We make a gas generator with our own hands. Is it possible to repair a gas generator yourself? Gasoline generator operating principle

Autonomous generators are often irreplaceable, and full list their possible applications will be very long - from providing electricity for a weekend beach party to constantly working at a private building. A wide range of work performed has given rise to a large number of types of autonomous generators, differing both in design and in characteristics. What they have in common is the principle of operation - an internal combustion engine of one type or another rotates the shaft of an electric generator, converting mechanical energy into electrical energy.

• A household generator is, as a rule, a portable unit with a gasoline engine, not intended for long-term operation, and having a power of several kVA.
• Professional generators have increased power and continuous operation time, and for greater fuel efficiency and increased service life, diesel engines are usually installed on them. Moreover, if household electric generators produce single phase current voltage is 220 V, then professional generators are overwhelmingly three-phase, designed for 380 V output voltage. Large dimensions and weight force either to place powerful generators on a wheeled chassis, or make them stationary.

So, in this classification we have already discovered a number of design differences. Let's look at them in order.

Engine

As you know, a gasoline engine can work both on a two-stroke cycle and on a four-stroke cycle. At the same time, low efficiency and limited resources make two stroke engines not the most best choice for driving an electric generator, although they are simpler in design, which means cheaper and lighter.

The four-stroke engine, although it more difficult and more expensive, consumes significantly less fuel and able to work much more. Therefore, generators with a power of up to 10 kVA, as a rule, are equipped with engines of this type.

There is no need to look for the benefits of your own gas generator; they lie on the surface.

Garage owners summer cottages, private houses (provided that these objects have an unreliable power supply, or are not electrified at all) have long appreciated the benefits of backup power supply.

Even if you live in cottage village with normal power supply, possible emergency situations. Loss of energy for a long time will lead to spoilage of food in the refrigerator in the summer, and malfunction of the heating boiler in the winter.

Therefore, many homeowners purchase industrial generators, the cost of which cannot be called economical.

Another direction for mobile power plants is tourism, expeditions and performing work using power tools in autonomous mode.

This useful device It is not an overly complex device, so it is quite possible to assemble a gas generator with your own hands, including 220 V.

Of course main reason such a decision is the desire to save. If you purchase components for mobile power station in the store - the cost of parts will exceed the savings on assembly.

Therefore, a homemade gas generator will become profitable only if it has shareware components.

The most expensive spare parts are: the drive (gasoline engine) and the electric motor, which will act as a generator. These are the ones that need to be selected from the “trash” available in the storerooms.

What power plant can be selected for a generator?

First of all - power. In mobile power plants, the following ratio is used: for every kilowatt of electricity generated (not in peak, but in normal mode), 2-3 l/s of engine is supplied.

Important! This proportion works with properly selected components and minimal losses. It should be remembered that even the most inexpensive generator from the Middle Kingdom was designed by engineers.

As a rule, gas generators are developed as a complex, that is, a generating element is developed for a specific motor. For homemade installation you should choose a coefficient of 2-4 l/s per 1 kilowatt of energy. Otherwise, at full load the engine will quickly fail.

Many people use at work and Everyday life gasoline power generator. The market today is saturated with such devices, and in order to make a choice, you need to have an idea of ​​what it is and what it is needed for.

Gasoline generator is an autonomous power supply system that uses gasoline as the fuel consumed.

Classification of gasoline generators.

Gasoline power plants can be classified according to a number of criteria. Each electric generator is prepared to operate under certain conditions and under certain loads.

• Professional and household;
• Portable and stationary;
• Two-stroke and four-stroke;
• Single-phase and three-phase;
• By power: up to 4 kW, up to 15 kW, up to 30 kW.

Household generators are ideal for private homes or long-term outdoor trips. Usage professional units necessary in enterprises to connect complex instruments.

Portable models have low power (up to 5 kVA), weight and dimensions, allowing them to be moved to another location.

Two-stroke are installed on low-power gasoline units, the power of which does not exceed 1 kW. In all other cases, a four-stroke engine is installed.

Most private consumers can limit themselves to a single-phase electric unit. Three-phase is much more expensive, and it is not a fact that its functionality will ever be in demand. At the same time, for most household electrical networks It is single-phase current that flows.

1. Home power plants. Power does not exceed 4 kW. This is enough to provide electricity to a private home, warehouse or small workshop. Gasoline generators of this type are not intended for round-the-clock operation. The maximum period of non-stop operation is 4 hours. The system must then be given time to cool down and then restarted.
2. Industrial BGU. They have a power of up to 15 kW. Suitable for trade organizations and construction sites. The improved design extends the non-stop operation of the generator to 10 hours. BGUs are distinguished from diesel generators of the same class by their lighter weight and dimensions.
3. Gasoline power plants with power up to 30 kW They are most often used to supply power to office buildings or large warehouses. These devices are installed permanently, in pre-prepared premises.

Gasoline generator device.

The design of a gasoline generator is similar to that of diesel units.

The key component of the unit is the engine.

Two types of motors can be used:

1. Two-stroke. Installed on low-power units for short-term operation.
2. Four-stroke. They have an increased margin of safety. The period of uninterrupted operation is 5-7 hours. Motor resource – 3-4 thousand engine hours.

The engine is equipped various systems. One of them is responsible for the fuel supply, the other for noise reduction, the third for the lubricant supply. The package also includes an exhaust pipe.

The power generated by the engine determines the type of generator used alternating current– single-phase or three-phase.

If the planned load exceeds 5 kW, the power plant is equipped with a three-phase generator.

In addition, electric generators can be asynchronous and synchronous. Some budget models are equipped asynchronous generators with a simple design.

Synchronous generators are capable of withstanding threefold voltage surges.

High-quality and error-free operation of the key internal components of the electrical unit is monitored using instrumentation.

A diagram of a gasoline generator shows the location of all components electrical installation, and their influence on the operation of the unit. The frame frame of the structure connects all the nodes into a single working complex.

The principle of operation of a gasoline generator.

In order to properly and timely service the device and identify possible problems, you need to have an idea of ​​how the electric generator works.

The operating principle of a gasoline generator is as follows.

The power of a gas generator is determined by the number of turns of the stator winding. As a rule, the power of gasoline mini-power plants does not exceed 12 kW.

There are several reasons to own a miniature power plant. These include frequent interruptions in the supply of electrical energy in rural areas, and new construction, when electricity has not yet been supplied to the construction site. The best option– this is an acquisition finished design. On the market big choice gasoline and diesel power plants of all possible power output ranges. The problem is their high cost.

If you have the necessary parts and materials, as well as experience and desire, it is quite possible to assemble a homemade gas generator.

Gasoline generator device

The principle of operation of a gasoline generator is the same as that of most any power plants based on the conversion mechanical energy to electric. An external force rotates the generator armature, and the stator windings are induced electrical voltage. In the case of a gasoline generator, the armature rotates the gasoline engine. However, instead of gasoline, it can be used with the same success. diesel engine. The only difference is the fuel used - gasoline or diesel.

So, what is included in a gasoline generator? Main parts:

• Gasoline engine (two- or four-stroke);
• Generator;
• Monitoring, protection and management circuit;
• Speed ​​stabilization device;
• Fuel tank;
• Frame for attaching all components.

Selection of components

How to make a gas generator with your own hands? The main parts are the engine and the generator. The engine can be any suitable gasoline engine from a chainsaw, motor cultivator, motorcycle or moped.

The motor power should slightly exceed that required at the output of the electric generator. A certain difficulty is the ratio of power expressed in kilowatts (characteristics of electric generators) and in horsepower, usually used for the characteristics of internal combustion engines. Various sizes are related to each other by the following relationship:

1 kW = 1.36 hp

Thus, a 2 hp chainsaw engine. translated into kilowatts it has 1.47 kW.

If you have a choice, it is better to go with a four-stroke engine, since a two-stroke engine has the following disadvantages:

• The need to use a mixture of gasoline and special oil as fuel;
• Inability to use fuel tank large volume, because fuel mixture tends to separate, and the viscous and heavier oil will end up at the bottom of the container;
• Low efficiency.

An equally difficult task is choosing a generator. It is theoretically possible to use any electric motor as an electric generator, since these devices are reversible and can perform each other’s functions. It is tempting to use an AC motor so that the output immediately produces an alternating voltage with the necessary parameters. But in practice this is not feasible for a number of reasons:

• Impossibility of accurately stabilizing the rotation speed of an internal combustion engine. Thus, as the engine speed changes, the output voltage and frequency will change;
• High complexity of the control scheme.

In industrial gas generators, special windings loaded onto a capacitor are used. As the speed increases, the voltage frequency increases, accordingly, the capacitor resistance drops, and the load on the control winding increases. That, creating additional magnetization, slows down the generator rotor, reducing the rotation speed. When the frequency decreases, the reverse process occurs. In practice, this requires a complete change in the design of the engine, introducing into it additional winding and is unlikely to be feasible at home.

The only way out of the situation is to use a generator direct current.

Best for homemade gas generator Car generators are suitable because:

• It is possible to stabilize the output voltage by using the vehicle's standard voltage regulator;
• Possibility of connecting any generator to replace a failed one;
• DC voltage conversion by using a source uninterruptible power supply.

We need to dwell on the last point in more detail. It is clear that a car generator produces a constant voltage. Its value is 12-14 V. But how to convert it to an alternating voltage of 220 V? The solution is simple - use an uninterruptible power supply unit, which has a car generator connected instead of a battery.

It is quite possible that the uninterruptible power supply unit will be the most expensive part of the homemade home power station, since devices with a power of more than 500 W have a sharp increase in their cost. There are several options for increasing the permissible power:

• Conversion of an existing uninterruptible power supply to higher power values;
• Purchase of a faulty powerful one and its subsequent repair;
• Build your own design.

The first option requires great skill in repairing radio-electronic devices, since it requires:

• Replacing the standard transformer with a more powerful one;
• Replacing output transistor switches (possibly along with their wiring);
• Alteration or adjustment current protection for a new output current range.

Manufacturing completely homemade design requires no less knowledge, but there is no need to reproduce many unnecessary functions of an industrial device. Thus, the cost of a homemade converter may be lower than the other components of a homemade power plant.

The easiest way is sometimes to use a faulty converter. They are often written off due to inoperability, although the only thing that is faulty is accumulator battery. Price powerful batteries for uninterruptible power supplies is high and amounts to most the cost of the device, so sometimes it is more profitable to purchase a new uninterruptible power supply than to change the battery in the old one.

Note! Despite the fact that the generator is connected instead of a battery, the battery, although of minimal capacity, is necessary to smooth out the pulsations of the generator. Otherwise, the uninterruptible power supply will not start or will fail.

You can also use ready-made inverter converters of the required power.

Interfacing the engine and generator

Rotation from the engine to the generator is transmitted by a belt drive or gearbox. But the gearbox has a large mass and high noise, so it is better to use a belt drive.

Engines and generators are characterized different meanings rated speed, therefore the pulleys on the shafts of these devices must provide a certain gear ratio. It is calculated simply: how many times the generator speed should be less than the engine speed, the same number of times the diameter of the generator pulley should exceed the diameter of the engine pulley. For example, a generator passenger car designed for a nominal speed of 5000 per minute, and the chainsaw engine operates at 10,000 revolutions per minute. Thus, the diameter of the generator pulley should be twice the diameter of the engine pulley.

Note! You cannot take a pulley diameter that is too small, since strong bending of the drive belt will shorten its service life and reduce the coefficient useful action, since part of the engine power will be lost due to belt bending. In practice, you can use pulleys with minimum diameter not less than 100 mm.

It is tempting to use generators with original pulleys. But, if a flat belt is used there, then find a similar one required length quite difficult, therefore, to facilitate the search for the right belt, the pulleys need to be made for a V-belt. There are many such belts of all possible lengths in any auto shop or car market, and their cost is low.

Pulleys are made of duralumin or textolite. Any turner can do this for a nominal fee. The main thing is to ensure a tight fit on the generator and engine shaft.

Gas tank

As a gas tank, you can use a metal sealed container with a filler neck with a lid and a fitting for supplying fuel to the carburetor. It is best to use the fuel tank from any vehicle. The main thing is its good condition and suitable dimensions.

Plastic containers must not be used:

• Plastic becomes brittle in the cold;
• Some types of plastic are gradually broken down by gasoline;
• Plastics tend to become electrified and accumulate static electricity, which can cause the fuel to ignite.

Assembly of the structure and adjustment

The gasoline generator is assembled on a suitable platform. During assembly, the main thing is to ensure strict parallelism and location of the generator and engine pulleys in the same plane. Otherwise, the belt may slip off and cause increased wear. The distance between the pulleys is chosen so that the belt is tensioned and does not slip during operation.

Important! Don't overdo the tension. This will cause a decrease in efficiency and wear on the belt and pulleys, and most importantly, the bearings of the engine and generator shafts.

Having another pulley, even if it is of small diameter, you can make a belt tensioning device using a spring of the required elastic force.

The gas tank is placed in the highest part of the structure so that gasoline can flow by gravity into the carburetor. It is important to prevent the tank from heating up with the heat of a running engine. If necessary, provide thermal insulation using asbestos pads.

Important! Asbestos dust is not toxic, but it can be harmful to the lungs, so you need to wear a respirator when working with asbestos.

Don't forget the fuel filter.

The assembled structure should ensure ease of starting the engine and access to all elements: carburetor, spark plugs, voltage regulator.

The adjustment consists of setting the required voltage using the generator's standard regulator. Some generators, for example, from Samara and newer cars, have a built-in regulator that does not allow adjustment.

If the voltage is below the permissible level, the uninterruptible power supply will not start, giving a signal that the battery is severely discharged. A high value may cause damage to circuit elements.

As you can see, assembling a home gas generator is quite feasible. With your own hands assembled gas generator is capable of working no worse than the factory one, but you should know that this can only be done if at least some of the components are available. Manufacturing a power plant from scratch in the complete absence of parts will lead to costs exceeding the purchase of a finished structure.

Video

Issues of power backup continue to be popular among electricity users. For these purposes, manufacturers are now mass-producing electric generators various types and capacities. Among all the designs of such devices, a special place is given to elite models that operate on the principle of generating high-quality electricity.

To do this, their algorithm implements a method of inverter transformation of the main parameters electrical signals. Due to this they got the name inverter generators.

They can be produced with different powers, but the most popular among the population are models from 800 to 3000 watts.

The energy source for powering the engine can be:

petrol:

diesel fuel;

natural gas.

How does an inverter generator work?

The design of the device, enclosed in a single housing, includes:

internal combustion engine,

alternator:

inverter conversion unit;

connectors for connecting output circuits;

management and control bodies for monitoring technological processes.

To connect electrical appliances, a general industrial output of electricity is used through three power contacts of a conventional standard socket.

Besides AC voltage, the generator produces direct current, which can be used for charging, for example, used for starting a car engine. For this purpose, the delivery set includes special clamps for connecting to its input terminals.

The generator is equipped with protections that automatically open the power circuit when an excessive load is connected to the output contacts. Protections also monitor the technical condition of the engine, especially the achievement of a critical oil level. When it becomes insufficient to lubricate all moving parts, the engine will automatically stop due to the protection. To prevent this from happening, it is necessary to monitor the oil level in the crankcase.

Such generators are usually equipped with a four-stroke engine with overhead valves.

Operating principle of the inverter unit

The diagram of the interconnections of various technological processes occurring when inverting signals is illustrated in the figure.

The internal combustion engine spins a conventional generator, producing electrical energy. Its flow is directed to a rectifier bridge, consisting of power diodes located on powerful cooling radiators. As a result, a pulsating voltage is produced at its output.

After the bridge, a capacitor filter operates, smoothing out the ripples to a stable straight line, characteristic of DC circuits. Special design electrolytic capacitors selected for reliable operation with voltage above 400 volts.

The reserve is made to exclude the impact of pulsating peaks in the amplitude of the operating voltage of 220 V: 220∙1.4 = 310 V. The capacitance of the capacitors is calculated based on the power of the connected load. In practice, it ranges from 470 µF and above for one capacitor.

The inverter receives rectified stabilized direct current and produces high-quality harmonics from it.

Various technological process algorithms have been developed for the operation of the inverter, but best shape The signal is provided by bridge circuits with a transformer.

The main element that generates the sinusoid signal is a semiconductor transistor switch assembled on or MOSFIT.

To form a sinusoid, the principle of creating a repeatedly repeating periodicity is used. To implement it, each half-cycle of voltage fluctuation is formed by the operation of a certain pair of transistors in the mode of high-frequency pulses with a corresponding amplitude that changes over time according to the sine law.

The final leveling of the sine wave and smoothing of the pulse peaks is performed by a high-pass low-pass filter.

Thus, The inverter unit is used to convert the electricity generated by the generator windings into a stabilized value with precise metrological characteristics, providing a steady-state frequency of 50 Hz and a voltage of 220 volts.

The operation of the inverter unit is carried out by a control system that controls through feedback All technological processes generator from various states of the internal combustion engine to the shape of the voltage sine wave and the magnitude of the load connected to the output circuits.

In this case, the current coming from the generator windings to the conversion unit can differ significantly in frequency and signal shape from the nominal values. This is the main difference inverter models from all other structures.

The use of inverters allows you to achieve significant advantages compared to conventional generators:

1. They have increased efficiency due to automatic adjustment of the engine speed during operation and creation optimal mode for it according to the effective load value.

The greater the force applied to the engine, the faster its shaft begins to rotate under conditions where the fuel consumption is strictly balanced by the control system. With traditional generators, fuel consumption depends little on the applied load.

2. Inverter generators produce an almost perfect sine wave when powering consumers under load. This current High Quality very important for the operation of sensitive digital equipment.

3. The dimensions of elite models are compact, lightweight compared to conventional devices with the same power.

4. The reliability of inverter generators is so high that their manufacturers guarantee them a double service life compared to simple analogues.

Inverter generators are designed for use in three modes:

1. long-term operation under a rated load not exceeding the output power declared by the manufacturer;

2. short-term overload for no more than half an hour;

3. starting the engine and bringing the generator into operating mode, when it is necessary to overcome large forces to counteract the rotation of the rotor and the capacitive load in the power section circuit.

In the third mode, the inverter can withstand a significant amount of opposing instantaneous power, but its operating time is limited to only a few milliseconds.

How to start the engine

To do this, you need to perform a number of operations. Let's consider their sequence using the example of one of the available models of the ER 2000 i generator. Sequence of actions:

1. check the oil level, because without it, starting will not happen due to blocking by protections and a very high probability of breakdown;

2. add fuel - without it, the engine will have nowhere to receive energy to create rotational motion;

3. open the fuel tank cap valve;

4. switch the throttle to the “Start” position;

5. set the fuel tap handle to the “Operation” position;

After this experiment, we connect digital computer equipment to the DC output and see that it works reliably. When using conventional generators without an inverter unit, failures of microprocessor-based digital devices are often observed due to low quality supply voltage.

Inverter generators are equipment that uses complex electronic database. Correct observance of operating conditions, as well as careful transportation and provision of temperature and humidity conditions during storage are a guarantee of its long-term performance.

When constantly in winter time in an unheated garage for everyone internal parts Condensation may form, which will cause failure of electronic components.