The difference between an inverter and a conventional generator. What is an inverter generator and is it worth buying one?

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 AC mains voltage 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.

Pay attention! 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 cost. 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 size of the load, the degree of charge of the battery and the amount of remaining fuel. The inverter circuit contains a microcontroller, with the help of which all kinds of additional monitoring and control functions are 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.

Pay attention! 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 difficulties of country life and construction are often associated with ensuring uninterrupted power supply. These problems, as a rule, have to be solved by purchasing an autonomous power source - a generator. The purchase of complex equipment is justified not only in cases of problems with a stable supply of electricity. A backup power source may be needed completely unexpectedly. And then, even in the event of a sudden power outage, the main systems of the house continue to function.

At the moment, there is such a variety of models and options of generators on the market that it is really difficult to figure out which one is suitable for solving a particular problem.First you need to decide how much power the house consumes. It is clear that each homeowner will have his own figure. On average, a country house needs at least 10-15 kW to maintain supply systems. A small country house or change house consumes 2.5-5 kW.

It is much more difficult to determine, without experience of use, which type of generator to choose: inverter, regular gasoline or diesel.
Let's look at the pros and cons of each option.

Conventional generators.
Essentially, it's a small power plant in your garage - fuel is burned, the engine turns a generator, mechanical energy is converted into electrical energy.
Pros:

Large selection of generators of different capacities. From “crumbs” of 1 kW to serious machines of 8-10 kW or giants of 20-40-100 kW, intended for industrial use.
Ease of use and relative reliability subject to operating conditions.
Low price compared to inverter analogues. On average, the cost of a 4.5 kW generator will range from 25-45 thousand rubles.

Cons:

The generator must operate at a constant load. Using a generator with a load of less than 25% leads to its premature failure.
High fuel consumption at partial load.
Noise when the engine is running. A working generator should be located as far as possible from living quarters or in a soundproof box.

In such generators, the quality of the generated electricity directly depends on the optimal load chosen for the engine - it must rotate at a constant speed. That is, the main problem of such machines is not frequent breakdowns, as users sometimes complain, but illiterate use.When the generator is operating at rated powerand with regular maintenance it will serve for many years without complaints. Another problem that may arise when using such a generator is changes in the output voltage when the engine speed increases or decreases. For home lighting and some appliances, small changes in voltage are not critical, but for some expensive systems - refrigerators, circulation pumps, smart home systems or gas boiler controllers, any change in power quality can lead to equipment failure or premature breakdown.

When choosing a generator, you need to pay attention to the additional capabilities of modern models:

protection system when the oil level is critically low, which automatically stops the engine if the oil level is below the minimum.
overload protection system that will turn off the generator in time
voltmeter to monitor output voltage
wheels for transportation

Inverter generators.

The operating principle of an inverter generator differs from the classical scheme in that electricity is not supplied directly to the network. First, when fuel is burned, high-frequency alternating current is produced, then it is converted to direct current and accumulated in the battery.

Pros:

Stable characteristics of generated electricity.
Reduced fuel consumption, since there is no need to constantly operate the engine at certain speeds. As the load decreases, fuel consumption also decreases proportionally.
Inverter generators are always more compact than conventional generators of similar power. This allows you to use them not only permanently in country houses, but also to take it with you on a picnic or fishing.
Inverter generators are virtually silent.

Cons:

High cost of the generator. On average, a 3.5 kW generator will cost more than 50 thousand rubles, while a regular gasoline generator of the same power will cost about 20-30 thousand rubles.
The structural complexity of the inverter unit and the impossibility of its element-by-element repair, only replacement as an assembly.
Power restrictions. Inverter generators with a capacity of more than 6 kW are not found.

An inverter generator will be an ideal solution for providing uninterrupted power supply to sensitive devices that are afraid of voltage surges: heating boilers, laptop chargers, computers, and complex electronic equipment.

That is, it turns out that if there is a need to constantly provide electricity to premises, buildings, construction sites, and to solve the problem of emergency lighting, then it makes sense to consider a conventional diesel or gasoline generator. Working at full load, it will last a long time and will not require repairs or additional investments for a long time. Timely oil changes and the use of high-quality fuel increase the service life of the generator.

In case of emergency power supply to a residential building, literally crammed with electrical appliances, it is better to use inverter-type generators. Replacing and repairing numerous equipment that burned out due to a sudden power surge will cost more than the most expensive generator.

If you need to solve both problems at the same time, then you can choose a combined option, using both inverter and conventional generators at the same time. The plot, lighting of the garage, house and bathhouse can be provided with energy using a conventional generator, for example. this model is 6.5 kW.

But the heating boiler, complex kitchen appliances, it is better to connect the pump in the well to an inverter-type generator, which can be chosen from several 3.5 kW models, such as this

or 2.5 kW, which can be viewed at link.

Inverter generators are commonly called autonomous power sources that are successfully used to generate high-quality electricity. In most cases, such equipment is used in the form of temporary or permanent ones, if the periods of continuous operation are insignificant. At the same time, inverter generators are recommended for instruments that are highly sensitive. In most cases, the equipment is successfully used in schools, hospitals and other government institutions, where even minor surges in electrical voltage are prohibited.

Operating principles of inverter generators

An inverter generator can only be purchased if the operating principle is completely clear. Otherwise, exploitation can bring significant discontent and even turn out to be too dangerous.

An inverter generator is traditionally created on the basis of a special unit, which must include a microprocessor, a rectifier, and a converter.

So, what is the operating principle of an inverter generator?

There is the possibility of generating high-frequency alternating current.
The rectifier allows you to convert the resulting current into direct current.
It is assumed that current can be accumulated in capacitive filters, which are produced in the form of batteries.
There is an opportunity to stabilize the oscillations of electrical waves.
Inverter generators allow you to convert the energy that comes from capacitive filters into alternating current. In this case, it is assumed that the required frequency and voltage indicators will be achieved. Subsequently, AC power must be supplied to the end user. As a result of the working process, you can see an ideal sine wave, which guarantees that the quality of the received electricity is maintained at optimal level.

The above operating principles make it possible to obtain a stable voltage, which ensures protection for very sensitive devices. It should be noted that inverter generators can operate automatically.

The cost of refueling equipment can be halved thanks to full and constant control over the level of fuel, oil, as well as the performance of the running engine.

The design features of modern generators make it possible to guarantee a high level of equipment protection. For this purpose, a built-in air cooling system is traditionally used. However, if the load is reduced to a minimum level, an automatic transition to an economical mode is expected, as a result of which rapid wear of the equipment can be avoided and maximum service life can be guaranteed.

What are the important advantages of inverter generators?

Supposed supply only high quality current. Previously, simple household appliances were offered, and electronics were not popular. Nowadays, high-quality current is required everywhere, since only in this case can the successful and long-term service of digital electronics be guaranteed. Almost every type of equipment has delicate and vulnerable electronic components, as a result of which electrical voltage drops are unacceptable. Only inverter generators can guarantee high quality current.
Saving on fuel. It is assumed that the engine speed can be adjusted automatically, as a result of which the inverter automatically determines the amount of energy required for operation. As a result, excessive fuel consumption is completely eliminated.
Inverter generators boast compact dimensions. The microprocessor board does not require special windings or large ventilation equipment. Dimensions are reduced by 2–3 times, but the functionality of the equipment is still maintained at a decent level. Reduced dimensions lead to weight reduction.
Minimum noise level, which is guaranteed thanks to a special protective casing. During operation, the equipment emits no more than 66 dB, which assumes there is no noise.
Resistance to external factors. The mechanism is protected from moisture and dust.

Disadvantages of inverter generators

Despite the numerous advantages, disadvantages also need to be noted.

High cost. Modern equipment is more expensive than conventional models. At the same time, the price turns out to be 2–2.5 times higher. Despite this, optimal savings in the future are guaranteed, because the equipment will not melt. Moreover, repair activities will not be a frequent task.
Limited selection. The range of inverter generators turns out to be insignificant. Despite this, you can still find a suitable model.
Power limitation. Basically, the power of the equipment does not exceed 8 kW, but this is enough for everyday tasks. It should be noted that 1 kW is enough for going out into nature, 2 - 3 kW - for powering the most important electrical appliances, 5 kW - for a small private house, 7 - 8 kW - for a large residential building.

Despite the presence of certain disadvantages, you can understand whether this choice should be made or whether it is best to give preference to another proposal.

Interesting generator review:

If you think about it, any generator can be broken down into two independent components: the internal combustion engine and the alternator. It is their specificity, design and technical parameters that determine the size of the mini-power station, the noise it makes, and, of course, the price of the device.

Most people believe that the leading role in this duet is played by the engine, which sets the rotation necessary to produce electrical energy. In fact, the design of the alternator (a device that converts mechanical energy into electrical energy) is a much more important factor.

There are two versions of alternators: standard and inverter.

In order to decide which generator to purchase, you should understand what the fundamental difference between their designs is. The following factors should also be taken into account: understanding the purpose of using a gasoline generator and the issue of cost. Let's consider the operating principle of each alternator separately.

Standard alternator.

Conventional alternators consist of a series of copper coils. This design generates a fairly coarse electrical signal.

For the generator to operate, the engine must operate at maximum speed, regardless of the network load. Accordingly, spending a constant amount of fuel and producing a certain level of noise. The electric current produced by the generator is not as pure as equipment manufacturers usually require. Therefore, conventional generators are not recommended for powering precision electronics. The advantages of standard generators, undoubtedly, are their availability in any power segment and relative cost. Manufacturers such as Honda and Europower produce a huge range of standard generators to suit any need.

Inverter.

Inverter generators, in turn, use a different type of alternator and produce very clean alternating current. And inverter technology helps reduce the weight and size of the generator. Moreover, it allows the engine to operate at different frequencies, reducing fuel consumption and noise emissions.

An inverter generator connected to your computer will allow you to continue working even if your network loses power. Excellent representatives of this branch of generators can be called. The produced power of 2 kVA will allow you to provide electricity to even 2 computers at once in case of problems on the line.

The disadvantages of inverter generators compared to standard ones are also obvious: their high relative cost and the absence of models with a power above 7 kVA. From this side, we can say that the ideal option for providing, for example, a country house with energy, would be a combination of backup power sources. For ordinary consumers, you can supply a standard high-power model that can power all devices in the premises, for example, with noise reduction technology. And for particularly demanding electronic systems, you can always have a compact inverter-type generator in reserve.

The inverter generator has an operating principle that is somewhat different from its other analogues. The alternating current is converted into direct current by the rectifier, after which the ripples are smoothed out by capacitive filters. Then, with the help of powerful switches (a bridge circuit of transistors or thyristors), the current is again converted into alternating current. High quality of output parameters is ensured not only by smoothing ripples, but also by a control system with feedback circuits.

How does an inverter generator work?, you can look at the example of any of its models. The mechanics of the device are outwardly quite standard: it is usually a gasoline or diesel engine connected directly to an electric generator (without a clutch). These two main units are mounted on a frame and covered with a noise-insulating casing. The fuel tank and the starting system - electric or manual - are also located here.

What is the difference between an inverter generator and a classic one? The presence of a primary alternator, which is actually nothing more than a very ordinary alternator, is quite crude. With such a generator, when operating, the engine is immediately set to the highest speed without taking into account the network load, i.e., the maximum possible amount of fuel is consumed and the highest noise level is produced.
The difference between an inverter generator is a different type of alternator and the production of pure alternating current. This is reflected in a reduction in the weight and dimensions of the installation. In addition, it allows the engine to change speed, which reduces fuel consumption and noise levels.

Pros and benefits of an inverter generator

An inverter generator has significant advantages compared to a conventional device:

features a more economical operating mode due to the inverter ignition system and automatic adjustment of engine speed depending on the load;
direct connection of the generator to the engine, which reduces the weight and dimensions of the installation by almost half;
reduced noise level due to the special design of the noise-absorbing casing and effective mufflers;
has high environmental performance thanks to a modern, highly efficient system of improved fuel combustion, which reduces harmful emissions to a minimum.

What do consumers say?

Reviews inverter generator receives a variety of different ones. This is partly due to the fact that some people do not take into account the specific purpose and specifics of the device: providing fastidious current consumers with a high-quality variety - the unit is not intended for simple generation of electrical energy. There are standard generators for this. Feedback from experts about inverter generators is always positive.