critical power distribution system

7/24/2019 Critical Power Distribution System

1/77

Critical Power Distribution Systems

IEEE Presentation

May 2005

Mike Filley


2/77

Critical Power Distribution Systems 2

Tonights Points o! DiscussionWhat is a Critical Power Distribution System?

NEC Considerations

Classical Distribution Systems

Addition of Enery Storae and Power !eneration cre ates a Critical Pow er Distribution System

Some "e#resentati$e Systems

"eliability Princi#les "eliability $ersus A$ailability

What does it mean anyway? %he im#ortance of #ro#er commissionin

Sinleoint&of&failure analysis

%he system mustbe maintainable

"eliability $s' Safety

Enery Storae Systems

!roundin Considerations

Achie$in (etter Selecti$ity


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Critical Power Distribution Systems )

Critical Power Distribution Systems

*ound in client facilities where a$ailability of electric#ower must be maintained +,,- of the time. industrialfacilities with )/01123 #roduction schedules4 datacenters4 telecommunications facilities '''

Where un#lanned 5and sometimes #lanned6 #ower

interru#tions can create se$ere and ad$erse 5economic6im#act

*or the #ur#oses of toniht7s discussion4 those systemswhich ty#ically fall under NEC Article ,2&8#tionalStandby Systems

%y#ically contain multi#le utility sources4 electrochemicalor electromechanical enery storae systems 59PS64and on&site #ower eneration


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"ational Electrical Co#e Consi#erationsArticle ,, Emerency Systems & Systems intended to

su##ly4 distribute4 and control #ower and illuminationessential for safety to human life4 in the e$ent of failure tothe normal su##ly:fire #um#s4 o#eratin room and life&su##ort e;ui#ment4 non&unit based emerency and eandatory testin and record&ee#in

!round&fault tri# not re;uired4 detection recommended

@f batteryro$ided4 +&+12 hour su##ly

>ulti#le transfer switches for emerency4 leally re;uiredstandby4 and o#tional standby circuits

%em#orary or #ortable source re;uired durin maintenance

New re;uirement4 selecti$e coordination with su##ly side8CPD7s


5/77


"EC Consi#erations $cont#%

Article ,+ eally "e;uired Standby Systems&Systemsty#ically installed to ser$e loads4 such as heatin andrefrieration systems4 communications systems4$entilation and smoe remo$al4 sewae dis#osal4lihtin4 and industrial #rocesses that4 when sto##ed

due to outae of the normal su##ly4 couldcreate ha=ardsor ham#er rescue of fire&fihtin o#erations /, second a$ailability

Wirin may share normal system raceways

Second #riority to emerency systems

!round&fault #rotection not re;uired New re;uirement. selecti$e coordination with all su##ly&side

8CPD7s


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Critical Power Distribution Systems /

"EC Consi#erations $cont#%

Article ,2 8#tional Standby Systems & Systemsinstalled to #ro$ide alternate #ower source for industrialand commercial buildins:to ser$e loads such asheatin and refrieration4 data #rocessin andcommunications4 and industrial #rocesses that4 durin a

#ower outae4 could cause discomfort4 serious #rocessinterru#tion4 damae to #roduct or #rocess: Parallel o#eration #ermitted if com#lies with Art ,0

Portable sources #ermitted w1o transfer e;#t if normal sourceisolated and o#eration su#er$ised by ;ualified #ersonnel

!round fault #rotection is re;uired

Automatic o#eration re;uires disconnection from #rimarysource

%y#ical #rotections include #hase loss4 sync chec orsynchroni=in relay4 re$erse current or #ower


7/77Critical Power Distribution Systems

IEEE Stan#ar# &'& (e# )ook !or )asic

Design Consi#erations in a Distribution

System

Safety

"eliability

System "eliability Analysis and %otal 8wnin CostSim#licity of 8#eration

>aintenance

*le


8/77Critical Power Distribution Systems B

*hat #o we nee# !rom critical +ower,

Ne$er oes downProtect e;ui#ment to minimi=e damae at the #oint of

fault

>aaintainable

-.

/TIIT1 .


9/77Critical Power Distribution Systems

Classical3 Distribution Systems

Sim#le "adial oo# and %a#&Sinle #rimary cable loo#

Primary Selecti$e&*ully redundant dual #rimary cables

Secondary Selecti$e&two transformers&double endedsubstation&oad fed from both transformers normally4

one transformer if necessary' Primary1Secondary Selecti$e&Dual #rimary cables4 two

transformers in double ended substation confiuration'

Secondary or s#ot networ&%ransformers o#erated in#arallel4 utili=in networ #rotectors or /120F1relays with circuit breaers'


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C.SSIC.3 DIST(I)/TI4" S1STEMS

(.DI.


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Critical Power Distribution Systems ++

44P Primary


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Critical Power Distribution Systems +2

Primary Selectie 6 ine Selector

)/S . )/S )


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Critical Power Distribution Systems +)

Primary Selectie 6 Du+le7 Main


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Secon#ary Selectie


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Secon#ary Selectie

>ay be ey&interloced or Automatic %hrowo$er System +' >ain&%ie&>ain' %wo sources with both su##lyin load

#ower' oss of $oltae on either source effects automatictransfer to remainin $oltae source and feeds all loads'

2' Normal&Alternate' Alternate source may be second utilitysource or on&site customer owned enerator' All loads fed

from one source' @f enerator is alternate source4 loadsheddin may be necessary de#endin on eneratorca#acity'

)' "e&transfer to normal mode' What is customer tolerancefor dead bus durin re&transfer? Should re&transfer bedelayed? Should closed transition be considered if both

sources are utility?


16/77

Critical Power Distribution Systems +/

Secon#ary S+ot "etwork


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Critical Power Distribution Systems +

The integration o! energy storage an#

+ower generation e8ui+ment into these

classical schemes +ro#uces critical +ower

#istribution systems


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Critical Power Distribution Systems +B

. )asic Critical Power System

-enerator9.TS9/PS w9 Single /tility Fee#


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:ow to -enerate Power,

(9S A (9S (

!ENA

!EN(

9%@@%GA

9%@@%G(


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Critical Power Distribution Systems 2,

)lock (e#un#ant


21/77

Critical Power Distribution Systems 2+

:ow to -enerate Power,

)/S . )/S )

-E"

.

-E"

)

/TIIT1

.

/TIIT1

)


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Parallelling ; Synchroni


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Critical Power Distribution Systems 2)

M= or = -eneration,

-E"

.

-E"

)


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(eliability 6 De!inition

%he #robability that the e;ui#ment will not fail within thene


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(eliability 6 De!inition

What is your reliability atae 0,?

%he #robability that the the e;ui#ment will not fail within the

ne


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Critical Power Distribution Systems 2/

*hat is your )reakers (eliability

"eliability when?How do you come u# with the answer?

System

(eliability

Time $1ears% 500


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:ow is it #one,

@EEE !old (oo

>aes fundamental assum#tions about reliability

Assumes reliability declines e


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Critical Power Distribution Systems 2B

System .ailability 6 The More /se!ul

In#e7

M/T

MDT

System

(eliability

Time

M/T > Mean /+time

MDT > Mean Downtime

.ailability >M/T

M/T ? MDT


29/77


:ow /se!ul is it,

'- Power A$ailability at Com#uter "acs

%ranslates to 0'2 minutes ofoutae

@s it one 0'2 minute outae?

8r 0, of / second outaes?

How about maintenance? Howdoes that come into thee;uation?

What about human factors?


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Critical Power Distribution Systems ),

The C)EM. or ITI Cure


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Critical Power Distribution Systems )+

So@ :ow #o you Make Sense out o! all This,

Do not use reliability and a$ailability numbers as anabsolute measure

9se these for com#arati$e analysesConsider the maintainability factor

-.

/TIIT1 ./TIIT1 .


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Critical Power Distribution Systems )2

*hat #oes a )athtub hae to #o with

Critical Power System Commissioning,

Failure

(ate$Failures

91ear%

Time

In!ant

Mortality *earout

@n "eality4 *ailure "ate is not Constant


33/77

Critical Power Distribution Systems ))

Startu+ =ersus Commissioning

%he oal of e;ui#ment startu# %o brin the e;ui#ment to a #oint where it can be safely eneri=ed

%he oal of system commissionin %o brin the e;ui#ment to a #oint where it would #ro#erly function4

deli$erin the le$el of reliability that is sti#ulated in system desin


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4.DS

Testing /n#er Full oa# Fin#s More than

Aust oose )olts

/TIIT1

Tie )us

PC

2

4.DS oa# )ank


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:ow to

Commission

%est under full load

%est real&life #erformance under $arious failure modes

%he oal is to mae it fail

Do not rela< your standards

Do not cut any corners

%rust4 but $erify each function

+,,- #hysical chec

+,,- control system chec

+,,- C% #olarities and ratio chec

+,,- acti$e com#onent 5circuit breaer4 relay4 etc6 checChec normal4 maintenance and failure modes


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Critical Power Distribution Systems )/

Single Point o! Failure .nalysis

%he hand renade rule +

1 Due credit is given to Mike Mosman, P.E.

%he chain saw rule +


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9tility at '- a$ailability 5B hour outae #er year6 Necessitates bacu# enerators

>aintainability >aintainability is enineered in the desin of the data center

such that each #iece of e;ui#ment can be shut down for

maintenance without Ieo#ardi=in the critical loadsE$ery Power Path (aced u#

No sinle failure Ieo#ardi=es the critical load

Consideration must be i$en to fault clearin

Consideration must be i$en to the effect of roundin

methodConsideration must be i$en to arc flash

Mission Critical@ Present Para#igm


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Critical Power Distribution Systems )B

*hat about (eliability sB Personnel

Protection,

@n critical #ower systems4 there often are limited o#tionsfor shuttin down e;ui#ment4 unless redundant #aths for#ower ha$e been fully desined into the system:sometimes an almost im#ossible tas'

*or reliability4 we want breaer selecti$ity4 which usually

means e


39/77


Personnel Sa!ety

Some o#tions to consider to reduce arc flash ha=ards.

Concurrent short circuit1coordination1arc flash analyses

(arriered construction

F (us insulation

Jone selecti$e interlocin on round fault and shorttime #rotecti$e functions

Hih resistance roundin

"emote o#eration

"emote breaer settin chanes


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*hat about Energy Storage,

/PS To+ologies

Double Con$ersion Static 9PS

"otary >&! Sets

ine @nteracti$e Static %echnoloy "otary %echnoloy


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The Double Conersion /PS

M-E@ iebert

/TIIT14ut+ut FM(

Hih osses & /- to +,-

*ilter in the in#ut is a #roblem

(atteries tae a lot of s#ace and ha$e en$ironmentalissues

A$ailable short circuit is low & ) times rated current

How do you round the out#ut?

Critical

oa#


42/77


Double Conersion (otary

The Motor 6 -enerator Set

/TIIT1 4ut+ut Machine

Hih osses

*lywheel has hih #ower deli$ery ca#ability4 but lowenery storae

A$ailable short circuit can be hih 5+3 < rated am#s6 &this is a ood thin

How do you round the out#ut?

In+ut Machine

Flywheel

Criticaload


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DCDC

Stator

(otor E7citer

Electrical oa#

Power Source

Stator

The :ybri# (otary M6-

System Fan

Start motor

)rushless E7citation

Motor an# -enerator *in#ingsin a common Stator

Common (otor with

Dam+er win#ing

=ertical .rrangement

!or low )earing oa#

Unloaded Guide Bearing

Thrust )earing

Filter Choke


44/77


Double Conersion (otary

Piller /niblock

N'C'

N'8'

A9%8'(GPASS

"EC%@*@E"

@NFE"%E"

A'C' @NP9%

"EC%@*@E"

_

~

*GWHEE


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*hich is the Most E!!icient *ay,

/TIIT1

UPSCriticaload

/TIIT1

PowerConversion

Equi.

Criticaload


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Shunt Connecte# Power Con#itioning

/TIIT1

Criticaload

Control Com+onents

KE7citationKSha!t Power

=0 0

=m

=m =0 Synchronous Con#enser

0

0 Synchronous -enerator


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Shunt Connecte# Power Con#itioning

/TIIT1

Criticaload

=0 0

=m=m =0 Synchronous Conerter

0

.CC/SI"E


48/77


/TIIT1

Criticaload

The ine Interactie Static /PS

.PC@ Delta Conersion


49/77


/TIIT1

Criticaload

The ine Interactie Static /PS

.ctie Power@ Cater+illar

4ut+ut FM(

Hih S#eed *lywheel

K"ated 20, LW4 +) seconds #er module

K+3 hih4 )2 diameter

K"uns at about ,, "P>

KParallel multi#le modules


50/77


ine Interactie (otary /PS

:iTek

/TIIT1

(otary /PS

4ut+ut Machine

Critical

oa#

No tuned harmonic filter

osses in 3- raneChoe M synchronous machine acts as a filter'

Absorbs load harmonics and blocs utility $oltae harmonics

"eulates $oltae and su##lies the reacti$e #ower need of the load

3- +-

# > GH


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ine Interactie (otary /PS

Piller

/TIIT1

Critical

oa#

3- +-


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Switchgear Design Consi#erations@

-roun#ing

Solid or hih resistance?

9nrounded systems

%FSS a##lication issues

9PS e;ui#ment and the method of roundin Double Con$ersion 9PS

ine @nteracti$e 9PS


53/77


System -roun#ing

An intentional connection to round

8AD


54/77


Metho#s o! System -roun#ing

/ngroun#e#

:igh (esistance -roun#e#

" ,

Power Juality Problem

Soli#ly -roun#e# Power .ailability Problem


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/ngroun#e# System an# .rcing Fault

-roun#

4.DS

Arcin*ault

A

( C

A

( C

A

( C

!

!!


56/77


Soli# -roun#ing

2GG =

2F for fluorescent lihts

Foltae to round $ery stable

%FSS de$ices a##liedeffecti$ely


57/77


Soli# -roun#ing

2GG =

Electrician7s Wrench to round

Short circuit

Arc and blast

Power a$ailability #roblem &!round *ault interru#tsthe circuit


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.n .lternatie@ :(-

Hih a$ailability#ower

Safety

*ault current islimited by theresistor to below +,am#eres

ess co##er & no neutral

So *hats the Catch,


59/77


So *hats the Catch,

@s it si=in the resistor?

Cable ca#acitance issues?

%he #roblem with hih resistance roundin is in maintenancere;uirements

PowerWillContinueto Flow


60/77

Critical Power Distribution Systems /,

/PS 4ut+ut )oar#

-roun# Fault Design Problem



61/77

Critical Power Distribution Systems /+

-/TIIT1

To oa# )ank

C4MP/TE(

/PS

M4D/E

/PS

M4D/E

ST.TIC

S*ITC:

!"#$ %E$

&P'

&P2

!()' !()2!()S


Circulating Currents an# "uisance Tri+s


62/77

Critical Power Distribution Systems /2C4MP/TE(

/PS

M4D/E

ST.TIC

S*ITC:

-E"

-F -F

-F -F -F

-F

-F-F

-F

/TIIT1

-F

Circulating Currents an# "uisance Tri+s


63/77

Critical Power Distribution Systems /)

:ow )ig o! a Problem is it,

Enouh to cause inad$ertent tri#s4 which reducesystem reliability and lon term a$ailability

Eliminate !round fault #rotection?Defeat round fault #rotection?

%y#ical Solution is to reduce the sensiti$ity of

round fault #rotection

Eliminate -F Protection


64/77

Critical Power Distribution Systems /3

!round *ault

C4MP/TE(

/PS

M4D/E

ST.TIC

S*ITC:

-E"/TIIT1

-F -F

-F -F -F

Eliminate -F Protection


65/77

Critical Power Distribution Systems /0

(ami!ications,

NEC article 2+0'+, re;uires round fault#rotection of feeders

9nless it increases ha=ards

Emerency circuits eM/T

M/T ? MDT


66/77

Critical Power Distribution Systems //

De!eat the -roun# Fault Protection

/TIIT1 4ut+ut FM(

Critical

oa#/PS

-roun#

Fault

(e#ucing the Sensitiity o! -roun# Fault Protection


67/77


g y

-)-.

Can you Design a -roun# Fault Protection


68/77

Critical Power Distribution Systems /B

Can be set as sensiti$e as desired 5minimi=e e;ui#ment re#airtime in case a round fault does occur6

@s im#er$ious to any and all circulatin currents & no nuisancetri##in due to circulatin currents

A round fault in one bus only tri#s the circuit breaers thatfeed directly into that bus

@s reasonable in cost

Can you Design a -roun# Fault Protection

System that BBB,

S8uare Ds Solution . Di!!erential System


69/77


-/TIIT1

To oa# )ank

C4MP/TE(

/PS

M4D/E

/PS

M4D/E

ST.TIC

S*ITC:

!"#$ %E$

&P'

&P2

!()' !()2

!()S

Jone of Protection

S8uare Ds Solution 6 . Di!!erential System

S8uare Ds Solution . Di!!erential System


70/77

Critical Power Distribution Systems ,

-/TIIT1

To oa# )ank

C4MP/TE(

/PS

M4D/E

/PS

M4D/E

ST.TIC

S*ITC:

!"#$ %E$

&P'

&P2

!()' !()2

!()S

Jone 2

S8uare D s Solution 6 . Di!!erential System


71/77


The Sim+le Double En#e# Substations


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/PS 4ut+ut -F@

The Solution

>8D+

B

>8D2

)

/

B

) 0

03

/

/

0

2 )

2 3

+

+

2

3


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9tili=es einimal addition of e


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.chieing )etter Selectiity

Desins usin standard circuit breaers do not offero#timi=ed selecti$ity in the instantaneous rane

Newer eneration solid state circuit breaers #ermit useof #hysically smaller4 hih am#erae frame breaers

which use reduced am#acity lon&time tri# settins

%he instantaneous adIustment rane on these breaersis e


75/77


Enhancing Short Circuit Selective

Coordination with Low Voltage Circuit

BreakersData )ulletin

>ay be found at www's;uared'com & #roduct su##ort & technical library & circuit #rotection

( l * l# E l K&


76/77


(eal *orl# E7am+le K&

MaLor State /niersity :ealth Center 8ne&line descri#tion

%en 3B,G12F emerency lihtin #anelboardse$aluated

*ed from one of two #ower #anelboards

*ed from one of two A%SOs

A%SOs fed from a utility fed switchboard and from aenerator fed switchboard

"esult of selecti$e coordination study

Achie$ed full selecti$e coordinationby chanin breaer

selection @ncreased cost of S;uare D e;ui#ment on Iob 5oriinally

/026 by 2'- 5breaers only6

( l * l# E l K&


77/77

(eal *orl# E7am+le K&

critical power distribution system

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