OSHA 3256-07N Fire Service Features of Buildings and Fire Protection Systems
Stephen Oliver, V•I Chip Inc. soliver@vicr , +1 978 749 3256
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Transcript of Stephen Oliver, V•I Chip Inc. soliver@vicr , +1 978 749 3256
SC
’07,
11-
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Stephen Oliver, V•I Chip [email protected], +1 978 749 3256
From the 380V DC Bus to sub-1V Processors: Efficient Power Conversion Solutions
SC’07, Reno NV, 11-14-07
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Abstract
• Without a major architectural review, data centers may consume 100 Billion kWhr by 2011. i Additionally, inefficient power and cooling techniques may be the downfall of Moore’s law. ii
• One efficiency improvement proposal iii is for the adoption of high voltage DC distribution to enable the AC – 384V stage to be bypassed and the downstream sub-systems (or blades) to be fed directly from the data center distribution busses. This paper represents a follow-on step and proposes high efficiency, high power density power conversion solutions from the HV bus down to processor and low-/medium- and high-power loads.
• A baseline sub-system is established with a total load of 1320W:– 6x processors (1V, 120A)– 6x memory (1.5V, 50A)– Miscellaneous loads (12V, 12.5A)
• Potential conversion steps considered are 380V-12V-1V and 380-48-1V with bus converter, synchronous buck converters and factorized power regulators with sine amplitude converters.
• Efficiency, power density and annual electrical running cost comparisons are presented.
i. “Report to Congress on Server and Data Center Energy Efficiency” (p56), U.S. EPA ENERGY STAR Program, Andrew Fanara, August 2, 2007ii. “The Invisible Crisis in the Data Center: The Economic meltdown of Moore’s Law”. Kenneth Brill, Uptime Institute, 2007iii. “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007.
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‘Original’ Traditional High Power System (IBA)
• AC-48VDC ‘Silver Box’ + 48-12V DC-DC ‘Brick’ + VRM/VRDs to loads
• As designed:– ‘High’ efficiency (~65%), ‘small’ size, ‘cost effective’– Powered 1.5-2.5V processors, few concerns over energy costs
• Over time:– AC-12VDC SMPS & VRM efficiencies / densities improved
– IBA bus converters considered expensive and unnecessary
• As a result, use of a 12V-only bus increased
Rect., EMI& Inrush
12VAC 380VDCPFC 1.xV CPURegulatedHV DC-DC
AC-DC ‘Silver Box’1.xV Memory
VRx
VRx
DC-DC‘Brick’
48V
Backplane
Motherboard
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‘Later’ Traditional High Power System (12V)
Rect., EMI& Inrush
12VAC 380VDCPFC 1.xV CPURegulatedHV DC-DC
AC-DC ‘Silver Box’
Motherboard / Blade
1.xV Memory
VRx 1.xV CPU
Motherboard / Blade
VRx 1.xV Memory
VRx
VRx
• AC to 12V ‘silver box’• 12V distribution• Synch Buck POLs to load voltages
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12V Bus Concerns
• 12V bus is– Established– Proven– Multi-sourced
• 12V Bus is also…– Inefficient
• Distribution / connector losses• Low efficiency synch buck POLs (especially for sub-1V loads)
due to duty-cycle limitations
– Expensive• Large connectors, heavy bus bars, lots of copper, high electricity bills
– Out of date• Only used in new systems due to incumbency and for legacy loads
(e.g. 12V disk drives)
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Efficiency Improvements
• Higher voltage bus (380VDC* and / or 48VDC)
• Direct 48V-sub 1V conversion• Provide 12V for legacy / low power loads
* “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007.
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Revision #1: 380V to the Blade / Motherboard
Rect., EMI& Inrush
12VAC 380VDCPFC 1.xV CPU
HVBCM
AC-HVDC ‘Silver Box’
Motherboard / Blade
1.xV Memory
12V 1.xV CPUHV
BCM
Motherboard / Blade
1.xV Memory
• Silver Box AC-“post-PFC” 380VDC
– Reduces silver box size by >50%
• 380V distribution direct to blade– Eliminates distribution loss in system
(I2R loss at 380V is 0.1% of 12V loss)– Minimize connector size and cost
• 380-12V conversion on the blade– Minimize 12V distribution distance
VRx
VRx
VRx
VRx
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HV DC-DC Conversion
• Bus Converter Module (BCM)– Isolated, Unregulated– Voltage transformer /
current multiplier
• Sine Amplitude Converter Topology– ZVS, ZCS, >1Mhz switching frequency
• 384:12V = 300W @ 95.5%• 384:48V = 330W @ 96.5%
• 1.1 in2 package (>1000W / in3)– 1.28 x 0.87 x 0.26in– 0.5 oz / 15 g each
SACControl
PP P
D
D
D D
D+IN
-IN
+OUT
-OUT
P=Power TransformerD=Drive Transformer
Cres
D
D
U.S. and Foreign Patents and Patents Pending
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Revision #2: Direct 48V-to-load conversion
Rect., EMI& Inrush
48V
AC 380VDCPFC
AC-HVDC ‘Silver Box’
Motherboard / Blade
1.xV Memory
• Same 380V direct to blade• 380-48V conversion on the blade• 48-1.xV highest efficiency, smallest converter at the load
– Minimize 12V on-blade distribution loss
PRM VTM
1.xV CPUPRM VTMHV
BCM
48V
Motherboard / Blade
1.xV MemoryPRM VTM
1.xV CPUPRM VTMHV
BCM
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Direct 48V-to-Load Conversion
Pre-Regulator Module (PRM)• Non–isolated, regulator• ZVS Buck – Boost Topology
– ZVS, >1MHz switching• Performance
– 320W in 1.1in2 package– Power Density >1,100W/in3
– Efficiency = >97% at 320W out• Input : Unregulated 48V• Output : Regulated (26-55V)
VTM
US and Foreign Patents and Patents Pending
• PRM + VTM = Isolated, regulated, voltage transformation direct to load
ZVS B-BControl
IL
+IN
GND GND
+OUT
Voltage Transformation Module (VTM)• Isolated, voltage transformer• Sine Amplitude Converter Topology
– ZVS, ZCS, >1Mhz switching frequency• Performance
– Up to 100A in 1.1in2 – >96% Efficient at 300W out
• Input : Regulated 26-55V from PRM• Outputs : 0.8 - 55V, up to 100A (13 models)
SACControl
PP P
D
D
D D
D+IN
-IN
+OUT
-OUT
P=Power TransformerD=Drive Transformer
Cres
D
D
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Space-saving Powertrain – and no ‘Bulk’
• Direct 48V-to-load conversion with 2 V•I Chips• PRM can be located remotely
– Increased space on motherboard / near load– Reduced power dissipation at load
• Move POL Capacitance to input of VTM– Reduce capacitance by 1/k^2– Additional space and cost savings
LoadSource LoadSource LoadSource
1,000uFhere
1uFhere
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Powertrain & Distribution Efficiency
• High conversion efficiency and smallest footprint from 380V-load• Convert 380V to 1.5V, 200A
– Total “380V-to-load” Efficiency = 85.2%• 96.5% x 97% x 91%
– Total PCB power component footprint = 4.4 in2 ( 4 chip solution )• With fewer caps, smaller filters, smaller heatsinks
• Co-locate HV BCM & PRM, place only the VTM at the load= highest distribution efficiency (I2R) and least space taken at the load
1.5V200A380V 48V VF (48V)
HV BCM PRM
VTM
VTM
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Legacy, Low Power Loads
Rect., EMI& Inrush
48V
AC 380VDCPFC
AC-HVDC ‘Silver Box’
Motherboard / Blade
1.xV Memory
• Step down from 48V to create 12V for legacy / low power loads.• Simple unregulated DC-DC converter
PRM VTM
1.xV CPUPRM VTMHV
BCM
Motherboard / Blade
xVLow
PowerLoads
VRx
BC
M 12V
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Systems Comparison• “System”
– Blade / Motherboard Content:• 6 processors (1.0V, 120A ea.)• 6 memory (1.5V, 50A ea.)• Miscellaneous rails (12V, 150W total)
– Infrastructure:• 30 blades / Motherboards• Board impedance 1.5mΩ• Rack distribution impedance 2.0mΩ
– Operation:• Duty cycle = 65%• Air conditioning = 50% efficient• Electricity = $0.1028 per kWhr*
• Systems:– [AC 12V] 1.xV (baseline)– [AC-384V] 12V 1.xV– [AC-384V] 48V 1.xV– [AC - 48V] 1.xV
[…] = silver box
* Nevada industrial electricity price July ’07 ( http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html )
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Efficiency Comparison: AC-Loads
• In all cases, adoption of higher voltage improves efficiency• 380V in rack and 48V on blade / motherboard has highest efficiency
– +8.7% pts over baseline
• Improved efficiency 380V-Load means smaller PFC / EMI section.
70
72
74
76
78
80
82
84
86
[AC - 12V] - 1.xV [AC-384V] - 12V - 1.xV [AC-384V] - 48V - 1.xV [AC - 48V] - 1.xV
AC
-Lo
ad
Eff
icie
nc
y (
%)
+8.
7% p
ts
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Power Loss (per Blade / Motherboard)
• Reduction of 173W per blade / motherboard vs. baseline
150
200
250
300
350
400
450
[AC - 12V] - 1.xV [AC-384V] - 12V - 1.xV [AC-384V] - 48V - 1.xV [AC - 48V] - 1.xV
Po
we
r L
os
s p
er
Bla
de
(W
)
173 W
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0
25
50
75
100
125
150
175
200
225
[AC - 12V] - 1.xV [AC-384V] - 12V - 1.xV [AC-384V] - 48V - 1.xV [AC - 48V] - 1.xV
Ele
ctr
icit
y S
av
ing
sp
er
Ye
ar
pe
r B
lad
e (
$)
Utility Savings ( per Year per Blade / Motherboard )
• 380V in rack and 48V on blade / motherboard has highest saving ($202 per year, per blade / motherboard)
$20
2
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Conclusion
• 12V-only distribution systems have limitations in high power computing applications– Lower load voltages and larger load domain power– Duty cycle limitation of synchronous buck conversion– Increased I2R distribution loss
• Higher voltage (380V and / or 48V) distribution greatly reduces distribution loss– Direct 48-to-load conversion offers high efficiency and small size– Enable up to 8.7% pts efficiency improvement over 12V baseline– Significant running cost savings
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References
• “Report to Congress on Server and Data Center Energy Efficiency” (p56), U.S. EPA ENERGY STAR Program, Andrew Fanara, August 2, 2007
• “The Invisible Crisis in the Data Center: The Economic meltdown of Moore’s Law”. Kenneth Brill, Uptime Institute, 2007
• “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007
• “Datacenter Power Delivery Architectures : Efficiency and Annual Operating Costs”, Yeaman (V.I Chip), Digital Power Forum, September 2007