning and operating parameters.
- Availability of special buttons, with which you can control the device, greatly facilitates the operation process.
- Grounding is mandatory requirement, which must be implemented before operating the generator.
- During work, The efficiency of an asynchronous device can periodically decrease by 30-50%; it is not possible to overcome the occurrence of this problem, since this process is an integral part of energy conversion.
Very often, lovers of outdoor recreation do not want to give up amenities everyday life. Since most of these conveniences involve electricity, there is a need for a power source that you can take with you. Some people buy an electric generator, while others decide to make a generator with their own hands. The task is not easy, but it is quite doable at home for anyone who has technical skills and the necessary equipment.
Selecting a generator type
Before you decide to do homemade generator at 220 V, it is worth thinking about the feasibility of such a solution. You need to weigh the pros and cons and determine what suits you best - a factory sample or a homemade one. Here main advantages of industrial devices:
- Reliability.
- High performance.
- Quality assurance and access to technical support.
- Safety.
However, industrial designs have one significant drawback - very high price. Not everyone can afford such units, so It’s worth thinking about the advantages of homemade devices:
- Low price. Five times, and sometimes more, lower price compared to factory electric generators.
- Simplicity of the device and good knowledge of all components of the device, since everything was assembled by hand.
- The ability to modernize and improve the technical data of the generator to suit your needs.
An electric generator made by yourself at home is unlikely to be highly efficient, but it is quite capable of meeting the minimum requirements. Another disadvantage of homemade products is electrical safety.
It is not always highly reliable, unlike industrial designs. Therefore, you should take the choice of the type of generator very seriously. Not only savings will depend on this decision cash, but also life, the health of loved ones and oneself.
Design and operating principle
Electromagnetic induction underlies the operation of any generator that produces current. Anyone who remembers Faraday's law from the ninth grade physics course understands the principle of converting electromagnetic oscillations into direct electric current. It is also obvious that create favorable conditions supplying enough voltage is not that easy.
Any electric generator consists of two main parts. They may have different modifications, but are present in any design:
There are two main types of generators depending on the type of rotor rotation: asynchronous and synchronous. When choosing one of them, take into account the advantages and disadvantages of each. Most often, the choice of folk craftsmen falls on the first option. There are good reasons for this:
In connection with the above arguments, the most likely choice for self-made is an asynchronous generator. All that remains is to find a suitable sample and a scheme for its manufacture.
Unit assembly procedure
First, you should equip your workplace with the necessary materials and tools. Workplace must comply with safety regulations when working with electrical appliances. The tools you will need are everything related to electrical equipment and vehicle maintenance. In fact, a well-equipped garage is quite suitable for creating your own generator. Here's what you'll need from the main parts:
Having collected necessary materials, begin to calculate the future power of the device. To do this, you need to perform three operations:
When the capacitors are soldered in place and the desired voltage is obtained at the output, the structure is assembled.
In this case, the increased electrical hazard of such objects should be taken into account. It is important to think through correct grounding generator and carefully insulate all connections. Not only the service life of the device, but also the health of those who use it depends on the fulfillment of these requirements.
Device made from a car engine
Using the diagram for assembling a device for generating current, many come up with their own incredible designs. For example, a bicycle or water-powered generator, windmill. However, there is an option that does not require special design skills.
Any car engine has an electric generator, which is most often in good working order, even if the engine itself has long been scrapped. Therefore, having disassembled the engine, you can use finished product for your own purposes.
Solving a problem with rotor rotation is much easier than thinking about how to make it again. You can simply restore a broken engine and use it as a generator. To do this, all unnecessary components and accessories are removed from the engine.
Wind dynamo
In places where the winds blow without stopping, restless inventors are haunted by the waste of nature's energy. Many of them decide to create a small wind farm. To do this, you need to take an electric motor and convert it into a generator. The sequence of actions will be as follows:
Having made his own windmill with a small electric generator or a generator from a car engine with his own hands, the owner can be calm during unforeseen disasters: there will always be electric light in his house. Even after going outdoors, he will be able to continue to enjoy the conveniences provided by electrical equipment.
Content:Electrical engineering exists and operates according to its own laws and principles. Among them, there is the so-called reversibility principle, which allows you to make a generator with your own hands from an asynchronous motor. To solve this problem, knowledge and a clear understanding of the operating principles of this equipment are required.
Transition of an asynchronous motor to generator mode
First of all, you need to consider the operating principle of an asynchronous motor, since it is this unit that serves as the basis for creating a generator.
An asynchronous type electric motor is a device that converts electrical energy into mechanical and thermal. The possibility of such a transformation is ensured by the voltage that occurs between the stator and rotor windings. Main feature asynchronous motors lies in the difference in the rotational speed of these elements.
The stator and rotor themselves are coaxial parts round section, made of steel plates with grooves inside the ring. In the whole set, longitudinal grooves are formed where the winding is located copper wire. In the rotor, the winding function is performed by aluminum rods located in the grooves of the core and closed on both sides by locking plates. When voltage is applied to the stator windings, a rotating magnetic field is created. Due to the difference in rotational speed, an EMF is induced between the windings, which leads to rotation of the central shaft.
Unlike an asynchronous electric motor, a generator, on the contrary, converts thermal and mechanical energy into electrical energy. The most widely used are induction devices, characterized by the induction of an interwinding electromotive force. As in the case of an asynchronous motor, the reason for the induction of EMF is the difference in the speed of the magnetic fields of the stator and rotor. It quite naturally follows from this, based on the principle of reversibility, that it is quite possible to turn an asynchronous motor into a generator, through certain technical reconstructions.
Each asynchronous electric generator is a kind of transformer that converts the mechanical energy of the electric motor shaft into alternating current. This occurs when the shaft speed begins to exceed synchronous speed and reaches 1500 rpm and above. This speed is achieved by applying high torque. Its source can be the internal combustion engine of a gas generator or the impeller of a windmill.
When the synchronous rotation speed is reached, the capacitor bank is switched on, in which a capacitive current is created. Under its action, the stator windings self-excite and electric current begins to be generated in the generation mode. Reliable and stable operation of such a generator capable of delivering an industrial frequency of 50 Hz, subject to certain conditions:
- The rotation speed should be higher than the operating frequency of the electric motor itself by a slip percentage of 2-10%.
- The rotation speed of the generator must match the synchronous speed.
How to make a generator
Having certain information and practical skills in electrical engineering, it is quite possible to assemble a functional generator with your own hands from an asynchronous motor. First of all, you need to calculate the real, that is, asynchronous speed of the electric motor that will be used as a generator. This operation can be performed using a tachometer.
Next, it is necessary to determine the synchronous frequency of the electric motor, which will be asynchronous for the generator. As already mentioned, here you need to take into account the amount of slip, which is 2-10%. For example, as a result of measurements, a rotation speed of 1450 rpm was obtained, therefore, the required operating frequency of the generator will be 1479-1595 rpm.