Uninterruptible power supplies are critical components of data center infrastructure. They regulate power from a fluctuating grid and protect data centers from blackouts, brownouts, sags, and surges.
A UPS has three main parts: a rectifier, energy storage, and an inverter. These convert AC power into DC power for use by the equipment.
Redundancy is duplicating critical components in a system to increase reliability and reduce downtime. This translates to systems with more than one feed or generator for data centers if a component fails. It also means having backups of key data and IT infrastructure.
UPSs with redundancy can tolerate brief output power disruptions such as overvoltage surges and under-voltage brownouts without draining the limited reserve battery power. This is achieved by using multiple power taps in the autotransformer. Switching between the different power taps may cause a momentary interruption in the connected equipment (similar to changing a tire on your car, which might briefly chirp).
The most common redundant models are standby and line-interactive UPSs. These models provide basic protection for desktop computers and other electronic devices requiring immediate shutdown when the AC power goes out. A more advanced option is the double-conversion online UPS, which provides much more robust protection than a standby or line-interactive UPS. In this type of UPS, the rectifier drives a DC/AC inverter, even when powered by a normal AC. This technology can support the peaks and valleys of a power supply and condition and boost power for better quality, but it will cost more than standby or line-interactive models.
The UPS and data center infrastructure contains equipment sensitive to power fluctuations. Even a brief momentary interruption in utility power could cause equipment to shut down abnormally and lose valuable data. UPS systems can provide battery power to devices during instantaneous voltage dips or outages to prevent this from happening.
UPS systems come in two different types: standby and line-interactive. The former monitors the power line and switches to battery backup only when a problem is detected. As a result, this type of UPS is typically less expensive than the line-interactive variety. However, this also means that a data center will not receive any protection from AC current fluctuations during normal operation.
Line-interactive UPS systems are designed to condition and regulate AC power from the utilities. As a result, they can support much higher load levels and are better equipped to handle power fluctuations. Additionally, they can operate at full capacity for longer periods than the standby variety.
In addition to determining the proper size of UPS, it is important to consider the type of batteries used. While lead-acid is the most common option, Lithium-ion batteries offer superior longevity and performance. It is also a good idea to purchase a system that features replaceable batteries to reduce the total cost of ownership over time.
UPS systems ensure data centers can operate at all times, preventing data loss and safeguarding work-in-progress. They regulate power from a constantly fluctuating grid, eliminating the risk of power fluctuations that would otherwise take down servers and cause hardware failures. They also offer backup power during a power outage or brownout.
UPSs are available in various form factors, including rack-mounted units and freestanding devices. Choosing which type to deploy depends on the size of the data center and its power requirements. Rack-mounted UPSs are more convenient for some organizations than freestanding models, but either can perform the same job. Companies with substantial power requirements often choose to deploy both types.
When evaluating UPS systems, look for one with an LCD control panel that displays helpful information like voltage, frequency, backup time, and more. You can also purchase an optional network management card to customize UPS capabilities with SNMP, web, SSH, or telnet management tools.
UPS batteries are crucial to the performance of your UPS system. The battery types you use can significantly impact how quickly your UPS switches to backup power and how long it runs when the power is off. Invest in the highest quality batteries, such as open-vented (VLA) or lithium-ion.
UPS systems protect mechanical and digital machines with interim power, suppressing power surges and ensuring continuity of operations. UPS devices have battery packs that turn on when the device detects a loss of power from its primary source. The batteries supply power temporarily until administrators can save data/progress, shut down equipment, or longer-term backup power systems kick in.
UPS power sources are available as individual units, high-performance models with multiple outlets, or full data center UPSs. Individual units function on a one-to-one basis and provide backup power to hardware devices. High-performance UPSs have outlets that admins can plug multiple hardware devices into, and these typically support devices uninterruptedly for 30 minutes during a power outage. Full data center UPSs power multiple hardware devices simultaneously and last up to 60 minutes until admins can engage other backup systems.
Most UPS power sources come in open-vented (VLA) or lithium-ion batteries. Lithium-ion batteries are more expensive but offer higher reliability and lower maintenance costs over their lifecycles. They also reduce energy consumption, which cuts down on overall costs. When choosing a UPS, look for a model that provides a pure sine wave in its battery-back mode. This output type is important for powering sensitive hardware because it produces a more stable, smoother curve than simulated or modified sine waves.