Using an uninterruptible power supply. Uninterruptible power supply: purpose and types

Greetings, my dear readers! In the current Russian realities, owners of desktop computers are forced to solve problems of uninterrupted power supply. Decide this problem possible using sources uninterruptible power supply. Their diversity on the computer market allows you to choose a UPS to suit your specific needs. We will talk about what a UPS is and what uninterruptible power supplies there are in this article.

A UPS, or uninterruptible power supply, is a device that acts as an energy “battery”. In the event of a power outage, the UPS automatically switches the computer's power supply to power from the built-in batteries, which allows you to correctly shut down the work and save all the necessary documents.

Variety of uninterruptible power supplies

Uninterruptible power supply is your guarantee of the safety of documents and computer components as a whole. After all, if the computer is turned off incorrectly, the HDD, And motherboard, and RAM.

We figured out what an uninterruptible power supply is. Let's move on to the next question.

What types of UPS are there?

Uninterruptible power supplies are divided into three types:

1. Offline UPS;
2. Line-interactive UPS;
3. Online UPS (double conversion UPS).

Let's look at each type of uninterruptible power supply separately. This information will help you when choosing a UPS for your own needs.

Offline UPS

Principle of operation of this type power source is automatic switching computer or other connected device to be powered by built-in batteries when disconnected from the external power supply.

Often a mechanical relay acts as a switch, so you may hear a clicking sound when the UPS switches from an external power source to the batteries and vice versa.

This type has become widespread among ordinary users and in offices.

TO pros Such UPSs include simplicity, compactness and low cost. The main minus is the impossibility of stabilizing the input voltage, and therefore your computer will not be protected from sudden voltage changes. This species also exhibits increased wear and tear on batteries.

Line-interactive UPS

This type of uninterruptible power supply is in most cases used to protect network and other telecommunications equipment, as well as groups of computers.

The main feature of these sources is the ability to adjust the output voltage without connecting to batteries, regardless of the voltage (high or low) at the input.

Pros This type of UPS is small in size, low cost, automatic voltage regulation, and economical.

But he also has minuses– this is a relatively long switching to batteries, the impossibility of adjusting the shape of the output voltage when operating from an external power supply, the change in output voltage occurs in steps.

Double conversion UPS

This type of UPS performs voltage conversion twice: the input AC voltage is converted to DC, and then the DC is converted to a reference AC voltage and supplied to the devices.

This type is used where a reference voltage is required, and the powered devices are demanding on the quality of the power supply. The connected devices can be very different: regular workstations, file servers, network devices and other power-hungry equipment.

pros Online UPS has significant: full control input and output voltage, zero waiting time for switching to batteries, connected equipment does not in any way affect the external power grid.

Minuses There are also: high cost, complex design, self-consumption of electricity in double conversion mode.

The first type of UPS is quite sufficient for home and office use. But if you have the financial opportunity, I would recommend the latter type to you. This is the most reliable type of protection for your computer equipment from low-quality voltage.

Main characteristics of the UPS

A UPS has several main characteristics that you should pay attention to when purchasing. Let's look at them below.

1. Power. This characteristic directly determines what equipment can be connected to this UPS. Always choose a source with power reserves. This will avoid possible problems with a lack of power.

Usually this characteristic indicated by the value VA or W. If the value is indicated in VA (VA), then multiply it by 0.6 to get the value in Watts that are more understandable to us.

1. UPS type. I talked about the types of uninterruptible power supply systems above. We came to the conclusion that the most optimal would be a double conversion UPS, but for home needs an offline or line-interactive source would be sufficient.
2. Battery life. This value is very important, since it determines how long the computer will work without external power supply. Usually time battery life can be set in the range of 5-30 minutes. Please note that at maximum load on the UPS, the operating time without electricity is significantly reduced.

These three characteristics are the most important. In addition to them, the UPS has many more characteristics. For example, when choosing a UPS in a store, pay attention to what power connectors are installed in the source, whether there is a display and additional interfaces (RJ-11, USB), how many batteries are installed, and others.

Frequently encountered problems

1. The most the main problem which occurs most often in a UPS is a failure battery. A dead battery can be determined by the fact that the uninterruptible power supply stops supporting the load - when the power goes out, the computer immediately turns off. Also, a damaged battery can manifest itself in a different way: the uninterruptible power supply does not turn on at all, or it turns on and beeps continuously. I wrote about how to change the battery in a UPS. It says about a specific UPS, but the replacement principle is practically the same in all sources.
2. The UPS may not turn on at all due to a blown fuse.
3. If the uninterruptible power supply starts normally, but the computer does not turn on, then check the wires; they may come out of the sockets.

I hope my article was useful to you and you learned something new. If you still have questions, you can ask them in the comments.

By purchasing a UPS (Uninterruptible Power Supply) for personal computer or other household appliances, you solve many problems at once “in one fell swoop”. You will no longer have to constantly save it while working with a document, for fear of losing data due to a sudden power outage. Also, you now don’t have to worry at all that the power supply or, even worse, the hard drive will fail as a result of incorrect shutdown. If “trouble” happens, you can complete it within a few minutes. important work with the program and calmly turn off the computer. All this is due to the fact that the uninterruptible power supply almost instantly reacts to changes in indicators in the power grid and begins to work as a backup source of energy. The user's task is only to help the device perform its functions effectively. The service life of both the UPS itself and the consumers connected to it directly depends on responsible handling of equipment.

Commissioning

As a rule, when using new equipment, the preparatory stage is the most difficult. After all, you need to know as accurately as possible how to properly install and connect the device, what requirements must be met, and how to avoid mistakes. Before connecting your computer to an uninterruptible power supply, you must fulfill several very important conditions.

Under no circumstances should you turn on the device immediately after bringing it from outside. . It is especially important to follow this rule when the temperature outside is sub-zero. The “bespereboynik” must sit properly in the room, otherwise there is a possibility that condensation formed due to a sharp temperature change will cause a breakdown. Immediately before startup, the UPS must be dry. If it is severely frosty outside, the waiting time before turning on should be at least four hours.

Choose the most suitable location to install the device . The case of the uninterruptible power supply should not be located where it can be exposed to sunlight. Also, there should be no heating devices nearby, and the room itself should have a normal level of humidity. Install the device in such a way that nothing blocks the ventilation openings (they must have free access to air for effective cooling).

Carefully monitor the temperature regime . For most models of this type of equipment, the recommended operating temperature range is from 0 to +40 °C (ideally, for stable operation of the device, the temperature should always be between +20 and + 25 °C).

Route wires carefully . The power connection cable and wires connecting the UPS to the load must be located in such a way that there is no tension and the possibility of accidentally touching them is eliminated. The power cable must be connected to a grounded outlet, as required by safety regulations.

Wait until the battery is well charged . Immediately after turning on the UPS for the first time, it will not be possible to work with the load fully; the diagnostic system will generate an error (in some cases, a message will pop up that the battery is faulty and requires replacement). This happens because new batteries are not charged, and therefore are not capable of supporting power to connected consumers. In order for the batteries to be fully charged, leave the UPS plugged in for a day, since the first charge takes longer than planned.

For some uninterruptible power supply models to work effectively, you need to install some software on your computer. The product should include a disc that can be easily installed by almost anyone. regular user PC. Many modern UPSs have a self-diagnosis system that must be activated before the first start-up (after which the correct connection will be checked, as well as the proper functioning of the internal operating elements). In the event of any malfunction, for example, when the “phase” and “neutral” inputs are reversed or there is no grounding, the device will beep or display an error code. To immediately determine what’s wrong, carefully read the instructions before use, then all the signals will be clear to you, and you can quickly eliminate the error.

Connecting and operating the UPS with a load

Finishing preparatory stage, you can start using the UPS by connecting a load to it. Let's give an example of a standard connection diagram for efficient operation of computer equipment in domestic conditions: a UPS and a printer (or scanner) are connected to the surge protector, and system unit The computer and monitor are connected to the UPS itself. In principle, if there is a connector for a printer on the UPS panel, you can connect one to it, but only on the condition that it is an inkjet printer and its power consumption was initially included in the total load power when purchasing an uninterruptible power supply. Never even try to connect laser printer, since it is much more powerful than inkjet, and at the time of peak loads it can overload the UPS. You should also not connect lighting fixtures or other household appliances, which is not in such dire need of protection during a power outage. The same can be said about the use of these devices. in offices: the load from all connected servers to one UPS should in no case exceed its capacity.

What are the consequences of large overloads? A large number of power consumption will certainly lead to an unjustified load on the uninterruptible power supply, and there may not be enough power to power the computer. It happens that the device simply “drops” the load, which causes an emergency shutdown of computer equipment and loss of data, and what’s even worse is that important working parts may break down (for a UPS it’s a battery, for a PC it’s a hard drive or power supply). Agree that additional repair costs will be an unpleasant surprise.

Correct compliance with permissible power loads guarantees that the uninterruptible power supply can effectively support the operation of computer equipment for the time declared by the manufacturer during power outages. You will have time to save important information to your hard drive or removable media and shut down correctly.

It should be noted that it is not recommended to use the entire reserve time to continue working at the computer. If it is possible to save the data earlier and turn it off, do so. Thus, you can preserve the battery capacity and reduce the load on the uninterruptible power supply. In general, experienced specialists advise using an uninterruptible power supply in conjunction with a generator for long-term operation without a central power supply: when the power goes out, the equipment will operate on the UPS for a few seconds, and then the load can be transferred to the electric generator without interrupting operation.

How to extend the life of a UPS?

Since the uninterruptible power supply basically ensures the operation of the equipment connected to it for a period of time from 10 to 20 minutes, the battery is subject to the greatest wear. On average, the service life of rechargeable batteries reaches 3 years with proper use. Although for “ON-LINE” type devices this period can be increased to 5 or even 10 years, thanks to modern technologies that allow more careful charging/discharging of the battery. Do not try to artificially extend the “life” of the battery by disassembling it and adding distilled water, as some people do, based on experience. car batteries. The UPS is equipped with special sealed or, as they are also called, maintenance-free batteries. When the resource of such a battery is exhausted, it is necessary to replace the old one with a new one. However, there are several rules that, if followed, will help extend the life of your batteries.

№ 1. Avoid cases where switching to battery power is not justified. For example, a small power surge occurs and the entire load switches to battery operation. This may be due to the fact that the upper and lower transition thresholds are incorrectly configured. By changing them to the correct ones, based on the power grid indicators, at which the equipment will function stably, you can avoid increased load on the batteries. The adjustment is carried out either on the control panel or through a program installed on the computer.

№ 2. Be sure to ensure that the uninterruptible power supply does not overheat under any circumstances. For normal battery operation, the ambient temperature, including inside the device body, should not exceed 30 °C. Regardless of whether natural or forced cooling occurs during operation of the device, it must be as efficient as possible.

№ 3. Eliminate the possibility completely mechanical impact to the device (shocks, falls, etc.). You need to install the UPS in a place where it will be stable and nothing will accidentally fall on it.

Many buyers ask themselves the following question: is it necessary to have a spare battery? This will only be justified if the uninterruptible power supply is used intensively and may need a backup battery charge. But if there is no such need, storing the battery for several years “just in case of fire” will not be rational - since it will already lose its performance properties.

As for the efficiency of the UPS as a whole, it largely depends on you. If you have carried out all the preparatory work correctly, followed the recommendations on operating conditions and promptly responded to signals from the diagnostic system, then you can be sure that the likelihood of breakdowns will be minimal. If a problem does occur that cannot be resolved using the methods described in the instructions, do not try to disassemble the uninterruptible power supply yourself. Better contact service center, where you will receive qualified assistance with warranty and post-warranty service.

Uninterruptible power supply, UPS, UPS- as soon as they call this simple device capable of providing uninterrupted energy supply at sites of special importance. Such facilities primarily include nuclear energy enterprises, oil production and oil refining complexes and social infrastructure facilities.

No less important acquires uninterrupted power supply and at home: effective operation of local computer networks and personal computers directly depend on electricity. In the event of power outages or a complete shutdown, it will allow the computer to work for a few more tens of minutes, which is enough to save the necessary data and safe shutdown computer.

It is clear that UPS prices for one computer and UPS prices for large production will differ from each other. Therefore, choosing UPS/UPS, you need to know about certain types of such devices.

Classification and types of UPS

Based on various parameters, UPS It is customary to divide it into several types. If we use power as the determining factor UPS, then among them there are devices of high, medium and low power. This or that power class is used for various purposes, and it is clear that using a power of several hundred watts will not be entirely appropriate for a single computer at home.

Another classifying parameter defining types UPS, it is generally accepted to consider the operating principle of uninterruptible power supply systems themselves. In this regard, the following categories are distinguished: UPS as online (on-line), offline (off-line) and linear-interactive (line-interactive).

Offline uninterruptable power source During normal operation, it provides connection to the main power supply. In emergency mode, the power is switched to backup sources, in this case to batteries. Main advantage UPS The offline type remains its ease of execution and unpretentiousness in operation.

Linear interactive UPS In addition to the switching device, they include an incoming voltage stabilizer. That is uninterruptable power source this type not only provides autonomous power supply devices during a power outage, but also protects against low or high voltage without a general switch to emergency mode.

Online uninterruptable power source built on the principle of double voltage conversion. The AC voltage received at the input is transformed into DC using a rectifier, and then becomes AC again using an inverter. All this helps to establish a stable level of output voltage, and also dampens interference from the main supply network.

Uninterruptible power supply systems are currently becoming very popular. It doesn't matter where he lives modern man, - in a city apartment, in a country house, various Appliances, digital computer technology, life support systems.

Purpose and categories of UPS

The requirements for the quality of power supply for all these devices are increasing. External power quality electrical networks does not always satisfy the population. Sharp voltage drops occur, both in the direction of decreasing and increasing its value. This has a very adverse effect on the operation of household equipment, and sometimes leads to its failure. Protect yourself from such troubles installation of uninterruptible power supplies helps, from which devices that are most sensitive to such sudden changes are powered.

Depending on the circuit solutions that determine the main characteristics of uninterruptible power supplies, they can be divided into several categories. Each of them ensures uninterrupted operation of a certain group of consumers.

Backup UPS

They can only protect simple home appliances and desktop computers.

If the mains voltage is normal, consumers are connected directly to it. When the voltage in the network fluctuates, the equipment switches to power from the battery, which is integral part UPS. Noise and high-frequency impulses are partially suppressed, the voltage is maintained at a given level, and the battery is recharged. Stabilization of the mains voltage supplying equipment connected to its output is not carried out for uninterruptible power supplies of this category.

The need to switch to battery operation in each uninterruptible power supply model is determined differently. The limits of network operation are determined by the developer of this model. They are installed based on the conditions of normal functioning of the consumer equipment.

Battery operation will continue until the voltage in the network returns to normal. After this, the switch occurs in the opposite direction. The source battery must provide at least a five-minute reserve when operating from it. This is enough to save data on the computer and trouble-free shutdown of the consumer equipment.

The disadvantages of uninterruptible power supplies in this category include the following:

1. Lack of mains voltage stabilizer.
2. Long switching time (~20 ms).
3. Step form of output voltage.
4. Presence of high frequency interference.

Switch to offline mode power supply occurs at any slight deviation of the mains voltage parameters from the norm. This leads to rapid battery wear.

Linear interactive sources

Models in this category are equipped with network voltage stabilizers, which are made according to an autotransformer circuit. Switching of its windings, depending on the value of the input mains voltage, occurs stepwise according to the commands of the microprocessor built into the UPS circuit. Thus, it is possible to maintain a voltage at the output of the unit close to normal (220−230) V. Additionally, the circuit has a filter that protects the consumer from network interference.

Connecting the battery and disconnecting from the network occurs when the voltage parameters at the input of the unit go beyond the stabilization thresholds. The number of autotransformer terminals is not enough to maintain the rated voltage at the output. There are also tolerances on the shape of the input signal. In case of large distortions, a transition to the battery power supply mode of the consumer equipment is also carried out.

The process of switching to battery power is fairly smooth for most consumers and takes no more than 4 ms.

Thus, Comparing sources of this category with backup UPSs, you can notice their advantages:

1. Mains voltage stabilization has a stepwise nature.
2. The output voltage shape is close to a sinusoid.
3. Network interference filtering.
4. Saving battery life due to fewer starts.

Ferroresonant power supplies

At their core, they are linear active sources. A ferroresonant transformer serves as a mains voltage stabilizer. It can store magnetic field energy, which maintains voltage in secondary winding transformer at switching moments. The transition process lasts no more than (8−16) ms. This is acceptable for most consumers. The voltage form at its output is sinusoidal, protected from network interference. The source performs its functions based on commands from its own network analysis and control unit.

Linear uninterruptible devices

Double conversion UPSs fall into this category. They include an AC-to-DC converter (rectifier) ​​and a DC-to-AC converter (inverter). The output voltage of the inverter is used to power the equipment connected as a load. Rectifier voltage is used for recharging internal battery. It is included in the rectifier circuit and is constantly in active mode, which depends on the quality of the input AC voltage.

The positive qualities of a UPS in this category include:

1. Output voltage stability.
2. Possibility of replacing the battery without shutting down the UPS.

The disadvantages include:

1. Low coefficient useful action(efficiency).
2. Battery life is reduced due to constant operation.

Devices in this category are used to operate the equipment of large organizations whose servers store important data. They must be saved in case of any changes in the network and any disruptions in its operation.

Main characteristics

When purchasing a UPS, you must carefully understand the requirements for it. It is necessary to choose the model that best satisfies the “price - quality” criterion.

When choosing uninterruptible source power, much attention should be paid to comparing characteristics different models. These include the following:

• UPS power.
• battery life.
• switching time to battery operation and back.
• range of input voltage changes.
• limits for changing the network voltage frequency.

Power is calculated from the total load of the source. Its value should be at least one and a half times greater than the power of consumers. The optimal power of a unit installed in an apartment is considered to be 1000 VA (1000 volt-amperes).

The switching time directly depends on the size of the load connected to the this moment to the source output. The more current it consumes, the shorter the battery operating time. The capacity of the installed battery also determines the operating time.

Any UPS model has visual signaling elements. These can be light bulbs of different colors, LED indicators, which determine the state of the uninterruptible power supply at the current moment.

Constantly lit green indicators are a sign of normal operation of the unit. If the LED operates in pulse mode (its intermittent glow), then problems are possible or have already arisen. This is a warning signal that attracts attention.

A constant glow of the red indicator indicates an emergency situation. Its occurrence is accompanied by warnings sound signals in the form of intermittent beeps.

Operating rules

Correct operation of the equipment is the key to its long and reliable operation. The basic rules that must be followed when operating an uninterruptible power supply include:

• The need to constantly monitor the light indication and sound alarm of the unit.
• Connecting consumers that really require uninterruptible power.
• Grounding the UPS using a socket with three sockets for connecting the device plug.

If there is a power outage, you must turn off all equipment that is turned on at that moment. It is advisable to leave the UPS plugged in for possible battery recharging after the network fault is resolved. Operating the unit with a discharged battery results in quick exit it is out of order. The battery life is limited and is no more than 5 years.

Compliance with these simple but necessary rules will extend the life of all equipment that requires uninterrupted power supply, and most importantly, will allow you to save important information on hard drives computers, which could be irretrievably lost in the event of sudden malfunctions in electrical networks.

UPS stands for "uninterruptible power supply". Abbreviation in English - UPS (Uninterruptible Power Supply) , therefore the names UPS, YUPS, and oopsnik are also common.

The main function of an uninterruptible power supply is to ensure the supply of electricity to the equipment connected to it during outages in the main network. But, depending on the type of equipment, the parameters of such autonomous power supply may be required to be radically different. Accordingly, the UPS market offers different types devices that differ in a lot of parameters:

• principle of operation: offline, linear-interactive, online;
• type of automatic voltage regulation;
• quality of filtering network interference;
• capacity (number of ampere-hours, or in other words - how long the battery life will last);
• time to switch to batteries during a power outage;
• possibility of connecting additional external batteries;
• various additional functions (filtering sockets, sockets for telephone and network cable, LCD display, synchronization with PC), etc.

How to choose a UPS with such a variety of models ? How to understand how they differ? In this article we will look at the main types of uninterruptible power supplies, their differences, and what additional functions manufacturers equip UPS with. In the next one - how to choose a UPS depending on the features of your equipment, how to calculate it required power etc.

Three main types of UPS

Off-line (Back-UPS, backup, Standby) uninterruptible power supply

Example of a backup UPS: model .

The operating principle of this type of uninterruptible power supply is very simple:

As long as there is electricity in the network within the set values, the UPS supplies the connected devices with voltage directly from the network, while simultaneously recharging the battery. The power passing through the UPS is not regulated; pulses and noise are filtered at the simplest level, using passive filters. The signal shape corresponds to the network signal, i.e., a sinusoid.

As soon as the mains power is lost, the UPS switches to battery power. Inverter converting D.C. from the battery to AC output, this type of UPS has one of the simplest installed, so the waveform does not follow the correct sine wave. The maximum that manufacturers do is to bring it somewhat closer to a sinusoid, making it stepwise.

The UPS also switches to off-line autonomous power supply if the voltage level in the network falls below or rises above the threshold values, they can be different depending on the brand of uninterruptible power supply.

Switching time to batteries in various models ranges from 5 to 20 ms. This is relatively long, and for some equipment models such a long delay may adversely affect operation . The long-term operation of the relay is due to the fact that the device needs the phases of the mains and battery voltages to coincide when the autonomous power is turned on, and since they are not synchronized, this takes some time.

Scheme of operation of a backup uninterruptible power supply.

Pros of Standby UPS:

• inexpensive price,
• high efficiency,
• silent operation.

Flaws:

• long switchover to battery operation (from 5 to 20 ms);
• the output signal shape is not a sinusoid;
• filtering interference, noise and impulsesquite rough on the line;
• there is no voltage and frequency adjustment when operating from the network.

Line-interactive UPS

Example of a line-interactive UPS: model

Buyers choose this type of uninterruptible power supply most often, as it optimally combines functionality and price.

IN schematic diagram operation of line-interactive UPS includes AVR - module for automatic regulation of incoming network voltage. That is, unlike a backup UPS, it not only passes power through itself, but also stabilizes it, although not smoothly, but in steps.

When operating from the mains at normal voltage levels, the line-interactive uninterruptible power supply passes the incoming signal through passive interference and noise filters, while the battery is charged.

When the voltage in the network increases or decreases, the line-interactive UPS makes its stepwise adjustment. When the voltage reaches a certain threshold, the AVR lowers or lowers it by a fixed amount (or percentage). Several such threshold-steps can be specified in the AVR operating scheme; also, for working with a lower and higher level, a different number of adjustment steps can be assigned (for example, 2 for an increase, and 1 for a decrease).

If the mains voltage drops or rises to values ​​that lie outside the available input range of the uninterruptible power supply, the device switches to battery operation, just as in the case complete shutdown electricity. These minimums and maximums may vary depending on the load on the UPS. For example, if the UPS is 70% loaded and the voltmeter shows 160V in the network, the uninterruptible power supply switches to the batteries. And at 30% load and a voltage of 150V, it still makes adjustments using an AVR transformer.

Some linear-interactive models are no different in the shape of the output signal from backup-type uninterruptible power supplies: they have a stepped sine wave. Some manufacturers, especially with the growing demand for UPS for boilers, equip their uninterruptible power supply systems with inverters that produce the correct sine wave.

The switchover time to battery operation in a pure sine wave line-interactive UPS is faster than that of its standby counterparts. The reason is that in UPSs of this type, the voltage waveforms coincide (both from the network and from the battery, this is a sinusoid), which speeds up phase synchronization and, accordingly, the start of autonomous power supply.

Pros of line-interactive UPS:

• reasonable price,
• silent operation,
• automatic regulation of incoming voltage,
• in some models - pure sine wave at the output,
• switching time is less than in backup ones (on average 4-8 ms, in some models 2-4 ms).

Flaws:

• no frequency adjustment,
• insufficiently complete filtering of interference, noise and network impulses,
• voltage regulation is not smooth, but stepwise,
• The efficiency is lower than in an off-line uninterruptible power supply.

Double conversion UPS (on-line)

Double conversion UPS example: model .

This is the most expensive, but also the most best view UPS. It is optimally suited for expensive, capricious equipment, for which it is important not only constant pressure, but also frequency, as well as effective noise filtering, a pure sine wave signal and no delays when switching to battery operation.

In fact, such an uninterruptible power supply operates constantly, stabilizing, filtering the incoming signal, equalizing the frequency and shape of the output signal.

In mains mode, the incoming AC voltage is stabilized and converted to DC by the rectifier and distributed between the battery (for recharging if necessary) and the inverter. The inverter converts direct current into alternating current, producing an output signal in the form of a pure sine wave, correct frequency, correct voltage. Interference and noise are completely absent - they simply do not remain after double conversion.

This constant “inclusion” of the uninterruptible power supply into the network provides one of its significant advantages: Instant switching to battery operation. Actually, it’s hard to even call it “switching”, since power passes through the rectifier, battery (during charging) and inverter constantly. When the network voltage drops below threshold values ​​or there is a complete power outage, the inverter simply begins to take part of the energy from the battery, and not from the rectifier. It happens instantly.

Double conversion UPSs usually have another operating mode: bypass. This is a backup line that goes directly from the input to the output of the UPS, bypassing the rectifier, battery and inverter. It allows in critical moments for the UPS: overload (for example, with starting currents), failure of the inverter and others - to supply electricity directly to the connected devices, avoiding failure of the device elements.

Full time job The UPS has a certain disadvantage: increased heat generation, which requires effective cooling. Therefore, UPS online are most often equipped with fans, which makes their operation in residential areas not as comfortable as other types of silent uninterruptible power supplies.

Pros of online UPS:

• constant voltage stabilization,
• constant frequency stabilization,
• pure sine wave at the output,
• effective filtering of noise, impulses and interference,
• Instant switching to batteries.

Flaws:

• high price,
• increased noise level,
• the lowest efficiency among all types of UPS.

When choosing an uninterruptible power supply, you need to take into account that there are exceptions. Some line-interactive UPSs may cost more than online models from another manufacturer, the switching time to battery operation in a backup UPS may be no more, or even less, than in some line-interactive UPS, etc. Therefore, In any case, you need to read the specifications specific model.

Additional UPS functionality

In addition to determining the type of uninterruptible power supply you need, when choosing a UPS you should also pay attention to what functionality is included in it. UPS can have various additional functions and design features:

Synchronization with PC. This feature is not present in the cheapest models, but it is very convenient. Using a special software The UPS transmits data in real mode to the computer about the state of the power line and battery charge level. In addition to the purely informational component, there are also opportunities such as, for example, autonomous shutdown computer with data saving in all applications during a power outage.

Cold start. An uninterruptible power supply equipped with this function can be turned on when there is no power in the network. For example, the lights went out, you saved the documents, turned off the computer and UPS, but after some time there was an urgent need to copy the document to a flash drive. A UPS with cold start support can be turned on, even if there is still no power, and get the job done.

Previously, connectors for connecting devices in a UPS looked basically like this:

This IEC 320 standard connector is perfect for connecting various computer equipment. However, equipment with a regular power cord is the same WiFi router, you can’t connect it to it. For these purposes, you can use a surge protector with a similar connector, which is connected to the UPS, and then connect various equipment to it. But this is not always convenient.

Therefore, now many models have simply begun to be supplemented with Schuko-type sockets (in our country they are often called Euro sockets) so that the equipment can be turned on directly:

Sockets for filtering interference. A UPS may be equipped with an outlet or several for sensitive equipment that does not provide power support during a power outage but protects the connected equipment from utility power interference.

Sockets for telephone line, twisted pair. High-voltage pulses can be transmitted not only directly via an electric power cable, but also in the event of various accidents and breakdowns - both via a telephone cable and twisted pair cable. To protect telephone, network and computer equipment, some manufacturers provide special connectors (input/output) where you can connect a telephone or Internet line.

To be continued in the next article.

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