In conditions of unstable power supply, it often makes sense to insure yourself and protect yourself from unpleasant surprises that centralized power grids can present.

For example, you can often observe how the voltage in the network drops or jumps. This can most clearly be seen by paying attention to how an ordinary incandescent lamp glows - if it flickers or burns at full intensity, it means that there is a problem in your electrical network. Insufficient voltage levels or voltage fluctuations can cause malfunctions of sensitive equipment, loss of computer data, and other unpleasant consequences.

Sudden increases in voltage are also possible, most often caused by short circuits or lightning striking wires or a substation. Despite the measures taken to protect against lightning, such cases occur from time to time and, in addition to malfunctions, can lead to equipment failure.

In addition to the listed network disruptions, a complete loss of voltage is also possible - short-term or quite long. As a result, production is paralyzed and they stop working. various systems- communications, security, life support and others.

Therefore, in some cases it is necessary to take additional measures and install equipment that will minimize Negative consequences failures of the centralized power grid.

There are two types of such systems - uninterruptible power supply systems and guaranteed power supply systems. Below we will look at how they differ.

Differences between uninterruptible and guaranteed power supply systems

An uninterruptible power supply system most often implies the presence of uninterruptible power supplies (UPS), which, if necessary, switch the equipment powered by them to battery operation. During normal mains operation, the UPS batteries are charged. UPSs are also equipped with surge protectors that help cut off high-frequency interference in the electrical network, voltage surges, etc.

This measure is effective if your network experiences short-term outages or voltage surges - UPSs cope with such troubles quite effectively. However, in order to maintain the operation of equipment or office equipment during a long outage, the resources of uninterruptible power supply systems are not enough. All they can do in an emergency is give users a few minutes to turn off office equipment normally and save the necessary data.

To withstand prolonged power outages, guaranteed power supply systems, or SPS for short, are required. In addition to uninterruptible power supplies, such a safe system requires the presence of a diesel generator set (abbreviated as DGS), which acts as an emergency power supply unit during a long-term outage of the central power grid, and necessary equipment control and management, which allows the UPS and diesel generator set to interact as a whole.

Design and uninterruptible power supply installation are justified if there are frequent power outages, and there are consumers at your site for whom the uninterrupted and high quality of power supply is considered critical.

Under such conditions, losses from failures in the power grid can be so significant that they will many times exceed the cost of purchasing and installing special equipment; you should also be concerned about installing such a connection scheme at strategic sites or in cases where a power outage could result in human casualties.

The purpose of creating the SGE and the requirements for it

So, in order to create a guaranteed power supply system at any facility, everything is clear - such a system must guarantee a stable, high-quality power supply for responsible energy consumers in the event of incorrect operation of centralized power grids. The result of creating such a system at the facility is to ensure normal operation of the equipment during emergency operation of the central power supply.

When equipping a facility with guaranteed power supply systems, the main groups of particularly responsible energy consumers who need to be connected to a protected electrical network are identified.

First of all, this includes the network equipment that makes up the local computer network - servers, routers, personal computers, etc. Communication equipment (in particular, automatic telephone exchanges), life support systems (ventilation and air conditioning systems), and various medical equipment, on which the health and life of patients depends.

Security and security systems (video surveillance, security and fire alarm, system emergency lighting and fire extinguishing and others), also fully justify connecting to a protected power supply network, since the consequences of failure of such systems can be quite serious.

As for the requirements for the operation of guaranteed power supply systems, the main ones are stable and uninterrupted power supply to all consumers powered by the system, maximum protection against voltage surges and high accuracy output current parameters in terms of compliance with existing standards.

Also, when designing and creating a guaranteed power supply system, it is important to take into account the convenience and efficiency of use, for which modern SGE have a high degree of automation.

Thus, a necessary condition for such a system is a prompt response to the quirks of the power grid and automatic transfer of consumers to work from a protected network. When the parameters of the central power supply are normalized, the system also automatically turns off.

In addition, it is important to be able to remotely administer the system if necessary and to have a means of informing the administrator about problems that have arisen.

Structure and principle of operation of the SGE

Since each facility has its own characteristics, the configuration of the guaranteed power supply system in each case is developed for specific conditions.

However, despite the fact that quite often when developing SGE it is necessary to resort to non-standard solutions, schematically such systems usually look similar.

The main blocks of the system are, first of all, standalone source energy (usually a diesel generator), one or more uninterruptible power supplies (UPS), as well as DC power supply units. Also, such a safe and reliable solution involves the use of system monitoring and management tools and special software.

During normal operation of the centralized power supply network, the diesel generator set is in standby mode, and the power supply to the connected equipment is provided through an uninterruptible power supply. The UPSs themselves in this situation also charge their batteries, acting as a surge protector.

If a failure occurs in the electrical network, the system controller starts the diesel generator; while this is happening, the connected equipment operates from the UPS. After the diesel generator set has reached the specified speed, the load is switched to it, and the UPS batteries are recharged from the diesel engine.

After the problems with the centralized power grid have been eliminated, the controller switches the equipment from power supply from the diesel generator set to the external network. During this process, consumers are also powered by a UPS. The diesel engine of the unit is also switched off automatically after the equipment has switched to normal power supply.

The autonomous operation time of consumers from the guaranteed power supply system depends on the operating life of the diesel generator set (the volume of fuel in the tank and its consumption) and the capacity of the UPS batteries. If the fuel resource is almost exhausted and the centralized power supply has not been restored, the operator must decide to shut down the work of consumers or continue it until the resources of the diesel generator set and the uninterruptible power supply are completely depleted.

In conclusion, here are some tips on what to look for when choosing an OEM for your equipment: emergency power supply systems.

The main requirements are guaranteed power supply, its high quality and reliability of the supplied equipment, as well as its compliance with domestic standards. Guided by this parameter, it is important to choose serious companies as suppliers that have weight and authority in the domestic power equipment market.

Such companies will also be able to guarantee you qualified technical support and maintenance of the supplied equipment. Finally, when supplying equipment, factors such as prompt delivery and acceptable, economically justified prices for products may also be important.

What determines the need to use
In our age of rapidly developing information technologies the load on existing power supply networks increases significantly. It is becoming extremely difficult to guarantee the uninterrupted operation of telecommunications and computerized systems, and cases of voltage drops and accidents in electrical networks are becoming more frequent. Creating a reliable power supply network will eliminate downtime and loss of important data due to power outages, extend the life of the company's technical infrastructure, and, ultimately, save on costs.

Reliable power supply for commercial, industrial and state enterprises possible with the help of guaranteed and uninterruptible power supply systems. If you decide to equip a facility with a guaranteed or uninterruptible power supply system, you need to decide on the number and category of consumers who will receive guaranteed or uninterruptible power supply, and the length of time during which autonomous power supply will be provided.

An extract from the PUE (Electrical Installation Rules) provides definitions of the basic concepts relating to guaranteed and uninterruptible power supply systems:

Electricity consumers are a single electrical receiver (ER) or a group of ER, united by a single technological process and located in a certain territory.

Types of electrical receivers:

• ES of category 1 are objects whose power supply interruption is associated with:

Threat to people's lives;
- threat to state security;
- significant material damage;
- disorder of important technological processes;
- disruption of the operation of objects of particular importance in public utilities;
- disruption of communication and telecommunications systems.
ES of category 1 should be provided with power supply using two independent and mutually redundant sources; a short-term interruption of power supply is allowed only for automatic transition to backup power.

• EP1 category of a special group are objects on the uninterrupted operation of which depends the possibility of preventing:

Threats to human life;
- threats of explosions and fires.
A special group should be provided with an additional, third independent and mutually redundant power source.

• EP category 2 are objects whose power supply interruptions lead to:

Massive failure of production;
- downtime (of workers, equipment and industrial vehicles);
- disruption of the work of the urban and rural population.
ES of category 2 in normal mode should be provided with power supply from two mutually redundant independent power sources.

• ES of category 3 are all other objects that do not require backup power. Power supply is provided from a single source with the condition that the period of repair work electrical networks will not exceed 1 day.

Guaranteed power supply system

When using only a diesel generator set (DGS) at a facility as a backup source, the facility is powered using a guaranteed power supply scheme.
Guaranteed power supply supplies electricity when the voltage supply in the main power supply network is interrupted to consumers of the 1st category (according to Chapter 1.2.17 PUE), while the parameters electric current must comply with GOST13109-87.

Guaranteed power supply system:

• Provides guaranteed power supply to connected consumers.
• Automatically starts (with no more than 3 attempts) the diesel generator after 9 seconds from the moment of deviations in the values ​​of the basic supply network from the requirements of GOST 13109-87 and when the power supply is completely stopped.
• Provides automatic transfer of external network load to the diesel generator and back.
• Signals to the control post when emergency events occur with diesel generator set equipment.

The facility's guaranteed power supply system must meet the following requirements:

• The MTBF of diesel generator sets must be at least 40,000 hours.
• The capacity load of the diesel generator set should be more than 50%; with less load of the diesel generator set, only short-term operation is recommended, and a load of 30% will entail the supplier’s refusal to provide a warranty for the equipment.
• Emergency start and load acceptance when exiting standby mode in hot standby cannot exceed 9 seconds.
• It is necessary to create conditions for routine maintenance and repair of a diesel generator set while the power supply system is running.
• Remote monitoring of diesel generator set operation is required.
• Completely eliminate parallel operation of diesel generator sets and external system power supply

Uninterruptible power supply system

When using an uninterruptible power supply (UPS) at a facility as a backup source, the facility is powered using an uninterruptible power supply circuit. Consumers who use power from a UPS when the supply of electricity through the main power grids is interrupted are called uninterruptible power supply consumers.

The uninterruptible power supply system provides consumers of the 1st category of a special group with electricity without breaking the sinusoid of the supply voltage, corresponding to GOST 13109-87 (according to Chapter 1.2.17 of the PUE).

The uninterruptible power supply system provides:

• Uninterrupted power supply without breaking the sine wave of electricity consumers connected via a UPS.
• Fully adjustable output voltage.
• Pure sinusoidal output voltage.
• High system efficiency.
• Compatible with diesel generator sets with a power reserve factor of less than 1.3.
• Maximum protection against shutdowns, surges, surges and power surges.
• Possibility to connect several UPSs in parallel.
• Autonomous support of electrical load for 20 minutes.
• Uninterrupted load switching through external and built-in bypass to power supply from external power networks.
• Availability of galvanic isolation of circuits (at the input and output).

When creating an uninterruptible power supply system at a facility, it is necessary to take into account certain requirements:

• Due to a single failure of any of the UPS elements, the performance of the system should not be completely disrupted.
• The SBP must have a service life of at least 10 years.
• Neutral cables of incoming electrical networks and transformer substations substations should not be overloaded.
• Regulated maintenance and repair of the UPS must be carried out without interrupting the building's electrical system.
• Monitoring of UPS parameters must be remote.
• After the service life of autonomous batteries has expired in the absence of external voltage, technological processes must be completed correctly.

Sharing on-site uninterruptible and guaranteed power supply schemes

When equipping an object with a diesel generator set and an uninterruptible power supply, the power supply to the object is carried out using an increased reliability scheme using an uninterruptible and guaranteed power supply.

If the main supply voltage is lost, a signal is automatically sent to start the diesel generator set. The diesel generator set starts up within 5-10 seconds when voltage is not supplied to consumers. When the diesel generator set reaches the rated frequency and voltage mode, the power supply to consumers is restored.

When the diesel generator set starts, the UPS switches to batteries. The power supply to consumers during the start-up of the diesel generator comes from the UPS batteries. Thus, a break in the sinusoid of the supply voltage is eliminated.

At the moment the external power grid voltage returns, consumers are disconnected from the diesel generator set and connected to an external source. For a short time, consumers of guaranteed power supply remain without voltage; The diesel generator stops and it goes into standby mode.

The possibility of power supply from the diesel generator set for a certain time is determined specific consumption fuel depending on the load and the amount of fuel in the tank. It is possible to refuel the diesel generator set during operation. If the fuel in the fuel tank runs out, the automatic control unit of the diesel generator set will shut down the diesel generator set.

When creating a scheme for uninterrupted and guaranteed power supply at a facility, the following requirements must be taken into account:

• The use of an on-line class UPS, since the load will be protected from all existing problems in the electrical network.
• The UPS power must match the load.
• The UPS must include rechargeable batteries. The battery backup time should be at least 5-10 minutes.
• In order to reduce the non-linear current distortion arising from the UPS, the UPS should be used with IGBT active rectifiers or 12-pulse rectifiers.
• Recommended UPS selection, which smoothly switch to network power from the battery.
• The power ratio of the diesel generator set and UPS should be equal to 1.3.
• The diesel generator set must be equipped with an electronic speed controller of the drive motor and an automatic output voltage regulator

This article is intended for practitioners who have to deal with the problems of ensuring high-quality power supply to security systems.

Terminology and abbreviations that will be used in this article:

• battery— sealed acid battery with gel electrolyte.
• GENERATOR- a diesel or gasoline power plant that generates alternating single-phase voltage 220 V or three-phase 380 V.
• INVERTER- a device for providing uninterruptible power supply, based on the conversion of direct current from batteries AC single-phase voltage 220V or three-phase 380V. It is implied that
• INVERTER contains battery necessary to ensure the required operating time at a given power.
• UPS— this abbreviation will mean “computer uninterruptible power supply” of low power.
• UPS— Uninterruptible power supplies (or IVEPR— secondary power supply sources are redundant).
  Such devices are designed to power equipment that does not have its own built-in power supply. Part UPS included battery.
• IRP— Backup power supplies. Designed to provide power to equipment that has its own main power source and an input for additional redundancy.

CHOOSING A CATERING STRATEGY

First of all, consumers should be divided into groups according to the criticality of the power supply and the required backup time.

• - Relatively low cost - on average, a gasoline generator will cost $400-500 per kW, and a diesel generator is about 1.5 - 2 times more expensive;
• — High quality output voltage;
• — Possibility of long operating time.

Flaws:

• — special premises are required;
• — need for maintenance;
• — inability to provide uninterrupted power supply — it takes time to start the generator.

Diesel generators are cheaper to operate, so it makes sense to use them only for organizing long-term backup power for high-power facilities (more than 5 kW). At lower powers or for short-term use, a gasoline generator will be more economical.

Buy GENERATORS It only makes sense to import them and only from specialized companies. Many good brands of Japanese (eg Yamaha), French (SDMO) and Italian production are imported to Russia.

INVERTER- this is what is usually called a converter from low voltage DC to high AC. In other words - energy battery to alternating current 220 V. Inverters are rarely used in their pure form, but are integral part uninterruptible power supply systems, which are usually called UPS. UPS There are two types - on-line and off-line. UPS off-line are cheaper and simpler - the inverter turns on only when the mains voltage fails. The on-line circuit is a double conversion circuit. First, the mains voltage is reduced and rectified, after which the direct current is converted into alternating 220 V using an inverter. When the mains voltage fails, energy is used battery. Such a circuit provides the highest quality power, since it does not depend on the quality of the input voltage. On-line inverters are both voltage stabilizers and filters. This perfect solution to provide 220 V power to consumers. But they also cost significantly more than conventional off-line devices.

Another important parameter for INVERTERS And UPS is output waveform:

• - pure sine - the most complex and expensive devices;
• - approximated sine - an intermediate option, there may be different degrees of approximation;
• - modified sine, meander, quasi-sine - the most common and inexpensive option inverter.

It must be remembered that some types of loads are very sensitive to the shape of the supply voltage. The modified sine cannot be used to power consumers with transformer power supplies and sensitive equipment.

output power - for inverters it is usually indicated in Volt-Amps (VA, VA). Unlike Watts (W, W), which indicate the effective power consumption of alternating current, volt-amperes characterize the amplitude values ​​of currents and voltages in the load. The existence of such a unit is due to the fact that phase shifts can occur in alternating current circuits.
For a simple resistive load VA = 1.41 x W
It is extremely careful to connect a load with a power indicated in Watts to a source whose power is indicated in VA. If such a need arises, then for calculations multiply the load value in Watts by 1.41
Purchasing a good INVERTER — a big problem. There are very expensive models, intended for telecommunications and computer equipment.
The “middle class” is practically absent from the market. As a rule, problems with the service, and INVERTER- a very expensive and complex device.
There are good domestic devices, but their manufacturers - defense factories - suffer from poor marketing. Buy a computer UPS low power is as easy as shelling pears.

LOW-VOLTAGE UPS and IRP

Almost all IRPs existing on the market are similar to each other and differ only in the capacity of the installed batteries.
Therefore, we will focus on UPS. Based on their circuit design, UPS can be divided into transformer and pulse.
In turn, transformer UPSs can be equipped with a linear or PWM stabilizer.
Switching UPSs for security systems are rarely used due to low reliability and high level interference
Transformer sources with a linear stabilizer are optimal for low currents.
At high currents, PWM stabilizers are increasingly being used, although linear circuits are still unrivaled in terms of reliability and maintainability.

One of the most important parameters— MAINS SUPPLY VOLTAGE. In Russia, the standard for electrical networks allows a voltage range of 187…242V (220V -15% +10%).

Foreign requirements are more stringent, so imported UPSs are not recommended for use in our networks. Moreover, some domestic UPSs are produced with parameters stated in the range of 220V ± 10%.
The use of such UPSs in real networks is fraught with either chronic undercharging of the battery or failure of stabilization, which is completely unacceptable for security systems. Because in many regions, low voltage in the network is normal condition, UPSs with an extended power supply range of about 150...250V have appeared on the market.

The lack of clear standards for UPS leads to arbitrariness in definitions and terminology, which often confuses the consumer.
It must be remembered that the main parameter of the UPS that characterizes its load capacity is the RATED OUTPUT CURRENT - this is the current that can be supplied to the load when powered from the network ALWAYS, regardless of the circumstances, arbitrarily long time and while maintaining the ripple level - at any permissible network voltage in the range of no worse than 187...242 V, at any condition of the battery, in the permissible operating temperature range. This is the only current you can count on when building a system.
Often, UPS manufacturers indicate as the main parameter the current supplied to the load without a connected battery (sometimes called the maximum current),
but we must remember that part of this current is taken away to charge the battery, and only the rated current can be guaranteed to be supplied to the load.

All professional UPSs have protection against deep battery discharge. Often UPSs allow you to connect additional power sources to increase the operating time in reserve mode.
Many UPSs have increased output currents in standby mode (in the absence of a network) or for a short time, which makes it possible to significantly optimize the power supply to alarm systems, warning and fire extinguishing systems.

You should choose a UPS or IRP only of domestic production and only from manufacturers specializing in the production of UPS.
It has already become a saying that “only lazy people don’t make power supplies.” But in reality there are no more than 4-5 companies in Russia that produce reliable and proven sources, provide a wide range of products, technical support and a distribution network.

Project documentation in pdf

ELECTRICAL PART

1.1. Main circuit

The main circuit of the power plant ensures the delivery of 100% of the calculated operating power in all operating modes of the fish processing complex and may have reserve generating capacity available.

According to the data of consumed electrical loads, the maximum operating power consumption is 2019 kW. The installed generating capacity of the 3 diesel generator sets is 2.44 MW, which provides a power reserve. The diesel generator group always has the option of switching on the diesel station SDMO X1250 with a power of 1000 kW or SDMO V550 C2 with 440 kW.

The switchgear of the guaranteed power supply system (GPS) is made in the form of 3 cabinets connected to 3 sections of the ASU. Cabinets with switches are disabled in normal mode. If there is a power failure in a certain section of the ASU and its absence for a certain time, the corresponding generator starts up and is connected to the section buses while simultaneously turning off the main input of this section.

Switchgears, busbars and power cables are selected in accordance with the maximum short-circuit currents for thermal and electrodynamic resistance.

The switching equipment corresponds to short-circuit currents in terms of breaking capacity.

Local control of generators and SGE switches is carried out on generator control panels. From the main control panel of the plant in the control room, monitoring of the state of switches and the normal or emergency state of generators is provided.

1.2. Power supply system.

A group of diesel generator sets with an installed capacity of 2.44 MW is designed to operate in emergency mode (no voltage at the main input of the ASU) and is designed on the basis of 2 diesel generators 1250 kVA type X1250 and 1 generator 550 kVA type V550 C2 from SDMO.

3 generators G-1, G-2 and G-3 are connected to 3 sectional busbars of the plant's ASU switchgear.

Automatic switching on of generators G-1, G-2 and G-3 is ensured using a control panel type MICS Kerys from SDMO. Generators are equipped with standard protection kits.

Input distribution devices are designed based on the company's cabinets, devices and busbars Schneider Electric installed in the reserve room (29), see “Equipment and cable routes layout plan”. All electrical equipment that may be energized if the insulation is broken is connected to the grounding of the power supply system, which is in turn connected to the grounding device of the plant's ASU.

1.3. Power plant equipment

The guaranteed power supply system (GPS) includes:

2 diesel generator sets X1250 from SDMO with a power of 1000 kW each in container design;

Diesel unit V550 from SDMO with a power of 440 kW in a protective casing;

Input (connection) system for guaranteed power supply;

SGE diesel fuel supply system;

Own needs of SGE (cabinet SNGP).

The operating mode of diesel stations is peak.

The power generator system is a functional complex, which includes, in addition to diesel units, the necessary power generation input systems, automation, control and management.

Total electric power SGE systems -3050 kVA. Type of current - alternating, 3-phase, frequency 50 Hz. Rated voltage - 0.4 kV. Switchgear switchgears are designed for switching and transmitting three-phase alternating current with a voltage of 0.4 kV and 4800 A total current.

A group of 3 diesel generator sets is designed to operate in autonomous mode. Each diesel generator set includes its own Switchgear 0.4 kV for input (connection) of generators G-1 ÷ G-3 to ASU sections.

MICS Kerys control panels are installed at each diesel station. The automated control system (MICS Kerys control panel) provides an operating mode with power generation based on load (within the rated power of the generators).

At the output of the generators, an AIPR type switching unit is installed (for X1250 diesel stations complete with a diesel generator set for the (existing) V550 C2 diesel generator set, an AIPR 1250 A unit is ordered separately.

1.4. Electricity supply own needs SGE.

Power supply for the SGE's own needs from the ASU is provided according to reliability category I. The auxiliary cabinet of SGE SNGP has two independent inputs from different sections of the plant's ASU and automatic input of a reserve at the input.

On the outgoing feeders of the SNGP it is planned to install circuit breakers for protection against short-circuit currents and overload currents. Cable routes from SNGP are supposed to be made openly in a steel tray on cable shelves and in steel pipes when entering the diesel generator set and passing through the walls.

1.5. Grounding of the guaranteed power supply system.

As a grounding device for the SGE, it is planned to create a grounding device consisting of vertical electrodes of a steel angle l = 3 m, connected to each other by a steel strip of 50x5 mm, connected to the grounding device of the ASU of the plant.

The resistance of the combined grounding device is no more than 4 Ohms. The project provides for a TN-C-S grounding system.

In the reserve room of the guaranteed power input cabinets, an internal grounding loop is constructed, which is connected to the grounding device and to the metal casings of the power supply input cabinets. In this room, the PEN conductor is divided into PE and N. The connection of the GE input cabinets with the plant's ASU is carried out by 5-wire busbars with separated PE and N.

AUTOMATION

In this set project documentation developed following systems automation and control:

Voltage monitoring system at the main inputs of ASU sections and automatic start-up and connection of diesel generator sets to the corresponding sections;

A system for automatically supplying fuel from a reserve tank to generator tanks depending on their filling.

The automatic start and connection system for the diesel generator set is based on the MICS Kerys control panel included in the delivery package (for the existing G-3 it must be ordered separately).

The automatic fuel supply system is controlled by a special controller for groups of pumps of the SAU-MP type, depending on the position of the level sensors in the fuel tanks of the diesel generator set.

Control of the operation of the SDMO V550 C2 and SDMO X1250 is carried out by connecting the standard control panels of the units to the cable network and transmitting the main “states” of the systems to the control room.

The operator’s workplace is located in the plant’s control room, room 29, see “Equipment and cable routes layout plan.”

When the values ​​of the controlled parameters of diesel stations go beyond the specified settings, the station automation (MICS Kerys) generates an “Accident” event and transmits it to the control room via a cable channel.

The controllers (MICS Kerys panels) are powered from the diesel station’s own needs, and above from the SNGP cabinet.

Stable operation industrial equipment, telecommunications and computing equipment, and other computer equipment are the key to stable operation of the enterprise. For this purpose, uninterrupted and guaranteed power supply systems are used, which supply connected consumers with electricity in the event of a power failure in the electrical network.

Solutions from Inter ID

The Inter ID company supplies equipment for backup power supply systems and Supplies to them. We will help you choose equipment models depending on the tasks assigned, and we will perform installation, maintenance, maintenance and modernization of the installed complex. The cost of work is calculated individually for each client.

Structure of SBGE

In SBGE, uninterruptible power supplies (UPS, UPS) and diesel generator power plants (DES, SGU) are used in parallel, which provide the equipment with energy in case of accidents in main power grids. SBGE consist of a general power supply system, UPS, SGE, distribution power supply network, performance monitoring devices and grounding components. The EPS includes transformer substations, input distribution devices, distribution and group boards and networks. UPSs consist of UPS, distribution boards and group networks. SGE contain diesel generator sets, distribution boards and devices for automatic switching on backup power.

Classification

Depending on the design of the equipment and the consequences that result from disconnecting devices from the power supply network, electrical receivers are divided into 3 categories. A break in the power supply of category 1 facilities is associated with disruption of the operation of communication and telecommunications facilities, leads to disruption of production processes, material losses, and poses a threat to people’s lives. These devices are provided by two independent power supplies. Interruptions in the operation of category 2 electronic devices lead to production failure and downtime; a pair of independent sources are connected to these devices. Disabling category 3 EDs does not lead to serious consequences; they are powered from a single source.

To ensure the operation of the equipment, the following are used:

• Guaranteed power supply systems consist of diesel generator sets that automatically start within 9 seconds after a power outage or deviation of network parameters from the values ​​regulated by GOSTs;
• Uninterruptible power supply systems involve the use of a UPS; they are characterized by an adjustable output voltage and parallel connection of several UPSs;
• Combined options provide for the simultaneous use of SGE and UPS; they are recommended for use in cases where increased reliability of energy supply is required; they are characterized by the use of on-line class UPS with protection against possible problems supply network, rectifiers to compensate for nonlinear current distortions and a backup time of at least 10 minutes.

Differences between SGE and SBE

Uninterruptible power supply systems switch powered equipment to battery operation. During normal operation of the power grid, the batteries installed in the UPS are charged, and the built-in network filters cut off high-frequency interference and other distortions. It is advisable to use UPS during short-term power outages or voltage surges to correctly shut down the devices and save the necessary information.

During long power outages, it is more advisable to use SGE with diesel generator sets. When the central power grid is disconnected, the diesel generator set plays the role of an emergency power supply unit. To operate the UPS and diesel generator set in a single complex, special equipment is used.

Design

In the process of developing the SBGE, a number of factors are taken into account. The following design stages are distinguished:

• A feasibility study is being developed based on terms of reference, used for infrastructure and industrial purposes;
• Technical and economic calculations are used for technically simple linear objects and are performed in a reduced volume relative to the feasibility study;
• The preliminary design contains calculations of parameters, selection of diesel generator sets, UPS and other components, estimates of work performed;
• The working draft contains detailed calculations of parameters and the selection of specific equipment models;
• Working documentation is drawn up after approval of the working design; it contains installation diagrams for installing equipment, connecting equipment, etc.

Depending on the complexity of the objects, design is carried out in one, two or three stages.

Installation and connection

When installing SBGE at a facility, groups of responsible electricity consumers are identified, for which backup sources are primarily needed:

• Personal computers, routers, routers, servers and other network equipment, PBX and other communications equipment;
• Life support systems (ventilation and air conditioning), medical devices;
• Security and safety services - access control system, video surveillance, fire alarm, emergency lighting.

To ensure reliable operation of the equipment, static UPSs with on-line support are used. These devices are always on and instantly switch to battery power if a network problem occurs. The complexes are designed for stable operation of connected equipment from 15 minutes to a couple of hours. If the power supply is turned off for longer than a specified period of time, the power generator sets are automatically turned on.

Requirements

The following requirements apply to the installed SBGE:

• Power supply of computer network components, telecommunications and other low-current equipment with specified power quality parameters;
• The configuration of the complex provides for the normal operation of components and connected loads in the event of failure of one element;
• Automatic and manual control modes, including remote control;
• Constant monitoring of voltage and other network parameters, statistical accounting;
• The required level of compensation for interference from power supplies and UPS rectifiers, external influence, prevention of third-party unauthorized access, equipment malfunction and data loss.

Maintenance

Maintenance of an uninterruptible and guaranteed power supply system includes servicing installed UPSs, maintenance of diesel generators and switchboard equipment. Before carrying out work, a service agreement is concluded for the maintenance of these installations, removable batteries, input and output panels to which the UPS is connected.

At maintenance held visual inspection components, cleaning from dust, lubrication of moving parts, changing oil, batteries with exhausted life and other wearable components, checking fasteners. The operation of the UPS from batteries is checked when switching to bypass, returning from it, and other modes. Records of inspection results and resolved problems are recorded in a special journal so that during the next maintenance, engineers pay attention to possible problem areas.