Kinetic wind generator: device, operating principle, application

A modern kinetic wind generator allows you to take advantage of the power of air currents, converting it into electricity.For this purpose, there are factory-made and home-made models of devices that are used both in industry and in private households.

We will tell you how wind turbines of this type are designed, and introduce you to the features of the device and design options. The article we have proposed shows the strengths and weaknesses of a wind power plant. Do-it-yourselfers will find useful diagrams and assembly recommendations here.

Wind generator operating principle

The operation of a wind generator is based on the transformation of the kinetic energy of the 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 fixed to the axis of the device leads to circular movements of the rotor generator, thereby generating electricity.

Wind energy is one of the most promising sectors of renewable energy. Modern designs make it possible to cost-effectively harness the power of air currents, using it to generate electricity

The resulting unstable alternating current “drains” into the controller, where it is converted into direct voltage that can charge the batteries. From there, the power is supplied to the inverter, where it is transformed into an alternating voltage with an indicator of 220/380 V, which is supplied to consumers.

The power of a wind generator directly depends on the power of 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

Various versions of wind generators differ significantly from each other.

The diagram below shows the internal structure of a classic horizontal wind generator. Such models are most often used both in industry and in everyday life.

Industrial devices are a complex multi-meter structure, the installation of which requires a foundation, while a household model can consist of a minimum of components (DC electric motor 3-12V, electric capacitor 1000 uF 6V, silicon rectifier diode).

A typical installation includes the following components:

• alternating current generator (power depends on the speed of wind flows);
• blades that transmit rotation to the generator shaft (often they are additionally equipped with gearboxes and rotor speed stabilizers);
• the windmill mast to which the blades are attached (the higher these elements are, the more wind energy they can receive);
• batteries that store energy, allowing it to be used when there is little or no wind flow. The battery also performs the function of stabilizing the electrical energy supplied from the generator;
• controller - converter of alternating voltage received from the generator into direct voltage, which is used to charge the battery. The controller is controlled by turning the blades, which allows you to take into account where the air flows are moving;
• AVR is an automatic switching device that connects the wind generator with other energy sources (solar panels, power grid);
• wind direction sensor - a device that makes it easier for the blades to find the wind flow;
• an inverter for converting direct current from batteries into 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 an inverter-modified sine wave that produces a square sine wave. Devices of this type are suitable for heating elements, incandescent lamps and other devices that are undemanding to network quality;
• three-phase voltage inverters designed for three-phase electrical networks;
• pure sine wave units that produce energy for more sensitive equipment;
• network inverters that can operate without batteries. Such devices are designed for circuits that involve electrical energy entering directly into the general network.

When choosing models, be sure to pay attention to the type of inverter.

Types of Wind Generators

When classifying wind turbines, the following characteristics can be taken into account:

• appointment;
• design features;
• number of blades;
• the materials from which they are made;
• axis of rotation;
• propeller pitch.

Let's take a closer look at the two most commonly used classifications.

Classification of wind generators by purpose

There are types of wind turbines that differ in purpose. The main characteristics of devices, for example, power, depend on this.

Industrial wind turbines

Such devices are installed by large energy companies or the state to supply electricity to industrial facilities.Turbines, with a capacity of tens of megawatts, are usually located in wind areas (open hills, coasts).

Wind farms, where dozens of wind turbines are installed, are located not only on land, but also in shallow water. The resulting electricity is usually used for industrial purposes

The generated electricity, as a rule, goes directly into the network, while for stability and regulation of the speed of rotation of the blades, wind turbines are equipped with additional mechanisms.

Commercial Wind Generators

Such installations are used to generate electricity for sale or to provide electricity to production in regions with a low-power electrical network (or no electricity grid at all). Such wind power plants consist of a cluster of electric generators, which can have different capacities.

Energy from commercial installations can be fed directly into electrical utilities or used to charge a large array of batteries, where it is stored and converted to feed the grid.

Household wind devices

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 land owners without approval from the authorities; for higher masts, special permission must be obtained.

Windmills of low and medium power can serve as a source of electrical energy for cottages, dachas, country houses, and farms

Household wind generators are suitable for charging batteries with a voltage of 12/24/48V, the energy from which is transformed into a voltage of 220 Volts.Such devices make it possible to completely or partially solve the problem of power supply to small objects that are located far from the centralized power grid.

With guidelines for choosing a wind generator to provide energy to a private home read the articlededicated to this interesting issue.

Types of wind turbine designs

Based on their design features, devices can also be divided into a number of categories, although all varieties come down to two main types: vertical and horizontal.

Classic horizontal wind turbines

Such installations (they are also called propeller or wing) usually have 3-5 blades mounted on a horizontal axis. Rotating at high speed, such elements allow you to obtain the maximum amount of energy (KIEV up to 0.4).

Moreover, the amount of electricity generated largely depends on the height of the device (the higher it is, the greater the result).

A horizontal wind turbine uses lift, which occurs when pressure increases at the point where direct air flow passes through the blades and is reflected from these elements.

These devices are typically installed in wind farms where energy is generated for industrial and commercial use, but they are also suitable for domestic use.

An interesting solution for a horizontal windmill is a model with one blade; the following selection of photos will familiarize you with its features:

Vertical wind turbines

The operating element of such installations is a rotating wind wheel. Due to their design features, such structures differ by type (“Barrel”, “Savonius”).

The following photo selection will introduce you to the principle of the Savonius vertical generator turbine:

Despite the low KIEV index (0.1-0.2), they are widely used: vertical installations operate on turbulent air flows, so they can be placed even in areas where strong winds rarely blow.

The operation of vertical wind generators does not depend on the direction of the winds. They are easy to install and operate, and such devices can be installed close to the ground

To improve the efficiency of vertical wind turbines, manufacturers often increase their dimensional parameters, which leads to a significant increase in cost. Since such installations are quite fragile, they require increased protection from hurricanes and other natural phenomena.

Wind generators "Rotor Daria"

Such devices belong to the category of vertical wind turbines, but have pronounced differences in design. Thanks to such features, noise reduction is achieved, and KIEV also increases, which approaches the performance of horizontal models.

A low-pressure turbine with an axis of rotation perpendicular to the air, proposed in 1931 by the French aircraft designer Georges Darrieus, has found wide application in wind energy.

The disadvantage of such designs is the low starting torque (due to the presence of only two blades, it is difficult for the device to start on its own). To solve the problem, the “Savonius + Darier” hybrid is often used.

Sailing wind installations

For such installations, the principle of constructing both vertical and horizontal wind turbines can be used. The main design feature is a wind wheel covered with many blades or sails, while such models do not have an aerodynamic profile.

There are many models of sailing wind generators, which differ in the number of blades, weight, and power. All these parameters should be taken into account 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.Such designs are easy to install and operate, and the combination of high torque and low speed allows you to directly drive various useful mechanisms, for example, a pump for pumping out water.

The following gallery will introduce you to one of the models of sailing wind turbines implemented in practice:

Generator for wind turbine

Wind turbines require conventional three-phase generators to operate. The design of such devices is similar to models used on cars, but has larger parameters.

Wind turbine instruments have a three-phase stator winding (star connection), from which three wires come out and go to the controller, where the alternating voltage is converted to direct voltage.

The generator rotor for a wind turbine is made of neodymium magnets: in such designs it is inappropriate to use electrical excitation, since the coil consumes a lot of energy

A multiplier is often used to increase turnover.This device allows you to increase the power of the existing 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 high blade rotation speeds, multipliers are not required, which simplifies and reduces the cost of the design.

Specifics of wind generator assembly and installation from the washing machine and wind turbines from a car generator is described in detail 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 the decision to purchase a wind turbine or abandon it depends on them.

Advantages of wind devices

The advantages of devices using wind energy include:

• Environmental friendliness. The installations use a renewable energy source that 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 plants can be built almost everywhere: on plains, in mountains, in fields, on islands and even in shallow waters. Wind energy is especially valuable in remote places where it is difficult to extend conventional electrical communications. Wind generators in this case make it possible to establish an energy supply for objects, ensuring its independence from random factors (for example, fuel not delivered on time).
• Efficiency of use. Modern models process the energy of even weak winds - the minimum limit is 3.5 m/s.In this way, it is possible to supply additional electricity to the centralized network, as well as organize power supply to individual objects (island or local) regardless of their power.
• A worthy alternative to traditional sources. Stationary wind power plants can completely provide electricity to a residential building or even a small industrial facility. In this case, the turbine will accumulate the required supply of electricity in batteries, intended for use during calm periods.
• Economical. Compared to traditional sources of electrical energy (gas, peat, coal, oil), bicycle 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 costs of transportation and storage of fuel by up to 80%.

The average power of a wind turbine differs several times from the peak load. A wind generator is responsible only for the amount of energy produced over a certain period of time at the average monthly wind speed characteristic of a given area.

For a more accurate assessment of wind resources, you can use specially derived data (Weibull parameters). These indicators reflect the distribution of winds of different strengths characteristic of a particular area. It is important to take such information into account when developing wind farm projects with a capacity of tens of MW.

The power generated by a wind turbine is proportional to triple the wind speed.Consequently, this indicator is very small when wind flows are weak, but when they intensify, it increases sharply. Due to the variability of wind direction and speed, stabilizing components must be included in the design of a wind turbine.

Rules and formulas for calculating wind generator power are given here, we recommend that you familiarize yourself with the 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.

As the load increases, the battery may discharge. It is important to take this feature into account when choosing a household unit; its power must match the monthly or annual electricity consumption rate

It should be noted that the effective use of wind flows is facilitated by a variety of wind generator designs.

Horizontal turbines perform well in flat areas where there is a lot of wind, while vertical turbines work better in regions with turbulent flows found low to the ground (upper hills, mountain ranges).

The main disadvantages of wind turbines

At the same time, wind turbines also have their negative sides:

• The magnitude of the wind force is difficult to predict in advance, as it changes frequently. Because of this, it is advisable to consider a safety net by providing a backup energy source (solar panels, connection to the electrical network).
• Vertical devices are at risk of destruction of the propeller blades due to the effects of centrifugal forces when the blades rotate around the main axis. As a result of this effect, important structural elements become deformed and destroyed over time, and the mechanism fails.
• It is better to install wind turbines in free space, since nearby buildings can “dampen” the wind, forming a “dead” air zone.
• To save excess energy from wind turbines, it is necessary to include in the design the use of batteries and other additional devices that serve to convert the generated electricity into current with suitable consumer characteristics.
• When operating, wind generators produce noise that can cause discomfort to people and scare away animals. The blades of the installations can also cause the death of birds flying towards them.
• According to some experts, wind turbines can degrade the reception of radio and television broadcasts.

Negative aspects can also include the rather high cost of such units, however, the low cost of the energy source largely offsets this factor.

Connection diagrams and methods

Although a wind turbine can operate autonomously, much better results can be achieved using combined schemes that combine a wind turbine with solar panels, a centralized power grid, diesel or gas energy sources.

Autonomous operation. In this case, a single installation is installed, with the help of which wind energy is captured and accumulated, which is then converted into the electric current needed by consumers.

The diagram shows the simplest way to use a wind generator, which is advisable to use in regions where strong winds constantly blow

Combining a wind generator with solar panels. The combined option is considered a reliable and efficient method of power supply. If there is no wind, the battery runs on solar panels, and in cloudy weather and during the night, charging occurs from a wind turbine.

An ideal option for a private home or farm located far from a centralized power grid. This combined scheme allows the use of two types of renewable energy

Combined operation of a wind generator and power grid. A wind turbine can be combined with electrical communications.

This arrangement is typical for industrial and commercial devices. Connection to electrical communications is also provided for some models of household wind generators

If there is an excess of electricity produced, it goes to the centralized network, and if there is a shortage, it is possible to use electric current from the general energy system.

Nuances of using wind generators

Currently, wind turbines are used in various sectors of the national economy. Industrial models of varying capacities are used by oil and gas, telecommunications companies, drilling and geological exploration stations, production facilities and government agencies.

The wind turbine can be used as an additional source of energy in hospitals and other institutions to ensure continuous power supply in emergency situations

Particularly noteworthy is the importance of using wind turbines for the prompt restoration of damaged electricity during cataclysms and natural disasters. For this purpose, wind generators are often used by units of the Ministry of Emergency Situations.

Household wind turbines are perfect for organizing lighting and heating in cottage communities and private houses, as well as for economic purposes on farms.

There are some points to consider:

• Devices up to 1 kW can provide a sufficient amount of electricity only in windy places.Typically, the energy they generate is only enough to power LED lighting and power small electronic devices.
• To fully provide electricity to a dacha (country house), you will need a wind generator with a power of over 1 kW. This indicator is enough to power lighting fixtures, as well as a computer and a TV, but its power is not enough to supply electricity to a modern refrigerator that operates around the clock.
• To provide energy to a cottage, you will need a wind turbine with a capacity of 3-5 kW, but even this figure will not be enough to heat houses. To use this function, you need a powerful option, starting from 10 kW.

When choosing a model, you should take into account that the power indicator indicated on the device is achieved only at maximum wind speed. Thus, a 300V installation will produce the specified amount of energy only at an air flow speed of 10-12 m/s.

For those wishing to build a wind generator with their own hands, we offer next article, which provides useful information in detail.

Conclusions and useful video on the topic

The video below provides detailed information about the operating principle and design of a household model of a wind generator:

A wind generator is an excellent source of electrical 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, household models can be made with your own hands.

Please write comments in the block below. Tell us about how you built a wind generator on your property, or about how your neighbors’ wind turbine works.Ask questions, share useful information and photos on the topic.