Uninterruptible Power Supplies: types and characteristics

an uninterruptible power supply device

The main task of an uninterruptible power supply (UPS or UPS) - to provide power equipment at the time of power failure in the network.

Secondary features, depending on the device type may be protection against surges and changes the input voltage, the mains frequency changes and network interference.

The device includes:

• an electronic control unit,
• one or more batteries,
• inverter,
• output means of the graphic information,
• electric filters.

Control block (Logic part). Monitors in real time the state of the mains power supply and load status.

Accumulator battery. It serves to store electric power and supply an electric current in standalone mode UPS.

Inverter. Converts the battery DC current (12) in alternating predetermined voltage (220 V).

graphic information output means. Data on the UPS status in real time are displayed on the LED, or displayed on the LCD.

Electric filters. All units are equipped with backup power equipment, surge protection devices and network interference.

• Filters surge. It is a chain of the fuse and a varistor connected in parallel (whose resistance sharply decreases at a certain tension). It increases sharply at a voltage exceeding the varistor network discovery threshold current in the input circuit, causing the fuse to blow and disconnect the appliance from the mains
• Filters from network interference. It consists of passive radio elements (resistors, inductors, capacitors) and designed to filter noise present in the electrical network.

Hours device in standalone mode depends on the electric capacity of batteries and the load current consumption. It may be from one minute to one hour of continuous operation (or a few hours).

Types and Characteristics of uninterruptible power supplies

constructing circuits UPS Topology

Modern emergency backup power supply devices operate on three basic schemes. Each scheme has its own distinctive features. They differ from the protection efficiency of various abnormal conditions, and cost features work in standalone mode.

Standby (Off-Line) scheme - the load is connected to the mains via passive filters that exclude the network interference and power surges. In the transition (the disappearance of the external power supply) in standalone mode load circuit connected to the inverter fast relay (switching time is from 4 to 12 ms).

Advantages:

• High efficiency coefficient circuit (99%, powered by the network).
• The low cost of the device.

Disadvantages:

• Large switching time when you go offline and back to normal mode.
• No protection against lowering or raising the voltage.
• inexpensive inverter device does not provide a sinusoidal signal at the device output offline.

Line-interactive scheme (Line-Interactive) - based on the same principle of operation as the backup. A distinctive feature is the presence of auto-transformer compensates for the change in voltage.

Similarly scheme and operate at higher voltage, by reducing the number of windings included.

Advantages:

• To continue the work of the network in the event of abnormal conditions associated with a decrease or an increase in voltage.
• The reduced time of switching from mains to inverter, by synchronizing voltages.

Disadvantages:

• The inverter output differs from the sinusoidal shape.
• No function of frequency control in AC mode.
• Loss on autotransformer cause lower efficiency in comparison with a backup scheme.

The double conversion scheme (online) - alternating current supplied to the input of the power supply is filtered and converted to DC by the diode bridge. The rectified current provides a continuous charge of the battery and power inverter which outputs an alternating voltage of predetermined magnitude and frequency.

Advantages:

• No delay time required for switching from the regular off-line.
• Monitoring and control (if necessary) the frequency at the output device.
• Protect load equipment from any changes in the electrical parameters of the network and network interference.

Disadvantages:

• The need for forced cooling of the inverter in all operating modes.
• Efficiency online-low circuit (80 to 96.5%, except for high capacity models with intelligent modes - their efficiency can reach 99%).
• The high cost compared to other schemes uninterruptible power supply devices.

Maximum power output

maximum (Full) UPS power determines the maximum load power, which may be connected to this unit.

total power consists of two values ​​(maximum and reactive), measured in volt-amperes (A × B, V × A).

active power is determined by the amount of resistive load elements, i.e. the amount of electric energy conversion into thermal or other energy. The unit of this power is the watt (W, W).

reactive power depends on the presence of the load circuit element possessing inductance or capacitance (capacitors, inductors), it is measured in volt-amperes reactive value (var, var).

When choosing a power supply for a load having a similar engine, consider the starting currents, to avoid damage and false alarm protection.

The standard UPS computer, do not plug laser printers.

Working hours

Uninterruptible power supplies are designed to operate in two modes, the normal (from the network) and autonomous (battery). When operating on line voltage, load capacity does not exceed the capacity of UPS, it operates indefinitely.

While working in standalone mode determined by the capacity of the battery, UPS efficiency action and electrical power consumed by the load.

• E - Battery capacity (battery)
• U - Battery voltage
• W - The electric power required by the load
• ή - Efficiency
• T - time work

power connectors

Rosette with a reserve. Is a plug type CEE 7 (earthing-pin) connected to the UPS via the inverter output voltage that ensures that the disappearance of the network equipment. It is used to connect peripheral equipment of a personal computer, or the connection of the PC (in the absence of special computer connectors).

Outlet without reserve. Secondary equipment, for which continued operation after the power supply is not important (printers, fax machines, speakers, etc.) to the UPS is connected via outlet 7 CEE, fed from the mains through electric filters or separating transformer. When you unplug the power supply voltage to these outlets are not available.

Computer C13 / C14 with a reserve. Special connector for computer equipment.

special adapters are used to connect devices with CEE 7 plug.

Computer C13 / C14 without reserve. Connector for connected equipment, non-critical to the disappearance of the power supply and provides filtering of interference, and overvoltage protection.

Terminal blocks with a reserve. Used to connect to the UPS, without the use of connectors, equipment that does not allow a break in the power supply. Used in medium and high power applications (from a few kilowatts).

Terminal Blocks without reserve. Are used to connect the connecting wires of equipment that does not require a backup power source. The terminals are connected to the mains via an isolating transformer, electric filters or directly.

The form of the output signal

sinusoid. Mains voltage is a sinusoidal signal that varies in time with the frequency of 50 Hz. All equipment is designed to operate on the network, powered sinusoidal voltage.

Much analog equipment (with transformer UPS) may not work correctly with the form of power supply other than the sine wave.

Such sinusoidal. To reduce the device manufacturer sets the inverter having the output voltage is not pure sine wave and an approximate square wave or a sinusoid.

Voltage other than the sine wave, is allowed feeding apparatus with pulsed blocks or in equipment with AC conversion into direct current.

Function and protection

voltage Regulation. Function the user changes the output voltage is only UPS constructed based on the double conversion scheme.

The user through the device control panel can set the voltage at the output of block (one for both modes). The inverter device is capable of changing the voltage conversion over a wide range (from 200 to 250 volts).

cold start. This function starts the uninterruptible power supply without mains voltage.

Connecting an external battery. UPS medium and large capacity, have the ability to connect additional (external) batteries. In this battery life increases proportionally additional capacity batteries.

Batteries can be connected one by one, to the special terminal devices and a special block intended for this purpose through the slot.

Hot battery replacement. Function for the possibility of replacing the battery without disconnecting from the network and (or) load. Provided by the internal bypass devices or external batteries, used in devices that supply sophisticated electronic equipment that does not allow the temporary shutdown.

Additional compartments for batteries. Battery cabinets and blocks are multiple batteries in an enclosure.

bypass. This function connects the uninterruptible power supply input to its output. That is, the load equipment is connected directly to the network through a filter or isolation transformer. Bypass function is implemented in power supplies with double conversion.

The UPS units are two types of bypass:

• Manual. Switching to this mode by the user, if necessary, repair or replace the battery, and if necessary, connect the equipment to the network directly.
• Auto. It is used when starting the equipment with large inrush currents, UPS failure or overload, and when a fault or deep discharge batteries.

Server (rack-mount) installation. Powerful power supply for installation in special rooms (server) - intended for installation in special racks (racks) or cabinets. This type of installation will streamline the equipment, save space and ease of installation.

All racks have a series of standard sizes, the most common of which - the 19-inch.

The height of the rack-mounted objects should always be a multiple integer units (to match the mounting holes).

Sound alarm. Most uninterruptible power supplies are equipped with built-in speakers, beep if necessary to draw attention of the user, or in an emergency.

Such signals occur during low battery or power failure, the transition to the battery operation mode - this intermittent sound signal with a frequency of 1 kHz.

Display. Modern devices, ensuring uninterrupted power to output information are equipped with liquid crystal displays. The display shows the status of UPS and batteries at a time, change the parameters of the device, via the user menu.

management interfaces

RS-232 (COM-port). To connect the UPS to a PC or server use a serial interface. With its help program is being implemented safely shut down your computer at a critical level - setting power options, and transfer of information on power supply status.

USB (Universal Serial Bus). The same functions performed by the RS 232 serial interface.

LAN. Network cable allows you to connect the UPS to the Ethernet network, with the help of which the user can obtain information on work equipment, electrical parameters, change settings, UPS, being at an arbitrarily large distance From him.

SmartSlot. This option extends the functionality of the UPS by connecting it to other devices.

Protection

Short circuit. If a short-circuit resistance of the electrical circuit sharply decreases (approaches zero). The current increases dramatically, and the voltage is reduced. This process is accompanied by the release of a large amount of heat that can damage the UPS and the load equipment.

overload. When the load power exceeds the control unit issues a command to load shedding output and alarm messages.

transient protection. In the event of transient electrical networks having high voltage pulses. Could lead to equipment damage. To prevent damage to the UPS and load limiters are used varistor.

From RF interference. Present in the electrical network of high-voltage component can cause damage or malfunction of equipment. To suppress unwanted interference apply special filters, Suppressors (representing the high-frequency capacitor and inductor).

Data line protection. Apart from the power circuit, the UPS can protect WLAN, antenna cable or telephone line.

• Antenna cable. Because of atmospheric electrical charge in antenna feeder farms can appear high voltage pulses. To protect the host equipment use special uninterruptible power supply. On such devices the housing block there are two connector. One comes from the antenna, the second - is attached to the receiver. To protect the high-frequency signal from the high-frequency bursts used a special filter.
• The local network. two RJ-45 connectors are located on the fixture. When connecting to the input and output LAN UPS filters installed inside protect the connected devices (modems, routers, network adapters, etc.) By high bursts.
• Telephone line. RJ-11 type connectors are used to connect to an uninterruptible power source telephone lines. UPS smoothes voltage peaks in the telephone network when they occur and provides protection of connected devices (telephone, fax, modem, etc.).

Connector emergency stop. For emergency, remote disconnect from the network in case of emergency function is used Emergency Power Off EPO.

The user can stop the supply of energy by opening remotely installed, contacts at the entrance to the emergency shutdown (EPO-port) UPS - such function is implemented in the computer rooms and premises ASU TP.

Advantages and disadvantages

Benefits:

• Protection of equipment against power failure.
• Protection of equipment against abnormal operating modes of the power supply (spikes, voltage rise and voltage, frequency variation).
• Protection of communication lines (LAN and telephone networks, antenna and feeder lines).
• Control of electrical parameters.

Disadvantages :

• High price.
• Additional energy cost (low efficiency).
• The need for preventive maintenance and repair.

How to choose the Uninterruptible Power Supply

Proper and trouble-free functioning of electronic equipment depends on the quality of supply, and hence on the rationality UPS selection. Selection of an uninterruptible power supply is carried out according to several criteria:

Compliance with the UPS power capacity connected devices. Maximum power uninterruptible power supply should not be less than the maximum power the connected loads (UPS to create a reserve power, load power exceeds 20-30%).

load power is calculated by adding up the maximum power of all the attached equipment.

load requirements to the form of the UPS output signal. When choosing it is necessary to consider the form of the output voltage (sine wave, square wave or sine wave approximated). Much equipment (analog blocks) may malfunction or be damaged when applying them on the supply voltage is not appropriate shape.

Requirements for the switching time on the battery. Many types of equipment do not allow short-term (in the battery switching) power interruption. The guide to the technical operation of the equipment usually describes the requirements for the characteristics of the supply voltage.

In the selection start from the fact that the maximum switching time from devices constructed according to the backup circuit, and the smallest (zero) in the double conversion schemes.

Economic expediency. Assess the need for installation. Taking into account the risk factors (such as frequently occur in the network abnormal modes, the mains filter does not provide overvoltage protection equipment) and the criticality of the suspension of operation of the equipment with the disappearance electricity.

Hours offline. The duration of battery life depends on the capacity of the battery, amount of battery, device efficiency and power connected loads.

If necessary, long battery life is recommended to use a power device configuration long time (non- own batteries) and a series connected batteries, the capacity necessary for the required runtime equipment.

Type of shell. Depending on the intended source location is selected rack or floor of the housing. For server, ACS cabinets and similar equipment optimally suited Rack. For home and office computers, and for a single UPS location, floor type housing will satisfy mounting conditions.

Exploitation

When the UPS is operating, consider the requirements for the placement of each model (temperature, ambient dust, vibration, etc.).

Do not operate the UPS modes, which are not provided for him by the manufacturer.

It must be verified integrity of insulation of wires connecting apparatus. If any, should be run self-diagnostics block. By visual inspection, make sure that there is no swelling and battery sag.

If there is damage to the battery or fast discharge (subject to the nominal load) it needs to be replaced.

In operation, the device is prohibited to connect and disconnect the mains wires to it, close the terminal.

Guarantee

At the time of sale the seller is obliged to fill in and assure corporate warranty card to the device.

If a malfunction occurs in the UPS within the warranty period, the customer is required to apply for the repair of the nearest to it manufacturer service center. List of Service Centers are listed on the manufacturer's website.

If you can not repair, the owner shall be issued an act of non-repairable. When dealing with this act in the place of purchase of the goods the consumer has the right to replace the faulty UPS on the same (new). Or (in the absence of such) to return the amount paid.

The user when accessing the service center must submit the completed warranty card. The warranty period begins on the date of sale device.

Note that some manufacturers set a maximum guarantee period from the date of production of goods (30 months).

Specialized devices that require installation (pre-commissioning) should be served by special service centers of the manufacturer. The service is paid and is not included in the manufacturer's warranty.

In the case of self-installation of the owner and the subsequent failure of the device, it is not covered under the warranty.

malfunctions

When an emergency occurs, the device will beep and display the error code (lit LED), the user needs to compare it to the error code table (supplied with the device), and to determine damage.

• A blown fuse in the input circuit. To resolve this problem, check the UPS for short circuit and replace the fuse.
• Damage to the varistor. In the breakdown of the varistor due to overvoltage, it is necessary to make a replacement, replace a blown fuse in the input circuit. Enter the unit into operation.
• Overload trip. It wants to reduce the power of devices connected to the UPS.
• Trip protection against short circuits. It is necessary to detect and remove the short circuit in the output circuit or load the UPS.
• Battery fault. You need to replace the battery.

With other faults, it is advisable to contact a qualified service center.

Manufacturers of uninterruptible power supplies

3Cott

The range of companies - about two hundred products, including three commercial UPS line. The basic concept of the brand - the budget costs. On average, the prices of goods on the 10 - 30% lower than competitors.

Segment power supplies and accessories to them presented three dozen units. Three leading brands of the brand on the Russian market - SE, SOHO and Micropower.

UPS brand 3Cott designed to protect power PCs and workstations from electromagnetic and radio frequency interference, power surges, high emissions and other problems. The equipment line-interactive type is designed for a different capacity.

In addition to the power supply in the range of companies represented voltage regulators and batteries. Production has the certificate of conformity of the EAC and served under warranty in a reception center service center The Staten, on average, for two years from the date of sale.

APC

Products brand APC (Schneider Electric) are positioned as a versatile solution that can be implemented worldwide. UPS companies are designed for various systems with voltages of 100 to 240 and can be used in a home office, and industrial processes (including high complexity).

The main product groups - Back-UPS and Back-UPS Pro. In addition to these products the company sells software and devices for administration of industrial uninterruptible power supply.

One of the specialties of the brand - the sea and ship mobile systems that are resistant to high vibration and comply with international regulations.

The company develops solutions to protect against power interruptions of telecommunications networks such as FTTH and wireless networks, landline subscriber access. Warranty products Schneider Electric is carried out by a unique registration number on the label on the casing with a bar code.

Crown

The range of companies represented CROWN UPS for homes, offices, industrial equipment. Also, the manufacturer implements the voltage regulators and specialized models.

UPS for home office equipment represented by a series of "Home & Office" (500-1200 VA). Products for networks and servers - single phase sources (1-10 KW), which can be used to protect telecommunications with high quality demands power.

Industrial UPS (10-600 kVA) allow to solve any production problems power protection.

In addition to the power supply and voltage stabilizers company sells inverters, batteries and accessories.

The warranty period for the product is 12 months from the date of sale or up to 15 months from the date of manufacture, which can identify the serial number on the product package. Service takes place upon presentation of a receipt or bill of lading in Authorized Service Centers.

CyberPower

In the line of CyberPower brand features products for residential, industrial and telecommunications office systems. Company feature - a strong science base.

Research conducted at its headquarters in the US and Europe, helped CyberPower Systems to implement more than 50 patents and provide qualified service and technical support to local markets.

The company is the budget of the UPS to protect the power supply in the country, at home and in the office. Range power emergency power systems ranging from 600VA to 7500 VA, which will use them for household appliances and industrial loads.

Warranty service will be provided within 12 months from the date of sale.

Delta

UPS company's range of Delta Electronics is available in four model line - Amplon, Agilon, Modulon and Ultron. brand products marketed as maximally economical and compact (with exceptional stability and a high efficiency parameters).

Agilon family of products with a power range up to 1.5 kVA is designed to protect home PCs and peripherals. Single-phase UPS brand Amplon (1 kVA) are used to protect server and network equipment.

Three-phase Ultron (ranging from 10 kVA) - online UPS to protect data centers and industrial equipment. Modular UPS Modulon (20 kVA) are used in complex industrial processes, with the need to backup or expansion within the same column (without the use of additional equipment).

The service is provided in Delta service centers or partners of the company under the terms of the warranty policy for each specific product group.

Eaton

The range of Eaton - about two dozen brands of UPS Powerware, which can be found in offices around the world. The basic concept of the brand - customer orientation.

The model number of the UPS presented with a variety of power range (from 500 VA to 275 KW) and technical capabilities - to protect your home office equipment, and telecommunications networks and industrial processes.

Eaton Warranty service is carried out through a network of authorized service centers.

The warranty period depends on the type of product:

• 12 months for Eaton EX RT devices or Eaton MX / MX Frame
• up to 36 months for the Eaton Ellipse PRO-type systems and industrial UPS.

Emerson

Among the range of Emerson Network Power (NYSE: EMR) - a wide range of UPS for the protection of information and communication technology systems.

The portfolio of hardware and software solutions helps the brand to implement complex technological tasks Administration consumption and distribution of energy in complex production processes, creating a power system with high efficiency and the level of availability.

After-sales service maintenance is carried out by authorized service centers Emerson Network Power, subject to the warranty policy of the company.

FSP

The model number of the company is represented by more than eighty FSP UPS for home, office and industrial use.

FSP company's products are sold in three major segments:

• double conversion device,
• line-interactive units,
• UPS backup.

Overlapped range of power On-line UPS - from 1K to 210K. Model SOHO and SMB (line-interactive) are designed for office and home use, and are focused on devices with power from 400VA to 2K. Redundant UPS (from 400VA to 800VA, off-line) used at home or in a small office.

Product quality in line with international standards ISO 9001 and 14001. Own Research Center head office in Taiwan has been certified by CTDP systems, UL, TUV, CSA, NEMKO. FSP also cooperates with the test labs OBL and LGA in Germany.

UPS FSP warranty service by a network of service centers RSS (www.rss.ru). The warranty on the line-interactive, online and off-line UPS - 2 years from the date of production.

Huawei

The range of Huawei presents the UPS with different architectures and power range. brand models are suitable for home, office and industrial use. Warranty service takes place in an authorized service center. More information - on the company's website.

INELT

The range of companies INELT - UPS with different power range, to protect the home, office, and industrial equipment.

The line includes specialized products on-line UPS, with redundancy (6 to 600 KW), a series of LT (Powerful device for use with larger capacity batteries) and a modular system for protecting data center (INELT Monolith XM 20-520 kVA).

maintenance products "Intellidzhent Power" is carried out in a network of service centers, the warranty on the brand policy. Dates are determined by product serial number and are from 2 years after the sale of up to 2 years old and 25 weeks from the date of issue.

Ippon

the company's products are designed to protect electrical equipment in the home, office, industrial environments and adapted to Russian conditions.

The range of the brand is a line-interactive, off-line and on-line UPS models and accessories for the installation and administration of uninterruptible power supplies.

Service under the guarantee shall be made within 2 years from the date of sale or 2 years and 6 months from date of manufacture. A full list of authorized service centers "Network Computer Clinic» (Ippon partner) published on the site.

Powercom

POWERCOM Taiwanese company offers a wide range of solutions to protect power grids from backup "Home" to the UPS equipment with double conversion for large server and telecommunication systems.

In addition to the uninterruptible power supply company sells hardware and software to administer operating systems.

The company's products meets the ISO9001 and ISO14001, and standards EAC customs union.

The company's products have a wide functionality and adapted to the needs of Russian customers.

Warranty service will be provided for 2 years after the sale, an authorized service center.

Powerman

Lineup Powerman company is a line-interactive and on-line UPS with power from 600VA to 3000VA. A wide range of power and diverse architecture design solutions will allow the use of the UPS brand for home and corporate office, and for complex telecommunications systems and servers.

In Russia, the service provides a "TD Taipei" (St. Petersburg) and a network of regional centers-partners in accordance with the warranty policy of the company within 24 months from the date of sale.

Riello

Italian brand Riello UPS manufactures a wide power range (from 400 to 6400 KW, VA) and are widely used in almost all fields. The company's products are certified by the Ministry of Communications and is recommended for use in industrial and critical public facilities.

Riello UPS service guarantee 2 years from the date of receipt of the product by the consumer, in accordance with the company policy.