380 vdc power distribution alternatives for datacom applications

DC Power Distribution Alternatives for DatacomApplications

BJ SonnenbergManager Business Development

2

Emerson Network Power, Energy Systems North America, Inc.; Proprietary and Confidential Information.

Increasing rack power density

Increasing component integration on site

Modularity & Scalability

`

Forces re-evaluation of all available topologies

Increasing drive for efficiency

>40kW

Traditional AC UPS Powered

Telecom 48V DC Configurations

New 48V DC Topologies

NewHigh Efficiency

Topologies

< 2 kW

Future Higher Voltage

Topologies

DC PowerAC Power

Data Center Trends

3


Modular System, Row-based

Advantages of integrated, modular UPS systems:High power density in a compact footprintReduced field wiring and copper contentTargeted for row-based deployments; no need for dedicated power room

Maintenance Bypass

3

Source: Intel

TraditionalAC UPS

DC UPS

480VAC

BB

MV

DC/DCPSU

Rack

AC/DC DC/AC

Primary Dist.

B B AC/DCB

CDU PSU

VR

12V

PDU

B

480VAC

MV

DC/DCPSU

BB

CDU

VR

12VAC/DC

RectifierPDU

Data Center Power Protection andDistribution Basic Architectures

Attributes of a DC UPS:Simple input and output distribution, easy to parallel ,no load balancing (derating)Minimal conversion stages grid to chip –high end-to-end efficiency and reliabilityHigh power quality - isolated from mains, no harmonicsSafe voltages at point of use (48VDC systems)

B

UPS Bypass

Server

Rack

Server

48V/380DC

System optimization challenge – best overall system topology for a specific application , not necessarily optimization of individual existing components.

300-400VDC

4


Improved Efficiency with DC Solutions

Elimination of conversion stages and simplified distribution

5


Facility distributionoptimization

Rack/server distributionoptimization

Renewable resources Microgrids

Megatrends in Data Center Distribution Evolution

• Decrease utility power consumption – peak shaving and over time.Address all loads , not only compute loads (lighting , cooling , etc)Server virtualization

• Maintain high availability• Best system utilization – rightsizing , no stranded power• Scalability• TCO

6


Impact of Renewable Energy Sources - Example of Telecom Facility Transformation Vision

Utility

Gen

DC UPS

AC UPS

Batt

Batt

FacilityAC loads

AC computeloads

Telco and dccompute loads

DCAC

Utility

Gen

FacilityAC loads

DC computeAnd telco loads

48VDCTelcoLegacy loads

DCDC

DC UPSBatt

FacilityDC loads

AC computeLegacy loads

ACDC

Utility

FacilityAC loads

DC computeAnd telco loads

DC EnergyStation

Batt

FacilityDC loads

GreenGenerator

48VDC

400VDC

400VDC

Present

Interim

Ultimate

Many transition paths

DC facilitates and optimizes use of renewable resources

7


Elements of an Optimized Power Distribution –Grid to ChipBEST COMPROMISE OF THE FOLLOWING

Efficient facility distribution to equipment racksAbility to easily connect renewable energy resourcesEfficient equipment rack distributionEfficient server PCB distribution – optimize conversion stages

Eliminate stranded powerOperate at peak efficiency at any loadScalabilityLow TCOLow initial costReliability

8


Edited from source: NTT FACILITIES, INC.

300NEDO PJ.(Sendai)

380US DC Demo

575 [to 48]Validus428 (192cell)

600 NEC(U.S.)

900 BS (U.K.)

750 Ordinance (JPN)

1500 IEC

Law, Regulation,Code, and

Stds.

Telecom(Number of

Cells)

Rating voltage of parts and elements

Distr.Gen.

374 (168cell)

321 (144cell)

Dis

trib

utio

n ef

ficie

ncy

Cab

le D

ista

nce

High

450

300

Demos(Reference)

0

200

600

800

1000

DC

Vol

tage

311(JPN)

354(EU)373(U.K.)

320

405

350

Benefit of HVDC system

AC ICT input

voltages( Peak )

Operatingbulk - voltage

380

Short

Long

ETSI Std.(draft)

420

260

380

324V (US

Why 380VDC - Voltage Range Selection Based on Several Criteria

Low

Server PS

9


Which DC Voltage?Depends on facility size/application :

1. Scalable facility level distributionSites/PODs requiring battery back-up - -48VDC “in row” solutions Facility/application with renewable energy availability –380VDC – simpler interface

2. Server rack level distribution-48VDC or 380VDC for racks with power densities > 10kW

10


Power Room Constraint

Room-basedUPS

Row-based UPS

AdditionalData Center

Raised Floor Space

Data CenterRaisedFloor

As rack densities increase, power room size increases proportionally;i.e. a 10x increase in density results in a 10x increase in power room size.

Data CenterRaised Floor

Data CenterRaised Floor

Data Center@ 2kW per Rack

High-Density Data Center @ 20kW per Rack

Sw

itchgearUPS /

Battery Room

Sw

itchgear

No UPS Room,

Increased computing

space

Power and Switchgear Room

Row-based UPS architecture offers ~30% more computing capacity

11


380V DC Application Alternatives

Facility level distributionServer rack distribution

12


380VDC System Components

CONVERSIONFACILITY

DISTRIBUTIONRACK

DISTRIBUTION

CommunicationsSystem cabinet

Rectifier

Controller

Storage , batteryflywheel ,etc

Bus duct,ancillary

switchgear

Power stripsconnectors to

servers

Power supply

13


DC Rectifier and System Design Philosophy

Modular approach selected for scalability and reliability

Maintain same reliability and maintainability as 48VDC systems

Provide input/output isolation to avoid protection coordination issues

Minimize footprint – space savings

High scalability and ease of expansion ( from 12.5kW up )

Efficiency gains through conversion improvement and facility design

Ready to accept renewable energy sources

Offer multiple ratings by use of standard building blocks and conversion cabinet configurations and a set of input/output interface accessories

14


With Energy OptimizationWithout Energy Optimization

Active power management increases overall system efficiency

Unneeded power conversion units (PCU’s) set to standby in low-load conditionsOptimizes individual PCU load for greater system efficiencyUseful for sites with variances in loadPeriodically cycles energized PCU’s for even run time

33%

33%

33%

33%

33%

33%

Standby

Standby

Advantage of High Modularity – Improved Efficiency with Energy Optimization Mode

56%

56%

56%

Standby

33%

33%

33%

33%

33%

33%

Standby

56%

56%

56%

56%

StandbyN+1 redundancy

maintained

15


1U high 10KW RectifierFeature

Input voltage windows 260 to 530VAC

Output power 10KW

Power factor 0.99

THD <5%

Output voltage 297 to 400V

Max output current 30A

Efficiency 95%

Safety UL/CE

16


Emerson’s 380V V0 Solution (Present)Feature

Input 480VAC with 3 phase 4 wire

Output 297 to 400V

Provides up to 100KW in each rack

Load insulation detection function

Max 7 output load connection with load measurement

Over load and on/off detection function

Standard server rack 600(w)*1000(D)*2000(H) :mm

17


Future Offer -System Sizing and Configuration Considerations

Rectifiers space in cabinet (cooling,safety)DC output configurations – bus duct vs hard wire/Tier levelAC input configurations – Tier levelMaintainability level – facility level and DC UPS systemComponents rating limitation (today)Footprint optimizationEase of installation/expansion

Tier 1/2/3 – N+M configuration with multiple inputs/outputs Tier 4 configuration – 2N

18


400VDC System Building BlockImplementation Example

1000ACB

1000ACB

20 -22 Rectifiers250kW N+1

C

C

Distr. A

40 MCCBs

8 brksup to 125A

Individuallymonitoredoption

Draw-out or Plug-in Breakers PreferredFused Disconnects acceptable

480VAC Battery orflywheel

480VAC Battery or flywheel

1. Any part of the system can be maintained without system shutdown

2. Distribution breakers can be added and wired without system shutdown

3. Top and bottom entry provided4. All external wiring run in conduits –

sufficient space to be provided forconduit terminations

5. Failure of either bus A or B should not affect the other bus

6. For single corded loads only one distribution is required

7. Rectifiers can be added or replaced without system shutdown

8. System can operate without battery9. Individual Rectifier failure does not

affect the output bus10. All cabinet connections must be with

conduit11. UL / CSA / CE approved

Includeprovisionfor internalbussing

Loads A

Loads A Loads B

Loads BController

Distr. B

40 MCCBs

8 brksup to 125A

Individuallymonitoredoption

Current / VoltageMonitor

400ACB

400ACB

19


Output Connectivity Options –BusDuct Advantage

400VDCUPS DistrA DistrB

BatteryFlywheel

Bus duct Wire in conduit

BatteryFlywheel

400VDCUPS

ServerRack

ServerRack

A B

A B

Bus duct

BatteryFlywheel

400VDCUPS

ServerRack

A B

Bus duct

800A CB limit230kW

Distribution options:1.Fuses – shorter clearing time2.Breakers – easier to operate3.Bus duct plug-ins – space,scalability

20


250kW 250kW 250kW

UtilityA

UtilityB

1200A

250kW

UtilityA

UtilityB

400A

250kW

UtilityA

UtilityB

400A

250kW

UtilityA

UtilityB

400A

250kW 250kW 250kW

UtilityA

1200A

250kW

Utility

400A

250kW

Utility

400A

250kW

Utility

400ATIER 2

TIER 3

OR

OR

AC Input Configurations –Example of 250kW System Scalable to 750kW

21


Partial 2N Concept

BatteryFlywheel

400VDCUPSn=+1

400VDCUPSN+1

400VDCUPSRed.N+1

ServerRack

Non critical

ServerRack

Future

400VDCUPS

FutureN+1

BatteryFlywheel

Future

Server Room or Electrical Room

Server Room or Electrical Room

Server Room

Facility Loads

BatteryFlywheelOptional

ServerRack

Critical

400VDCUPSN+1

AB

22


Server Rack Distribution

Power strip50A input ~14.5kW 12 positions

Single strip can power up to 12 2U servers at 1200W – A or A+B or 24 1U servers at 600W

For A only configuration up to20 2U servers,40 1U servers(two strips) – total rack power available – 29kW

Power strip50A input ~14.5kW 12 positions

Single strip can power up to 2 blade chassis at 14.5kW – A or A+B

For A only configuration up to 4blade chassis (two strips) – total rack power available – 29kW

12- 40

servers

Blade chassis exampleHPc7000 today

3x2700W power supplies ~8kW maxTypical load- 4-6kW

Feed A Feed B Feed BFeed A

Connector UL listed at 5A or 20AEnd of discharge voltage ~ 290VDC

23


380V DC Application Alternatives

Facility level distributionServer rack level distribution

24


380VDC Sub-RackSun Container–UCSD POC Site

2 X 10kW 400VDCController

Output Breakers400V-48V Converters

25


48VDC or 380VDC Sub-Rack Concept

Building blocks:• 12.5-15kW 380VDC• 6000W 48VDC

Horizontal shelf mounting shown . Shelves can also be mounted vertically

26


Rack Distribution Copper Content

Assumptions:1. 92 servers/rack at 275W-300W 2. Two power systems/rack – 13.5kW each, n+13. Rack power ~ 27kW4. Currents calculated at end of battery discharge – 1.75VDC

27


Rack Layout -Optimized

13.5kW

13.5kW

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

Cross bar – 20”12V – 625A @1.75V48V - 156A @1.75 V380V – 23A @1.75V

Distribution bar – 47.25”12V – 312 A48V – 78A380V – 12A

Server plug 12V - 25A48V – 6.25A380V - ? (5A plug standard)

30A,480V, AC,3phase input plug

28


Rack Layout –Full Bus Sizes

13.5kW

13.5kW

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

11x300Wservers3375W

Cross bar – 20”12V –1250A @1.75V48V - 312A @1.75 V380V – 46A @1.75V

Distribution bar – 47.25”12V – 614A48V – 156A380V – 24A

Server plug 12V - 25A48V – 6.25A380V - ? (5A plug standard)

30A,480V, AC,3phase input plug

29


Back-up

30


Example of Hybrid System Evolution in Enterprise Building -Existing System

Solar Array

PVInverter

ACDistr.

480/208VPDU

Utility350-800V 480Vac 480Vac

480Vac

208/120VAservers

Lighting

100kW

Eff 93%

Eff – 98%?

PS eff – 92%?

Solar to server eff = .93x.98x.92= .838Utility to server eff = .98x.92=.90Lighting and distribution losses not included

Load larger than PV output .Solar power fed back to utility.

Meter

31


Hybrid System Migration -Scenario 1

Solar Array

PVInverter

ACDistr.

NetSure ITM48V DC UPS 380VDC

Converter

Utility350-800V 480Vac 480Vac

480Vac

48VDC Loads

380VDCLoads

Converter to24VDC

Lighting24VDC

100kW

Already existing on site

Existing Emersonproducts

PS eff – 95%?

Meter

Solar to server eff = .93x.97x.95=.856Utility to server eff = .97x.95=.92Lighting and distribution losses not included

32


Solar Array

ACDistr.

NetSure ITMWith Battery

380VDCConverterNo battery

Utility300-400V 480Vac

48VDC Loads

Vehicle charge station

Appliances

380VDCLoads

100kW

Converter to24VDC

Lighting24VDC

380VDC distr. backbone(already considered for buildings/residential applications)

Estimated efficiencies – detailed study in progress

380-48VDCConverter

DC/DCRegulator380VDCoutput

Hybrid System Migration -Scenario 2

Eff- 97% Eff- 97%

PS eff – 95%?

Solar to server eff = .97x.95 = .92Utility to server eff = .97x.95 = .92Lighting and distribution losses not included

ReplacesExisting PVInverter

33


400VDC System VoltagesCell type Number of Number of Nominal Operating VDC Operating VDC Min VDC 48VDC

cells blocks VDC @2.25VDC/cell @2.17VDC/cell @ 1.75VDC/cell multiplesend of discharge

144 24 288 324.00 252.00 6.00150 25 300 337.50 262.50 6.25156 26 312 351.00 273.00 6.50162 27 324 364.50 283.50 6.75

VRLA -6 V 168 28 336 378.00 294.00 7.00block 174 29 348 391.50 304.50 7.25

180 30 360 405.00 315.00 7.50186 31 372 418.50 325.50 7.75

equalizeWet cells 162 324 364.50 351.54 283.50Single cell 163 326 366.75 353.71 285.25

164 328 369.00 355.88 287.00165 330 371.25 358.05 288.75166 332 373.50 360.22 290.50167 334 375.75 362.39 292.25168 336 378.00 364.56 294.00169 338 380.25 366.73 295.75170 340 382.50 368.90 297.50171 342 384.75 371.07 299.25172 344 387.00 373.24 301.00173 346 389.25 375.41 302.75174 348 391.50 377.58 304.50175 350 393.75 379.75 306.25176 352 396.00 381.92 308.00177 354 398.25 384.09 309.75178 356 400.50 386.26 311.50179 358 402.75 388.43 313.25180 360 405.00 390.60 315.00

To optimize battery applications the voltage range should be:

Nominal 336VDC-352VDCMin 294VDCMax 400VDCTypical operating voltage 378VDC VRLA

386VDC Flooded cellsNot counting cable voltage drop.

OutsideETSI spec

380 vdc power distribution alternatives for datacom applications

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