Using an uninterruptible power supply for multiple devices. Why do we need an UPS. What are the UPS

All types of uninterruptible power supplies are designed to perform a set of the following basic functions

• Protection against small and short interruptions in the mains power supply.
• Filtration of arising impulse disturbances and noise reduction.
• Standby power supply to the load during the set automation period.
• Short circuit and overload protection.

More complex models have a set of additional functions:

• Automatic deactivation of protected equipment in case of longer critical power outages, as well as restart when the required parameters are restored.
• Monitoring of the main parameters of the source functioning, tracking the level of its operability.
• Display of basic information about the operating UPS, as well as the parameters of the input voltage of the mains supply.
• Automatic alarm in case of abnormal calls.
• Presence of an installed timer for configurable switching off or switching on of the consumer at a set time.

Scope of application depending on the type of UPS

Backup uninterruptible power supply- the most common in this market segment. It is widely used in combination with home or office computers or low-power LAN workstations. It is also effective in terms of protecting household appliances that do not require a special quality of power supply, allows power outages for a certain time and the occurrence of deviations from the input voltage parameters on average + -5%.

Interactive uninterruptible power supply can also act as a backup. However, its main tasks are broader: in addition, it performs step voltage stabilization, which makes it possible to use it in combination with electrical devices with increased inrush currents. This is any device or other equipment that uses an electric motor, the start of which requires increased power for a short time. In particular, the operation of the refrigerator in conditions of deviation from the norm of voltage parameters can lead to its overload and failure. However, the efficiency of these protective devices is slightly lower than the same parameter for the backup ones.

Online or double conversion uninterruptible power supply Provides the most effective protection for file servers and more complex workstations. It is used in combination with the equipment of financial institutions, medical clinics and research scientific centers. That is, almost everywhere, where absolutely high-quality power supply is needed with the absence of even short-term voltage dips. But in everyday life, such devices are, firstly, ineffective (high cost at low loads), and they are also distinguished by increased noise and impressive heat release.

Application by current type

Online or double conversion uninterruptible power supply

Such uninterruptible power supplies are necessary to ensure the protection of electrical devices that are connected to a network with a voltage of 24 V, 48 V and 60 V.

AC UPS

Uninterruptible power supplies of this type are used in combination with the most important consumers who require a voltage of 220 or 380V.

Power application

UPSs are divided into three groups according to their capacity:

• - low-power;
• - medium power devices;
• - high power modular systems.

Low-power UPSs are widely used for domestic purposes, as well as for protection from possible critical situations of individual consumers in offices or small industries.

Medium power devices are responsible for high-quality and uninterrupted power supply to local networks, data centers and various telecommunication equipment, as well as remote communications.

The high power uninterruptible power supply has several advantages at once. It is able to provide protection for both an individual residential cottage and a large production process. In addition, such a UPS is a kind of modular system that allows you to synchronize several sources in one 19 "" rack to obtain higher power values ​​when solving specific technological problems.

Uninterruptible Power Supply, UPS, UPS- as soon as they do not call this simple device capable of providing uninterrupted power supply at facilities of particular importance. These facilities, first of all, include nuclear energy enterprises, oil production, oil refining complexes and social infrastructure facilities.

Equally important is uninterrupted power supply and at home: the efficient operation of local computer networks and personal computers directly depends on electricity. In the event of a power outage or when it is completely turned off, it will allow the computer to work for several tens of minutes, which is enough to save the necessary data and safely turn off the 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 these or those types of such devices.

UPS classification and types

Based on various parameters, UPS it is customary to divide into several types. If power is used as the determining factor UPS, then among them devices of high, medium and low power stand out. One or another power class is used for various purposes, and it is clear that using a power of several hundred watts will not be entirely advisable at home for one computer.

Another classifying parameter defining types UPS, it is considered to be the principle of operation of the uninterruptible power supply systems themselves. In this regard, such categories are distinguished. UPS as online (on-line), offline (off-line) and line-interactive (line-interactive).

Offline uninterrupted power supply unit during normal operation, it provides connection to the mains supply. In emergency mode, power is switched to backup sources, in this case to batteries. The main advantage UPS the offline type remains its simplicity of execution and unpretentiousness in work.

Line-interactive UPS in addition to the switching device, they include an input voltage stabilizer. That is uninterrupted power supply unit this type not only provides autonomous power supply devices during a power outage, but also protects against undervoltage or overvoltage without general switching to emergency mode.

Online uninterrupted power supply unit built on the principle of double voltage conversion. The AC voltage arriving at the input is transformed into a DC voltage with the help of a rectifier, and then, with the help of an inverter, it becomes AC again. All this contributes to the establishment of a stable level of the output voltage, and also suppresses the interference of the main supply network.

Greetings, my dear readers! In the current Russian realities, the owners of stationary computers are forced to solve the problems of uninterrupted power supply. You can solve this problem using uninterruptible power supplies. Their variety in the computer market allows you to choose a UPS for your specific needs. We will talk about what a UPS is and what types of uninterruptible power supplies are in this article.

A UPS, or uninterruptible power supply, is a device that acts as a "battery" for energy. In the event of a power outage, the UPS automatically switches the computer to power from the built-in batteries, allowing you to shut down gracefully and save all the documents you need.

Variety of uninterruptible power supplies

Uninterrupted is your guarantee of the safety of documents and computer components as a whole. Indeed, if the computer is turned off incorrectly, the hard drive, the motherboard, and the RAM can be damaged.

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

What kind 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 consider separately each type of UPS. This information will help you when choosing a UPS for your own needs.

Offline UPS

The principle of operation of this type of power supply is to automatically switch a computer or other connected device to power from the 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 external power to batteries and vice versa.

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

TO pluses such UPSs can be attributed to 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 surges. Also, this species has an increased wear of 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 what voltage (high or low) is at the input.

Pluses This type of UPS are small in size, low cost, automatic voltage regulation, economy.

But he also has minuses- this is a relatively long switching to storage batteries, the impossibility of adjusting the shape of the output voltage when operating from an external power supply, the change in the 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 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. Connected devices can be very different: ordinary workstations, file servers, network devices and other equipment that requires power.

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

Minuses are also available: high cost, complex design, electricity consumption "for oneself" in double conversion mode.

The first type of UPS is enough for home and office. But if there is a financial opportunity, then 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 a few basic features to look out for when buying. Let's consider them below.

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

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

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

These three characteristics are the most important. In addition to these, the UPS has many more characteristics. For example, when choosing an uninterruptible power supply 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.

Frequent problems

1. The most important problem that a UPS most often encounters is the failure of the battery. A dead battery can be determined by the fact that the uninterruptible power supply ceases to hold the load - when the electricity is turned off, 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 an uninterruptible power supply in. It says about a specific UPS, but the principle of replacement in all sources is practically the same.
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 jacks.

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

By purchasing a UPS (Uninterruptible Power Supply) for a personal computer or other household appliances, you "in one fell swoop" solve many problems at once. You no longer have to constantly save it while working with a document, fearing loss of data due to a sudden power outage. Also, now you can absolutely not worry about the fact that as a result of an incorrect shutdown, the power supply unit or, even worse, the hard drive will fail. If a "nuisance" happens, you will be able to complete important work with the program within a few minutes and quietly turn off your 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 efficiently. The service life of both the UPS itself and the consumers connected to it directly depends on the 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 correctly install and connect the device, what requirements must be observed, and how to avoid mistakes. Before you connect your computer to an uninterruptible power supply, there are a few very important conditions that must be met.

Never turn on the appliance immediately after bringing it from the street. . It is especially important to observe this rule when the temperature outside is below zero. "Uninterruptible" must properly settle in the room, otherwise there is a possibility that the condensate formed due to a sharp temperature drop will cause a breakdown. The UPS must be dry immediately before starting. If it is severe frost outside, then the waiting time before turning on should be at least four hours.

Choose the most suitable place to install the appliance . The case of the "uninterruptible power supply" should not be located where the sun's rays can fall on it. Also, there should be no heating devices nearby, and the room itself should have a normal level of humidity. Install the appliance so that nothing is blocking the ventilation openings (there must be free access to air for effective cooling).

Observe temperature control carefully . For most models of this type of equipment, the recommended operating temperature range is from 0 to +40 ° С (ideally, for stable operation of the device, the temperature should always be in the range from +20 to + 25 ° С).

Route wires carefully ... The mains connection cable and the wires connecting the UPS to the load must be located in such a way that there is no interference with the possibility of accidental bumping. The power cable must be connected to a grounded outlet as required by safety regulations.

Wait for the battery to charge well ... Immediately after the first switching on of the "uninterruptible power supply", it will not be possible to fully work with the load, the diagnostic system will give an error (in some cases, a message pops up that the battery is faulty and needs to be replaced). This is because the new batteries are not charged, which means they are not able to support the power supply of the 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 the scheduled one.

Some uninterruptible power supplies (UPS) require some software to be installed on your computer to work effectively. Included with the product should be accompanied by a disk, which can be easily installed by almost any ordinary PC user. Many modern UPSs have a self-diagnosis system that must be activated before the first start (after which they will check the correct connection, as well as the correct functioning of the internal working elements). In the event of any malfunction, for example, when the inputs "phase" and "neutral" are reversed or there is no ground, the device will beep or display an error code. To immediately determine what is the matter, carefully study the instructions before use, then all the signals will be clear to you, and you can quickly eliminate the error.

UPS connection and operation with load

Upon completion of the preparatory stage, you can start using the UPS by connecting the load to it. Let's give an example of a standard connection diagram for the efficient operation of computer equipment in a domestic environment: a UPS and a printer (or scanner) are connected to a surge protector, and a computer system unit and a monitor are connected to the "UPS" itself. In principle, if there is a printer connector on the UPS panel, you can connect one to it, but only on condition that it is an inkjet and its power consumption was originally included in the total load power when purchasing an uninterruptible power supply. Never, even try to connect a laser printer, as it is much more powerful than an inkjet printer, and during peak loads it can overload the UPS. Also, you cannot connect lighting devices and other household appliances that are not so urgently in 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 "uninterruptible power supply" should in no case exceed its capacity.

What are the big overloads fraught with? A large number of electricity consumers will certainly lead to an unnecessary load on the uninterruptible power supply, and there may not be enough power to power the computer. It happens that the device simply "dumps" the load, which causes an emergency shutdown of computer equipment and loss of data, and what is even worse - important working parts may break down (for a UPS it is a battery, for a PC - a hard drive or a power supply). Agree that additional repair costs will be an unpleasant surprise.

Correct observance of the permissible power loads is a guarantee that the uninterruptible power supply can effectively support the operation of computer equipment during the time specified by the manufacturer during power outages. You will have time to save important information to your hard drive or removable media and shut down gracefully.

It should be noted that it is not recommended to use the entire reserve of time to continue working at the computer. If it is possible to save data earlier and turn it off, do it. Thus, you can save battery capacity and reduce the load on the uninterruptible power supply. In general, experienced specialists advise to use an uninterruptible power supply together with a generator for long-term operation without a central power supply: in case of a power outage, the equipment will work from the UPS for several seconds, and then the load can be transferred to the generator without interrupting work.

How to extend the life of the UPS?

Since basically the "uninterruptible power supply" ensures the operation of the equipment connected to it for a period of 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 devices of the ON-LINE type, this period can be increased to 5, or even all 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 refilling with distilled water, as some people do, based on the experience of using 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 a few rules that you can follow to help extend battery life.

№ 1. Avoid situations where switching to battery power is unnecessary. For example, a small voltage surge occurs and the entire load is switched 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 indicators of the power grid, at which the equipment will function stably, you can avoid an increased load on the batteries. The adjustment is carried out either on the control panel or through the program installed on the computer.

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

№ 3. Completely exclude the possibility of mechanical impact on the device (shock, falls, etc.). The UPS must be installed in a location where it can be stable so that nothing will accidentally fall on it.

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

As for the efficiency of the UPS in general, it largely depends on you. If you have carried out all the preparatory work correctly, followed the recommendations for operating conditions and responded in a timely manner to signals from the diagnostic system, then you can be sure that the probability of breakdowns will be minimal. If, nevertheless, some problem occurs that cannot be eliminated using the methods described in the instructions, do not try to disassemble the uninterruptible power supply yourself. It is better to contact the service center, where you will be provided with qualified assistance in warranty and post-warranty service.

As civilization develops, it begins to consume more and more energy, in particular, electric - machine tools, factories, electric pumps, street lamps, lamps in apartments ... it to the sources of electricity, because now, in many cases, the loss of electricity is tantamount to the loss of the channel for delivering the information flow. This situation is most critical for a number of the most modern industries, in particular, where the main production tool is computer networks.

It has long been calculated that after a couple of months of work, the cost of information stored on a computer exceeds the cost of the PC itself. For a long time, information has become a kind of product - it is created, evaluated, sold, bought, accumulated, transformed ... and sometimes lost for a variety of reasons. Of course, up to half of information loss problems arise from software or hardware failures on computers. In all other cases, as a rule, problems are associated with poor-quality computer power supply.

Providing high-quality power supply to PC components is the key to the stable operation of any computer system. The fate of whole months of work sometimes depends on the shape and quality characteristics of the mains supply, on the successful choice of power components. Based on these considerations, the research methodology outlined below was developed, designed to further become the basis for testing the quality characteristics of uninterruptible power supplies.

1. GOST provisions
2. UPS classification (description, diagram)
   • Offline
   • Line-interactive
   • Online
   • Basic types by capacity
3. Physics
   • a. Types of power, calculation formulas:
     • Instant
     • Active
     • Reactive
     • Full
4. Testing:
   • Test purpose
   • General plan of the
   • Parameters to check
5. Equipment used in testing
6. Bibliography

Everything related to power grids in Russia is regulated by the provisions of GOST 13109-97 (adopted by the Interstate Council for Standardization, Metrology and Certification instead of GOST 13109-87). The regulations of this document fully comply with international standards IEC 861, IEC 1000-3-2, IEC 1000-3-3, IEC 1000-4-1 and publications IEC 1000-2-1, IEC 1000-2-2 in terms of electromagnetic compatibility levels in power supply systems and methods for measuring electromagnetic interference.

The standard indicators for power grids in Russia, established by GOST, are the following characteristics:

• supply voltage - 220 V ± 10%
• frequency - 50 ± 1 Hz
• harmonic distortion of the voltage waveform - less than 8% for a long time and 12% - for a short time

Typical power supply problems are also discussed in the document. Most often we have to deal with the following of them:

• Complete loss of voltage in the network (no voltage in the network for more than 40 seconds due to violations in the power supply lines)
• Subsidence (short-term decrease in the voltage in the network to less than 80% of the nominal value for more than 1 period (1/50 of a second) is a consequence of the inclusion of powerful loads, externally manifests itself as flickering of lighting lamps) and bursts (short-term increases in voltage in the network by more than 110% of the nominal for more than 1 period (1/50 of a second); appear when a large load is disconnected, externally appear as flickering of lighting lamps) voltages of different duration (typical for large cities)
• High-frequency noise - radio frequency interference of electromagnetic or other origin, the result of the operation of powerful high-frequency devices, communication devices
• Frequency deviation out of range
• High-voltage surges - short-term voltage pulses up to 6000V and duration up to 10 ms; appear during thunderstorms, as a result of static electricity, due to arcing of switches, they do not have external manifestations
• Frequency run-out - a change in frequency by 3 or more Hz from the nominal (50 Hz), appear when the power source is unstable, externally may not appear.

All these factors can lead to failure of rather "thin" electronics, and, as is often the case, to data loss. However, people have long learned to defend themselves: mains voltage filters, "damping" surges, diesel generators that provide electricity to systems in the event of a power outage on a "global scale", finally, uninterruptible power supplies - the main tool for protecting personal PCs, servers, mini-automatic telephone exchanges and others. Just about the last category of devices and will be discussed.
UPS classification

The UPS can be "divided" according to various criteria, in particular, by power (or application) and by the type of action (architecture / device). Both of these methods are closely related to each other. By capacity, UPSs are divided into

1. Uninterruptible Power Supplies low power(with full power 300, 450, 700, 1000, 1500 VA, up to 3000 VA - including on-line)
2. Small and medium power(with full power 3-5 kVA)
3. Medium power(with full power 5-10 kVA)
4. High power(with full power 10-1000 kVA)

Based on the principle of operation of devices, two types of classification of uninterruptible power supplies are currently used in the literature. According to the first type, UPSs are divided into two categories: on-line and off-line, which, in turn, are divided by reserve and line-interactive.

According to the second type, UPSs are divided into three categories: reserve (off-line or standby), line-interactive (line-interactive) and Double-conversion UPS (on-line).

We will use the second type of classification.

Let's first consider the difference between types of UPS. Sources of the reserve type are made according to the scheme with a switching device, which in normal operation provides connection of the load directly to the external power supply network, and in emergency mode - transfers it to power supply from storage batteries. The advantage of this type of UPS is its simplicity, the disadvantage is the non-zero switching time to battery power (about 4 ms).

Line Interactive UPS made according to the circuit with a switching device, supplemented by an input voltage stabilizer based on an autotransformer with switched windings. The main advantage of such devices is load protection against overvoltage or undervoltage without going into emergency mode. The disadvantage of such devices is also a non-zero (about 4 ms) switching time to batteries.

Double conversion UPS voltage differs in that in it the AC voltage entering the input is first converted by a rectifier into a DC, and then - with the help of an inverter - again into an AC. The battery is permanently connected to the output of the rectifier and the input of the inverter and supplies it in emergency mode. Thus, a sufficiently high stability of the output voltage is achieved, regardless of voltage fluctuations at the input. In addition, interference and disturbances that are abundant in the supply network are effectively suppressed.

In practice, this UPS class behaves like a linear load when connected to AC power. The advantage of this design is the zero switching time to battery power, the disadvantage is the decrease in efficiency due to losses during double voltage conversion.

All reference books on electrical engineering distinguish four types of power: instant, active, reactive and complete. Instant power is calculated as the product of the instantaneous voltage value and the instantaneous current value for an arbitrarily chosen moment in time, that is

Since in a circuit with resistance r u = ir, then

The period average power P of the circuit under consideration is equal to the constant component of the instantaneous power

The average AC power over the period is called active ... The unit of active power, volt-ampere, is called watt (W).

Accordingly, the resistance r is called active. Since U = Ir, then

Reactive power - a value characterizing the loads created in electrical devices by fluctuations in the energy of the electromagnetic field. For a sinusoidal current, it is equal to the product of the effective current and voltage by the sine of the phase angle between them.

Full power - total power consumed by the load (both active and reactive components are taken into account). Calculated as the product of the rms input current and voltage. The unit of measurement is VA (Volt-Ampere). For sinusoidal current is

Almost any electrical device has a label indicating either the total power of the device or the active power.
Testing

The main purpose of testing- demonstrate the behavior of the tested UPS in real conditions, give an idea of ​​additional characteristics that are not reflected in the general documentation for the device, in practice, determine the influence of various factors on the operation of the UPS and, possibly, help determine the choice of one or another uninterruptible power supply.

Despite the fact that there are currently a great many recommendations for choosing a UPS, during testing we expect, firstly, to consider a number of additional parameters that should be inquired before purchasing equipment, and secondly, if necessary, adjust the set of selected methods and parameters testing and develop a basis for future analysis of the entire power path of the systems.

The general plan for testing is as follows:

• Specifying the device class
• Indication of the manufacturer's declared characteristics
• Description of the scope of delivery (availability of a manual, additional cords, software)
• A brief description of the appearance of the UPS (functions located on the control panel and a list of connectors)
• Battery type (with indication of battery capacity, serviceable / non-serviceable, name, possibly - interchangeability, the ability to connect additional battery blocks)
• "Energy" component of the tests

During testing, it is planned to check the following parameters:

• The input voltage range at which the UPS operates on utility power without transferring to batteries. Larger input voltage range reduces UPS transfers to battery and extends battery life
• Time to switch to battery power. The shorter the transfer time, the lower the risk of failure of the load (device connected via the UPS). The duration and nature of the switching process largely determine the possibility of the normal continuation of the equipment operation. For a computer load, the permissible power interruption time is 20-40 ms.
• Oscillogram of switching to battery
• Switching time from battery to external power supply
• Oscillogram of switching from battery to external power supply
• Battery life. This parameter is solely determined by the capacity of the batteries installed in the UPS, which in turn increases with the increase in the maximum output power of the UPS. To provide autonomous power supply for two modern SOHO computers of a typical configuration for 15-20 minutes, the maximum output power of the UPS should be about 600-700 VA.
• Output voltage parameters for battery operation
• Pulse shape at the beginning of battery discharge
• Pulse shape at the end of battery discharge
• UPS output voltage range when input voltage changes. The narrower this range, the less the effect of changes in the input voltage on the supplied load.
• Output voltage stabilization
• Output voltage filtering (if any)
• UPS behavior during output overload
• UPS behavior in the event of a load failure
• Calculation of UPS efficiency. Defined as the ratio of the output power of the device to the power consumption from the power source
• Total Harmonic Distortion, which characterizes the degree to which a voltage or current waveform differs from a sinusoidal one
  • 0% - sinusoid
  • 3% - distortions are invisible to the eye
  • 5% - distortion is visible to the eye
  • up to 21% - trapezoidal or stepped waveform
  • 43% - the signal is rectangular

During testing, we will use not real workstations and servers, but equivalent loads, which have a stable consumption pattern and a power utilization factor close to 1. The following set is currently being considered as the main equipment that will be used during testing:

1. GOST 721-77 Power supply systems, networks, sources, converters and receivers of electrical energy. Rated voltages over 1000 V
2. GOST 19431-84 Energy and Electrification. Terms and Definitions
3. GOST 21128-83 Power supply systems, networks, sources, converters and receivers of electrical energy. Rated voltages up to 1000 V
4. GOST 30372-95 Electromagnetic compatibility of technical equipment. Terms and Definitions
5. Theoretical Electrical Engineering, ed. 9th, revised, M.-L., Energiya publishing house, 1965
6. Advertising materials of the company
7. Internet resource