Features of the UPS for industrial facilities

Uninterrupted power supply is important both for a separate machine at an industrial enterprise, and for a large industrial complex as a whole. Modern energy systems are quite complex and reliable, but they do not always cope with this task. What types of UPS are used for industrial facilities? What requirements should they meet? And are there any special conditions for the operation of such equipment?

Requirements for industrial UPS

Given the purpose, we can identify the main characteristics that should be in uninterruptible power supplies for industrial facilities:

• High power output. It is determined by the capacity of the equipment used in enterprises.
• Maximum reliability. It is laid at the design stage of construction sources. In their manufacture, components are used that can multiply the reliability of devices. This, of course, increases the cost of the UPS, but at the same time increases the service life of both the sources themselves and the equipment they provide with electricity.
• The thought-over design facilitating diagnostics, service and repair of uninterruptible power supply units. This approach provides free access to all system units and minimizes the time required to disassemble or replace UPS components.
• The ability to scale and smooth capacity. This is necessary with increasing power requirements.

Types of industrial UPS

For industrial purposes, there are three main types of uninterruptible power supplies:

1. Standby (differently Off-Line or Standby). Such sources are equipped with automatic switches, which, in the event of a power failure, transfer the load to the batteries. These are simple and inexpensive systems, but they are not equipped with network voltage regulators (which means that the batteries wear out faster) and take a certain time to transfer power to the batteries (about 4 ms). Such UPSs handle only short-term power outages and are used to service non-critical production equipment.
2. Line-interactive. Such sources are equipped with transformers to stabilize the output voltage. As a result, the number of switching power supply to the batteries is reduced and battery life is saved. In this case, the UPS is not designed to filter out noise and control the shape of the voltage. They are optimal for uninterrupted power supply of equipment for which only the magnitude of the input voltage is important.
3. Online (On-Line). In such sources there is a double voltage conversion. First, from AC to DC (it is fed to batteries), and then back to AC, which is used to power industrial equipment. In this case, not only the magnitude of the voltage, but also the phase, frequency, and amplitude of the alternating current are precisely controlled. Some manufacturers, instead of double conversion, use bidirectional inverters, which in turn serve as a rectifier or inverter. Online UPS systems save energy and are more efficient. Such sources are suitable for protecting powerful and parameter-sensitive network equipment.

In addition, industrial UPSs can be divided into two groups depending on the type of feed load:

• The first includes uninterruptible power supplies, which are used to protect against power outages of production processes and work equipment. A backup or line-interactive UPS can be used for this purpose.
• To the second - the UPS, which are used for uninterrupted power supply of IT-infrastructure: data storage systems or servers. For this suitable on-line type sources.

Operating conditions for industrial UPS

Enterprises of different industries have their own specifics, and therefore different requirements are imposed on uninterruptible power supplies. In fact, each such project is unique and needs to optimize equipment for its conditions. Here are just a few examples of production specifics:

• UPSes involved in oil refineries to ensure the safe operation of distillation columns are used for emergency power supply not only for control systems, but also for actuators. Accordingly, they must have high power.
• At the stations for the production of geothermal energy, a by-product is released: gaseous sulfur dioxide. When in contact with atmospheric moisture, it forms sulfuric acid vapors. It is able to quickly destroy the materials used for the manufacture of uninterruptible power supplies.
• On offshore oil platforms, another danger is high humidity, salt, and the possibility of horizontal or vertical movement of the base on which the UPS is installed.
• Metallurgical plants have strong electromagnetic fields that can cause interference and trigger the source circuit breakers.

The above list can be replenished with dozens of other examples. At the same time, regardless of the specifics of the industrial enterprise, reliable operation is required from uninterruptible power supplies for 15–25 years. We can identify two main factors affecting the functioning of the UPS:

1. Accommodation Sources are strongly discouraged from being placed near energy consumers. They must be protected from the effects of high temperature, polluted air or mechanical stress. For the UPS, the optimum temperature is 20–25 ° C, but they continue to work properly at temperatures up to 45 ° C. Increasing it further reduces battery life because all chemical processes in them are accelerated.
   
   Dusty air is also harmful. Fine dust plays the role of abrasive and leads to wear of the working surfaces of the fans and the failure of their bearings. You can try to use the UPS without fans, but it is much safer to initially protect them from such effects. To do this, the equipment must be placed in a separate room with a supported temperature regime and clean air.
2. Energy recovery. The very idea of ​​returning a part of the electricity to the network and its reuse is certainly useful. It allows you to reduce energy costs. Recovery systems are actively used, for example, in railway transport, but they are harmful to uninterruptible power supplies. When using reverse energy increases the voltage on the DC bus. As a result, protection is triggered and the UPS goes into bypass mode. It is impossible to completely eliminate the consequences of recovery. They can only be minimized using transformer uninterruptible power supplies.