Today, a huge number of different UPS models are available, depending on the consumers being serviced and the power supply parameters. To choose the device you need according to its characteristics, and then operate it correctly, you need to know what a UPS is, why it is needed, what its functions, design, types, and parameters are. We will talk about this and other aspects of using this unit in the article.
Main UPS Functions
- Ensuring uninterrupted power supply. A short circuit, planned or emergency power outage are the realities of our lives, which lead not only to household inconvenience, but can damage and even completely disable electrical equipment. It can also lead to data loss on your home PC or office equipment. To prevent this and maintain the operability of the devices, the load is connected to the main network via an uninterruptible power supply. This is the UPS's priority assignment. In the event of significant fluctuations in mains voltage, power outage, or other force majeure, the UPS switches consumers to power from built-in or external batteries, which allows the equipment to operate offline for a while.
- Protection against power surges and power outages. The dual conversion UPS models (the STARK COUNTRY ONLINE UPS line) and the line-interactive type (the STARK COUNTRY LINE-INTERACTIVE UPS line) have a voltage stabilization function. If the power grid parameters deviate from the norm, as energy flows inside the UPS, the power supply characteristics are aligned to load-acceptable values, which is very important for sensitive home or office equipment.
- Maintaining stable voltage and frequency of equipment power supply. The UPS is equipped with the option of filtering frequency and pulse interference, reducing electrical noise. To inform users, there is also a light and sound indication of the states of the power supply system, displaying the values of voltage and frequency, and the power consumption of the load.
- Protection against electrical interference in local low-current networks. Most models are equipped with a low-current local area network protection system. Network equipment is protected by connecting information cables through dedicated RJ-45 and RJ-11 connectors.
Uninterruptible power supplies, primarily new generation models, have other additional features: cold start (starting without connecting to the main network, using battery power), timer for switching off/on the load at a set time, parallel connection, correct shutdown of protected IT equipment in critical conditions, remote monitoring of UPS, emergency monitoring, signaling, etc .
The STARK COUNTRY ONLINE UPS line has one of the widest functionality. For example, the frequency conversion function makes it possible to use the UPS in networks with different network frequencies at the UPS input and output.
UPS applications in various fields
The use of uninterruptible power supplies affects almost all areas where electricity is used. Thus, the STARK COUNTRY ONLINE series includes a wide range of applications. The possibility of using it in one area or another depends on the power of the unit. According to this criterion, three main consumer groups can be distinguished:
- Large commercial and industrial enterprises. This includes large production facilities, business centers, hotels, warehouses, as well as institutions with critical equipment. A high-power UPS is required to provide their power supply.
- Household systems. This group includes small offices, retail outlets, cafes, small businesses, summer cottages, etc. As a rule, these facilities use equipment with low power consumption, therefore, low-output UPS units are used. They are used to provide power to specific household consumers in the house – they are installed on a specific device, for example, on a freezer. The same UPS units are used for Smart Home systems in a country house, as well as for heating equipment.
- Information technology. These include equipment in the field of telecommunications, remote communication devices, local area networks of data centers, etc. To ensure their continuous operation, as a rule, a medium-power UPS is installed.
|
|
|
UPS design
Regardless of the design scheme and functionality, each model of an uninterruptible power supply includes the following main design components:
- Accumulators (energy storage devices).They accumulate electricity to power the load in an autonomous mode. To extend the autonomy of the UPS, additional external batteries can be supplied. The battery characteristics, primarily the capacity, determine the battery life of the UPS.
- An inverter is a device for converting direct voltage to alternating voltage. Generates a stable sinusoidal voltage without distortion (pure sine) at the UPS output.
- Rectifier (charger) – for charging the battery and applying constant voltage to the input of the inverter.
- The controller (electronic control unit). It is designed for the correct functioning of the UPS. Provides automatic operation of the UPS and battery in accordance with the specified parameters. Allows you to adjust the device settings.
The design may also include a bypass unit, booster, user interface, monitoring interfaces, filters, and other additional elements.
UPS types by design
In accordance with the International Standard IEC 62040-3 "Uninterruptible Power Supply Systems (UPS)", UPS systems are classified into three types according to the construction scheme:
- Backup (off-line or standby). A budget option. Due to the lack of built-in surge protection, they are used only in networks with relatively stable voltage and for power supply that is undemanding to a short-term (up to 12 ms) loss of load supply voltage during the transition to autonomous mode.
- Line-interactive. They are equipped with a built-in step-by-step output voltage stabilizer, which allows them to be used in networks with significant voltage deviations from the norm, but also allow a short-term (4-8 ms) loss of output voltage when switching to offline mode.
- Double conversion (online). The main feature of the UPS circuit is the absence of an autotransformer and switching elements in the power unit that are subject to mechanical wear. Therefore, online UPS systems are able to work much longer than analogues of other types. Important advantages are the clean sine at the UPS output both in the input network mode and offline mode, zero switching time to offline mode.
|
|
|
Basic characteristics of the UPS
You should choose an uninterruptible power supply based on what exactly the UPS is required for. What parameters the device should have depends on its purpose and the nature of the connected load. Let's look at the main characteristics of the UPS.
- The output power transmitted to the consumer is measured in watts (active) or volt-amperes (full). This is the main selection criterion, it indicates the permissible maximum load. These values must exceed the power consumption of the connected devices by a margin of 20%. If the load has high inrush currents, such as a submersible borehole pump, the UPS is selected based on the maximum inrush current
- Switching time to battery power and back (inertia). It is measured in milliseconds and ranges from 0-12 ms. Some particularly sensitive devices need to be backed up only by an online UPS with a switching time of 0 ms.
- Output waveform (Uhf). The voltage applied to the load during battery operation can be with an ideal ("clean") or modified sine wave. Most electrical appliances require a "clean" sine, which can only be provided by online and offline models, such as the STARK COUNTRY ONLINE series UPS.
- Battery life is the duration of battery power supply in minutes. It is determined by the battery capacity and the power of the protected load. For UPS with built-in batteries, the average is 4-10 minutes. This is enough time to save data on a personal PC. For industrial and office equipment, as a rule, the autonomy time increases to 30-45 minutes. In this case, it is recommended to choose models with the ability to connect external batteries with increased capacity. Models of all STARK COUNTRY UPS lines allow using only external batteries.
- Voltage correction function – adjusts the value and shape of the output signal without switching to offline mode. It is available in UPS online.
- Charger current – the higher this parameter, the more capacious the batteries can be connected and provide long-term autonomy. Using a powerful built-in charger, STARK COUNTRY UPS allows you to achieve several hours of autonomy, and in some cases even tens of hours.
You should pay attention to other characteristics, including input voltage, phase ratio, frequency control (for online models), permissible load, solar panel connection, remote control and monitoring, service life, etc .
Specifics of UPS operation
Let's take a closer look at the functioning features of each type of UPS.
- The principle of operation of an off-line UPS (backup type). The second name of the device, standby, means "in standby mode." In normal mode, if there is voltage from the input network, it supplies it directly to the outputs, while maintaining the battery charge. When the voltage drops or subsides, the relay switches to battery power for the load. The transition time is from 3 to 12 ms, for some devices such an interruption is critical. Another disadvantage of this type of UPS is that it usually has a modified sine wave in offline mode, which is unacceptable for many devices, such as circulation pumps and heating equipment. The devices can be used to protect devices that are undemanding in terms of current quality, such as transformers. Compatible with office and home PCs. It is important to know: STARK COUNTRY brand off-line UPS provides a clean sine at the output in offline mode.
- The principle of operation of the Online UPS (double conversion). The alternating voltage comes from the mains, in the rectifier it is transformed into a constant (with battery charging), then in the inverter it is converted back to an alternating with an ideal sine wave at the output. This technology ensures complete independence of the output voltage quality from the network condition. Due to this, the most effective load protection is achieved not only from loss of central power supply, but also from voltage deviations from the norm.
Since the battery is always permanently connected to the rectifier and inverter in an online UPS, the transition to offline mode is instantaneous. This guarantees the most effective protection of the connected load. UPS of this type can be used to power highly sensitive equipment even with low quality of electricity in the network. Suitable for protection of server equipment, video equipment, electronic control unit of heating boilers, etc. They are usually produced with a high output power factor, many models are designed for use in combination with a fuel electric generator and external batteries.
It is important to know: Online UPS of the STARK COUNTRY brand can work with an isolation transformer at the output.
- The principle of operation of a linear interactive UPS. The main difference from a backup type UPS is the presence of an AVR – automatic voltage regulator. This element has several fixed adjustment steps, for example, two steps for lowering and three for increasing. When the voltage drops below the norm, the AVR turns on the boost step, normalizing the characteristics. When increasing, on the contrary, the "lowering" step is activated. If the mains voltage disappears or its values exceed the values of the regulator, the UPS switches to battery power using a relay. Devices of this type can be used in servers, engineering systems, banks, PBX, etc. Almost all models of STARK COUNTRY UPS are equipped with a sinusoidal output voltage inverter, which increases the possibilities of using linearly interactive UPS systems for electric motors, pumps, refrigerators and other critical equipment.
UPS operating conditions
For proper operation and safety of the uninterruptible power supply itself and the equipment connected to it, the UPS operation requirements must be observed.
|
- Temperature regime. The recommended temperature range for most UPS models is from 5 to 40°C. The optimum temperature for stable operation is considered to be 20-25 ° C. A lower temperature can cause condensation, which can cause a short circuit. Too high a temperature negatively affects the cooling of the device and shortens the battery life. It is unacceptable to place radiators and heating devices nearby, as well as sunlight.
- Humidity – this indicator should not exceed 80%.
- Ventilation. The heat generated during operation must be constantly removed either by forced ventilation, that is, by a fan, or by natural air circulation around the device body and through its body. The distance from the air vents to the wall or other surface should be at least 15-20 cm.
- Electrical protection. The cable for connecting to the electrical network and the wires connecting the unit to the connected devices must be positioned without tension. It is necessary to exclude the possibility of their damage due to negligence, it is advisable to fix them on the wall. The power cable should be connected to a grounded outlet (in models up to 3 kW). Do not overload the UPS, connect only the really necessary load.
- After-sales service. It is necessary to periodically perform tests on the operability and capacity of the batteries and include the UPS self-test procedure. It is necessary to ensure the maintenance of an uninterruptible power supply by concluding an agreement with the relevant organization.
Conclusion
Thus, an uninterruptible power supply is necessary in the home, office, and workplace in order to ensure the continuous operation of connected equipment in the event of a short-term or prolonged power outage. In addition to this function, the UPS stabilizes the output voltage and filters out interference. All this prolongs the service life of equipment, including expensive ones, and prevents the risk of premature equipment failure.
When choosing a UPS, it is necessary to be guided by its characteristics and the characteristics of the protected load. Reliable devices of proven brands, such as STARK COUNTRY, will provide the best protection. The variety of models allows you to make the best choice for you.