In these generators, a static system consisting of fixed elements (power transformer, rectifiers, etc.) converts the alternating current at the generator outputs to direct current to power the excitation winding and regulate the generator voltage.
The generator circuit with a static excitation system (Fig. 1) consists of stator windings 1, rotor windings 2 and a static excitation system (excitation unit and control unit). The excitation block consists of a power transformer 3, selenium rectifiers 4, a block of capacitors 5 and power supply rectifiers 6. The elements of the excitation block are mounted on a cast base, which is attached to the generator frame and is closed from above with a cap. The control unit 7 consists of PV operation switches, a voltage setting resistor of the switchgear and separate resistors for regulating droop 8. With the help of units 7 and 8, installed on a separate board, the output parameters of the generator are controlled. The principle of operation of the generator is similar to the operation of a generator with a machine excitation system, except for the operation of a static system.

Rice. 1. Schematic diagram of a generator with a static excitation system.

To maintain the voltage at the generator terminals unchanged at any load, it is necessary that the generator excitation current change in accordance with the value and nature of its load. The static excitation system (Fig. 1) uses the principle of phase compounding. In the winding w2 of the compounding transformer 3 and selenium rectifiers 4, two components of the excitation current are added and rectified: from the winding w1 proportional to the generator voltage, and from the winding wc proportional to the generator current, shifted relative to each other at an angle depending on the nature of the load (cosφ).
The static excitation system automatically provides a change in the excitation current when the value and nature of the generator load changes. Since the rectifiers 4 have a non-linear resistance, which does not provide initial self-excitation, the system has a resonant circuit formed by the capacitance Xc of the capacitors C4-C6 connected to the wK winding and the leakage inductance XL of the primary winding w-,. A special selection of parameters at a frequency of 50 Hz provide XL=XC, and then the excitation current will no longer depend on the resistance of the rectifiers 4 and the excitation winding during the initial self-excitation.
The parameters of transformer 3 ensure the stability of the generator voltage at cos φ from 0.4 to 1.0 with an accuracy of ±5%.
For more accurate voltage stabilization (± 3%), a special control winding w„ is used, into which a direct current is supplied. When a direct current flows through the winding w, a magnetic flux is formed, which closes along the core of the transformer 3. With a change in the direct current flowing through the winding shu, the constant magnetic flux of the core 3 changes and, consequently, the excitation current of the generator in the winding Wz- Since the winding wy is powered by a constant current from two consecutive counter sources: rectifier 4 (current /v is proportional to the generator excitation voltage) and power supply rectifier 6 through resistor RU and droop resistance CC1 (current /vp does not depend on the load and is unchanged for any mode), then /u = /vp -(-/v) and, therefore, the excitation voltage of the generator will increase with increasing load.
With a load with a smaller cos φ, the excitation voltage increases more than with loads with a large cos φ, and, therefore, the magnetizing current of the transformer 3 (Lsh>/v) will decrease more with reactive loads of the generator than with active ones. Due to this, the parameters of the phase compounding system are corrected and a greater accuracy of regulation of the generator voltage with respect to the load is achieved than with the uncontrolled version of phase compounding.
The generator voltage setting is regulated by the resistor RU, connected in series to the winding circuit of the dow, and the control current component /E can be adjusted by the resistor CC1.
The static excitation system has the following advantages: no moving parts, high mechanical strength of structures, reliability and high accuracy of voltage regulation, low operating costs.
For initial excitation, generators can have a resonant system with capacitors (generators of the DHF, ESS, GSF-100-BK, OS, GSS-104-4B types), or a storage battery (ESS-5, GSF-100M, GSF-200), or initial excitation generator (SGDS-11-46-4), or voltage transformer (ESS-5). The principle of operation of a static excitation system is the same for all types of generators, with the exception of initial excitation circuits.
The technical characteristics of generators with a static excitation system are given in Table.

Technical characteristics of DPP generators with a static excitation system

Continuation of the table.

GSF generators

The generators of the GSF series have a power of 100 and 200 kW, are flanged, protected, on two shielded bearings, connected to the engine using a coupling and a flanged end shield.

The device and principle of operation of the HSF generator and the DHF generator are similar. The initial excitation of the GSF-200 and GSF-100M generators is carried out by applying a DC pulse from the battery; the initial excitation of the GSF-100 BK generator is carried out using a resonant system with capacitors.

GSS generators

The diesel power plant uses only a four-pole generator GSS-104-4B of the 10th dimension and the 4th overall length.
The generator is splash-proof. with self-ventilation, on two shield bearings. The generator is mated with the drive motor by an elastic coupling. The device and principle of operation of this generator are similar to the device and principle of operation of the DHF generator.

SGDS generators

The SGDS series has a device similar to that of the SGD generator, but the excitation winding is powered by a static self-excitation system consisting of phase compounding transformers, a power rectifier unit, a separate rectifier and an initial excitation generator. The operation of the excitation system of this generator is similar to that of the static excitation system of other generators.

Huter DY3000L. General form

The article was born when I was invited as a specialist to connect a Huter generator without autostart in the country. Moreover, I was tasked with making the generator connection scheme as safe as possible and requiring minimal consumer (end user) intervention. That is, an Automatic Backup Power Switching (ATS) scheme was assembled, the options for which will be discussed in the article.

And about how this generator works, . Its electrical circuit is also given.

As always, we will consider the theoretical side of the issue, conduct an analysis, and then I will give several ATS schemes, from simple to complex.

Generator connection. Variants of ATS schemes for a generator

I must say right away that the generator has nothing to do with it, in this case it is just a backup power source. This source can be not only a generator, but also a second phase, and a phase from another substation or another line. Automatic transfer switch (ATS) schemes are universal and can work in different situations.

In principle, what is there to connect? The generator has a regular socket, a plug is included, what's the problem? But where does the wire from the plug go? And how to make the connection scheme convenient, correct, and most importantly, safe?

The most dangerous thing in connecting a generator is when voltages from the generator and from the city meet. Or the voltage from the generator will go to the city, where a team is working on the line in full confidence that the network is de-energized. And PZ (portable grounding) is not imposed (

It would seem that it is easier - to put the switch, and there are no problems.

At the end of the article - a photo with an example of such a switch.

So many do, and I do, depending on the financial capabilities of the client. Just remember two important things:

1. Do not switch under load!
2. Correctly select the protection and current of the knife switch (switch).

But we are not looking for easy ways, give us automation and protection from accidents and the human factor.

Therefore, I propose to consider the second version of the scheme:

2. Scheme of connecting the generator through a voltage control relay. The simplest AVR scheme.

In the second ATS scheme, a voltage control relay KV is used. In fact, this is an ordinary relay that is on when the voltage from the city is normal. And the changeover contact will be in the left position according to the diagram.

When the voltage from the city disappears, the relay turns off, and the circuit takes on the form shown - the load is powered by the generator.

The voltage control relay is the basis of any ATS circuit. For single-phase circuits, this is a conventional relay that is powered from the main phase.

3. Scheme of connecting the generator through relays and contactors. ATS with amplification

The third circuit differs from the second in that it can pass much more current through itself. The KV voltage relay is used only for its intended purpose - it automatically switches the load by supplying power to the coil of the corresponding starter.

When there is voltage from the city, KV is turned on, it turns on the contactor KM1 with its normally open (NO) contact, and phase L1 is supplied to the load (output of circuit L).

When the voltage from the city stops coming, KV turns off, and with its NC contact it turns on the KM2 contactor, and the L2 phase goes to the load.

The scheme is excellent, and even working. But using it is extremely dangerous. Due to the lack of protection against short circuit “phase L1 to phase L2”. Such a short circuit can occur due to a malfunction (sticking of contacts, jamming of relays or contactors), or due to the notorious human factor - what if the collective farm electrician decides to press the KM2 starter when KM1 is on?

According to statistics, in the case of a correct attitude to planned preventive maintenance, 90% of malfunctions and accidents occur due to the human factor!

So, in order to reduce the probability of accidents by an order of magnitude, in practice the following ATS scheme is used for the generator:

Its difference from scheme 3 is only that protections are introduced into it from the simultaneous switching on of contactors KM1 and KM2. Protection has two stages - electrical and mechanical.

Electrical blocking is implemented on the NC contacts KM1 and KM2, which mutually exclude the simultaneous activation of the starters.

Well, the practical scheme of automation will look like this:

5. ATS scheme for connecting a generator with interlocks and protections

Breaking the “city” zero is necessary for additional security. The fact is that at the output of the generator there is no concept of “working zero” and “phase”, and they can be called so conditionally. And in case of sticking of the “phase” contact, when the zero N1 is not broken (as in scheme 4), a voltage of 220V will go to the city line.

I assembled this scheme, now I'll show you how.

The design of ATS automation for connecting a generator

5_Assembled and connected ATS circuit. Do not judge strictly for installation.

On the left - two bipolar automata, then - the REK77-3 relay for 3 changeover contacts. The third NO contact, which is not shown in diagram 5, is connected in parallel with the motor switch SB1. When there is power from the city, the generator cannot be started in any way. And when the generator is running, and power from the city appears, the generator stops.

Starter KM2 + KM1 - reversible, Ukrainian. Each of them has three power contacts in parallel. The KM1.N starter breaks zero, its coil is connected in parallel with the KM1.L coil.

By the way, Alexandria (Ukrainian) contactors and tepushkas have been used a lot in practice - they have an optimal price / quality ratio. But after the well-known events of 2014, they disappeared from sale ... Let's move on to China.

In total, this is how the dacha automation for the generator turned out:

More ATS schemes for generators

Bonus - what I found on the Internet useful on the topic. Three-phase ATS. They differ only in the fact that a phase control relay is used, and in the number of contacts.

Three-phase AVR from the company AMK. Reserve - generator, zero breaks.

ATS for 3 phases. Reserve - another line (substation), common zero, does not break.

Installation example of a three-phase ATS. This AVR is mounted in a shield higher than human height and installed in a branch of Sberbank. It is powered by different city lines.

Control circuit of a three-phase AVR. Used phase control relay EL-11E and an intermediate relay

A bunch of protections - there are automatic machines on the EL and on the power supply of the contactors. I also wanted to put an automatic machine for a couple of amperes on the control circuit, but at the last moment I changed my mind.

There is no mechanical blocking. But the contactors are modular, closed, and who in their right mind in Sberbank will poke contactors. You still need to get into this room.

Important! when starting some generators, the voltage is unstable in the first seconds. This may negatively affect some load. This must be taken into account, in normal ATS with controllers they set a delay of up to a minute! For overclocking and exit to mode.

UPD: Connecting the boiler to the generator.

Often a generator is bought to be used in the winter to power the boiler of the heating system. There are some features here.

For imported phase-dependent boilers, it is important that the power system be with a solidly grounded neutral, i.e. zero and earth are connected together, and polarity (phase-zero) was observed when connected.

It often happens that if the boiler is plugged into the socket the other way around, i.e. change zero and phase, it stops working.

In the case of a portable generator, which is discussed in the article, there is neither zero nor phase. They must be made artificially - one output of the generator will be the phase (L2), and the second (N2) will be planted on the ground, i.e. we ground.

In addition, as you know, boilers are very sensitive to the shape of the voltage. And at the output of a conventional generator, the sine is “dirty”, if necessary, I’ll take an oscillogram. First of all, this happens because the alternator that generates electricity is brushed, and because of the brushes, sparks, dips, and similar unpleasant things occur.

It is because of this that Off-line and Smart UPS are not suitable for boilers. There, the output is a quasi-sine with a bunch of harmonics, . And for boilers, Online UPS is used (double conversion uninterruptible power supplies). For such a UPS, the shape, magnitude and frequency of the voltage at the input is not particularly important, because it cooks a constant voltage from all this porridge, from which it then electronically receives a pure sine. And if the boiler is powered through such a UPS, then a conventional generator can be used for its backup power.

For boilers and other sensitive equipment, it is recommended to use inverter generators - this is a generator plus an online UPS. The inverter generator includes a conventional generator, which is controlled by a controller, and an inverter that produces a pure sine - what boilers need.

Addendum to the article. Switch.

Here is a photo of the MP-63 TDM switch, with which you can manually switch the street-generator. The scheme is at the beginning of the article.

Switch for switching the voltage source. It is in the middle position.

Attention! 63A on the case is not a thermal current, and the switch does not “knock out”, ! This is the maximum operating current.

Taking advantage of the illiteracy and gullibility of buyers, many sellers of switchboard and power generating equipment often sell low-quality or frankly dangerous automatic start units. Thinking about buying a generator with automatic equipment? Then this article is for you!

What is ATS (Auto Transfer Transfer)?

Let's first understand what this abbreviation is. In the language of electrical engineering, this A automatic IN water R reserve. And in the language of consumers, it is an automatic switch from the main network to the power plant and back. Its principle of operation is simple. One of the main elements of such a switch is the so-called contactor group. These are contactors, and in the language of consumers, this is an element that monitors whether there is "light" or not. And after the disappearance, the contactors signal this to the "brains". The brains here are called the controller. And he, in turn, gives out commands further, switches to power from the generator and starts it. Well, when the main network appears (they gave light!), The controller switches back to the network and turns off the electrical installation. That's the whole job of the automatic switch. There are also advanced features, but about them later.
So, we got acquainted with the principle of operation of the cabinet, now it's time to talk about what you need to rely on when choosing automation, so as not to make trouble for yourself in the future. When buying a generator, many do not pay attention to automation for a power plant, but in vain. Because, as our chief engineer says, bad automation begins to hum in six months, warm up in a year, and there it’s not far from a fire. This is serious stuff, so jokes aside.

How to choose automation for a generator?

There are two types. Description:

1. Box with contactors. For industrial type power plants (1500/3000 rpm liquid cooled) with an automatic panel, a full shield is not required. Everything is already in the generator itself. Controller, circuit breakers, etc. And therefore, as a rule, a box with contactors and an emergency shutdown button is supplied to such power plants. I don’t see the point in writing this type especially, the main thing is that the contactors are not Chinese, and there is an emergency shutdown button for the electrical installation.

2. Full ATS shield. It is placed on portable equipment with a manual panel.
This is what usually becomes the subject of deception. Basically, this product does not meet the requirements for such products, but for which they ask for "good" money.

IMPORTANT!

Not automatic at all. Some sellers give out various kinds of products for an automation unit. For example, on the Internet you can find automation for 8-12 thousand rubles, or even 3500! But unfortunately, miracles do not happen, at least in the market of switchboard equipment .. What is this if not an automatic start unit? What you can find for 12 thousand (note that this is only a kit for Chinese electrical units) is nothing more than a parody of power plant control, it all connects with a special Chinese connector directly to the panel and does not have any real automation functions, but this is not the most important. The generator is controlled from such a unit not with the help of electromechanical elements, which are designed for very long operation and overload, but with the help of electronic components. This is the main danger. With a strong power surge, such "automatics" will not instantly turn off the network so that the refrigerator, TV, as well as the wiring do not burn out, but simply burn itself out. The same applies to "automatic devices" for 5500 rubles, where a fee is frankly placed, and the function of switching off and on is implemented using electronic components according to the "low current" principle. The irresponsibility and greed of such producers is striking. This will not only not work, it is simply simply dangerous. The average market cost of a full-fledged automatic transfer of the reserve is now 30-40 thousand rubles for 25-63 amperes.

Automation without a controller. The sale of a much cheaper version of the AVR is widespread. What does it mean? This means that the automation for the electric unit will be real, working, but there will be no part of the controls. For example, there will be no controller. Is it bad? Yes! The control parameters of the electrical installation are entered into the controller. This means that there is no shutdown due to low and high voltage, there is no check of the parameters of the power plant, fixing events, errors, which are then used for diagnostics - all this is not available! Do you want to know how the operation will look like? There will be 1 or 2 LEDs, and the instructions will say: blinked once, then that, blinked 2 times, another, blinked 2 times with a delay, the third. The master, who comes to you, either refuses to study this buffoonish system or, swearing loudly, asks for a higher payment.

So which AVR should you buy?

1. ABB/Schneider Electric contactors are installed in the unit.

2. The board is equipped with a DATAKOM/DeepSea controller.

3. On the front panel of the shield it has: an emergency shutdown button, an ammeter, a voltmeter, a light indication network / generator, a switch to manual mode, manual mode control.

4. If the unit is installed outdoors, the cabinet must have IP44-65 protection.

5. Elements inside the cabinet must be marked according to the scheme.

6. The cabinet must be supplied with an instruction manual with an ATS diagram.

Demand all of the above from the seller and the automation for the electric generator will not be an annoying factor for you, but a pleasant addition to the power plant....

Attention! The automatic start system (ATS) can be installed on any power plant with an electric start.

AVR (automatic) for diesel generator and gasoline generator

If the power plant (or gas generator) is used for backup (emergency) power supply, it can operate both in manual and automatic mode. The manual mode of a gasoline or diesel generator involves turning the power plant on and off at the command of a person. The automatic mode gives the chance not to participate to the person in work. In the event of a power failure, the automation itself will start the generator and turn it off when the power supply is restored. These functions are performed automatic transfer switch (ATS).

ATS functions

Degree of automation diesel generators and complexity AVR may be different. From simple switching on and off of the power generator to complex control and monitoring schemes for all processes and the state of the power plant.

In addition to the simplest functions used when working with gasoline generators, power plant automation may include:

• automatic maintenance of the temperature of the coolant or air inside the casing both during the operation of the station and in standby mode,
• monitoring the quality of the supplied electricity (voltage, frequency, etc.)
• control of the presence of fuel and oil with automatic and their pumping,
• a message about the start of the generator by cellular communication,
• remote transmission (up to satellite communication) of complete information about the state of the power plant to the control desk,
• control and maintenance of the battery,

Simple circuits are usually used to automate the power supply of small cottages and summer cottages. More complex automation systems are used to maintain the power supply of industrial facilities.

In automatic mode, the generator turns on a few seconds after a power failure and turns off after it is restored.

Stages of starting the generator in automatic mode

The general procedure for the operation of an electric generator in automatic mode has several stages necessary for operation in accordance with all instructions and requirements of GOST in terms of starting and stopping the power plant:

• Immediately after the power supply is turned off, the engine starts and enters its operating mode without load.
• If the generator does not start the first time, the automation will issue a command for several more start attempts at a certain interval.
• After the output of the power plant to the operating mode, the system will connect the object to the generator.
• If during the operation of the generator there will be a short-term restoration of the main power supply, the automation will maintain the power supply from the generator.
• After the restoration of the main power supply, the generator will be switched off with a transition to the main power supply channel.
• After that, the generator runs for some more time in order to stabilize the operation of the engine and secure against turning off the main source.

An automatic load switch is used to switch the power supply. It has all the necessary protection systems against overload and against the back-to-back operation of the generator and the network.

Another problem can be solved with the help of an automatic load switch. For example, if an object has a three-phase input, but there are no three-phase consumers, when using a three-phase generator, phase imbalance may occur. This could damage the generator. To avoid this, a single-phase generator must be used, and the phase combination will be performed on an automatic load transfer switch. The use of a single-phase generator and a three-phase automatic load transfer switch will improve the efficiency and reliability of the generator.

LLC "Independent Energy Systems" has been manufacturing based on controllers for many years own production. The controller includes high quality components, which determines the high reliability of our ATS units.

The ATS unit of the electric generator includes:

1. Controller board for autostart and automatic input of a reserve of an electric generator of our own production.
2. Power keys (contactors)
3. Charger for charging the battery of the electric generator.
4. Switches for selecting the operating modes of the unit.
5. Emergency stop mushroom button.

Main functions

• Security full cycle of work electric generator: automatic start of the generator in case of main input voltage transmission, or main input voltage out of the set range; burst of the electric generator and connection of consumers; control of work of the electric generator, protection against an overload; cooling and shutdown of the electric generator when the voltage of the main input appears.
• Selection of the type of redundant network: single-phase network - single-phase electric generator, three-phase network - single-phase electric generator, three-phase network - three-phase electric generator.
• Work with gasoline, diesel And gas power generators.
• Control of the air damper actuator (solenoid with return spring, DC motor) of gasoline and gas power generators.
• electric generator (option).
• Monitoring the voltage of the batteries of the uninterruptible power supply (UPS). Starting the generator when the battery of the UPS is discharged.
• test weekly generator start, at the set time and day of the week.
• Economy mode operation of the generator (the operating time and the downtime of the generator are set)
• Hour meter and time-to-maintenance meter
• Built-in event log and alarm log with date and time.
• Connection to a PC for reading/changing parameters and operating modes of the automation unit.
• Extending functionality by installing additional modules: , .

Summary table of characteristics

Distinctive features