What is a voltage regulator and what is it for. What is a voltage stabilizer for? Expert advice Why put a voltage stabilizer

Many have heard of voltage stabilizers at least once. But what a stabilizer is, not all people have an idea. In this material, we will tell you where the bypass is used, what it is for and how it works.

Now in every house or apartment there are a lot of imported equipment that is sensitive to voltage drops. These are primarily computers, refrigerators, electronic boards for autonomous heating systems, televisions, and other electrical appliances. It is recommended to install additional protective devices for such equipment: voltage stabilizers.

Bypass assignment

A feature of any power system is periodic surges or smoother voltage fluctuations. This indicator is influenced by many factors: the number of consumers on the line, the deterioration of cables, and more. As a result, in addition to the undervoltage, the consumer receives periodic voltage surges (especially during peak loads). Sensitive electronic boards are very demanding on this indicator and often fail precisely because of a drop or sudden voltage surges.

This is what a bypass is for - it stabilizes the voltage, smooths out sudden surges and brings its performance to acceptable values.

Types of protective devices

Depending on the purpose and type of performance, the principle of operation of the stabilizer may differ significantly. Consider the types of devices used.

Electromechanical

The principle of operation of this stabilizer is relatively simple: graphite brushes move along the transformer winding when the input voltage changes. The output value is changed in this simple way.

The photo shows a round regulating transformer with contact pads and a rotating brush

Early models used a manual method to move the brush (using a switch). This obliged users to constantly monitor the voltmeter readings.

In modern models, this process is automated using a small electric motor, which, when the input value changes, moves the brush along the transformer coil.

Among the advantages of this bypass, it is worth noting the reliability and simplicity of the design, high efficiency. The disadvantages include the low speed of response to changes in input parameters. In addition, mechanical parts wear out quickly, so this stabilizer requires periodic maintenance.

Electronic

Such a bypass is fully automated, and the principle of operation of the device is based on switching between windings using thyristors or triacs. In the electronic stabilizer, the microprocessor monitors the input voltage, and when the parameters are changed, it gives the command to close one and open another stage. Thus, the number of involved turns of the transformer is adjusted, which affects the output voltage indicators.

Among the advantages of electronic stabilizers are high-speed performance, low noise level, compact size of the device. Among the shortcomings, it is worth noting the stepwise regulation and the low load capacity of the electronic bypass.

Ferroresonant

The principle of operation of ferroresonant devices is based on the magnetic effect on the ferromagnetic cores of a stabilizing transformer. The first bypass, the principle of which is based on ferroresonant voltage stabilization, was released back in the mid-1960s. Since then, these devices have been constantly improved and improved. Modern ferroresonant stabilizers have the highest response speed (only 15–20 milliseconds), high control accuracy - about 1%, and a long service life.

In addition, special filters are installed in powerful devices to minimize electromagnetic interference. However, such bypasses have not found widespread use for domestic purposes due to the high cost, large body dimensions and the continuous hum emitted by the operating device.

Note! According to the installation method, a local or local bypass is distinguished for connecting a separate consumer. To connect to the electrical wiring and protect the entire apartment, stationary stabilizers are used, which are distinguished by high power and performance.

Having dealt with the definition of a stabilizer, here are some recommendations on what you need to pay attention to when choosing this device:

• Device power. It is necessary to take into account not only the power of the connected electrical appliance, but also a small power reserve, which a properly selected stabilizer should have. If the bypass is installed for the whole apartment, the power reserve should be about 30%;
• Stabilization accuracy. Although this parameter largely depends on the input parameters, choose devices with the minimum passport data (within 1-3%);
• Installation method: can be wall-mounted with vertical or horizontal mounting (for stationary models), as well as directly next to a separate electrical appliance;
• You should also pay attention to the compact size and quiet operation of the device;
• Price. Experts do not recommend purchasing cheap Chinese models. This is the case when it is not worth saving. A good and reliable protective device cannot be cheap. Give preference to domestic or proven European manufacturers;
• Warranty is an important aspect of choosing any electrical equipment. Chinese products are not covered by the warranty, while devices purchased from a specialized store can be exchanged if defective or repaired free of charge (during the warranty period).

Important! Most bypasses are single phase. They are designed to be connected to a 220V network directly in the apartment. For the three-phase connection, special stabilizers are used, designed to protect the entire cottage or industrial sites.

Now you know what a bypass is, what it is for, and learned the principle of operation of all types of voltage stabilizers.

There are many types of voltage stabilizers on the market now. These are electronic and electromechanical, hybrid and thyristor. But to say that some are better and others worse will not be correct. Each of them has its own scope. It's like saying that a Kamaz truck is worse than an urban business-class Mercedes. The first has its own scope, while the second has its own and cannot be replaced with one another. Kamaz is not suitable for delivering a businessman to a meeting, and you cannot bring 10 tons of cargo in a Mercedes. But on the contrary - Kamaz can easily transport 10 tons of sand, and Mercedes will comfortably deliver a businessman to a meeting.

So it is with voltage stabilizers. For example, relay stabilizers can work quietly even at sub-zero temperatures (up to -30 ° C), but is this ability needed if they stand inside a heated house? No.

But for summer cottages, the ability of relay switches to work at temperatures below zero is very useful.

Therefore, for a private house in stabilizers, qualities such as smooth regulation (so that the lights do not blink) and how much is the exact output voltage.

Voltage stabilizer for home how to choose

Smooth voltage regulation is the main feature electromechanical voltage stabilizers. Inside they have a copper winding, along which a brush travels with the help of a servo. When the voltage in the mains changes, the servo drive moves the brush along the winding, thereby smoothly equalizing the voltage. In addition, this adjustment method allows you to maintain a very high accuracy of the voltage at the output of the stabilizer (220V ± 3%), which is also important when used with home video and audio equipment.

But classic electromechanical stabilizers always have one very important drawback - this is a rather narrow input voltage range (up to 140V). This means that when the voltage in the mains falls below 140 volts, the electromechanical stabilizer simply turns off and de-energizes all electrical appliances in the house.

Electromechanical stabilizer design

To eliminate this drawback, the so-called hybrid voltage stabilizers capable of equalizing voltage in the range of 105V ... 280V. They got their name due to their design features. Inside the hybrids, in fact, there are 2 modules - electromechanical and relay. The main operating mode of hybrids is electromechanical (active when the input voltage changes in the range from 140V to 280V), with smooth and high-precision alignment of all fluctuations in the power grid. But when the voltage drops below 140 volts, the protective shutdown no longer works, but instead a relay unit is connected, which is able to pull out the drawdowns to 105V.

Advantages of hybrid stabilizers:

• smooth adjustment (bulbs will not blink);
• very accurate - hold 220V (± 3%);
• equalize the voltage with 105V.

The disadvantages include:

• floor version - Cannot be hung on the wall. Although using a special rack, you can install them one above the other;
• can only work at temperatures above 0 ° C.

Comparison of characteristics of electromechanical stabilizers:

In addition to hybrid devices for the home, they also put thyristor Surge Protectors. The role of the power switch in them is played by a semiconductor element, a thyristor. Thanks to this, it is possible to further expand the range of input voltages and pull out drawdowns up to 60V!

Due to the absence of moving parts, thyristor stabilizers create absolutely no noise during operation. This makes it possible to use them even inside city apartments. In addition, thyristor devices are considered the most durable among voltage stabilizers. Because of this, manufacturers often give them an extended warranty.

The advantages of thyristor stabilizers:

• cope even with abnormal voltage drops up to 60V;
• absolutely silent (noise level - 0dB);
• adjustment is carried out smoothly;
• high-precision - at the output we get 220V ± 5% (and 220 ± 3% for frost-resistant modifications)
• high response speed (20ms);
• made in a hinged version (do not take up much space and are conveniently mounted on the wall);
• have an extended warranty for 3 years.

disadvantages

• the production technology of thyristor stabilizers is quite expensive, so the price tag of the devices does not allow them to be installed in every home.

Comparison of characteristics of thyristor models:

First rule:

For the house, you need to install a voltage stabilizer with smooth adjustment (so that the bulbs do not blink). These requirements are met: electromechanical (hybrid) or thyristor stabilizers.

Step # 2 - Single Phase or Three Phase?

So, we have decided on the type of stabilizer - we need an electromechanical / hybrid or thyristor device.

Now you need to understand whether to put single-phase (at 220V) or three-phase (at 380V)?

There are two options:

• if one phase is connected to the house, then we select a single-phase stabilizer;
• it would seem that for a three-phase network there should be the same logical conclusion - for three phases, take a three-phase unit. But there is one caveat.
  All three-phase stabilizers are designed in such a way that when one of the phases disappears, protection is triggered in the stabilizer and it turns off, de-energizing the entire house. Therefore, only if there are three-phase consumers in the house, we install a three-phase stabilizer.
  If the consumers are only 220V, then it is better to put 3 single-phase voltage stabilizers (one for each phase). Most often, such a solution will even be cheaper in money.

What if you don't know how many phases are connected to the house?

The most common answer to this question is: "If you had three phases, you would know about it." Indeed, most of the old-built private houses have one phase and all household consumers are designed for 220V (TV, refrigerator, computer, video and audio equipment).

Three phases are often brought up to modern country cottages, because in addition to household electrical appliances, it is planned to install three-phase consumers at 380V.

2 or 3 wires are connected to the house - a single-phase network, 4 or more - three-phase.

Second rule:

If one phase is connected to the house, we stop at single-phase stabilizers.

For a three-phase network:

• if there are 380V consumers - we put one three-phase stabilizer;
• if the consumers are only for 220V, we put 3 single-phase stabilizers (one for each phase).

Step # 3 - Should it work at subzero temperatures?

So, now we know that depending on the consumers, you need to install a single-phase or three-phase device.

The next step is simple - will the stabilizer be in the heated room or not. Most often, the device is located in a technical room inside the house and there is no need for frost-resistant devices.

If suddenly it is necessary to work at temperatures below zero, then we remember this parameter in the stabilizer as important.

Third rule:

Most often, stabilizers are installed inside the house and there are no requirements for frost resistance. But if it stands in an unheated room, then we choose among stabilizers that can work at sub-zero temperatures.

Step # 4 - How much power do you need a stabilizer?

At the previous stages, we learned that a house needs a device with smooth adjustment, decided on the number of phases of the required device (single-phase or three-phase) and decided for ourselves whether it will stand in a heated room or a frost-resistant version is needed.

Now you need to understand how much power the device should have.

magazin energia ru

This issue must be carefully considered, since taking a stabilizer of low power, as a result, we will get frequent shutdowns of the stabilizer due to overload.

The basic rule that is usually followed when choosing a voltage stabilizer for a home is as follows:

For each private house or country cottage, an introductory machine is installed, which does not allow loading the electrical wiring of the house more than it is designed. This is not due to the "greed" of electricians, as if they do not want to allow the owner of the house to turn on appliances with more power than allowed. The reason is trivial - to prevent a fire from occurring. In order to prevent overheating of the wires and the occurrence of a fire due to this, an introductory machine is installed. If a person tries to simultaneously load the electrical wiring with devices of greater power than allowed, the input circuit breaker will perform a protective shutdown and prevent a fire in the house.

Most often, such introductory machines are placed on the house:

40 A (ampere) introductory machine

In order to find out what power a voltage stabilizer is needed for our house, the same formula is always used:

• Option number 1 - a single-phase 220V network is connected to the house
  In this case, we multiply the value of the input machine (we have 40 amperes) by 220 volts:
  40 * 220 = 8 800
  It turns out that our house needs a stabilizer with a capacity of no less than 8800 VA (volt-ampere) or 8.8 kVA (kilovolt-ampere).
  

  Knowing the typical power range of stabilizers:
  5, 8, 10, 15, 20, 30 kVA

  We understand that a stabilizer for 8 kVA will no longer cope with our load, but for 10 kVA it will be it.

• Option number 2 - a three-phase 380V network is connected to the house
  In the case of a three-phase network, the solution is as follows:
  • if there are 380V consumers at home - we put one three-phase stabilizer.
    Its power is calculated as follows:
    An introductory machine for private houses with a three-phase connection, most often 20 amperes.
    We multiply 20 amperes by 200V and multiply the resulting figure by 3 more:
    20 * 220 * 3 = 13 200
    It turns out that a three-phase stabilizer with a capacity of at least 13200 VA (volt-ampere) or 13.2 kVA is needed for the house. (kilovolt-ampere).
    Again, we take into account the power range of three-phase stabilizers (9, 15, 20, 30 kVA), we understand that we need a 15 kVA stabilizer.
    In total, a 15 kVA three-phase unit is needed.
  • If 3 phases are connected to the house, and all electrical appliances are ordinary, designed for 220V and there are no plans to install three-phase consumers, then it will be more efficient to install three single-phase stabilizers (one for each phase). This is done for the reason that if there is a voltage failure in one of the phases, the three-phase stabilizer will de-energize the entire house. When installing three single-phase stabilizers, this problem does not occur and electrical appliances on the remaining two phases continue to work.
    Power is calculated as for a conventional single-phase stabilizer (described above) with the difference that you need not one but three pieces:
    40 * 220 = 8 800
    In total, you need 3 stabilizers of 10 kVA each.

Fourth rule:

Depending on the number of connected phases:

• for a single-phase network (220V), a single-phase 10 kVA stabilizer is most often installed;
• for a three-phase network, either one three-phase stabilizer of 15 kVA or three single-phase of 10 kVA are installed (one for each phase).

magazin energia ru

Step # 5 - How much does the voltage drop?

In the previous 4 steps, we found out that a stabilizer with smooth and precise regulation is required for the house (electromechanical / hybrid or thyristor devices are suitable for this). We learned that with a single-phase network, a single-phase stabilizer is needed, and with a three-phase network - one three-phase or three single-phase (in which cases and which one is indicated in Step # 2). At Step # 3, we decided whether we need a frost-resistant device or whether it will stand inside the house, in a heated room. And at Step 4, we calculated the required power of the device.

And now we come to that small, but very important point, which 80% of people forget about when choosing a stabilizer.

In theory, everything is simple - I looked at the figure on the introductory machine, multiplied it by 220V, and a stabilizer is needed for such a power. But for some reason they forget that when the voltage drops (when the outlet is not 220V, but already 170V, 140V and below), the power that any stabilizer can produce also drops. And instead of the declared 10 kW (kilowatts), it already produces 8 or 7 kW. Thus, if the home network is fully loaded (electrical appliances with a total power of 10 kW are turned on and operating at the same time), the stabilizer will not be able to provide them with this power and, in order to avoid overheating and failure, protection will be triggered, which will turn off both the stabilizer and all electrical appliances in the house.

Dependence of the output power of the stabilizer on the voltage drop in the mains.

As you can see from the graph above, when the voltage drops to 170V, the stabilizer will be able to deliver a maximum of 85% of its power. If we take, for example, a 10 kW device, we get:
10 * 85/100 \u003d 8.5 kW total

With a voltage of 140V, we have 65% of the power:
10 * 65/100 \u003d only 6.5 kW

If our drawdowns reach 110V, then at the output you can count on only 40% of the power, and this is:
10 * 40/100 \u003d 4 kW total

It is for this reason that all electricians unanimously advise taking a voltage stabilizer with a power reserve of at least 30%.

The situation with increased voltage is not so common, but the power margin must be taken in this case:

Dependence of the output power of the stabilizer at increased voltage.

Already at 255V, the stabilizer begins to lose power, and at 275V it is capable of delivering only 80% of the declared values. A protective shutdown occurs at 280V.

Fifth rule:

With a low or high voltage, the power of any stabilizers drops. Therefore, you should always take a stabilizer "with a margin" in power (at least 30%).

Conclusions:

So, today we learned that for the house:

• only accurate stabilizers with a small error at the output and smooth regulation are suitable. This is necessary so that at the moment of voltage equalization the bulbs do not blink and the electronics in the house work normally. Electromechanical, hybrid or thyristor devices are suitable for these requirements;
• decided whether you need a single-phase or three-phase device;
• found out for themselves whether it will stand in a heated room or a frost-resistant device is required;
• learned that for houses with one phase supplied (220V), they most often take a 10 kVA (kilovolt-ampere) stabilizer, and for a three-phase network (380V), 15 kW (kilowatt) devices are chosen. And they learned to calculate the power of the required stabilizer individually for their home;
• remember that the stabilizer must be taken with a power reserve (at least 30%).

I hope we managed to help as much as possible with the selection of a stabilizer for the home. If you have learned something new for yourself and find this information useful, click on the social media buttons below and save this article to yourself so as not to lose.

In discussions of electrical circuits, the terms "voltage regulator" and "current regulator" are often used. But what's the difference between them? How do these stabilizers work? Which circuit needs an expensive voltage regulator, and where is a simple regulator sufficient? You will find answers to these questions in this article.

Consider a voltage regulator using the example of the LM7805 device. Its characteristics indicate: 5V 1.5A. This means that it is precisely the voltage that stabilizes and it is up to 5V. 1.5A is the maximum current that the stabilizer can carry. Peak current. That is, it can give 3 milliamperes, 0.5 amperes, and 1 ampere. As much current as the load requires. But not more than one and a half. This is the main difference between a voltage stabilizer and a current stabilizer.

Types of voltage stabilizers

There are only 2 main types of voltage stabilizers:

• linear
• impulse

Linear voltage regulators

For example, microcircuits BANK or , LM1117, LM350.

By the way, KREN is not an abbreviation, as many people think. This is a cut. The Soviet microcircuit-stabilizer, similar to the LM7805, had the designation KR142EN5A. Well, there is also KR1157EN12V, KR1157EN502, KR1157EN24A and a bunch of others. For brevity, the entire family of microcircuits began to be called "KREN". KR142EN5A then turns into KREN142.

Soviet stabilizer KR142EN5A. Analogue of LM7805.

Stabilizer LM7805

The most common type. Their disadvantage is that they cannot operate at a voltage lower than the declared output voltage. If it stabilizes the voltage at 5 volts, then it needs at least one and a half volts more to the input. If we apply less than 6.5 V, then the output voltage will "sink" and we will not get 5 V. Another disadvantage of linear stabilizers is strong heating under load. Actually, this is the principle of their operation - everything that is higher than the stabilized voltage simply turns into heat. If we supply 12 V to the input, then 7 will be spent on heating the case, and 5 will go to the consumer. In this case, the case heats up so much that the microcircuit will simply burn out without a radiator. All this leads to another serious drawback - a linear stabilizer should not be used in devices powered by batteries. The battery energy will be spent on heating the stabilizer. Switching stabilizers are devoid of all these disadvantages.

Switching voltage stabilizers

Pulse stabilizers - are devoid of linear disadvantages, but they are also more expensive. This is no longer just a three-pin chip. They look like a board with parts.

One of the versions of the pulse stabilizer.

Pulse stabilizers there are three types: lowering, increasing and omnivorous. The most interesting are omnivores. Regardless of the input voltage, the output will be exactly what we need. The omnivorous impulse does not care if the input voltage is lower or higher than necessary. He automatically switches to the mode of increasing or decreasing the voltage and keeps the set at the output. If the characteristics state that the stabilizer can be input from 1 to 15 volts and the output will be stable 5, then it will be so. In addition, heating pulse stabilizers so insignificant that it can be neglected in most cases. If your circuit will be powered by batteries or located in a closed case, where strong heating of the linear stabilizer is unacceptable, put a pulse one. I use the penny-pin configurable switching voltage regulators that I order from Aliexpress. You can buy.

Okay. What about the current stabilizer?

I won't open America if I say that current stabilizer stabilizes the current.
Current stabilizers are also sometimes called LED drivers. Outwardly, they look like switching voltage regulators. Although the stabilizer itself is a small microcircuit, everything else is needed to ensure the correct operation. But usually the entire circuit is called a driver at once.

This is what a current regulator looks like. The same circuit, which is the stabilizer, is circled in red. Everything else on the board is strapping.

So. The driver sets the current. Stable! If it is written that there will be a current of 350mA at the output, then it will be exactly 350mA. But the output voltage may vary depending on the voltage required by the consumer. Let's not indulge in the theory of that. how it all works. Just remember that you do not regulate the voltage, the driver will do everything for you based on the consumer.

Well, why do you need all this?

Now you know how a voltage stabilizer differs from a current stabilizer and you can navigate in their variety. Perhaps you still do not understand why these things are needed.

Example: you want to power 3 LEDs from the vehicle electrical system. As you can learn from, it is important for the LED to control the current strength. We use the most common option for connecting LEDs: 3 LEDs and a resistor are connected in series. The supply voltage is 12 volts.

With a resistor, we limit the current to the LEDs so that they do not burn out. Let the voltage drop across the LED be 3.4 volts.
After the first LED, 12-3.4 \u003d 8.6 volts remains.
We have enough for now.
On the second, another 3.4 volts will be lost, that is, 8.6-3.4 \u003d 5.2 volts will remain.
And enough for the third LED too.
And after the third, 5.2-3.4 \u003d 1.8 volts will remain.
If you want to add a fourth LED, it won't be enough.
If the supply voltage is raised to 15V, then that's enough. But then the resistor will also need to be counted. The resistor is the simplest current stabilizer (limiter). They are often placed on the same tapes and modules. It has a minus - the lower the voltage, the less the current on the LED will be (Ohm's law, you can't argue with it). This means that if the input voltage is unstable (in cars it usually is), then you first need to stabilize the voltage, and then you can limit the current with the resistor to the required values. If we use a resistor as a current limiter where the voltage is not stable, we need to stabilize the voltage.

It is worth remembering that it makes sense to install resistors only up to a certain current strength. After a certain threshold, the resistors begin to get very hot and you have to install more powerful resistors (why the power resistor is described in this device). Heat dissipation increases, efficiency decreases.

Also called an LED driver. Often, those who are not very versed in this, the voltage regulator is simply called the LED driver, and the switching current regulator is called good LED driver. It immediately outputs a stable voltage and current. And hardly heats up. This is how it looks:

Voltage stabilizers are pretty interesting devices. When a long time ago, back in the Soviet era of mass construction of "Khrushchev" and "Brezhnev", such a device was almost an obligatory neighbor of the TV: it was believed that plugging the "square friend" directly into the socket was fraught. Then TVs still began to be connected to the network "just like that" - and nothing ... Stabilizers turned into relics - but not for long. With the advent of household computers in everyday life, stabilizers returned and again took their place of honor - this time in the form of blocks with several outlets. Why do we need voltage regulators and why did they come back? Let's try to answer this question ...

Why were they needed yesterday ...

Let's start with why voltage stabilizers were needed at one time ... Here the answer is more or less simple - those who moved into new apartments in the 60s and 70s of the last century may themselves still remember that in the first few months (or even years) voltage fluctuations in the household network strongly deviated from the prescribed 220 volts. What was noticeable to the naked eye - from time to time the light bulbs began to shine half-heartedly, and sometimes burned out; the image on the screen of black-and-white television sets also faded and became barely distinguishable.

The reason for such troubles was, as a rule, the connection of a mass of new consumers to the network, in which the output voltage from the transformer substations was divided by a much larger number - and therefore it dropped from 220 to 210, or even 200 volts. And vice versa - when consumers were massively disconnected from the network (for example, they turned off everything that was possible, leaving for work), then the voltage in the network could jump for a long time to 240, or even 250 volts.

In such conditions, voltage stabilizers were indeed necessary. Moreover, the very first of them were not even automatic - they were an ordinary transformer, along the outer winding of which it was necessary to manually move the terminal.

Over time, they gave way to ferroresonant stabilizers, and when switching power supplies were installed in color TVs, the need for such voltage stabilizers disappeared altogether - fortunately, strong voltage fluctuations in the city power grid are a thing of the past. Now these fluctuations do not exceed, as a rule, 5%, last no more than a minute and are observed mainly in rural areas.

Why are they needed today

However, voltage regulators returned in the late 90s. Their return was associated with the massive distribution of household computers, for which even short voltage fluctuations could be fatal. Demand for voltage stabilizers reappeared - and multi-socket pads reappeared in numerous computer accessories stores ...

... which, in fact, quite often were not voltage stabilizers at all, since they differed from a set of ordinary sockets only by the presence of a parallel capacitor (sometimes in combination with an inductor). Which, in fact, could "cut" individual voltage fluctuations at a total frequency of 50 Hz - but that's all. However, for most personal computers, also equipped with switching power supplies (UPS), this was enough.

Paradoxically, but it is a fact - just the most, at first glance, "delicate" devices - computers and televisions - tolerate voltage fluctuations in the network the best and least of all need real voltage stabilizers.

Nevertheless, there are electrical appliances that need a voltage stabilizer in our homes - and in considerable quantities. First of all, these are new refrigerators of the latest models - they often have microprocessor control, which should ensure efficient operation of the compressor. And microprocessors do not tolerate voltage drops very well. The same picture is observed with washing machines - especially those that are designed to operate at 380 volts. Microwaves and dishwashers also do not tolerate power surges. Well, do not forget also about electrical appliances in summer cottages and in country houses - including those that are responsible for the operation of heating boilers.

How do stabilizers work?

In general, the principle of operation of voltage stabilizers remained the same as it was: they are still a transformer, one winding of which is supplied with electricity from the outlet (which can have a voltage of 198 and 240 volts), and on the other - "removed" exactly 220 volts. The required voltage is obtained by changing the number of turns on the "home" winding from which the voltage is supplied.

Therefore, in fact, the main difference between voltage stabilizers comes down to how exactly the working number of turns on the "home" winding will change - smoothly or in jumps.

Voltage regulation "surges" is provided by relay stabilizers.

In such stabilizers on the "home" winding, conclusions are made to a relay designed for 220 volts. If the "home" voltage turns out to be higher than 220 - then several relays are turned off, reducing the number of working turns on the home winding - and the "home" voltage drops. The relay response speed is from 10 to 20 milliseconds, and the increase-decrease in voltage with each actuation can be in different models of stabilizers from 1 to 5 volts.

The main advantage of relay stabilizers is reliability and simplicity of design, and the main disadvantage is some own consumption. After all, the "home" current passes through the windings of all relays and is consumed at the same time - and the more relays in the circuit, the greater the consumption.

Smooth voltage regulation can be provided by thyristor stabilizers, the circuit of which will look something like this.

According to the diagram, it is easy to see that the thyristor stabilizer is, in fact, also an AC-to-DC converter and vice versa. The smoothness of its operation is bought through the use of much more, much more expensive parts.
So which of the voltage stabilizers to prefer in specific conditions is up to you.

A 220V mains voltage stabilizer is a device that equalizes the voltage from the mains to a certain value, and gives consumers stable 220 volts, regardless of surges and drops on the line. The installation of such a device will provide protection of electrical devices from abnormal operating modes, such as high or low levels. In this article we will consider the device and the principle of operation of voltage stabilizers, as well as the types of these devices and their area of \u200b\u200bapplication.

Definition

A voltage stabilizer (CH) is a device designed to convert the input unstable voltage from the mains: underestimated, overestimated or with periodic surges, into a stable value at the output of the device and electrical appliances connected to it.

Let's paraphrase for dummies: the stabilizer makes it so that for the devices connected to it, the voltage is always the same and close to 220V, regardless of what it is supplied to its input: 180, 190, 240, 250 volts or even floats.

Note that 220V or 240V is the standard value for the Russian Federation, Belarus, Ukraine, and so on. But in some countries of the near and far abroad, it may be different, for example 110V. Accordingly, "our" stabilizers will not work there.

Stabilizers are different: both for operation in DC circuits (linear and pulse, parallel and series types), and for operation in AC circuits. The latter are often called "mains voltage stabilizers" or simply "220V stabilizers". In simple terms, such stabilizers are connected to the mains, and consumers are already connected to it.

In everyday life, CH is used to protect both individual devices, for example, for a refrigerator or a computer, and to protect the entire house, in this case a powerful stabilizer is installed at the input.

Classification

The design of stabilizers depends on the physical principles on which they operate. In this regard, they are divided into:

• electromechanical;
• ferroresonant;
• inverter;
• semiconductor;
• relay.

According to the number of phases, they can be single-phase and three-phase. A wide range of capacities allows us to produce stabilizers for both home and small household appliances:

• for TV;
• for a gas boiler;
• for the refrigerator.

So for large objects:

• industrial units (for example, three-phase industrial stabilizers Saturn);
• workshops, buildings.

Stabilizers are quite energy efficient. Electricity consumption is 2 to 5%. Some stabilizing devices may have additional protections:

• from;
• from;
• from;
• from frequency drops.

Operating principle

Voltage stabilizers are of different types, each with a different regulation principle. We will consider these differences later. If we generalize the principle of operation and structure of all types, then the mains voltage stabilizer consists of 2 main parts:

1. Control system - monitors the input voltage level and gives the command to the power unit to increase or decrease it so that the output is stable 220V within the specified error (control accuracy). This error is within 5-10% and is different for each device.
2. The power section - in servo (or servo-motor), relay and electronic (triac) - is an autotransformer, with the help of which the input voltage rises or falls to a normal level, and in inverter stabilizers, or as they are also called "double conversion" - an inverter is used ... This is a device that consists of a generator (PWM controller), a transformer and power switches (transistors) that pass or turn off the current through the primary winding of the transformer, forming an output voltage of the desired shape, frequency and, most importantly, magnitude.

If the input voltage is normal, then some models of stabilizers have a "bypass" or "transit" function, when the input voltage is simply supplied to the output until it goes out of the specified range. For example, from 215 to 225 volts the "bypass" will be turned on, and with large fluctuations, for example, with a drawdown of up to 205-210V, the control system will switch the circuit to the power section and start adjusting, increase the voltage and the output will already have stable 220V with a given error ...

Smooth and most accurate adjustment of the output voltage for inverter MVs, in second place are servo drives, and for relay and electronic ones, the adjustment occurs in steps, and the accuracy depends on the number of steps. As mentioned above, it lies within 10%, more often about 5%.

In addition to the above two parts, the 220V voltage stabilizer also contains a protection unit, as well as a secondary power supply for the control system circuits, the same protections and other functional elements. The general device is clearly shown in the picture below:

At the same time, the scheme of work in its simplest form looks like this:

Let's take a quick look at how the main types of voltage regulators work.

Relay

In a relay stabilizer, regulation occurs by switching the relay. These relays close certain contacts of the transformer, raising or lowering the output voltage.

The controlling body is an electronic microcircuit. The elements on it compare the reference and mains voltage. If there is a discrepancy, a signal is given by the switching relay to connect the increasing or decreasing windings of the autotransformer.

Relay MVs usually regulate electricity within ± 15% with an output accuracy of ± 5% to ± 10%.

The advantages of relay stabilizers:

• cheapness;
• compactness.

Disadvantages:

• slow response to voltage fluctuations;
• short service life;
• low reliability;
• when switching, a short-term power outage of the devices is possible;
• unable to withstand overvoltage;
• noise, clicks when switching.

Servo

The main elements of servo stabilizers are autotransformer and servo motor. If the voltage deviates from the norm, the controller sends a signal to the servo motor, which switches the required autotransformer windings. As a result of using such a system, smooth regulation and accuracy up to 1% of the total range are provided.

In servo-driven MV, one end of the primary winding of the transformer is connected to a rigid branch of the autotransformer, and the other end of the primary winding is connected to a movable contact (graphite brush), which is moved by a servo motor. One terminal of the secondary winding of the transformer is connected to the input power supply, and the second terminal is connected to the output of the voltage stabilizer.

The control board compares the input and reference voltage. For any deviations from the set ones, the servo drive comes into operation. He moves the brush along the branches of the autotransformer. The servo motor will continue to run until the difference between the reference and output voltage is zero. This whole process, from the inflow of poor quality electric power to the output of a stabilized current, takes place in tens of milliseconds and is limited by the speed of the brush movement by a servo drive.

Servo-driven mains voltage stabilizers are produced in various designs.

1. Single phase. Consists of one autotransformer and one servo drive.
2. Three-phase. They are classified into two types. Balanced - have three transformers and one servo drive and one control circuit. Regulation is carried out on all three phases simultaneously. They are used to protect three-phase electrical devices, machine tools, devices. Unbalanced - they have three autotransformers, three servomotors and three control circuits. That is, stabilization occurs in each phase, independently of each other. Scope: protection of electrical equipment in buildings, workshops, industrial facilities.

Advantages of servo stabilizing devices:

• high-speed performance;
• high stabilization accuracy;
• high reliability;
• overvoltage resistance;

Disadvantages:

• need periodic maintenance;
• require minimal device setup skills.

Inverter

The main difference between this type of MV is the absence of moving parts and a transformer. Voltage regulation is carried out by the double conversion method. In the first stage, the input AC current is rectified and passed through a ripple filter consisting of. After that, the rectified current is fed to the inverter, where it is again converted into alternating current and supplied to the load. In this case, the output voltage is stable both in magnitude and in frequency.

In the next video, you will learn about the principle of operation of one of the options for implementing a voltage converter from 12V DC to 220V AC. Which differs from the inverter voltage stabilizer primarily in the input voltage, otherwise the principle of operation is very similar and the video will allow you to understand how this type of device works:

Advantages:

• speed (the highest of the listed);
• large range of regulated voltage (from 115 to 300V);
• high efficiency (over 90%);
• silent work;
• small dimensions;
• smooth regulation.

Disadvantages:

• reduction of the regulation range with increasing load;
• high price.

So we examined how a voltage regulator works, what it is for and where it is used. We hope the information provided was useful and interesting for you!

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