Inverter-type gasoline generators - how to choose for your home and garden, review of models with prices. Inverter generators - basic concept, advantages, scope of application

25.09.2015

What are inverter generators?

Inverters are devices with a gasoline, diesel or gas fuel system that make it possible to convert, using a semiconductor rectifier, the input alternating current (220 V) into direct current (12 V) and, after smoothing its pulsations with capacitive filters, transform back the direct voltage current into alternating current with specified values. load parameters. Due to this conversion method, it is possible to obtain an output electrical signal characterized by high voltage and current accuracy.

These devices are generators of periodic voltage, which in shape is most often as close as possible to a regular sinusoid. Theoretically, they allow you to obtain an output current that has any necessary parameters that do not depend on the input voltage. In this case, it is possible to obtain not static current parameters, but adjustable current parameters of various frequencies and voltages. A constant voltage of 12 V is generated by the supplied batteries.

What are inverters used for?

One of the most popular ways to use an inverter is to use it as an emergency or backup source of electricity to power household appliances and devices that consume 220 V AC. Most often they are used to connect kitchen and office equipment, a TV, a refrigerator, as well as high-frequency equipment in a country house or country house when the power is suddenly turned off. Depending on the total power of the load connected to it, this equipment will be able to work autonomously for at least several hours. Also, with the help of inverter stations, power tools (power saws, drills, planers) are connected for carrying out repair and construction work in places where there is no 220 V supply. Such units are no less in demand among fishermen and hunters.

Basically, inverter stations are designed for occasional operation during spontaneous power outages. They are purchased once and last for many years. The long service life is explained by the reliability of the mechanism of these devices, ensured by the following factors:

the presence of a special ignition system at the heart of these devices, which guarantees quick start of the inverter;
control of devices using an automatic control system, which contributes to economical fuel consumption, the indicators of which are reduced by 40%.

Two types of inverter power plants

Depending on the shape of the output signal, these devices are divided into two groups that differ in cost. The first includes units with a pure sinusoidal output voltage, the second includes devices that provide a simplified output signal (trapezoidal sine).

Which inverters are better: pure or modified sine wave?

The advantages of models characterized by pure sinusoidal voltage are:

laptop computers;
laser printers and other copying equipment, magneto-optical disk drives;
digital clock;
sewing machines characterized by variable speed electric motors;
equipment with microprocessor control;
fluorescent lamps;
some medical devices (such as oxygen concentrators);
transistor-based power tools with variable rotation speed;
charging devices for cordless power tools.

From inverter generators, the output signal of which is a modified sine wave, most modern electrical equipment is able to function normally. Therefore, if you are faced with the task of providing autonomous power supply to standard household electrical appliances, such as a refrigerator, TV, lighting lamps, etc., then the most optimal and economical solution would be an inverter that generates a modified sine wave, and it is better to choose models with “pure sine” for more sensitive equipment.

Basic operating modes of inverters:

Long-term operating mode: provides for the operation of the inverter at rated power levels.
Overload mode: most of these units allow operation for no more than 30 minutes at maximum power, the value of which can be 1.5 times higher than the rated power. Such a large but short-term overload can occur when the refrigerator is turned on.
Start-up mode: within a few milliseconds, the power plant releases increased instantaneous power necessary to ensure the normal start of the device and overcome capacitive loads.

Which is better to choose an inverter or a generator?

Many users will quite rightly note that it is quite possible to use a conventional generator to organize independent power supply for electrical equipment. However, devices with an inverter system have a number of advantages, including almost silent operation, light weight and small dimensions, which is very important when used in domestic conditions. In addition, inverters do not contain moving parts in their design, which makes them more reliable and does not require periodic maintenance. In autonomous power supply systems for large facilities (for example, large cottages), inverter stations are often used in conjunction with an additional generator designed to charge batteries and increase battery life.

Advantages of inverter generators

The most important advantages of inverters are their wide capabilities, expressed in the conversion of electric current, as well as their high speed. Due to this, they are rightfully considered the best sources of independent power for welding equipment. In addition, they are perfectly compatible with a wide range of electrical appliances. These devices are equally suitable for household appliances, power tools and electronic equipment.

Thanks to the replacement of bulky electromechanical circuits with semiconductor boards, it was possible to achieve the most compact dimensions of inverters, as well as significantly reduce their weight compared to transformer generators and semi-automatic devices. The use of more modern element base and automation could not but affect the price of such devices in the direction of its increase compared to units made according to the classical design. But, despite this, the benefits that inverter generators provide, consisting of greater opportunities in terms of current conversion, efficiency and mobility, are significantly more important than one-time savings. In addition, the maintenance of such power plants is much simpler, and also not as costly and labor-intensive as that of analogues of other types due to the absence of an electromechanical part.

Consolidating all of the above, the most significant advantages provided by inverter power plants can be characterized by the following theses:

lightness, compactness and mobility (according to these indicators, they are several times superior to other types of generators), which allows them to be considered portable sources of autonomous electricity;
high efficiency due to accurate calculation of engine speed in accordance with the applied load;
silent operation due to the presence of a double soundproof housing and special mufflers;
the presence of models operating on bottled fuels (diesel fuel, gasoline), which is very convenient and practical;
high reliability and durability, which was achieved through excellent adaptability and resistance of internal parts and connections to external loads, as well as adverse factors affecting the external environment;
generating electricity of the highest quality.

Summing up

The features and advantages of generators with an inverter circuit listed in this article allow us to confidently declare the high functional, technical, as well as operational characteristics and performance of this equipment. In this connection, their use in educational and medical institutions, offices, private homes and country houses is absolutely justified to ensure the autonomous operation of household appliances, computing and multimedia equipment, security alarms, power tools, production devices and other equipment that requires a constant supply of electricity. .

Inverters are valued because they are able to generate adequate quality electricity to power the above-mentioned equipment, ensuring their safe operation. Once you buy such a device, you will once and for all forget about the problems of spontaneous power outages, surges and drops in mains voltage. In addition, the long service life of inverter stations helps to minimize the funds spent on repair work or the purchase of a new generator. Do not forget that in most cases, for the vast majority of household appliances, it is quite sufficient to supply a voltage characterized by a simplified form of the electrical signal, and the “correct” sine wave is important only for high-precision telecommunications, laboratory, measuring, medical and various professional equipment (HI-FI, HI-END audio and video equipment).

Various traditional types of generators have been available on the market for a long time. The operating principle of such equipment has remained virtually unchanged over all this time: a certain type of fuel is burned in an engine that is connected to a device that generates alternating current.

In addition to gasoline, diesel and other traditional types of generators, there are so-called inverter generators.

Inverter generators- these are gasoline mini-power plants, where the alternating current generated during fuel combustion is converted into direct current, which, after stabilization through electronic circuits, is converted back into alternating current.

Nowadays, inverter generators are still considered a novelty, the emergence of which was facilitated by the development of high-tech magnets and the improvement of electronic circuits. Compared to traditional generators, such devices produce higher quality electric current. They are also equipped with more complex electronic circuits, making them high-tech equipment.

Such positive aspects provide inverter generators with more efficient operation and smaller dimensions. The use of complex components not only reduces the size of the equipment, but also makes it more economical and less noisy in operation.

Many sellers forget that inverter generators are more advanced devices than conventional generators. Moreover, sellers often put them on a par with traditional units.

But the power from inverter generators is cleaner, making them suitable for use with sensitive electronics. And their small size and low noise level allowed them to become popular among summer residents, hunters, fishermen and tourists.

Inverter generator- this is the best choice for picnics, outdoor celebrations, country trips, hikes and even marketing events.

The relatively small size of inverter generators makes them easy to transport, which traditional devices cannot boast of. If you need to get more powerful equipment, then you just need to purchase and combine two inverter generators.

The design of conventional generators is often carried out according to a simple principle, while assuming the solution of the basic problem - generating a certain power. Factors such as equipment size are rarely taken into account by designers of traditional generators. Consequently, any unit of this kind is equipped with a capacious and, accordingly, heavy and bulky fuel tank.

The negative factors described above are completely absent from inverter generators, since their design initially involved the creation of compact devices. In addition, they were originally conceived as lightweight equipment without bulky and heavy fuel tanks.

And finally, inverter generators effectively solve the problem of exhaust gases.

To choose the right generator from the two types, it is important to know their operating principles and advantages. The operation of a conventional generator is that a gasoline or diesel engine spins a rotor with windings in a magnetic field, resulting in the generation of alternating current.

Classic generator

The speed of the motor, to which the rotor is directly connected, varies depending on the load. In a generator with a significant change in speed, the wear of rotating components and parts increases, which leads to a decrease in engine shaft speed. The following disadvantages of the classic generator also reduce its efficiency.

The generator of the classic version, when the load decreases, consumes the same amount of fuel as in the nominal mode. Also, under conditions of greatly varying speeds, soot appears on the piston group components, which impedes heat transfer and leads to premature engine wear.

The principle of operation of a classical generator

In the product instructions you can find a ban on the operation of a conventional electric generator at a load below 25%. The power of a classic electric generator must be adjusted to the load so that it operates at 80% of the maximum power, with a constant load.

This is the only way to extend the life of the generator and increase its efficiency. The positive aspect of this type of electric generator is its low cost. You can also extend the operating time of an electric generator if you periodically give it a full load and regularly carry out preventive maintenance.

The difference between an inverter generator and a conventional one

The operating principle of an inverter generator is somewhat different from a conventional one. An inverter generator is a double voltage conversion generator, just like the . The engine also spins the rotor of the electric generator in a magnetic field.

The generator produces alternating voltage supplied to the first converter with subsequent conversion to direct voltage to charge the batteries. The DC voltage is removed from the batteries and goes to the second DC voltage converter, where it is converted into AC voltage.

The parameters of the inverter generator are high, an alternating voltage sinusoid without distortion and excellent stabilization of the output voltage. Low engine speeds are sufficient to charge the battery. Low speeds increase engine life, fuel consumption decreases - this leads to increased efficiency of the inverter generator.

Inverter generator

At such speeds, the generator with a noise-absorbing casing becomes silent. The high quality of the output voltage allows the generator to be used to power any household appliances and electrical appliances. The inverter generator can work with any load. The electronics automatically adjusts the engine speed to suit any load.

Operating principle of an inverter generator

Electric generators are produced with a power of up to 6 kW, which is quite enough to supply high-quality voltage to a gas boiler and all electrical equipment in the house. Small inverter electric generators up to 2 kW are lightweight, they are convenient to transport in the trunk to the country house or take with you on a trip. The main disadvantage of such generators is their high cost, but it is compensated by the above advantages.

Inverter generators can be synchronous or asynchronous. Synchronous-type electric generators can easily withstand short-term overloads with starting currents. They are very suitable for working with household appliances. Asynchronous generators can withstand a short circuit; they are used to power electrical appliances that have heating elements - these are electric furnaces and water heaters.

Conclusion: It is recommended to choose a conventional generator for emergency power supply, lighting, and construction sites. For the electrical network of a private home, with a lot of electrical equipment and electrical appliances, an inverter generator with precisely selected power is better suited.

Small-sized power plants for home use have become widespread due to the fact that they can easily solve problems with power supply. Compact gasoline and diesel generators are used both to ensure uninterrupted power supply and to generate electricity in places where there are no power lines: at a construction site, at a picnic. The choice of consumers is complicated by the fact that there are several options for generators on sale:

Classic, using gasoline or diesel drive;
Inverter.

Both types operate on exactly the same principle: the work of the internal combustion engine is converted by a generator into an alternating current voltage of 220 V with a consumer power of up to several kW. The difference lies in the principle of stabilization of the output voltage parameters.

Design and operating principle

As already mentioned, both types of power plants have a similar design, which includes two main elements:

Internal combustion engine;
Alternator.

The electrical voltage of the AC mains must satisfy the following conditions:

Voltage level stability – 220V;
Frequency stability – 50Hz.

Failure to comply with voltage parameters may cause damage or inoperability of connected devices. This is especially true for voltage level stability. A deviation in the network frequency can lead to disruption of the normal functioning of devices that have AC motors in their design: circulation pumps for heating systems, compressors for refrigeration equipment.

Regular generator

In the classic version of the power plant, a gasoline or diesel engine rotates the rotor of an alternator. The alternating current voltage is removed from the stator windings and then goes to the distribution panel of the power plant for distribution to consumers.

An increase in current consumption by the load causes a braking force on the generator rotor, thus reducing the rotation speed. As a result, the amplitude value of the voltage and its frequency decrease. Reducing the load causes the opposite effect. The most dangerous phenomenon is that with a sharp decrease in power consumption, voltage surges that reach dangerous values are possible.

Stabilization of rotation speed in classical devices is carried out in two directions. The rotation speed of the internal combustion engine is directly controlled by a centrifugal governor, which regulates the fuel supply depending on the crankshaft speed. For finer adjustment, an additional stabilizing winding loaded onto a capacitor is provided in the generator stator. As the frequency of the alternating voltage increases, the resistance of the capacitor decreases. Consequently, the load on the additional winding increases. An increase in the current of the additional winding causes the appearance of a braking magnetic field, which reduces the rotor speed. When the speed decreases, the process occurs in the reverse order. The braking field of the stabilizing winding decreases, the stator speed increases.

From these considerations, the conclusion follows that the main disadvantage of classical generators is that, regardless of the load size, the rotation speed of the crankshaft of an internal combustion engine must be constant. That is, maximum efficiency is achieved only at maximum load. With minimal power from connected consumers, the engine will run in idle mode, wasting fuel.

Note! Long-term operation of the generator in low power consumption mode and at maximum mode is not recommended, since both an underloaded and overloaded gasoline internal combustion engine can quickly fail.

An inverter generator uses the same principle of generating electricity. The difference is that the output voltage of the generator does not go directly to the consumer. First of all, the voltage is converted to DC using a rectifier, smoothed by a filter capacitor, and then supplied to the inverter for conversion to AC. The inverter includes powerful transistor switches controlled by a microcontroller circuit.

This construction scheme has the following advantages:

Rectification of the generated voltage from the generator completely eliminates surges in amplitude and frequency;
The microcontroller circuit of the control unit instantly responds to changes in amplitude and frequency, sending the appropriate control commands to the output switches.

The accuracy of adjusting the output voltage parameters of inverter generators is one of the highest.

This is not one of the advantages of an inverter generator. An equally important feature is high efficiency. This is based on the fact that there is no need to strictly maintain the speed of the crankshaft and generator rotor. Anyway, the alternating voltage is first rectified. This means that when working with a low-power load, the generator rotor rotates at a low frequency, and fuel consumption is minimal. The built-in rechargeable battery makes a big contribution to reducing fuel consumption, since part of the generated voltage is used to charge it, and the battery is put into operation either to compensate for peak surges in power consumption, or when operating at a minimum load, when its capacity is sufficient to operate the inverter converter. This solution reduces the limitation on long-term operation at low load while maintaining the reliability of the system as a whole.

Advantages of inverters

The increasingly widespread use of inverter devices is due to their high performance characteristics:

Low fuel consumption;
Small dimensions and weight;
High reliability;
Excellent output parameters, especially in terms of power quality.

Disadvantages of an inverter generator

Possessing excellent electrical parameters and high efficiency, inverter generators have disadvantages that should be taken into account when choosing:

High price. A good inverter has a cost two to three times higher than that of a similar classic model;
Limited power. The permissible maximum power of most common models is no more than 5 kW;
You can also find 7 kW, but they are not yet very common, and their cost exceeds reasonable limits;
Difficulty in repairing in case of breakdown;
It is difficult to replace the battery if it fails.

Additional features

Many models of power plants have the ability not only to start manually, but also using an electric starter. This is important when using them in automatic power backup systems.

Most devices are equipped with protection against exceeding the permissible load current and sudden voltage surges. There is often an additional output for low voltage DC sampling.

Without exception, all devices have measuring instruments on the panel that allow you to monitor the value of the output voltage, and expensive multifunctional devices are equipped with liquid crystal displays that allow you to evaluate most parameters, including the shape of the output voltage, the load size, the degree of charge of the battery and the amount of remaining fuel. The inverter circuit contains a microcontroller, with the help of which various additional monitoring and control functions can be easily implemented.

The variety of models on the market makes it difficult to choose the right device. Usually the first place is the value of the permissible load power. The following power data can help with this:

Traveling outdoors – up to 1 kW;
Power supply for the most necessary household appliances in case of interruptions – 2-3 kW;
Power supply for a small private house or apartment - 5 kW;
Large house - 7 kW.

Note! If mini-power plants are used in construction, their power must be at least one and a half times greater than the power of the connected power tool. So, if a grinder with a power of 2 kW is used, then at the moment of start-up the current consumption exceeds the rated one by 1.5-2 times. Therefore, the generator power must be at least 3 kW.

Which generator to choose, classic or inverter? To power the vast majority of consumers, a conventional device is sufficient. The choice in favor of an inverter should be made in the following cases:

Frequent work with minimal load. The reason here is not only economics, but also a decrease in the reliability of a conventional device;
Requirement for high efficiency;
Minimum dimensions. Traveling into nature with a large power plant is difficult for obvious reasons.

A classic mini-power plant is more suitable if:

Requires work with a powerful load (more than 5-7 kW);
Long-term operation with minimal load is not expected;
The dimensions of the device are not decisive;
The cost of the equipment is important.

A gasoline engine runs on high-octane gasoline, while a diesel engine requires the appropriate diesel fuel to operate. Sometimes you can find a power plant design that operates using liquefied gas.

Common Misconceptions

The most common misconception, which is strongly supported by manufacturers of inverter generators, is the supposedly poor shape of the output voltage.

Firstly, the voltage from the generator stator without connecting any kind of semiconductor converters, on the contrary, has an ideal sinusoid. This is due to the very principle of operation of electric machines. Suffice it to remember that most power plants, hydraulic, thermal, nuclear, that is, based on the conversion of mechanical energy into electrical energy, operate on exactly the same principle as a home power plant. But semiconductor elements have a nonlinear characteristic, and obtaining a strict sinusoid using semiconductor converters, including inverters, requires great technical tricks.

Secondly, most modern consumers use built-in switching power supplies, which do not care about the shape and frequency of the voltage (within reasonable limits), since the first thing the power supply circuit contains is a rectifier and filter. Consumers such as irons, electric kettles and electric stoves generally do not care what voltage is supplied to the input. The only devices that care about the frequency and shape of the supply voltage are asynchronous motors and transformers.

The second common misconception is related to the complexity of the design of inverter generators. Here we can say that this applies mainly only to products from little-known manufacturers that offer cheap equipment. Leading companies have developed inverter circuit solutions to perfection, using only high-quality components and perfect assembly lines. The electronic circuitry of the control and monitoring unit for inverter devices is protected from moisture and dust, so good devices rarely fail and, if the recommended requirements are met, can last quite a long time.

As for breakdowns of internal combustion engines, most designs use drives that have been tested for a long time and have high reliability and durability. Provided that the required and high-quality fuels and lubricants are used and regular maintenance (replacement of filters, spark plugs), engine failure is unlikely.

As has been shown, the correct formulation of the requirements determines which device design to give preference to. Both types have their own areas of application, advantages and disadvantages, but can often be interchangeable, so it is impossible to categorically say which is better. Currently, until prices for inverter devices drop to reasonable limits, most buyers are focusing on conventional devices that use a gasoline engine with an alternating current generator and a simple control circuit.

Video

The modern market of electrical equipment currently offers two types of generators, with the help of which, by burning carbon fuel (gasoline, diesel fuel or gas), you can obtain electrical energy. This problem is urgent because the work of domestic energy supply organizations leaves much to be desired. And the periodic shutdown of the electric current supply is proof of this. So, in this article we will be interested in one question: an inverter generator or a conventional one - which is better?

To understand this issue, it is necessary to consider the operating principle of two types of generating equipment, the positive and negative aspects of design and operation, and pay attention to some positions regarding the economic side of the matter.

Classic generator

The operating principle of a conventional generator is quite simple. Carbon fuel, using a standard engine designed for a specific type of fuel, drives a shaft that is directly connected to the alternator. The latter is an alternating current electric generator that converts mechanical energy into electrical energy due to the rotor winding and magnets installed in its design.

That is, there are no intermediaries, so it is very important that the rotation of the shaft, and therefore the rotor, occurs at the same speed. Reducing or increasing the rotation speed leads to a decrease in the quality of electric current generation. This is the main disadvantage of a classic generator¸ because over time, rotating components and parts wear out, which mainly leads to a decrease in rotation speed.

But that's not all. Classic generators have one, so to speak, negative economic aspect. If the unit is not fully loaded (below the nominal value), then the fuel consumption will be high compared to the load indicator. And even more so if the generator will operate in this mode for a long time. In order for you to understand what we are talking about, we will give a simple example.

You purchased a 5 kW generator, and the power consumption of all household appliances and lighting in the house is approximately 3 kW. That is, almost half of the generating set will run idle. But at the same time it will “eat up” exactly 5 kW of fuel. Therefore, before buying this equipment, you need to accurately calculate the power consumption in the house. And then buy the device itself.

If a classic type generator is not operating at full load, soot begins to accumulate inside the internal combustion engine. And this will lead to a decrease in operating efficiency, that is, it will again directly affect fuel consumption. Plus, you will have to carry out repairs more often, which is also not a cheap pleasure.

Many consumers, when purchasing a generator set, rarely look at the instructions or data sheet. Namely, in these documents, manufacturers warn that operating the generator below 25 percent load is strictly prohibited. Usually the period during which such a load is allowed is also indicated, because there are many emergency situations in life. This period is indicated in hours per year. That is, exceeding this indicator removes all responsibility of the manufacturer.

Attention! The most surprising thing is that a large number of complaints from consumers come precisely for this reason. Therefore, we recommend that you first study the accompanying documents and then purchase or operate the generator.

Despite the fact that generators with classical technologies for generating electricity have so many disadvantages, they also have one rather significant advantage - this is an acceptable price of the equipment in comparison with other varieties. Let's add here the good reliability of the unit and a wide power range. As for reliability and long service life, all this will be possible in reality if the generator is fully loaded and a periodic technical inspection is carried out.

An inverter generator has a completely different way of generating electrical energy, although it is still the same alternating current device. It does not supply electricity directly, as happens in the classic model. Its design contains several intermediate components, the main one of which is the battery.

How is electrical alternating current generated?

At first, everything happens the same as in a classic device. That is, the internal combustion engine rotates a shaft that is connected to the alternator rotor. The latter produces alternating current.
The current passes through the power electronics and becomes DC. They charge the battery.
Now, in order to get alternating current again, an inverter is installed after the battery, which produces a current of the required voltage, or rather, 220 volts with a frequency of 50 Hz.

Why is such a complex scheme necessary, what is its advantage? Everything again comes down to hydrocarbon fuel consumption. For such a unit there is no need to maintain a constant rotor speed; it can be quite small, and this will be enough to charge the battery. True, with reduced rotation the charging time will increase. But in this case it is not so important. It turns out that the lower the rotation speed, the less fuel is consumed.

In addition, we can say that it is this parameter that affects the size of the generator. It becomes compact and lightweight. Plus - it's silent operation.

Flaws

Basically, there are two main disadvantages:

Cost of equipment. It is almost twice as high as the classic ones.
Design feature - the battery is an integral and non-separable part of the generator. That is, if the battery life has expired, you will have to replace the entire device.

As for the battery, there is another negative point. Its capacity may not support the required amount of electricity consumption. That is, you initially expected a certain load in the electrical network at home, but after a few months it increased. In this case, the battery will quickly discharge, and charging will be slow, and it will not be enough for the power consumption. You will have to turn off the generator, wait for the battery to charge, after which you can use the electrical network. Let's face it, it's inconvenient.

How to choose

First, let's start with the fact that in the “inverter generator” category there are no models with a power of more than 6 kW. Therefore, before purchasing this device, you need to accurately calculate the power consumption of lighting and household appliances in the house.
Secondly, if a generator is purchased for regular use, then it is better to give preference to classic models. But, as mentioned above, the load on the electrical network and the power of the equipment will have to be brought to equal levels.
Thirdly, if you need a small mobile generating unit that will supply electricity not to the entire house, but to some part of it or a certain number of current-consuming appliances, then the inverter type is the best option for this.

Conclusion on the topic

So, in this article an analysis was carried out on the topic: an inverter generator or a regular classic one - which is better? As you can see, it is impossible to answer this question unambiguously, so we recommend that you first determine the operating conditions of the equipment in the house, and then, based on the analysis, make the right choice.