Transcript Title (40 pt. Tahoma)

Increasing the Efficiency of UPS
Systems – And Proving It!
Richard L. Sawyer
Director, Critical Facilities Assurance
EYP Mission Critical Facilities
www.eypmcf.com
The Problem
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60% of US Energy bill is in buildings.
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Energy consumed by data centers more than doubled
between 2000 and 2005 – J. Koomey, Stanford University.
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U.S. Data center electrical bills totaled $2.7 Billion in
2005.
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A single, moderate size server in a data center has the
same carbon foot print as a SUV that gets 15 MPG
(R.Muirhead, Data Center Journal).
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A single rack with 6 Blade Server units consumes as
much power as 3 kitchen electric ranges (24-30Kw)!
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Relative Power Densities
Power Density
500
400
300
Watts/Sq.Ft.
200
100
0
Standard
Office
Building
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Mainframe
Data
Center
Modern
Server
Data
Center
Super
Data
Centers
21st Century Computing – Blade Servers
Power = Up to 6 kW
per Blade chassis or
30 kW per rack
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Where does the power go?
35%
30%
UPS = 18%
25%
Actual IT
Load is 30%
of Power
Consumed
20%
15%
10%
5%
U
hg
e
S
w
it c
H
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G
en
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ar
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at
io
if i
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um
id
tin
g
n
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U
R
A
C
P
ni
ts
P
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U
hi
lle
r
C
C
IT
E
qu
ip
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t
0%
APC-MGE:
Neil
Rasmussen
ghtning Strikes
aulty Switchgear
torms
igh Winds
alling Trees
raffic Accidents
OUTAGE
INPUT POWER
FROM
UTILITY/GENERATOR
aulty Switchgear
eavy Loads
oor Distribution
SAG
oor Distribution
SWELL
UPS
OUTPUT POWER
witching Operations
oor Filters
aulty Load Eq.
tatic Electricity
F Interference
armonics/
lectronic Loads
oor Distribution
ajor Utility
roblems
aulty
enerator
SPIKE
DISTORTION
PURPOSES OF UNINTERRUPTIBLE POWER SUPPLY
FREQUENCY
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1.Maintain clean, uninterrupted power during utility events
2.Power Conditioning
3.Isolation from other electrical loads
4.Separately Derived Source of Power
Strategy to Improve UPS Efficiency
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Technology: Make
the units more
efficient.
Selection: Size the
units more closely to
the load.
Application: Use
redundancy only
where it is needed.
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IBM Blue Gene
1.2 Megawatt
Understanding UPS Inefficiency Factors
No-Load Losses
Proportional Losses
Square-Law Losses
Paying the price to process power!
EPRI Efficiency Curves for UPS Products
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Typical UPS efficiency curve
Below 30% load
efficiency drops rapidly
Nominal 92% efficiency only applies
when UPS load is over 70%
100%
90%
80%
70%
UPS
Efficiency
60%
50%
40%
30%
20%
10%
0%
0%
10%
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20%
30%
40%
50%
60%
UPS Load
% of full power rating
70%
80%
90%
100%
13.5 KV
2(N+1) System
480
Primary Bus A
UPS
UPS
UPS
Bypass A
Load
Bank
13.5 KV
480
Each side must have
capacity to support
both critical loads but
maintain redundancy.
Primary Bus B
UPS
Total load cannot
exceed capacity of 2
UPS Modules.
UPS
Bypass B
UPS Output 2A
UPS Output 2B
EFFECTIVE DESIGN
LOAD = 33% of total
capacity, maximum.
Subsystem Bus A
UPS
Subsystem Bus B
Critical Load Bus A
Critical Load Bus B
Static
Static
Switch
Switch
PDU
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PDU
Critical Load
Load
Bank
Aggregate UPS Power Losses
EFFICIENCY
UPS internal power consumption (loss)
93.4%
93.3%
Power delivered to load
93.1%
}
}
Proportional and
square losses
92.8%
No-load portion of
loss stays constant
from full load all the
way down to zero load
92.4%
91.8%
Many data centers
operate in this range
90.7%
88.9%
85.5%
76.4%
No-load loss is
present even at
no load
0%
{
0%
10%
20%
30%
40%
50%
60%
UPS load
% of full power rating
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70%
80%
90%
100%
No Load Losses
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Definition: The power consumed by the UPS at 0%
load just to keep the UPS operating.
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Sources – Transformers, capacitors, logic systems,
fans, communications cards.
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Sometimes referred to as “tare”, “constant”, “fixed”,
“shunt” and “parallel” losses.
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Most significant inefficiency: Accounts for up to 40%
of UPS losses.
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Proportional Losses
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Definition: The power needed to process more power
through the UPS.
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Sources – Switching losses, capacitor and inductor
impedance, internal resistance
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Proportional losses increase as the output load the UPS
support increases.
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Proportional losses are directly related to the topology
(internal design) of the UPS.
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Square - Law Losses
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Definition: Losses related to the amount of current
flowing through the UPS.
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Power is the result of voltage times the current.
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Current does the work, and power is lost as the amount
of current flowing increases, by a square factor, hence
“square – law losses”.
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Power loss is in the form of heat.
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Square-Law losses are 1% to 4% at higher load
levels.
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Power Loss Component Graph
SQUARE-LAW
loss
Electrical
Loss in kW
PROPORTIONAL loss
(Waste due to
inefficiency)
NO-LOAD loss
No 10%
Load
30%
50%
70%
Load
Equipment Loading
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90% Full
Two devices with same nameplate efficiency can have significantly different
losses in actual operating range, due to the particular characteristics of their
PROPORTIONAL and NO-LOAD losses
Same nameplate
efficiency (full-load
loss)
Example: Two different 100kW UPSs
with 92% nameplate (full-load) efficiency
10kW
Loading where most
data centers operate
Electrical
Loss
UPS B has higher
proportional loss
(steeper line) but
lower no-load loss
UPS A No-load loss
(Waste due to
inefficiency)
UPS B No-load loss
But different performance
at actual operating load
0kW No
Load
10%
30%
50%
70%
Equipment Loading
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90%
Full
Load
One device can even have WORSE nameplate efficiency than another, yet have
lower loss in actual operating range, if it has a low NO-LOAD loss
Example: Two 100kW UPSs with
same 92% nameplate (full-load) efficiency
UPS A has better
nameplate efficiency
(lower full-load loss)
10kW
Loading where most
data centers operate
B
A
Electrical
Loss
UPS B has higher
proportional loss
(steeper line) but
lower no-load loss
UPS A No-load loss
(Waste due to
inefficiency)
UPS B No-load loss
0kW No
Load
But UPS B performs better
at actual operating load
10%
30%
50%
70%
Equipment Loading
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90%
Full
Load
Improving Efficiency
Technology
Selection
Application
Improving Efficiency – Fixing No-Load Loss
Effect of lowering NO-LOAD LOSS
Example: 100kW UPS with 92% full-load efficiency
10kW
Loading where most
data centers operate
Nameplate
efficiency goes from
92% to 94.5%
Same
improvement
in nameplate
efficiency
Electrical
Loss
Electric bill
savings
(Waste due to
inefficiency)
Original
No-load loss
But waste is roughly
cut in half in actual
operating range
0kW No
Load
10%
30%
50%
70%
Equipment Loading
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Lowered
No-load loss
90%
Full
Load
Improving Efficiency – Fixing Proportional Loss
Effect of lowering PROPORTIONAL LOSS
Example: 100kW UPS with 92% full-load efficiency
10kW
Nameplate
efficiency goes from
92% to 94.5%
Loading where most
data centers operate
Electrical
Loss
Electric bill
savings
(Waste due to
inefficiency)
(Unchanged
No-load loss)
Waste is reduced by
10-20% in actual
operating range
0kW No
Load
10%
30%
50%
70%
Equipment Loading
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90%
Full
Load
Application Efficiency – Zoned Redundancy
Rack Based UPS
Systems as needed
for 2N redundancy
M
UPS
F
I
R
E
Cold
Aisle
CRAC
UPS
Hot
Aisle
CRAC
UPS
Cold
Aisle
CRAC
HEAT
REJECT
S
E
C
U
R
UPS
Hot
Aisle
CRAC
Cold
Aisle
EPO
pdu
pdu
pdu
pdu
Central UPS for
one “N” side,
scalable, modular
system
M
UPS
HEAT
REJECT
CRAC
Site Availability – 99.995%
SYSTEM
MONITOR
Battery
WEBLINK
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$2,000+ per square foot
Commissioning UPS Systems
Availability
The Cost of Downtime
The Value of Commssioning
Data Center Tier Ratings
Tier 1
Tier 2
Tier 3Concurrently
Maintainable
Tier 4Fault Tolerant
No
Generator
Basic UPS for
IDF Room,
non-redundant
Single Utility or on
Radial line from Loop
99.671% *
N+1 UPS with
redundant
components
Single Utility Feeders,
N+1 Mechanical
System
99.741%
N+1
Generator
System
N+1 UPS with
redundant
components
One Active, One
Passive, Utility
Source, N+1
Mechanical System
99.982%
2N
Generator
System
2N UPS
Systems
Dual Active Utility
Feeders, 2N
Mechanical System,
compartmentalization
99.995%
Generator
* The Uptime Institute
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Maximizing Availability
Total Time - Downtime
Availability =
Total Time
• The only variable is Downtime
• Downtime sources: Equipment Failures,
Human Error, External Causes, Maintenance
Cost
of Downtime drives the Value of CFA!
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What does Downtime Cost?
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The Reliability Curve for equipment (IEEE)
Failure Rate
Infant Mortality
Period
End-of- Life Period
High Probability of
Downtime
Time (Data Center Life Span)
“The Bathtub
name
Curve” Conference
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The Value of Commissioning
Failures
Infant Mortality
Period
End-of- Life Period
Minimize
Time
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Commissioning UPS Systems
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Verify the full load performance of each module using
load banks – typical burn in is 4 hours at rated KW load
(hint: infrared inspections of all connections).
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Measure and verify the efficiency in the full operating
range at 5%, 10%, 15%, 20%, 25%..........
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Verify system redundancy under design load levels.
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Verify failure modes (under-voltage transfers, bypass
transfers, over load shutdown).
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Verify isolation modes for concurrent maintenance.
Assuring you get the reliability and efficiency you pay for!
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Questions?
Richard L. Sawyer
518-337-2049
[email protected]