Simple inverter

A transformer without a battery will make a working inverter for a car. The assembly process will proceed as follows:

1. disassembly of the uninterruptible power supply: removal of the battery, bite off the terminals, stripping the ends;
2. search for a connector for connecting to the network (if there is a connector, it should be removed, if not, the wires are bitten off the board, the ends are stripped);
3. the wires from the battery using a soldering iron must be connected to the wires from the connector located on the rear panel, the soldering points are not isolated;
4. the cigarette lighter socket is soldered to the device, observing the polarity and insulating the soldering points;
5. the internal speaker of the device is excluded (it is torn off with pliers or the board is removed);
6. assembling the case by adding standard sockets (for some UPSs, they are already included in the original design).

Read also: We will explain in detail how to connect an uninterruptible power supply to a computer

UPS for gas boiler

A computer UPS is also suitable for a gas boiler. Conversion process should be done like this:

1. removal of a faulty power supply;
2. creation of terminal clamps, taking into account the observance of polarity (it is better to make clamps of different colors to indicate plus and minus) by making 2 holes, fixing the terminal clamps and soldering to them the wires previously suitable for the internal power supply from the computer;
3. to prevent premature failure of the device due to overheating, it will be necessary to install fans with or without a housing connected in series (to start them, it is recommended to use an LED by soldering its leads to the winding of a small relay, and you will need to solder a wire from the incoming “+” battery to one of the relay contacts battery, and to the second - a free red wire from the fan, another free black wire is soldered to the minus of the battery).

12 volt source

Failed uninterruptible power supply can be adapted to a 12 volt source. This is done very simply. First, you will need to connect an outlet to the uninterruptible power cord. To do this, one end is initially cut off from it. After performing this procedure with the help of an uninterruptible you can charge your phone. By further simple transformations described above, it is possible to increase the power homemade device(see the part about the inverter).

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

A UPS, or uninterruptible power supply, is a device that acts as an energy "accumulator". 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 shut down correctly and save all the necessary documents.

Variety of uninterruptible power supplies

Uninterruptible is your guarantee of the safety of documents and computer components as a whole. After all, if the computer is turned off incorrectly, it can also HDD, and motherboard, and working memory.

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

What are UPS?

Uninterruptible power supplies are divided into three types:

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

Consider separately each of the types of uninterruptible devices. This information will help you choose a UPS for your needs.

Offline UPS

Principle of operation of this type power supply is automatic switching 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, and 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 inability to stabilize the input voltage, and therefore your computer will not be protected from sudden voltage drops. Also, this type has 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) at the input.

Pluses This type of UPS are small size, low cost, automatic voltage regulation, cost-effective.

But he also has minuses- this is a relatively long switching to batteries, the impossibility of adjusting the shape of the output voltage when working 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 the DC is converted to the 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 power-demanding equipment.

pros online UPS has essential: full control of input and output voltage, 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, power consumption "on oneself" in the double conversion mode.

For home and office, the first type of UPS is enough. But if there is a financial opportunity, then I would recommend you the last look. This is the most reliable type of protection for your computer equipment from low-quality voltage.

Main characteristics of the UPS

The UPS has several main characteristics that you should pay attention to 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 possible problems with a lack of power.

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

1. UPS type. I talked about the types of uninterruptible devices 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. Usually time battery life set in the range of 5-30 minutes. Please note that at maximum load on UPS time work 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 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.

Frequently occurring problems

1. The most common problem that occurs with the UPS most often is the failure of the battery. A dead battery can be identified by the fact that the uninterruptible power supply stops holding the load - when the electricity is turned off, the computer immediately turns off. Also, a damaged battery can manifest itself differently: 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 sockets.

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

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

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

• operating principle: offline, line-interactive, online;
• type automatic adjustment voltage;
• network interference filtering quality;
• capacity (the number of ampere-hours, or in other words - how long will it last for battery life);
• switching time to batteries during a power outage;
• the ability to connect additional external batteries;
• various additional functions (filtering sockets, sockets for telephone and network cable, LCD display, PC synchronization), 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 features manufacturers equip with UPS. In the next one - how to choose a UPS depending on the characteristics of your equipment, how to calculate its required power, etc.

Three main types of UPS

Off-line (Back-UPS, standby, standby) uninterruptible power supply

Redundant UPS Example: Model .

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

As long as there is power on the grid within the set values, the UPS supplies power to the connected devices directly from the grid, simultaneously recharging the battery. The power passing through the UPS is not regulated, the filtering of pulses and noise occurs at the simplest level, using passive filters. The waveform corresponds to the mains signal, i.e. sinusoid.

As soon as the mains power fails, the UPS switches to battery power. The inverter that converts the direct current from the battery into alternating current at the output is one of the simplest installed in this type of UPS, so the waveform does not correspond to the correct sinusoid. The maximum that manufacturers are doing is bringing it closer to a sinusoid, making it stepped.

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

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

Scheme of operation of the uninterruptible power supply reserve type.

Advantages of Standby UPS:

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

Flaws:

• long switching to battery operation (from 5 to 20 ms);
• the form of the output signal is not a sinusoid;
• filtering interference, noise and pulseson the line is quite rough;
• there is no voltage and frequency adjustment when working from the network.

Line Interactive UPS

Line Interactive UPS Example: Model

This type of uninterruptible power supply is most often chosen by buyers, as it optimally combines functionality and price.

AT circuit diagram operation of linear-interactive UPS included AVR - a module for automatic adjustment of the incoming mains voltage. That is, unlike a backup type UPS, it not only passes power through itself, but also stabilizes it, though not smoothly, but in steps.

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

When the voltage in the network rises or falls, 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). There can be several such threshold-steps in the AVR operation scheme, and a different number of correction steps can be assigned to work with a lowered and increased level (for example, 2 - for increasing, and 1 - for decreasing).

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

Some of the linear-interactive models do not differ in the form of the output signal from the uninterruptible backup type: they have a stepped sinusoid. Some manufacturers, especially with the growing demand for UPS for boilers, equip their uninterruptible power supplies with inverters that produce the correct sine wave.

Switchover time to battery operation in pure sine wave line-interactive UPSs is faster than that of its standby counterparts. The reason is that in UPSs of this type, the voltage curve shapes coincide (both from the mains and from the battery it is a sinusoid), which speeds up the phase synchronization and, accordingly, the launch of an autonomous power supply.

Advantages of line-interactive UPS:

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

Flaws:

• no frequency control
• insufficiently complete filtering of interference, noise and impulses of the network,
• 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, where not only constant voltage is important, 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 works 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, giving out a signal in the form of a pure sine wave, the correct frequency, the correct voltage. Interference and noise are completely absent - they simply do not remain after double conversion.

Such a constant "inclusion" of an uninterruptible power supply in the network gives one of its significant advantages: instant switch to battery operation. Actually, it's even difficult to call it "switching", since the power passes through the rectifier, the battery (during charging) and the inverter all the time. At the moment the voltage in the network drops below the threshold values ​​or a complete power outage, the inverter simply starts to take part of the energy from the battery, and not from the rectifier. It happens instantly.

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

The constant operation of the UPS has a certain disadvantage: increased heat dissipation, which requires efficient 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.

Advantages of online UPS:

• constant voltage stabilization,
• constant frequency stabilization,
• pure sine wave output
• effective filtering of noise, pulses and interference,
• instant switch 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 consider that there are exceptions. Some line-interactive UPSs may cost more than online models from another manufacturer, the transfer time to battery operation in a standby UPS may be no more, or even less than some line-interactive UPS, etc. Therefore, in In any case, please read the specs. specific model.

Additional UPS functionality

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

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

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

Previously, the connectors for connecting devices in an uninterruptible power supply looked basically like this:

This IEC 320 connector is great for connecting a variety of computer technology. However, equipment with a conventional power cord, the same wifi router, do not connect to it. For these purposes, you can use network filter with a similar connector that is connected to the UPS, and already include various equipment in it. But this is not always convenient.

Therefore, now many models have simply been supplemented with Schuko-type sockets (we often call them euro sockets), so that the equipment can be turned on directly:

Sockets for noise filtering. The UPS may be equipped with an outlet or multiple outlets for sensitive equipment that do not provide power during a power outage but protect connected equipment from mains interference.

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

Continued in the next article.

As civilization develops, it begins to consume more and more energy, in particular, electrical energy - machine tools, factories, electric pumps, street lights, lamps in apartments ... The advent of radio, televisions, telephones, computers gave mankind the opportunity to speed up the exchange of information, however, tied it to power sources, because now, in many cases, the loss of electricity is tantamount to the loss of a delivery channel information flow. This situation is most critical for a number of the most modern industries, in particular, where computer networks are the main production tool.

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 commodity - it is created, evaluated, sold, bought, accumulated, transformed ... and sometimes lost for a variety of reasons. Of course, up to half of the problems associated with the loss of information arise due to software or hardware failures in computers. In all other cases, as a rule, problems are associated with poor-quality power supply to the computer.

Ensuring high-quality power supply to PC components is a guarantee stable operation 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 following research methodology was developed, which is intended to become the basis for testing the qualitative characteristics of uninterruptible power supplies in the future.

1. GOST provisions
2. UPS classification (description, diagram)
   • Offline
   • Line Interactive
   • Online
   • Main types by capacity
3. Physics
   • a. Types of power, calculation formulas:
     • Instant
     • Active
     • Reactive
     • Complete
4. Testing:
   • Purpose of testing
   • General plan
   • Options to check
5. Equipment used in testing
6. Bibliography

Everything related to electrical networks in Russia is regulated by the provisions of GOST 13109-97 (adopted by the Interstate Council for Standardization, Metrology and Certification to replace GOST 13109-87). The standards of this document fully comply with the international standards IEC 861, IEC 1000-3-2, IEC 1000-3-3, IEC 1000-4-1 and IEC 1000-2-1, IEC 1000-2-2 publications 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
• voltage waveform distortion factor - less than 8% for a long time and 12% for a short time

specified in the document and typical problems power supply. 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 disturbances in the power supply lines)
• Sagging (a short-term decrease in the voltage in the network to a value of less than 80% of the nominal value for more than 1 period (1/50 second) is the result of turning on powerful loads, externally manifests itself as the flickering of lighting lamps) and surges (short-term voltage increases 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 turned off, outwardly manifest 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 up to 10 ms duration; appear during thunderstorms, as a result of static electricity, due to the sparking of switches, have no external manifestations
• Frequency run-out - a change in frequency by 3 or more Hz from the nominal (50 Hz), appear during unstable operation of the power source, may not appear outwardly.

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

UPSs can be “separated” according to various criteria, in particular, by power (or scope) and by type of operation (architecture / device). Both of these methods are closely related to each other. By power, UPSs are divided into

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

Based on the principle of operation of the 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: online and off-line, which in turn are divided into 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 start with the difference between UPS types. Backup Type Sources made according to the scheme with a switching device, which in normal operation provides connection of the load directly to the external supply network, and in emergency - transfers it to battery power. The advantage of this type of UPS can be considered 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 the protection of the load from 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 alternating voltage entering the input is first converted by the rectifier to direct, and then - using the inverter - again to alternating. Accumulator battery is permanently connected to the rectifier output and the inverter input and feeds it in emergency mode. Thus, a sufficiently high stability of the output voltage is achieved, regardless of fluctuations in the input voltage. In addition, interference and disturbances, which abound in the supply network, are effectively suppressed.

In practice, a UPS of this class when connected to a network alternating current behave like a linear load. The advantage of this design can be considered a zero switching time to battery power, a minus is a decrease in efficiency due to losses during a double voltage conversion.

In all reference books on electrical engineering, four types of power are distinguished: 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 point in time, that is

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

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

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

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

Reactive power - a value that characterizes 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 and 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 values ​​of the input current and voltage. The unit of measure is VA (volt-ampere). For a sinusoidal current is

Almost every electrical appliance 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 features, which are not reflected in the general documentation for devices, in practice to determine the influence of various factors on the operation of the UPS and, possibly, to 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 options, which you should ask before buying equipment, and secondly, if necessary, adjust the set of selected testing methods and parameters and develop a basis for future analysis of the entire power path of systems.

The general plan for testing is as follows:

• Specifying a device class
• Indication of the characteristics declared by the manufacturer
• Description of the scope of delivery (presence of manual, additional cords, software)
• Brief description of the appearance of the UPS (functions placed on the control panel and the list of connectors)
• Type of batteries (indicating the capacity of the batteries, serviced / maintenance-free, name, possibly interchangeability, the ability to connect additional battery packs)
• "Energy" component of tests

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

• The input voltage range at which the UPS operates on mains without switching to batteries. Larger input voltage range reduces the number of UPS transfers to battery and extends battery life
• Switchover time 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 operation of the equipment. For a computer load, the allowable power interruption time is 20-40 ms.
• Switch to battery waveform
• Switchover time from battery to external power
• Oscillogram of switching from battery to external power
• Offline time. This parameter is determined solely by the capacity of the batteries installed in the UPS, which in turn increases with the maximum output power of the UPS. To provide self-powered 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 settings for battery operation
• The shape of the pulse at the beginning of the discharge of the battery
• 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 input voltage changes on the supplied load.
• Output voltage stabilization
• Output voltage filtering (if any)
• UPS Behavior in Output Overload
• UPS Behavior During Load Loss
• UPS efficiency calculation. Defined as the ratio of the output power of the device to the power consumption from the power supply
• Nonlinear distortion coefficient, which characterizes the degree of difference between the voltage or current waveform from a sinusoidal
  • 0% - sinusoid
  • 3% - distortion is not noticeable to the eye
  • 5% - distortion visible to the eye
  • up to 21% - trapezoidal or stepped waveform
  • 43% - the signal is rectangular

When testing, we will not use real workstations and servers, but equivalent loads that have a stable consumption pattern and a power utilization factor close to 1. The following set is currently 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 Compatibility technical means electromagnetic. Terms and Definitions
5. Theoretical Electrical Engineering, ed. 9th, corrected, M.-L., Energia publishing house, 1965
6. Company promotional materials
7. Internet resource