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 ensuring that the generator connection diagram was as safe as possible and required minimal consumer (end-user) intervention. That is, an Automatic Backup Power (ABP) circuit was assembled, the options of which will be discussed in the article.

And about how this generator works... Its electrical diagram is also shown.

As always, let’s consider the theoretical side of the issue, carry out an analysis, and then I will present several ATS schemes, from simple to complex.

Generator connection. Options for ATS circuits for a generator

I’ll say right away that the generator has nothing to do with it, in this case it’s 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.

Basically, what is there to connect here? The generator has a regular socket, a plug is included, what are the problems? But where does the wire from the plug go? And how to make sure that the connection diagram is convenient, correct, and most importantly, safe?

The most dangerous thing about connecting a generator is when the voltages from the generator and from the city meet. Or the voltage from the generator will go to the city, where a crew 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 would be easier to install a switch, and there would be no problems.

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

This is what many people do, and this is what I do, depending on the client’s financial capabilities. Just don't forget about two important things:

1. Do not shift under load!
2. Select the correct protection and current of the circuit breaker (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. Connection diagram of the generator via a voltage control relay. The simplest AVR circuit.

The second ATS circuit uses a KV voltage control relay. In fact, this is an ordinary relay that is in the on state 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 regular relay that is powered from the main phase.

3. Connection diagram of the generator via relays and contactors. AVR with amplification

The third circuit differs from the second in that it can pass a much larger 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 KM1 contactor with its normally open (NO) contact, and phase L1 is supplied to the load (circuit output L).

When the voltage from the city stops coming, KV turns off, and with its NC contact it turns on the KM2 contactor, and phase L2 is supplied 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 contacts, jammed relays or contactors), or due to the notorious human factor - what if a collective farm electrician decides to press the KM2 starter when KM1 is turned on?

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

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

The only difference between it and scheme 3 is that it includes protection against the simultaneous activation of contactors KM1 and KM2. The protection has two stages - electrical and mechanical.

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

Well, the practical automation scheme will look like this:

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

Tearing 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 that way arbitrarily. And in the event of a stuck “phase” contact, when the N1 zero is not broken (as in diagram 4), a voltage of 220V will flow into the city line.

This is the diagram I put together, now I’ll show you how.

Design of automatic transfer switch for connecting a generator

5_Assembled and connected ATS circuit. Don't judge the installation too harshly.

On the left are two two-pole circuit breakers, then a REK77-3 relay with 3 switching 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. And when the generator is running and power comes from the city, 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 to the KM1.L coil.

By the way, I have used Alexandria (Ukrainian) contactors and heaters 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 what the dacha automation for the generator turned out to be:

More ATS circuits for generators

Bonus – what you found on the Internet useful on the topic. Three-phase automatic transfer switches. They differ only in the use of a phase control relay and the number of contacts.

Three-phase automatic transfer switch from the AMK company. Reserve - generator, zero breaks.

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

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

Three-phase ATS control circuit. Phase control relay EL-11E and intermediate relay are used

There are a lot of protections - there are automatic circuit breakers for the EL and for powering the contactors. I also wanted to put a couple of amperes on my control circuit, but at the last moment I changed my mind.

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

Important! When starting some generators, the voltage is unstable in the first seconds. This may have a negative impact on some loads. This must be taken into account; in normal ATS with controllers they set a delay of up to a minute! For overclocking and reaching the mode.

UPD: Connecting the boiler to the generator.

Often a generator is purchased to be used in winter to power the heating system boiler. There are some peculiarities here.

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

It often happens that if the boiler is plugged into the socket the other way around, i.e. change the 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 a phase (L2), and the second (N2) will be placed on the ground, i.e. ground.

In addition, as is known, boilers are very sensitive to the voltage form. And at the output of a conventional generator the sine wave is “dirty”; if necessary, I will take an oscillogram. First of all, this happens because... The alternator that generates electricity is brushed, and because of the brushes sparking, failures, and similar unpleasant things occur.

It is because of this that Off-line and Smart UPS are not suitable for boilers. There at the output there is a quasi-sine with a bunch of harmonics. And for boilers, Online UPS (double conversion uninterruptible power supplies) is used. For such a UPS, the shape, magnitude and frequency of the input voltage are not particularly important, because it cooks a constant voltage from all this mess, from which it then electronically receives a pure sine wave. And if the boiler is powered through such a UPS, then you can use a regular generator 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 regular generator, which is controlled by a controller, and an inverter, which produces pure sine wave - what boilers need.

Addition to the article. Switch.

I provide a photo of the TDM MP-63 switch, with which you can manually switch between street and generator. The diagram is at the beginning of the article.

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

Attention! 63A on the body 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 electrical switchboards and power generating equipment often sell low-quality or downright dangerous automatic start units. Are you thinking about buying a generator with automation? Then this article is for you!

What is ATS (automatic transfer of reserve)?

Let's first figure out what kind of abbreviation this is. In the language of electrical engineering this is A automatic IN water R reserve. And in the language of consumers, this is an automatic switch from the main network to the power plant and back. Its operating principle is simple. One of the main elements of such a switch is the so-called contactor group. These are contactors, and in consumer language this is an element that monitors whether there is “light” or not. And after a loss, the contactors signal this to the “brains”. The brains here are called the controller. And he, in turn, issues further commands, switches to power from the electric generator and starts it. Well, when the main network appears (the light is on!), the controller switches back to the network and turns off the electrical installation. That's all the automatic switch does. There are also advanced functions, but more on 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 get yourself into trouble in the future. Many people, when buying a generator, do not pay attention to the automation for the power plant, but in vain. Because, as our chief engineer says, bad automation starts to hum after six months, overheats after a year, and then it’s not far from a fire. This is a serious thing, 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 cooling) with an automatic panel, a full-fledged panel is not required. The electric generator itself already has everything. Controller, circuit breakers, etc. And therefore, such power plants are usually supplied with a box with contactors and an emergency shutdown button. I don’t see any point in describing 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-fledged AVR shield. Installed 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 this kind of product, but for which they ask for “good” money.

IMPORTANT!

Not automatic at all. Some sellers pass off various types of products as automation units. For example, on the Internet you can find automation for 8-12 thousand rubles, or even 3500! But unfortunately miracles don’t happen, at least in the electrical panel equipment market.. What is this if not an automatic start unit? What you can find for 12 thousand (note this only comes as a kit for Chinese electrical units) is nothing more than a parody of power plant control; it is all connected with a special Chinese connector directly into the panel and does not have any real automation functions, but this is not the most important thing. The generator is controlled from such a unit not using electromechanical elements, which are designed for very long operation and overload, but using electronic components. This is the main danger. In the event of a strong power surge, such “automation” will not immediately turn off the network so that the refrigerator, TV, and wiring do not burn out, but simply burn out on their own. The same applies to “automatics” for 5,500 rubles, where a board is explicitly installed, and the switch-off and switch-off function is implemented using electronic components according to the “low-current” principle. The irresponsibility and greed of such producers is amazing. Not only will this not work, it’s simply downright dangerous. The average market cost of a full-fledged automatic reserve input is now 30-40 thousand rubles for 25-63 amperes.

Automation without 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 and working, but some of the controls will be missing. For example, there will be no controller. Is this bad? Yes! The electrical installation control parameters are entered into the controller. This means that there is no shutdown for low and high voltage, there is no checking of power plant parameters, there is no recording of events, errors, which are then used for diagnostics - all this is not available! Want to know what operation will look like? There will be 1 or 2 LEDs, and the instructions will say: blinked once, that means this, blinked 2 times or another, blinked 2 times with a delay or a third. The master who comes to you either refuses to study this buffoonish system or, swearing loudly, will ask for a higher payment.

So which AVR should you buy?

1. The unit contains ABB/Schneider Electric contactors.

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

3. On the front panel of the switchboard it has: an emergency shutdown button, an ammeter, a voltmeter, a network/generator light indicator, a manual mode switch, and 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 diagram.

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...

Let's take a closer look at this issue

• Why do you need a generator?

1. Electrical independence
2. The ability to always enjoy the benefits of the 21st century
3. Ensuring the operability of vital infrastructure, home (dacha) or industrial site.

• What benefits does generator automation give you?

1. Autonomy of all systems
2. Time you can spend on other important tasks
3. Ensuring a comfortable level of living

How does the automation system for a generator work?

If the main network is lost, the autostart system panel controller attempts to start the generator and, if successful, after warming up the generator, switches the load from the main network to the backup one. If the startup attempt fails, the controller makes repeated startup attempts. When the main network appears, the controller, after a fixed waiting time, switches the load to the main network, and after cooling the generator, turns it off. The system operation algorithm is presented in Fig. 1.

Figure 1. How the generator autostart system works

How to automate generator startup?

The generator start automation system only works with generators equipped with an electric starter. If your generator does not have an electric starter, then you can check with the generator manufacturer whether it is possible to purchase and install an electric starter.

Fig 2. Honda generator electric starter.

When starting, the engine is spun by a commutator electric motor, which is shown in Figure 2. The commutator electric motor is powered by direct current from the battery (after starting, the battery is recharged from the generator driven by the main engine). But the electric starter has a significant drawback: in order to crank the crankshaft of a cold engine, especially in winter, it needs a large starting current, which is supplied by the battery, which rapidly loses maximum current and capacity as the temperature drops. Sometimes, together with the use of too viscous oil, this makes starting in cold weather impossible. Despite the presence of these disadvantages, using an electric starter is the most convenient way to start the engine of both gasoline and diesel, as well as gas generators.

To avoid problems starting the generator in winter, It is better to keep the generator in a warm room (or in a special box for the generator). But statistics show that on average 40% of our customers leave their generator outside. In such cases, we recommend change spark plugs in winter ignition and use all-season semi-synthetic oil.

What is needed to automate the starting of a generator?

To automate the generator, you will need to purchase an ATS Shield (ATS). This shield monitors the state of the network and switches the network to backup power, in our case it is a power plant.

Some generators already have an automatic generator start system installed from the factory, but these automated generators tend to be more expensive than conventional generators with an optional automatic generator start system installed (). At the same time, in both cases it is necessary to install an avr () () shield to protect from parallel connection of the generator to the main network, which can lead to serious damage to the generator or other serious consequences.

For those generators that do not have a factory automation system, You can purchase controllers produced by ANS-GROUP LLC.

Our controllers for generator autostart:

1. Automatic generator start block BAZG-10 NEW ()
2. Coordination module with ATS switchboard MS-1 ()
3. Coordination unit with AVR BS-1 panel ()
4. Damper control unit BUZ-1 ()
5. Coordination module for diesel generator Diesel MS-1 ()
6. Coordination block for diesel generator BS-1 ()

Drives for controlling the generator damper:

1. Generator damper control drive PUZ-1 ()
2. Generator damper control drive in the form of a lever PUZ-2 lever ()
3. Generator damper control drive PUZ-universal ()

Additional options that may be useful.

1. Remote start and monitoring of the system via GSM channel. You can add a GSM module to the system and be able to remotely control system parameters using short SMS messages, as well as start/stop the generator. This is a very important building block of the system. Even if an accident occurs, you will always be aware of events and will be able to influence the situation. (Details...)
2. Test run of the generator according to schedule. You can add a programmable timer to the system and you will be able to start the generator at a specific time. (Details...)
3. Accounting for generator operating time. You can add a generator hour meter to the system. This way you will always know how much your generator has worked and whether it is time for scheduled maintenance. (Details...)
4. Blocked fuel line. Fuel valve for an electric generator, which will shut off the fuel supply to the engine during idle time (More details...)
5. Remote automatic start of the generator from the key fob. You can add a radio module to the system and you can start the generator remotely, via a radio channel. (Details...)
6. Thermal relay, temperature control. Let's add a thermostat to the system and your generator will start when the temperature in the house drops or the temperature in the refrigerator rises. This way you can significantly save fuel. The generator will provide electricity to the boiler or refrigerator only when necessary. An example of such a system is shown in the figure below. (Details...)

Our automatic generator start systems have been successfully installed on generators:

• HUTER
• PRORAB
• ELITECH
• Eisemann
• BOAR
• FOREMAN
• TEKHENERGO
• HYUNDAI
• Hitachi
• TIGER
• GREEN POWER
• GREEN FIELD
• GESHT
• NILSON
• HONDA
• SUMMER RESIDENT
• BRIGGS & STRATTON
• Walsh
• Elemax
• Robin-Subaru
• Sturm!
• Aiken
• Fubag

and can be easily installed on similar models with an electric starter.

In these generators, a static system consisting of stationary elements (power transformer, rectifiers, etc.) converts alternating current at the generator terminals to direct current to power the field 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 unit consists of a power transformer 3, selenium rectifiers 4, a block of capacitors 5 and power supply rectifiers 6. The elements of the excitation unit are mounted on a cast base, which is attached to the generator frame and closed on top with a cap. Control unit 7 consists of switches for the operation of the PV, a resistor for the voltage setting RU and separate resistors for regulating droop 8. Using blocks 7 and 8, installed on a separate panel, 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, with the exception of the operation of the static system.

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

To maintain the voltage at the generator terminals unchanged under any load, it is necessary that the generator excitation current changes 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 the selenium rectifiers 4, two components of the excitation current are added and rectified: from the winding w1, which is proportional to the generator voltage, and from the winding wc, which is 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 ensures that the excitation current changes when the value and nature of the generator load changes. Since rectifiers 4 have a nonlinear resistance, which does not provide initial self-excitation, the system provides a resonant circuit formed by the capacitance Xc of capacitors C4-C6 connected to the winding wK, and the leakage inductance XL of the primary winding w-,. By special selection of parameters at a frequency of 50 Hz, XL=XC is ensured, 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 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 direct current is supplied. When direct current flows through the winding w, a magnetic flux is formed, which is closed through the core of the transformer 3. With a change in the direct current flowing through the winding, the constant magnetic flux of the core 3 and, consequently, the excitation current of the generator in the winding Wz changes - Since the winding wy is powered by constant current from two successively opposing sources: rectifier 4 (current /v is proportional to the excitation voltage of the generator) and supply rectifier 6 through the resistor RU and droop resistance CC1 (current /vp does not depend on the load and is unchanged for any mode), then /y = /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 larger cos φ, and, therefore, the bias current of transformer 3 (Ash>/v) with reactive loads of the generator will decrease more than with active ones. Thanks to this, the parameters of the phase compounding system are corrected and greater accuracy in regulating the generator voltage according to the load is achieved than with the uncontrolled version of phase compounding.
The generator voltage setting is regulated by a resistor RU connected in series to the winding circuit of the dow, and the control current component /E can be adjusted by resistor CC1.
The static excitation system has the following advantages: the absence of moving parts, high mechanical strength of structures, reliability and high accuracy of voltage regulation, and low operating costs.
For initial excitation, generators can have a resonant system with capacitors (generators of the DGF, ESS, GSF-100-BK, OS, GSS-104-4B types), or a rechargeable battery (ESS-5, GSF-100M, GSF-200), or initial excitation generator (SGDS-11-46-4), or voltage transformer (ESS-5). The operating principle of the 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 diesel generators with a static excitation system

Characteristic			ECC-82-4/M201	ECC-91-4/M201	ECC-5-61-4/M101	ECC-5-81-4/M101
Rated power. "W
Linear voltage, V
Stator current. A
Efficiency at 100% load
Rotation speed, rpm
Generator dimensions, mm: length
Generator weight, kg

Continuation of the table.

Characteristic

ECC-5-92-6/M101

ECC-5-92-6/M101

Rated power, kW

Linear voltage, V

Stator current, A

Efficiency at 100% load

Rotation speed, rpm

Generator dimensions, mm:

Generator weight, kg

Characteristic

OS-52/M101.M201

GSDS-11-46-4

Rated power, kW

Linear voltage, V

Stator current. A

Efficiency at 100%-Holi on-

Rotation speed, oo/mmn

Generator dimensions, m: length width height

840 400 400

Generator weight, kg

GSF generators

Generators of the GSF series have a power of 100 and 200 kW, flanged design, protected, on two shield bearings, connected to the engine using a coupling and a flanged bearing shield.

The design and operating principle of the GSF generator and the DHF generator are similar. The initial excitation of the GSF-200 and GSF-100M generators is carried out by applying a direct current 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 station uses only a four-pole generator GSS-104-4B of 10 dimensions and 4 dimensions.
The generator is splash-proof. with self-ventilation, on two shield bearings. The generator is connected to the drive motor by an elastic coupling. The design and operating principle of this generator are similar to the design and operating principle of the DHF generator.

Generators SGDS

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 block of power rectifiers, a separate rectifier and an initial excitation generator. The operation of the excitation system of this generator is similar to the operation of the static excitation system of other generators.

Static thyristor excitation systems DExS.GEN are designed to power the excitation winding of generators with a power of up to 60 MW with automatically controlled current in all operating modes. Performs the functions of control, protection, and indication of operating modes of the excitation system.

DExS.GEN excitation systems are thyristor excitation devices with direct digital control, manufactured on a modern element base. Excitation systems meet the requirements of GOST 21558-2000 and have developed service functions that facilitate setup and operation.

General information:

DExS.GEN excitation systems can be made either in a single-channel version or with redundant control systems and power parts. For redundant systems switching into operation of the reserve channel (in the event of a malfunction of the main channel or at the operator’s command) occurs “without impact”, without affecting the operation of the generator.

Excitation system design:

Structurally, the excitation system is made in one metal cabinetunilateral service with degree of protection IP22 (on request - IP31, IP54).

The excitation system cabinet contains:

• Power circuit protection devices;
• Control circuit protection devices;
• Microprocessor excitation regulator (for two-channel systems - two independent excitation regulators);
• Thyristor converter (for systems with power section redundancy - two independent thyristor converters);
• Starting resistances with a thyristor switch;
• Power backup circuits for control circuits;
• Controls and indications on the front door of the cabinet.

Contents of delivery:

The excitation system kit includes*:

• Control cabinet;
• Input cabinet;
• Thyristor converter cabinet;
• Field suppression cabinet;
• Input cabinet for working and reserve excitation;
• Conversion transformer;
• Rotor protective resistance;
• Switching cell for converter transformer;
• A set of technical documentation in Russian: passport, technical description and operating instructions, a set of diagrams and drawings, description of service software (on electronic media);
• Electronic media with documentation and service software;
• Spare parts kit (composition according to the Customer’s technical requirements);
• Digital complex for setting up maintenance of the “STAT” excitation system with a laptop.

*Depending on the parameters of the excitation system and the Customer’s requirements, the composition of the equipment included in the supply may be changed. The exact delivery set is indicated in the product passport.

Excitation system operating modes:

The excitation system provides:

• Initial excitation to a given setting from a source of operational direct current = 220 V or an auxiliary network of 0.4 kV 50 Hz.
• Generator idling.
• Automatic adjustment of the generator voltage to the network voltage with an accuracy of ±0.5% to ensure inclusion in the network using the precise synchronization method.
• Autonomous and parallel operation with the power system and loads and overloads acceptable for the generator.
• Unloading of the generator in terms of reactive power to a value close to zero during normal shutdown of the unit.
• Quick damping of the generator field by switching the operating thyristor rectifier to inversion mode during normal generator shutdown and during emergency generator shutdown, provided that the thyristor rectifier is in good working order.
• In the event of an emergency shutdown of the generator, field suppression is additionally ensured by the forced introduction of damping resistances into the winding circuit.
• Automatic and manual control mode.
• The transition from automatic to manual mode and back is smooth.
• The transition from the main regulator to the backup one and back is carried out shocklessly (for two-channel excitation systems).
• Automatic shock-free transition from the main thyristor converter to the backup one (for excitation systems with power section redundancy).
• The main mode of operation of the regulator is stabilization of the generator stator voltage with reactive current static.
• Forcing excitation with a given voltage and current multiplicity in the event of disturbances in the power system, causing a decrease in voltage on the station buses.
• Limitation of the forcing value of the exciter excitation current at a given level and duration.
• Limitation of exciter excitation current overload.
• Limitation of the minimum excitation according to a given diagram of permissible modes.
• Issuance of operational and emergency alarms.
• The excitation is switched off automatically when the generator switch is turned off under the influence of the excitation system or generator protection.
• Local or remote change of the voltage setpoint in the range from 80 to 110% in automatic regulator mode and from 0 to 110% in manual mode, relative to the rated voltage of the generator.
• Maintains voltage at the generator terminals with an accuracy of no worse than ±0.5% relative to the established static characteristic (with a given setting).

Excitation system protection

The excitation system provides the following types of protection:

• From loss of excitement;
• From an increase in generator stator voltage in idle mode;
• From reducing the generator stator voltage frequency in idle mode;
• From exceeding the exciter excitation current limit;
• From a malfunction of the thyristor rectifier control channel;
• From short circuits at the converter output;
• From excitation current overload;
• From reducing the insulation resistance of the excitation winding.

The parameters and range of settings are given in the technical documentation for the excitation system.

The activation of protections is displayed on the display, recorded in the controller’s event log, recorded on the output relays and transmitted to the protection circuit in the form of a discrete signal or via a digital interface.

Network synchronization (optional)

By agreement with the Customer, the exciter can be equipped with a synchronization device with the network, which provides:

• Automatic synchronization
• Manual precise synchronization

Automatic and manual fine synchronization operate both with local and remote control. Additionally, to ensure synchronous connection of the generator to the network, a synchronism control relay is built into the synchroscope; the output signal of this relay is connected in series with the signal to turn on the mains switch.

Telecontrol (optional)

The pathogen has the ability to be remotely controlled. Telecontrol – control carried out by operational personnel from a remote control point node or by dispatch personnel from a dispatch center using a coded signal transmitted over communication channels.

By means of remote control, the excitation system can receive the following commands:

• Increase the setting;
• Decrease the setting;
• Turn on excitation;
• Disable excitation (quenching);
• Enable regulation based on Ug (generator voltage);
• Enable regulation by Q;
• Switching regulators from primary to backup and vice versa;
• Reset protections;
• Enable offline mode;
• Enable manual controller mode;
• Disable manual mode (enable automatic mode) of the regulator.

If necessary, the scope of teams is agreed upon with the Customer at the detailed design stage. Telecontrol can be organized using specialized network cards using the MODBUS RTU, MODBUS TCP/IP, PROFIBUS DP protocols (RS485 and Ethernet interfaces) as agreed with the Customer.

The excitation system provides all the necessary measurements and information exchange with the station-level automated process control system and interaction with unit-level systems, including: measurement and generation of signals for the current and voltage of the generator stator, excitation circuit, as well as generator frequency at the main control room and on its own front panel, while communication with the station's automated process control system and aggregate level is provided via a serial interface RS485 and (or) Ethernet. The type of protocol, type of interface and the amount of necessary information transmitted to the automated control system must be negotiated separately with each Customer at the detailed design stage. 

Discrete signals

Discrete signals about the state of technological equipment are output in the form of binary signals “0” “1”. In this case, voltages of alternating current 220V, direct current 220, 48, 24V can be used as signal “1”. The input/output channels of analog and discrete signals are galvanically isolated from each other and relative to the ground.

Excitation control system

The excitation control system carries out automated control of excitation system devices, providing control functions for excitation system equipment.

The generator excitation system is made according to single-channel or two-channel (with 100% redundancy of control systems and thyristor rectifiers) circuits. The power supply for the control circuits is backed up from an operational DC source of 220V and/or from the auxiliary network ~220V, depending on the design.

In two-channel systems, each regulator (ARV1 and ARV2) is a full-featured generator excitation control system, has its own set of analog sensors (with individual galvanic isolation), discrete inputs and outputs, and protection devices. If a working channel is damaged, an automatic, shock-free transition to a working regulator is carried out.

Each channel provides automatic and manual excitation control; switching between manual and automatic control modes is shockless. Switching modes (Automatic/Manual) is carried out using a key on the front panel of the cabinet (in local control mode) or from the main control room (in remote control mode). Also, the manual mode is switched on automatically when the voltage measuring circuits are lost and the backup channel is simultaneously unavailable. Regulation of the generator voltage, regardless of the number of the active channel and the regulation mode, is performed with one key on the front panel or main control room.

The control system consists of the following interconnected modules:
1. Two independent microprocessor excitation controllers DExS (for two-channel systems);
2. Communication module iCM;
3. Operator panel DExS.OP.CM3;
4. Power backup system for auxiliary needs.

Automatic excitation regulator DExS

The control system is a multiprocessor excitation control unit DExS, which implements direct digital control of the thyristor exciter. High-speed digital signal processors with an FPU unit (floating-point unit) are used.

Advantages of DExS:

• It is a monoblock built-in module that provides full functionality for controlling generator excitation. Includes a complete set of inputs/outputs:
• Analog inputs allow direct measurement of signals from basic sensors (stator and rotor current and voltage).
• 16 digital inputs and 16 digital outputs = 24V.
• SIFU - 6 amplifiers of thyristor control pulses.
• High accuracy of controller calculations due to the use of floating point numbers.
• High computing speed. All analog signals and the excitation controller are processed at a constant frequency of 10KHz.
• There are no tuning elements at all. All settings are stored in non-volatile memory and are duplicated many times with the function of automatically restoring a faulty block of settings from a backup copy.
• Additional removable key for backing up settings.
• Thyristor pulse amplifiers with valve conductivity control.
• Automatic phasing SIFU - works correctly with any phasing.
• Automatic continuous measurement of rotor insulation resistance in the range of 0-2000 kOhm in 62 Ohm steps.
• Built-in 10,000 samples per second oscilloscope for 32 channels (32 any selected 16-bit registers) with configurable auto-trigger scripts, number of pre- and post-samples. Used for commissioning and as an emergency oscilloscope. Emergency oscillograms are copied into non-volatile memory after the generator is stopped.

iCM Communication Module

Thanks to the iCM module, external data consumers (process control systems, instrumentation and control equipment, operator panel) two DExS controllers (for redundant systems) are represented as one device.

The iCM communication module provides the following services:

• Synchronization of settings of DExS regulators (DExS settings must be completely identical throughout the entire operation of the exciter).
• Two-way exchange of information between two DExS and external data consumers (operator panel, PLC). For access from the automated process control system, iCM is equipped with:
• Ethernet 10/100T Mbit, MODBUS TCP/IP protocol
• RS485 protocol MODBUS RTU
• Transfer of data “from” and “to” the instrumentation and automation chain from a centralized source, through:
• 2 inputs 4-20mA
• 2 outputs 4-20mA
• 12 discrete inputs = 24V
• 8 discrete outputs =24V 150mA
• Primary accumulation of statistical data and oscillography on a micro-SD card with a capacity of up to 4GB (8 days of continuous recording).

Operator panel DExS.OP.CM3

Panel devices provide operational information about the main parameters of the system, while being non-volatile indicators (do not require an additional power source).
The operator panel increases information capabilities. The operator panel displays detailed information about the operation of the excitation system and generator, allows you to change settings, view event archives and statistics, and copy the necessary information to external storage devices.

Viewing statistics and waveforms from the event recorder is possible using the Ajuster software (via the interface) and the operator panel. The operator panel provides an advanced event registration service:

• recording waveforms and statistics on an SD card (can be removed for incident investigation);
• an oscillogram is a continuous recording for 30 days with a frequency of 100 records of all controller parameters per second;
• the oscillogram and statistics can be copied to a USB Flash disk or over the network to a disk on a remote server;
• access to files is possible via Ethernet using a secure SSH protocol;
• Using the operator panel, you can view the oscillogram of any event, within an arbitrarily specified time interval “before” and “after” the event.

Thyristor converters

The thyristor converter (rectifier) ​​is made according to a bridge circuit: with a rated excitation current of up to 400A, thyristor modules are used, installed on coolers with natural air cooling; rectifiers over 400A are manufactured using tablet thyristors, which are cooled using a combined method.

The combined cooling method combines natural and forced cooling. A special thermal control module measures the temperature of thyristor assemblies at several points using digital temperature sensors and turns on the fans only when they heat up above a given set point and turns off the fans after cooling the assemblies to a given temperature.

In excitation systems with a backup thyristor converter, each thyristor rectifier has an automatic switch at the input and a disconnector in the DC circuit. Signals from the switch and disconnector are fed into the regulator and when the switching equipment is turned off (when the protection is triggered or manually), an automatic transition to the backup rectifier occurs.

Field blanking

The field quenching of generators over 12.5 MW can be carried out by a controlled triac switch with a block of quenching resistors, and also, upon request, an automatic field quenching machine (AGP) can be installed - in this case, the field quenching circuit is located in a separate cabinet.

Power transformer

The thyristor rectifiers of the main and reserve channels are powered from a TE converter transformer, which can be connected to the generator buses using a self-excitation circuit or powered from a 0.4 kV source.

manufacturer's warranty

The manufacturer guarantees that the excitation system complies with the technical specifications subject to the conditions of transportation, storage, commissioning and operation in accordance with the established technical documentation.

Warranty period is 36 months.