Modern kinetic wind generator allows you to use the power of air flow, converting it into electricity. For this purpose, there are factory and homemade models of devices that are used both in industry and in private farms.
We will talk about how the windmills of this type are arranged, we will acquaint with the features of the device and design options. The article proposed by us shows the strengths and weaknesses of the wind power plant. Independent masters here will find useful schemes and recommendations for the assembly.
The content of the article:
- The principle of operation of the wind generator
- Wind generator device
Types of wind generators
- Wind turbine classification by purpose
- Varieties of windmill designs
- Wind turbine generator
Pros and cons of a wind generator
- Advantages of wind turbines
- The main disadvantages of wind turbines
- Connection schemes and methods
- Nuances of using wind turbines
- Conclusions and useful video on the topic
The principle of operation of the wind generator
The basis of the operation of the wind generator is the transformation of the kinetic energy of wind into the mechanical energy of the rotor, which is then converted into electricity.
The principle of operation is quite simple: the rotation of the blades mounted on the axis of the device, leads to circular motions of the rotor generator, thereby generating electricity.
Wind power is one of the most promising renewable energy industries. Modern designs allow cost-effective use of the force of air flow, using it to generate electricity
The resulting unstable alternating current "flows" into the controller, where it is converted into a constant voltage that can charge the batteries. From there, power is supplied to the inverter, where it is transformed into an alternating voltage with a 220/380 V indicator, which is fed to consumers.
The power of the wind generator directly depends on the power of the air flow (N), calculated according to the formula N = pSV3/ 2, where V is the wind speed, S is the working area, p is the air density.
Wind generator device
Different versions of wind generators are significantly different from each other.
The diagram shows the internal structure of the classic horizontal wind generator. Such models are most often used both in industry and in everyday life.
Industrial devices are a complex multi-meter design, the installation of which requires a foundation, while household The model may consist of a minimum of components (a DC electric motor of 3-12 V, an electric capacitor 1000 μF 6 V, a silicon rectifier diode).
Typical installation includes the following components:
- alternator (power depends on wind speed);
- blades that transmit rotation to the generator shaft (often they are additionally equipped with gearboxes, rotor speed stabilizers);
- the mast of the windmill, to which the blades are attached (the higher these elements are, the greater the amount of wind energy they can get);
- batteries that accumulate energy, which allows its use with a small wind flow or its absence. The battery also performs the function of stabilizing electrical energy from the generator;
- controller - converter of alternating voltage, obtained from the generator, into a constant, which is used to charge the battery. The controller is controlled by turning the blades, which allows to take into account where the air flows;
- AVR - the device of the automatic switching connecting the wind generator with other energy sources (solar panels, the electric network);
- wind direction sensor - a device that facilitates blades search wind flow;
- inverter for converting direct current from batteries to alternating voltage, which is used in electrical communications.
To better meet user needs, the device can be equipped with various types of inverters:
- devices with inverted sine wave, issuing a square sine wave. Devices of this type are suitable for heating elements, incandescent lamps and other devices that are undemanding on the quality of the network;
- three-phase voltage inverters designed for three-phase electrical networks;
- pure sine wave plants that produce energy for more sensitive equipment;
- network inverters capable of functioning without batteries. Such devices are designed for circuits involving the ingress of electrical energy directly into the common network.
When choosing models, be sure to pay attention to the type of inverter.
Types of wind generators
The classification of wind turbines can take into account such characteristics as:
- design features;
- the number of blades;
- the materials from which they are made;
- axis of rotation;
- screw pitch.
Let us consider in detail the two most commonly used classifications.
Wind turbine classification by purpose
There are varieties of wind turbines that differ in purpose. The main characteristics of devices, for example, power, depend on it.
Industrial Wind Turbines
Such devices are installed by major energy companies or by the state to supply electricity to industrial facilities. Turbines with a capacity of tens of megawatts are usually located on wind plots (open elevations, coasts).
Wind farms, where dozens of wind turbines are installed, are broken not only on the ground, but also in shallow water. The resulting electricity is usually used for industrial purposes.
The generated electricity, as a rule, goes directly to the network, while for stability and controlling the frequency of rotation of the blades of the wind turbine are equipped with additional mechanisms.
Commercial wind generators
Such plants are used to generate electricity for sale or to provide electricity to industries in regions with a low-power grid (or with its complete absence). Such wind farms consist of clusters of power generators that may have different capacities.
Commercial power can flow directly into electrical communications or used to charge a large array of batteries, where it accumulates and is converted to feed into power grid.
Household wind appliances
Low power units are used for private use. According to the rules, wind turbines with masts less than 25 meters high can be installed by landlords without the consent of the authorities; for higher masts, a special permit is required.
Wind turbines of low and medium power can serve as a source of electrical energy for cottages, villas, country houses, farms
Household wind generators are suitable for charging batteries with a voltage of 12/24 / 48V, the energy of which is transformed into a voltage of 220 volts. Such devices make it possible to completely or partially solve the problem of supplying electricity to small objects that are located away from the centralized power grid.
With guidelines for choosing a wind generator to provide energy to a private home will introduce the articlededicated to this interesting question.
Varieties of windmill designs
According to the design features of the device can also be divided into a number of categories, although all varieties are reduced to two main types: vertical and horizontal.
Classic horizontal wind generators
Similar installations (they are also called propeller or wing) usually have 3-5 blades mounted on a horizontal axis. Rotating with high speed, such elements allow to get the maximum amount of energy (KIEV up to 0.4).
At the same time, the amount of generated electricity depends largely on the height of the device (the higher it is, the greater the result).
A horizontal wind generator uses a lift force that occurs when the pressure increases at the point where direct air flow passes through the blades, reflecting from these elements
Such devices are usually installed in wind farms, where energy is generated for industrial and commercial use, but they are also suitable for domestic use.
Vertical Wind Turbines
The operating element of such installations is a rotating wind wheel. Due to the design features, such constructions differ in types (“Barrel”, “Savonius”).
Despite the low KIEV (0.1-0.2), they are widely used: vertical installations act on turbulent air flow, so that they can be placed even in areas where strong wind
The work of vertical wind turbines does not depend on the direction of the winds. They are easy to install and operate, besides such devices can be placed close to the ground
To improve the performance of vertical windmills, manufacturers often increase their dimensional parameters, which leads to a significant increase in cost. Since such installations are quite fragile, they require increased protection against hurricanes and other natural phenomena.
Wind Generators "Rotor Daria"
Such devices belong to the category of vertical wind turbines, however, they have pronounced differences in design. Due to similar features, noise reduction is achieved, and also KIEV grows, which is close to the performance of horizontal models.
The low-pressure turbine proposed in 1931 by the French aircraft designer Georges Daryet, with an axis of rotation perpendicular to the air environment, has found wide application in wind power engineering.
The disadvantage of such structures is a low starting point (due to the presence of only two blades, it is difficult for the device to start independently). To solve the problem is often used hybrid "Savonius + Darya."
Sailing wind installations
For such installations, the principle of both vertical and horizontal wind turbines can be applied. The main design feature is a wind wheel, covered with multiple blades or sails, while the aerodynamic profile of such models is absent.
There are many models of sailing wind generators, which differ in the number of blades, weight, power. All these parameters should be considered when choosing a device.
Despite the fact that sailing installations are characterized by low-speed and low efficiency, they are often used in the national economy. Similar designs are easy to install and operate, and the combination of high torque with low turns allows you to directly set in motion various useful mechanisms, for example, a pump for pumping out water.
Wind turbine generator
For the operation of the windmills need the usual three-phase generators. The design of such devices is similar to the models used on cars, but it has large parameters.
Wind turbine devices have a three-phase stator winding (star connection), where do the three wires go to the controller, where the transformation of the AC voltage into permanent.
The rotor of the generator for the wind turbine is manufactured on neodymium magnets: in such constructions it is impractical to use electric excitation, since the coil consumes a lot of energy
To increase the speed often used multiplier. Such a device allows you to increase the power of the current generator or use a smaller device, which reduces the cost of installation.
Multipliers are more often used in vertical wind generators, in which the process of rotating the wind wheel is slower. For horizontal devices with a high speed of rotation of the blades multipliers are not required, which simplifies and reduces the cost of construction.
Specificity of assembly and installation of a wind generator from the washing machine and wind turbines from car generator detailed in the articles we recommend.
Pros and cons of a wind generator
Let us consider in detail the advantages and disadvantages of wind turbines, since it is up to them to decide whether or not to buy a wind turbine.
Advantages of wind turbines
The advantages of devices using wind energy include:
- Environmental friendliness. Installations use renewable energy source, which can be used continuously, without causing damage to the environment. Electricity generated by wind generators replaces the energy of thermal power plants, reducing greenhouse gas emissions.
- Versatility. Wind power can be built almost everywhere: on the plains, in the mountains, in the fields, on the islands and even in shallow water. Wind energy is especially appreciated in remote places where it is difficult to stretch the usual electrical communications. In this case, wind generators make it possible to adjust the power supply to the facilities, ensuring it is independent of random factors (for example, from fuel not delivered on time).
- Use efficiency. Modern models recycle energy even weak winds - the minimum limit is 3.5 m / s. Similarly, it is possible to make additional delivery of electricity to a centralized network, as well as organize power supply of individual objects (island or local), regardless of their power.
- A worthy alternative to traditional sources. Stationary wind farms can fully provide a residential house or even a small production facility with electricity. In this case, the turbine will accumulate in batteries the required supply of electricity for use during non-windy periods.
- Efficiency. Compared to traditional sources of electrical energy (gas, peat, coal, oil), cycle turbines can significantly reduce energy costs. In many cases, building a wind farm is cheaper than connecting to existing power systems.
The use of wind turbines can be an alternative to the use of expensive diesel generators, further reducing the cost of transportation and storage of fuel up to 80%.
The average power of the wind turbine is several times different from the peak load. The wind generator is responsible only for the amount of energy production for a certain period of time with an average monthly wind speed characteristic of the area.
For a more accurate assessment of wind resources, you can use specially derived data (Weibull parameters). These figures reflect the characteristic distribution of winds of different strengths for a particular locality. Such information is important to consider when developing projects for wind farms with a capacity of tens of MW.
The power generated by the wind turbine is proportional to the tripled wind speed. Consequently, this indicator is very small in case of weak wind flows, however, when they increase, it increases dramatically. Due to the variability of the direction of the winds and their speed, it is necessary to provide stabilizing components in the design of the wind turbine.
Rules and formulas for calculating the power of a wind generator given hereWe recommend to get acquainted with very useful information.
In small autonomous systems, their function is performed by batteries, the charge of which begins to increase as soon as the power of the wind generator exceeds the load indicator.
As the load increases, the battery may run down. This feature of the work is important to consider when choosing a household unit, its power should coincide with the monthly or annual rate of electricity consumption
It should be noted that the effective use of wind flows contributes to a variety of designs of wind generators.
Horizontal turbines give high performance in flat places where there is a lot of wind, while vertical turbines work better in regions with turbulent flows observed low from the ground (in the upper part of hills, mountain ridges).
The main disadvantages of wind turbines
At the same time, wind turbines have their negative sides:
- The magnitude of the force of the wind is difficult to predict in advance, as it often changes. Because of this, it is advisable to think about safety net, providing for a backup energy source (solar panels, electrical connection).
- Vertical devices are exposed to the risk of destruction of the propeller blades due to centrifugal forces during rotation of the blades around the main axis. Due to this effect, important elements of the structure over time are deformed and destroyed, and the mechanism fails.
- It is better to install wind turbines in free space, since adjacent buildings can “quench” the wind, forming a “dead” air zone.
- To save the excess energy of wind turbines, it is necessary to provide for the use of batteries and other additional devices serving to convert the resulting electricity into current with suitable consumer characteristics.
- When working, wind generators emit noise that can cause discomfort to people, frighten off animals. Blades of installations can also cause the death of birds that fly to them.
- According to some experts, wind turbines can worsen the reception of radio and television broadcasts.
The negative aspects can also be attributed to the relatively high cost of such units, however, the cheapness of the energy source largely eliminates this factor.
Connection schemes and methods
Although the wind turbine can operate autonomously, much better results can be achieved with the help of combined schemes, combining a wind device with solar panels, centralized electricity, diesel or gas sources of energy.
Autonomous work. In this case, a single installation is put, with the help of which wind energy is captured and accumulated, which is then converted into an electric current required by consumers.
The diagram shows the easiest way to use a wind generator, which is advisable to use in regions where strong winds constantly blow
Combination of wind generator with solar panels. The combined option is considered a reliable and efficient way of power supply. In the absence of wind, the battery operates from solar panels, and in cloudy weather and during the night, charging comes from a wind installation.
Ideal option for the private house or the economy located in the distance of the centralized power supply network. Such a combined scheme allows using two types of renewable energy.
The combined work of the wind generator and power. The wind turbine can be combined with elektrokomcommunications.
Such a scheme is typical for industrial and commercial devices. Connection to electrical communications also includes some models of household wind generators.
With an excess of electricity produced, it enters the centralized network, and with its shortage it is possible to use the electric current from the common power grid.
Nuances of using wind turbines
Currently, wind turbines are used in various fields of national economy. Industrial models of different capacities are used by oil and gas, telecommunications companies, drilling and geological exploration stations, production facilities and government agencies.
The windmill can be used as an additional source of energy in hospitals and other institutions to ensure uninterrupted power supply in emergency situations.
Of particular note is the importance of using wind turbines for the rapid restoration of disturbed electricity during cataclysms and natural disasters. To this end, wind turbines are often used by the units of the Ministry of Emergency Situations.
Household wind turbines are perfect for organizing lighting and heating of cottage villages and private houses, as well as for economic purposes on farms.
It should take into account some points:
- Devices up to 1 kW can provide a sufficient amount of electricity only in windy places. Usually, the energy they produce is only enough for LED lighting and powering small electronic devices.
- To fully provide electricity to the cottage (country house), you will need a wind generator with a capacity of over 1 kW. This indicator is enough to power the lighting devices, as well as a computer and a TV, however its power is not enough to provide electricity around the clock working modern fridge.
- To provide energy to the cottage you will need a wind turbine with a capacity of 3-5 kW, but even this figure is not enough to heat homes. To take advantage of this feature requires a powerful option, ranging from 10 kW.
When choosing a model, it should be noted that the power indicator indicated on the device is achieved only at the maximum wind speed. Thus, an installation of 300V will produce the specified amount of energy only at the air velocity of 10-12 m / s.
Wishing to build a wind generator with our own hands, we offer next article, which detailed useful information.
Conclusions and useful video on the topic
The video below presents detailed information about the principle of operation and the device of a household model of a wind generator:
A wind generator is an excellent source of electric energy production, which will be especially appreciated by residents of remote areas. Various Russian and foreign enterprises offer a wide range of wind structures, in addition, domestic models can be made with your own hands.
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