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DATA CENTERSWhen it comes to power,quality mattersClean, uninterrupted power is the lifeblood of every data center. Bymeasuring the quality of power, operators can keep an eye on their datacenter’s health and stay informed about emerging issues.siemens.com
The basics of power qualityDATA CENTERS:When it comes to power,quality mattersWhen it comes to data centers, it’s all about uptime and reliability. Users expect noless than 99.999 percent availability year-round. To achieve that goal, operatorspay great attention to power and cooling redundancy. Great attention is also paidto cyber- and physical security, to prevent unauthorized access and ensure safety. Atopic that’s often underestimated is power quality, which can directly impactuptime and reliability.The basics of power qualityOptimal power quality means having clean and stable AC power that oscillates at50 Hz or 60 Hz to form a perfect sine wave, without noise or distortion in the linethat can guarantee continuous 24/7 operations of IT equipment. This correspondsto the ideal state, but in a data center different types of power quality problemscan arise. Here are the most common interferences: Voltage sag. Supply voltage falls under 90% of the normal voltage level foronly a few milliseconds. Possibly resulting in flickering for lighting and storageloss and data error Transients. Extremely brief overvoltages which can reach several thousandvolts. Possibly resulting in destroyed power supply units and IT hardwaredamages Harmonics. Multiples of basic oscillation. Possibly resulting in overheating ofequipment and malfunctioning of circuit breakers and fuses Voltage deviations. Result from switch operations in the power grid orstarting up heavy loads. Possibly resulting in reduced efficiencies and aShutdown due to an under-voltage trip.Power quality issues can make power infrastructure unstable, causingunforeseeable reboot of IT equipment or can lead to a much more critical scenario,such as a trip of a protection relay that causes a disconnection from the distributiongrid. It is therefore vital to exactly understand which components are causing theseproblems.2WHY POWER QUALITY MATTERS
The basics of power qualityVoltage sagTransientsSupply voltage falls under 90% of the normal voltagelevel for only a few milliseconds. Possibly resulting inflickering for lighting and storage loss and data errorExtremely brief overvoltages which can reach severalthousand volts. Possibly resulting in destroyed powersupply units and IT hardware damagesHarmonicsVoltage deviationsMultiples of basic oscillation. Possibly resulting inoverheating of equipment and malfunctioning ofcircuit breakers and fusesResult from switch operations in the power grid orstarting up heavy loads. Possibly resulting in reducedefficiencies and a Shutdown due to an under-voltagetripWHY POWER QUALITY MATTERS3
Finding weak spotsContinuously recorded and evaluatedUninterruptible Power Supply (UPS). To increasemeasurements relevant to power quality help toenergy savings the UPS will be processed in bypass-detect interfering issues and offer the chance toor eco-mode. Nevertheless, UPS needs to ensureprevent failures. Some of these issues do not seemthat the signal for activation comes up before theso obvious at first sight. These are five possibleITIC curve limits are reached. Such scenarios can beweak spots in data centers:recorded and documented in a disturbance recordMedium-voltage infeed and Automatic TransferSwitches (ATS). During normal operation it isby the SICAM Q200 using a very high samplingfrequency of 1 MHz.necessary to know about the power quality providedIt also needs to be considered that supra harmonicby the distribution network operator (DNO).pollutions won’t be reduced by an UPS, this resultsSwitching activities on DNO side produces voltagein a need of harmonics observation in a frequencydips and transients which could influence therange of 2 kHz up to 150 kHz which is part of thestability of the energy network inside the datastandard IEC 61000-3-40 Edition 3 and implementedcenter. On the other side - under so called notin the power quality recorder SICAM Q200.normal conditions - when the ATS switches intobackup mode and the diesel gensets supplies thepower for the building, it can emit harmonicsdistortions into the MV distribution network. ASICAM power quality recorder installed at an ATSprovides information about power quality issues inboth directions.Cooling system. Cooling is responsible for arelevant portion of the energy consumption in adata center. During the last two decades HVACmanufacturers, driven by sustainability directivesand energy efficiency measures, have shifted thedesign of cooling units by using pumps, fans, andcompressors controlled by variable frequency drives.Low-voltage main power distribution units. AAs a result, energy consumption has decreased oversubstantial number of nonlinear loads cometime, at the cost of introducing more non-lineartogether in a data center. Each rectifier consumescomponents that can lead to harmonic distortions.power in a nonlinear manner. Therefore, it can emitCooling systems are also subject to restart in case ofharmonics backwards to the distribution network. Ingrid outage when the back-up generators arecritical situations, that can result in an unwantedstarted up to provide power continuity to the wholeprotection release of one or more trips without afacility.real over-current incident. Investigating the cause ofsuch malfunctions is normally extremely timeconsuming and expensive. But with power qualityrecorders, harmonics are measured automatically,and operators become aware of any critical situationthat may cause a protection relay to trip. With thatinformation they can initiate the necessarypreventive maintenance to avoid any future trip.Power feed to the racks. The power supply ofservers and IT equipment in general can generateharmonic distortion. This results in a sinusoidalshape deformation influenced by IT load and leadsto a crest factor variation. While these powersupplies have improved the power factor of theservers over time, the on-board rectifier produceshigh-frequency disturbances, from 2 kHz up to 150kHz. These so-called supra harmonics reduce thelifetime of all kinds of capacitors inside electroniccircuits. Supra harmonics can furthermore lead toLED flickering and noise. Here, the SICAM Q200measures these harmonics and displays them in adiagram called Heat-Map. With this information, afaulty power supply can be detected early on. Andagain, in the framework of a preventivemaintenance approach it can be replaced before itcauses larger issues.4WHY POWER QUALITY MATTERS
Backup powerMV infeedPower managementTransformersUPSCooling AC SystemsLV main power distributionPower to racksHV supplyMeasure, record, analyze, improve.Measuring power quality with easy-to-install devices such as the SICAM Q100 andthe SICAM Q200 helps data center operators to get a thorough picture of theirinfrastructure’s health. Thanks to the modular and compact design, the housing ofa SICAM Q100 (96mm x 96mm) doesn’t require a separate cabinet and can beinstalled in any switchgear of brownfield and greenfield data centers. The devicemeasures power quality and performs analyses according to IEC 61000-4-30 Class AEdition 3. Power quality evaluation results are accessible via a web browser or viamanagement platforms such as EPMS or BMS. Security is ensured among otherswith role-based access control rules and crypto chips that accept firmwarepackages with Siemens’ signature only.As many power quality patterns become only recognizable over the course ofmonths or even years, a long-term monitoring strategy can help operators toidentify what processes are leading to a critical situation and thus prevent similarcases from occurring again. It also helps them to achieve the levels of availabilitythat have been targeted during the design phase (e.g. the “five 9s” or more) andavoid penalties in case of SLA infringements. A service interruption, in fact, mayhave severe consequences for the business, both in terms of missing revenues andloss of reputation. By providing continuous detection and traceable data records ofany power anomaly (even though it occurs randomly), power quality recorders arethe answer to operator’s request to continuously improve operationsWHY POWER QUALITY MATTERS5
Smart Infrastructure intelligently connects energy systems,buildings and industries, enhancing the way we live and workto significantly improve efficiency and sustainability.We work together with customers and partners to create anecosystem that both intuitively responds to the needs ofpeople and helps customers achieve their business goals.It helps our customers to thrive, communities to progress andsupports sustainable development to protect our planet forthe next generation.Creating environments that care.siemens.com/datacentersPublished bySiemens Switzerland LtdSmart InfrastructureGlobal HeadquartersTheilerstrasse 1a6300 ZugSwitzerlandTel 41 58 724 24 24The information and conclusions provided inthis document are based on review and analysisof 3rd party industry data. It is subject tochange and errors. 2021, Siemens
the SICAM Q200 helps data center operators to get a thorough picture of their infrastructure's health. Thanks to the modular and compact design, the housing of a SICAM Q100 (96mm x 96mm) doesn't require a separate cabinet and can be . avoid penalties in case of SLA infringements. A service interruption, in fact, may have severe .
