From processing and disseminating data, to housing proprietary assets, to ensuring the Internet remains accessible at all times, today’s data centers are vital to an organization’s daily operations. Instantaneous access to information is no longer simply a desire; in today’s Internet-driven world, it has become an absolute necessity. As a result, data center power has never been more important.
To operate safely and optimally, computers, servers, routers, network management devices and other sensitive electronic equipment within the data center all rely on continuous, clean DC power. Because the processors and power supplies within these devices can only handle small voltage variations without being susceptible to shut down or overload, the muscle behind ensuring continuous uptime in the data center falls upon the uninterruptible power supply (UPS). Without UPS power, outages and normal voltage fluctuations in the utility supply can take down critical loads, damage hardware, require expensive Service Level Agreement (SLA) payouts and spark other undesirable downtime tolls.
What is a UPS System and Why is it Important for Data Centers?
An uninterruptible power supply (UPS) is a power protection device that delivers a continuous supply of electric power to critical systems. UPSs maintain power in such a way that the transition from utility power to battery power is seamless and uninterrupted. In addition to immediately providing backup power to connected critical infrastructure and IT equipment in the event of a power failure, some UPSs also shield sensitive electronics from potentially damaging power anomalies within the utility power supply. The UPS equipment is inserted between a primary power source, such as a commercial utility, and the power input of the equipment being protected. In some data center configurations, UPSs are also responsible for bridging the gap between a power failure and the activation of another backup power source, such as a generator.
Benefits of Uninterruptible Power Supply Systems in Data Centers
There’s no downplaying the peace of mind that data center operators reap from having a reliable UPS system protecting critical equipment from power-related disruptions. Playing an integral role in ensuring the availability of IT infrastructure and data, data center UPSs afford numerous advantages, including:
- Preventing downtime ― By keeping connected equipment up and running during a power failure, UPS systems minimize data center downtime. The negative consequences of downtime can be enormous ― not only in terms of lost revenue and SLA payouts, but in negative impacts to an organization’s reputation and customer trust.
- Enabling data integrity ― By providing a stable power source that allows servers and storage systems to shut down properly, UPS systems prevent sudden power interruptions that can cause data corruption and loss.
- Aiding in business continuity ― With their ability to supply continuous power, UPS systems provide a seamless transition from primary power to backup power in the event of a power failure. In this way, critical equipment remains operational without interruption, helping an organization to achieve resilience, recovery and contingency.
- Reducing equipment damage ― Frequent power fluctuations and outages cause wear and tear on IT hardware. UPS systems provide clean, stable power that can extend the lifespan of servers, networking cables and equipment, storage devices and other sensitive electronics.
- Enabling proactive response ― Because many modern UPS systems offer remote monitoring and management capabilities, an organization’s IT staff is able to monitor conditions such as battery health and power usage, making it easier to respond to potential issues before they become expensive problems.
- Helping to lower operating costs ― Many UPS systems are designed to be energy-efficient, reducing electricity costs and environmental impact through technologies that optimize power usage. Although UPSs require an initial investment, they can save money in the long run by preventing costly downtime, equipment replacement and data recovery expenses.
- Ensuring regulatory compliance ― In industries subjected to strict compliance regulations related to data protection and business continuity, UPS systems can help meet these requirements by safeguarding data availability.
- Assisting in emergency response ― UPS systems can also buy IT professionals valuable time during a power failure, allowing staff to respond to the situation, initiate backup power sources, and gracefully shut down non-essential systems.
Types of Data Center UPS Systems
Today’s UPS systems come in a broad range of sizes, capacities and feature sets, with units designed to provide backup power to a single desktop computer all the way up to a massive megawatt data center. Many UPSs can also be easily scaled as the data center grows.
Although UPSs are available in several different topologies ― standby, line-interactive and double-conversion online ― the preferred data center design is almost always an online double conversion system. With this topology, the battery system is always connected to the critical systems it supports, and does not require switching to the power backup source. Double conversion units not only keep critical systems and equipment operational during a complete power failure, but safeguard devices against a broad range of power anomalies, including sags, surges, brownouts, frequency and harmonic distortion.
In modern data centers, the most advanced UPS systems rely on a transformer-less, multi-level topology that ensures the highest reliability and efficiency. Some manufacturers also use transistors such as silicon carbide, which increases the efficiency of UPS systems up to 98% in double-conversion mode.
Less critical equipment within data centers may also be protected by line-interactive UPSs, particularly in edge computing environments where IT staff may not be on site. This type of UPS can adjust the output in response to over- and under-voltage conditions without relying on the battery, with a switch transferring the load to the battery if a power failure is detected.
In a standby/offline topology, the UPS powers the load directly and only switches to backup power in the event of a power failure. Because this type of UPS is very basic, and does not provide protection against other power fluctuations, it is not suitable for the data center environment.
In order to meet the high uptime requirements for data centers, most online UPS systems within data centers are also configured for redundancy. Simply put, redundancy can be achieved when multiple UPSs and/or modules are tied together to support the load. There are several levels of redundancy, depending on how the UPS units are grouped together and how they are connected to critical systems. For example:
- N+1 redundancy ― “N” is defined as the full UPS capacity required to handle the total load. For simple redundancy, an extra module is installed, which is expressed as N+1. In this multi-module system, each UPS is capable of providing the required “N” power.
- 2N redundancy ― Enterprise-level IT equipment often supports dual power supply operation in which equipment is connected to multiple power sources. In a data center, these two sources are independent UPS systems; the “A side” and a “B side” can feed the computer equipment, with each side able to support the entire load capacity if needed.
- 2(N+1) redundancy ― In a 2(N+1) redundant power distribution system, instead of a single module UPS on each side, there are multiple modules. This provides N+1 redundancy on each side.
Components of UPS Systems
Regardless of the type of UPS system, all critical power battery backups are manufactured with several specific components, including:
The rectifier converts the input AC power into DC power, which is used to feed the UPS’s energy storage system.
2. Energy storage
Every UPS relies on some method of storing energy in case of a power failure. While batteries are the most common source, other options include flywheels and supercapacitors.
The inverter within the UPS converts the DC power from the rectifier or the energy storage system into AC power, which is needed to provide clean power to the load.
To further enhance reliability in double-conversion online UPSs, the units are equipped with an internal automatic static transfer switch that enables it to automatically transfer to bypass if a problem or fault is detected. Many UPS systems in data centers also make use of an external maintenance bypass, a piece of switchgear that allows manual transfer of the critical load from the UPS to a bypass power source. This enables safe maintenance work to be completed on the UPS.
Call Unified Power to Learn More About UPSs For Data Centers
Data center UPSs represent a crucial component in achieving high reliability, availability and integrity of IT infrastructure, data, and services. However, in order to ensure optimal performance, these UPS systems require regular preventive maintenance. As a national, one-stop service provider, Unified Power understands just how critical ongoing UPS health is to your data center. Our comprehensive preventive maintenance services ― including battery replacement, capacitor service, generator repair, and more ― help data centers to avoid unplanned downtime and costly repairs by providing the opportunity to catch potential issues early. Our team of highly trained technicians delivers industry-leading maintenance with fast response times. Visit our website for more information on our broad range of services, or to request a quote.