Data centers depend on their UPS systems to reduce downtime and keep servers and other equipment running. They also expect these devices to prevent damage caused by power line disturbances such as surges, spikes, and brownouts.
Data center managers must understand the key UPS components and how they work together to achieve reliability.
Redundancy
Many UPS models come with redundancies that ensure high availability. Redundancies may include extra batteries, extra system components, or backup systems in separate locations. There are different levels of redundancy available. Increased reliability means higher client satisfaction and revenue for data centers that depend on servers to process business transactions.
Enhanced Disaster Recovery: Data centers with redundant UPSs can better manage outages caused by natural disasters and other events. For example, UPSs with multiple battery cells can continue operating longer than a single cell, allowing them to power critical equipment until backup generators can take over.
Energy Storage: UPSs store energy through various methods, including rechargeable batteries and kinetic energy in heavy, rotating flywheels. However, most modern UPSs are modular, making adding battery modules or units easy to increase capacity and redundancy as needed. Modularity also reduces waste, as there is no need to over-buy in anticipation of future growth.
The type of UPS topology right for a data center depends on the load capacity, power protection level, and other features the facility requires. For example, small and home UPS devices feature a standby topology that switches to battery power when utility power is interrupted. Line-interactive UPS devices have a power regulator that conditions input voltage to safe, regulated levels before sending it to sensitive equipment. The UPS switches to battery operation if the conditioned power fails or exceeds pre-defined regulated limits.
Energy Storage
Data centers contain large amounts of valuable information, and any disruption in the power supply can have devastating consequences. UPS systems provide uninterrupted power to equipment, minimizing downtime and preventing data loss.
In data center operations, understanding how a UPS works in a data center is crucial for ensuring continuous power supply and protecting critical systems against power disruptions and outages.
Energy storage is an essential component of UPSs and can be used in several ways. Some UPSs use batteries to provide backup power for short periods, while others use flywheels to store energy mechanically in kinetic energy. The type of energy storage used in a UPS system can influence the topology and power capacity required, which is why most data centers use double-conversion online UPSs with internal automatic static transfer switches.
UPSs with energy storage can help protect data center devices against a broader range of power anomalies than traditional standby or line-interactive UPSs, including sags, surges, brownouts, frequency instability, and harmonic distortion. They can also support the bypass mode used by many large data centers, which allows them to work with their commercial power company to share the load during peak usage times, helping reduce electricity costs and avoid power outages in the local area.
UPS systems with energy storage are available in rack-mounted and freestanding form factors, with the choice between these two options largely a matter of data center design philosophy. Rack-mounted units are designed to accommodate multiple power modules in a close configuration, maximizing space within a cabinet or enclosure. In contrast, freestanding units can accommodate more extensive power requirements and can be arranged in a row of cabinets on the floor.
Inverters
A data center’s computers, servers, routers, and network management devices depend on continuous, clean DC power. Even slight voltage fluctuations can cause equipment to shut down or overload, disrupt applications, and create costly service-level agreement payouts and other undesirable downtime tolls.
To keep your operations running smoothly, the UPS system is designed to provide backup power for critical equipment in case of a power outage or abnormal power fluctuation. It accomplishes this by utilizing several key design features, including redundancy and a robust control mechanism.
A UPS system may be built with several different topologies to increase reliability. The most common in a data center is the online double conversion topology. This type of UPS system utilizes power electronics that incorporate a rectifier, energy storage system, and inverter. It can continuously run on the battery backup during regular operation and will only switch to commercial power when there is a problem with the primary source.
A reliable inverter is critical to the overall UPS performance. The inverter converts the DC power from the rectifier or energy storage system into AC power, supplying your equipment with stable, conditioned power. To reduce inverter failure, you can look for advanced technologies such as wide bandgap transistors and silicon carbide.
Monitoring
Whether your data center is a significant enterprise or an edge computing installation, UPS systems can help ensure critical equipment stays online during power problems. By regulating power from the fluctuating grid, UPS devices can prevent brownouts and drop-outs that can damage disk drives and corrupt valuable data.
UPS devices also bridge the gap between a power failure and the activation of backup power sources, such as generators. This role can significantly improve the reliability of your data center.
The essential components of an uninterruptible power supply (UPS) include a rectifier, an energy storage system, and an inverter. The rectifier converts AC power into DC energy to feed the energy storage system. The energy storage system can comprise batteries, flywheels, or supercapacitors. The inverter turns the stored energy into the required AC power to connect to the load.
Different UPS topologies provide varying levels of protection and performance. Choosing the correct topology for your data center depends on how much protection you need, the type of equipment being protected, and your overall power requirements.
Efficient data center UPSs use a modular design that allows you to purchase only the necessary capacity and redundancy. This reduces your upfront costs and helps you avoid overbuying in anticipation of future growth. Additionally, many manufacturers offer UPS battery frames designed to maximize white space in the rack, reducing your overall footprint.
