Uninterrupted supply electricity is a guarantee comfortable life in any season.
To organize autonomous power supply for a home, it is often used asynchronous generator, which you can also do yourself.
What it is
An asynchronous generator is a device alternating current, which, using the operating principle of an asynchronous motor, can produce electrical energy. It is also called induction. An asynchronous electric generator ensures rapid rotation of the rotor, the rotation speed being much higher than if they were rotated by a synchronous analogue of the device. A conventional AC induction motor can be used as a generator without any additional settings or circuit modifications.
Photo - asynchronous generatorArea of use asynchronous generator is quite wide:
- They are used as engines for wind power plants;
- In order to provide autonomous power to a house or apartment, or as miniature hydroelectric power stations;
- As an inverter (welding) generator;
- To organize uninterruptible power supply from alternating current.
In this case, the single-phase asynchronous generator must be turned on using the incoming voltage. Typically, this is done by connecting the device to power. But some models can work independently, by self-excitation, through serial connection capacitors.
Video: asynchronous motor device
Principle of operation
An induction electric generator produces electrical energy when the rotor speed is faster than synchronous. For the most common generator, this figure is within 1800 rpm, while the synchronous speed characteristics are about 1500 rpm.
Generator circuit The operating principle of an asynchronous generator is based on the conversion of mechanical energy into current energy, i.e., electrical. In order for the rotor to start spinning and producing current, a fairly strong torque is needed. The ideal, according to electricians, is the so-called “eternal idle”, in which an equal rotation speed is maintained throughout the entire operation of the asynchronous generator.
How to do it yourself
Buying an asynchronous generator is an expensive pleasure, especially since you can make it yourself. The principle of operation is simple, the main thing is to provide yourself with the necessary tools.
- According to the operating principle of the device, you need to configure the generator so that its rotation speed is higher than the engine speed. To do this, connect the electric motor to the network and start it. To calculate the engine speed, you need to use a tachogenerator or tachometer;
- You need to add 10% to the resulting value. Let's say specifications engine is 1200 rpm, which means the generator must have 1320 rpm (1200 * 0.1% = 120, 120 + 1200 = 1320 rpm);
- Further, converting an asynchronous motor into a generator includes selecting the required capacitance for the capacitors used (each capacitor between phases is similar to the previous one);
- Make sure that the container is not too large, otherwise the asynchronous generator will heat up;
- Select the capacitors necessary to ensure a certain rotation speed, the calculation of which was made above. Their installation requires special care; it is very important that they are insulated with special coatings.
This completes the arrangement of the engine-based generator. Now it can be installed as a source of energy. It is important to remember that a squirrel-cage device produces quite high voltage, so if you need 220 V, there is a reason to install a step-down transformer.
Scheme for connecting the engine as a generator This is what the diagram looks like on how to make a wind generator from an asynchronous motor, here the main differences are the rotation speed and the principle of switching on. As an example, we present to you a diagram of a wind hydroelectric power station, which includes an asynchronous gasoline generator.
It should be noted that it does not work with self-powering; in most cases, to turn on such a generator, a special walk-behind tractor or a control unit similar to an ignition switch is used.
Video: making an asynchronous generator from a single-phase motor - Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
As a generator with no high power, you can even use single-phase asynchronous motors from household electrical appliances - Geko washing machines, drainage pumps etc. Like a two-support motor, the motor from such devices must be connected in parallel to their winding. Another way is to use phase shift capacitors. They are not always different the required power, so it will be necessary to increase it to the required levels. Such a simple generator could be used to power light bulbs or modems. If you slightly alter the circuit, you will be able to connect this autonomous device even to a heater or electric stove. You can also make a similar generator using permanent magnets.
Photo - low-power generator - Any asynchronous generator (gasoline generator, electric, brushless) is considered a device with an increased level of danger, so try to isolate it;
- Each autonomous generator must be equipped with additional measuring devices in order to record data on its operation. This should be a frequency meter or tachometer, as well as a voltmeter;
- It is advisable to equip the generator with on and off buttons;
- This type of electric generator must be grounded;
- Be prepared for the fact that the efficiency of an asynchronous generator will drop by 30 and sometimes by 50% - this phenomenon is inevitable when converting mechanical energy into electrical energy;
- If necessary, the device can be replaced by synchronous brushless generators such as GS-200 or GS-250, asynchronous AIR 63, ESS 5-93-4у2 (75 kW), and others, the price of which is from 30,000 rubles in Krasnoyarsk and from 35,000 in Moscow;
- The thermal regime of an asynchronous generator is very important. Like an internal combustion engine, it can heat up from idle move, monitor the temperature of the device.
In modern realities, every homeowner is well acquainted with constant growth the cost of utilities - this also applies to electrical energy. Therefore, to create comfortable conditions living in suburban housing construction, both in summer and winter, you will have to either pay for energy supply services, or find an alternative way out of the current situation, fortunately natural springs energies are free.
How to make a wind generator with your own hands - step by step guide
The territory of our state is mostly plains. Despite the fact that in cities the access to wind is blocked by high-rise buildings, strong air currents rage outside the city. Therefore, self-production wind generator- only correct solution to provide country house electricity. But first you need to figure out which model is suitable for self-production.
Rotary
A rotary windmill is a simple converting device that is easy to make with your own hands. Naturally, such a product will not be able to provide electricity to a country mansion, but for country house will do just fine. It will illuminate not only housing construction, but also outbuildings and even paths in the garden. To independently assemble a unit with a power of up to 1500 watts, you need to prepare Consumables and components from the following list:
Naturally, you need to have a minimum set of tools: scissors for cutting metal, an angle grinder, a measuring tape, a pencil, a set wrenches and screwdrivers, drill with drills and pliers.
Step by Step Actions
Assembly begins with the manufacture of the rotor and alteration of the pulley, for which a certain sequence of work is followed.
To connect battery conductors with a cross-section of 4 mm and a length of no more than 100 cm are used. Consumers are connected with conductors with a cross-section of 2 mm. It is important to include a 220V DC to AC voltage converter in the open circuit according to the terminal contact diagram.
Pros and cons of the design
If all the manipulations are done correctly, then the device will last quite a long time. When using a sufficiently powerful battery and a suitable inverter up to 1.5 kW, you can provide power to street and indoor lighting, a refrigerator and a TV. Making such a windmill is very simple and cost-effective. This product is easy to repair and unpretentious to use. It is very reliable in terms of operation and does not make noise, annoying the inhabitants of the house. However, the rotary windmill has low efficiency and its operation depends on the presence of wind.
An axial design with an iron-free stator based on neodymium permanent magnets appeared on the territory of our state not so long ago due to the unavailability of component parts. But today, powerful magnets are not uncommon, and the cost of them has dropped significantly compared to a few years ago.
The basis of such a generator is a hub with brake discs from a passenger car. If this is not a new part, then it is advisable to sort it out and replace it. lubricants and bearings.
Placement and installation of neodymium magnets
Work begins with gluing magnets onto the rotor disk. For this purpose, 20 magnets are used. and dimensions 2.5 by 0.8 cm. To change the number of poles, you must adhere to the following rules:
- a single-phase generator implies the number of magnets corresponding to the number of poles;
- in the case of a three-phase device, a ratio of 2/3 of poles and coils is maintained, respectively;
- The placement of magnets should occur with alternating poles; to simplify their distribution, it is better to use a ready-made template made of cardboard.
If possible, it is advisable to use magnets rectangular shape, since in round analogues the concentration of magnetic fields occurs in the center, and not over the entire surface. It is important to meet the condition that magnets facing each other have opposite poles. In order to determine the poles, magnets are brought close to each other, and the attracting sides are positive, therefore the repulsive sides are negative.
A special one is used to attach the magnets. adhesive composition, after which reinforcement with epoxy resin is performed to increase strength. For this purpose, magnetic elements are filled with it. To prevent the resin from spreading, sides are made using ordinary plasticine.
Three-phase and single-phase type unit
Single-phase stators are inferior in their parameters to their three-phase counterparts, since vibration increases with increasing load. This is due to the difference in current amplitude resulting from the variability of its output over a certain period of time. In turn, in the three-phase analogue there is no such problem. This made it possible to increase the output of a three-phase generator by almost 50% compared to a single-phase model. Plus, due to the absence of additional vibration, no extraneous noise is created during operation of the device.
Winding coils
Every electrician knows that before starting to wind a coil, it is important to preliminary calculations. Homemade wind generator at 220V - a device operating at low speeds. It is necessary to ensure that battery charging starts at 100 rpm.
Based on these parameters, winding all the coils will require no more than 1200 turns. To determine the turns for one coil, you need to simply divide the total indicators by the number of individual elements.
To increase the power of a low-speed windmill, the number of poles is increased. In this case, the frequency of the current in the coils will increase. The winding of the coils should be thick copper wires. This will reduce the resistance value and, therefore, increase the current strength. It is important to consider that with a sharp increase in voltage, the current can be completely spent on the resistance of the windings. To simplify winding, you can use a special machine.
In accordance with the number and thickness of magnets attached to the disks, the performance characteristics of the device change. To find out what power indicators will ultimately be obtained, it is enough to wind one element and rotate it in the unit. To determine power characteristics, voltage is measured at certain speeds.
Often the coil is made round, but it is advisable to extend it slightly. In this case, there will be more copper in each sector, and the arrangement of turns becomes denser. The diameter of the inner hole of the coil should be equal to the dimensions of the magnet. When manufacturing the stator, it is important to take into account that its thickness must be equal to the parameters of the magnets.
Usually plywood is used as a blank for the stator, but it is quite possible to make markings on a paper sheet by drawing sectors for the coils, and use regular plasticine for borders. To give strength to the product, fiberglass is used, located at the bottom of the mold on top of the coils. It is important that the epoxy resin does not stick to the mold. To do this, it is covered with wax on top. The coils are fixedly fixed to each other, and the ends of the phases are brought out. After that, all the wires are connected according to a star or triangle pattern. To test the finished device, it is rotated manually.
Usually the final height of the mast is 6 meters, but if possible it is better to double it. Because of this, it is used to secure it. concrete base. The fastening must be such that the pipe can be easily lifted and lowered using a winch. A screw is fixed at the upper end of the pipe.
To make a screw, you need a PVC pipe, the cross-section of which should be 16 cm. A two-meter long screw with six blades is cut from the pipe. Optimal shape blades is determined experimentally, which allows increasing torque at minimum speed. To retract the propeller from strong gusts of wind, a folding tail is used. The generated electricity is stored in batteries.
Video: homemade wind generator
After considering the available options for wind generators, each homeowner will be able to decide on a device suitable for their purposes. Each of them has its own positive sides, and negative qualities. You can especially feel the effectiveness of a wind turbine outside the city, where there is constant movement of air masses.
The article describes how to build a three-phase (single-phase) 220/380 V generator based on an AC asynchronous electric motor. A three-phase asynchronous electric motor, invented at the end of the 19th century by the Russian electrical engineer M.O. Dolivo-Dobrovolsky, has now become predominantly widespread in industry, agriculture, and also in everyday life.
Asynchronous electric motors are the simplest and most reliable to operate. Therefore, in all cases where this is permissible under the conditions of the electric drive and there is no need for compensation reactive power, asynchronous AC motors should be used.
There are two main types of asynchronous motors: with squirrel-cage rotor and with phase rotor. An asynchronous squirrel-cage electric motor consists of a stationary part - the stator and a moving part - the rotor, rotating in bearings mounted in two motor shields. The stator and rotor cores are made from separate sheets isolated from one another electrical steel. A winding made of insulated wire. A rod winding is placed into the grooves of the rotor core or molten aluminum is poured. Jumper rings short-circuit the rotor winding at the ends (hence the name short-circuited). Unlike a squirrel-cage rotor, a winding made like a stator winding is placed in the slots of a phase-wound rotor. The ends of the winding are brought to slip rings mounted on the shaft. Brushes slide along the rings, connecting the winding to a starting or control rheostat.
Asynchronous electric motors with a wound rotor are more expensive devices, require qualified maintenance, are less reliable, and therefore are used only in those industries where they cannot be done without them. For this reason, they are not very common, and we will not consider them further.
A current flows through the stator winding connected to a three-phase circuit, creating a rotating magnetic field. The magnetic field lines of the rotating stator field cross the rotor winding bars and induce an electromotive force (EMF) in them. Under the influence of this EMF, current flows in the short-circuited rotor rods. Magnetic fluxes arise around the rods, creating a general magnetic field of the rotor, which, interacting with the rotating magnetic field of the stator, creates a force causing the rotor to rotate in the direction of rotation magnetic field stator.
The rotor rotation frequency is slightly less than the rotation frequency of the magnetic field created by the stator winding. This indicator is characterized by slip S and is for most engines in the range from 2 to 10%.
Most commonly used in industrial installations three-phase asynchronous electric motors, which are produced in the form of unified series. These include a single 4A series with a range rated power from 0.06 to 400 kW, the machines of which are highly reliable, have good performance and meet world standards.
Autonomous asynchronous generators are three-phase machines that convert the mechanical energy of the prime mover into alternating current electrical energy. Their undoubted advantage over other types of generators is the absence of a commutator-brush mechanism and, as a consequence, greater durability and reliability.
Operation of an asynchronous electric motor in generator mode
If an asynchronous motor disconnected from the network is set into rotation from any prime mover, then in accordance with the reversibility principle electric machines When the synchronous rotation speed is reached, a certain EMF is generated at the terminals of the stator winding under the influence of the residual magnetic field. If you now connect a battery of capacitors C to the terminals of the stator winding, then a leading capacitive current will flow in the stator windings, which is in this case magnetizing.
The battery capacity C must exceed a certain critical value C0, depending on the parameters of the autonomous asynchronous generator: only in this case does the generator self-excite and a three-phase symmetrical voltage system is installed on the stator windings. The voltage value ultimately depends on the characteristics of the machine and the capacitance of the capacitors. Thus, an asynchronous squirrel-cage electric motor can be converted into an asynchronous generator.
Standard circuit for connecting an asynchronous electric motor as a generator.
You can select the capacitance so that the rated voltage and power of the asynchronous generator are equal to the voltage and power, respectively, when it operates as an electric motor.
Table 1 shows the capacitances of the capacitors for excitation of asynchronous generators (U=380 V, 750...1500 rpm). Here reactive power Q is determined by the formula:
Q = 0.314 U 2 C 10 -6 ,
where C is the capacitance of the capacitors, μF.
| Generator power, kVA | Idling | |||||
| capacity, µF | reactive power, kvar | cos = 1 | cos = 0.8 | |||
| capacity, µF | reactive power, kvar | capacity, µF | reactive power, kvar | |||
| 2,0 3,5 5,0 7,0 10,0 15,0 |
28 45 60 74 92 120 |
1,27 2,04 2,72 3,36 4,18 5,44 |
36 56 75 98 130 172 |
1,63 2,54 3,40 4,44 5,90 7,80 |
60 100 138 182 245 342 |
2,72 4,53 6,25 8,25 11,1 15,5 |
As can be seen from the above data, the inductive load on the asynchronous generator, which reduces the power factor, causes a sharp increase in the required capacity. To maintain a constant voltage with increasing load, it is necessary to increase the capacitor capacity, that is, connect additional capacitors. This circumstance must be considered as a disadvantage of the asynchronous generator.
The rotation frequency of an asynchronous generator in normal mode must exceed the asynchronous one by a slip value S = 2...10%, and correspond to the synchronous frequency. Not fulfilling this condition will lead to the fact that the frequency of the generated voltage may differ from the industrial frequency of 50 Hz, which will lead to unstable operation of frequency-dependent consumers of electricity: electric pumps, washing machines, devices with a transformer input.
A decrease in the generated frequency is especially dangerous, since in this case the inductive resistance of the windings of electric motors and transformers decreases, which can cause their increased heating and premature failure.
An ordinary asynchronous squirrel-cage electric motor of appropriate power can be used as an asynchronous generator without any modifications. The power of the electric motor-generator is determined by the power of the connected devices. The most energy-intensive of them are:
- household welding transformers;
- electric saws, electric jointers, grain crushers (power 0.3...3 kW);
- electric furnaces of the "Rossiyanka" and "Dream" types with a power of up to 2 kW;
- electric irons (power 850…1000 W).
I would especially like to dwell on the operation of household welding transformers. Their connection to autonomous source electricity is most desirable, because when working from industrial network they create whole line inconvenience for other electricity consumers.
If household welding transformer is designed to work with electrodes with a diameter of 2...3 mm, then its total power is approximately 4...6 kW, the power of the asynchronous generator to power it should be within 5...7 kW. If a household welding transformer allows working with electrodes with a diameter of 4 mm, then in the heaviest mode - “cutting” metal, the total power consumed by it can reach 10...12 kW, respectively, the power of an asynchronous generator should be within 11...13 kW.
As a three-phase bank of capacitors, it is good to use so-called reactive power compensators, designed to improve cosφ in industrial lighting networks. Their typical designation: KM1-0.22-4.5-3U3 or KM2-0.22-9-3U3, which is deciphered as follows. KM - cosine capacitors impregnated with mineral oil, the first number is the size (1 or 2), then the voltage (0.22 kV), power (4.5 or 9 kvar), then the number 3 or 2 means three-phase or single-phase version, U3 (temperate climate of the third category).
In the case of self-manufacturing of the battery, you should use capacitors such as MBGO, MBGP, MBGT, K-42-4, etc. for an operating voltage of at least 600 V. Electrolytic capacitors cannot be used.
The option discussed above for connecting a three-phase electric motor as a generator can be considered classic, but not the only one. There are other methods that have proven themselves just as well in practice. For example, when a bank of capacitors is connected to one or two windings of an electric motor generator.
Two-phase mode of an asynchronous generator.
Fig.2 Two-phase mode of an asynchronous generator.
This circuit should be used when there is no need to obtain three-phase voltage. This switching option reduces the working capacity of the capacitors, reduces the load on the primary mechanical engine in idle mode, etc. saves "precious" fuel.
Single-phase asynchronous squirrel-cage electric motors can be used as low-power generators producing alternating single-phase voltage 220 V household use: from washing machines such as "Oka", "Volga", irrigation pumps "Agidel", "BTsN", etc. Their capacitor bank can be connected in parallel to the working winding, or use an existing phase-shifting capacitor connected to the starting winding. The capacity of this capacitor may need to be increased slightly. Its value will be determined by the nature of the load connected to the generator: active loads (electric furnaces, light bulbs, electric soldering irons) require a small capacity, inductive loads (electric motors, televisions, refrigerators) require more.
Fig. 3 Low-power generator from a single-phase asynchronous motor.
Now a few words about the primary mechanical engine, which will drive the generator. As you know, any transformation of energy is associated with its inevitable losses. Their value is determined by the efficiency of the device. Therefore, the power of a mechanical motor must exceed the power of an asynchronous generator by 50...100%. For example, with an asynchronous generator power of 5 kW, the power of a mechanical motor should be 7.5...10 kW. Using a transmission mechanism, the speed of the mechanical engine and the generator are matched so that the operating mode of the generator is set at the average speed of the mechanical engine. If necessary, you can briefly increase the generator power by increasing the speed of the mechanical engine.
Each autonomous power plant must contain minimum required attachments: AC voltmeter (with a scale up to 500 V), frequency meter (preferably) and three switches. One switch connects the load to the generator, the other two switch the excitation circuit. The presence of switches in the excitation circuit makes it easier to start a mechanical engine, and also allows you to quickly reduce the temperature of the generator windings; after completion of work, the rotor of the unexcited generator is rotated for some time by the mechanical engine. This procedure extends the active life of the generator windings.
If the generator is used to power equipment that is normally connected to the AC mains (for example, residential lighting, household electrical appliances), then it is necessary to provide a two-phase switch, which will disconnect this equipment from the industrial network during generator operation. It is necessary to disconnect both wires: “phase” and “zero”.
In conclusion, some general advice.
1. The alternator is a device increased danger. Use 380 V only when absolutely necessary; in all other cases, use 220 V.
2. According to safety requirements, the electric generator must be equipped with grounding.
3. Pay attention to the thermal mode of the generator. He "does not like" idling. Reduce thermal load possible by more careful selection of the capacitance of the exciting capacitors.
4. Don't go wrong with power electric current produced by the generator. If one phase is used when operating a three-phase generator, then its power will be 1/3 of the total power of the generator, if two phases will be 2/3 of the total power of the generator.
5. The frequency of the alternating current produced by the generator can be indirectly controlled by the output voltage, which in the “no-load” mode should be 4...6% higher than the industrial value of 220/380 V.
It is worth clarifying the definition “ electric generator" Most people 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. By definition, an electrical generator is a device that converts various types of 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.
Energy of sun
Solar battery — alternative source energy, is not very powerful, 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...
What else are good solar panels- 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 solar generator circuit is very simple.
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.
In addition to stationary systems, you can buy or make a portable one yourself solar power plant, the power of which will be quite enough to recharge a phone or tablet somewhere in nature.
DIY electric generator: wind energy
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.
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.
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.
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 air flow.
Horizontal axial modifications have more high 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 size and 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 was 4 meters per second chosen for the calculation?
As a rule, for central 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 turn 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 brittle material and can break into pieces if there is vibration. high speed. 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.
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, it is installed in 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 with your own hands 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 voltage 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, which at 200 rps has a maximum power of 250 Watts, at 24 V (enough with a margin).
After the propeller and the choice of generator, it is necessary to make a frame with a reliable design (after all, an “airplane” 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 wind 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.
The electrical part of the wind generator is the simplest: the diode bridge is connected to the battery through fuses and a voltage controller, 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.
Video
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 design of the device. Here are instructions for creating an electric generator with your own hands at home (video instructions included).
Electric generator: areas of application, principle of operation
Today we'll talk about an asynchronous electric generator, since it has a number of advantages that distinguish it from a classic synchronous one. The most important of them is a low clear factor. The fact is that synchronous generators are characterized by a fairly high clearing 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 country house, but, if we talk about industrial applications such devices, they are used to produce energy at wind stations, as welding units or as an autonomous means of maintaining 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 (created artificially) and creates a pulse that is converted into direct current.
Inside the generator there is a motor that generates electricity according to the following scheme: fuel is burned in the combustion chambers of the engine, which releases gas that drives the crankshaft. This, in turn, transmits an impulse to the driven shaft, which produces 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 the structural elements that 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 optimal).
- 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 assembly, 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. It’s worth trying to bring an idea to life only in cases where:
- have appropriate 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 purchased one
But such devices also have their disadvantages:
- 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 the device from 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, some useful tips regarding the proper operation of an 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 you have its basic structural elements 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!
