HVDC (High Voltage Direct Current) New Feeding Method for High Efficiency Data Centre
Copyright © 2011 NTT DATA INTELLILINK CORP.
Background APEC at Yokohama JAPAN （Nov. 2010） One of the Action list supporting the APEC leaders’ strategic growth is, ・Promote energy conservation activities through the introduction of more energy efficient ICT devices and systems, including data centres and ICT utilization in many sectors and new ICT services such as cloud computing (Green ICT). Recently, the situation at the data centre has widely changed. •Support for environmental protection • Initiatives to Green ICT •Correspondence to ICT technology with fast advancement. To achieve the Green data centre. •Air-conditioning efficiency improvement •Server consolidation by virtualization •High Voltage Direct Current ( HVDC )
Copyright © 2011 NTT DATA INTELLILINK CORP.
It is possible to achieve it by HVDC. 1. Energy-saving design Comprehensive efficiency ２０~３５％ improvement! Naturally, the electricity bill of operating is reduced and The CO2 emissions significantly reduced!
2. High-reliability design
3. Safety design
UPS is unnecessary. The system down is prevented by the n+1 composition.
The electric shock, an earth fault, and the arc problem are cleared.
Ｐower Supply Rack（ small-sized ！ From 1/5 to 1/10 compared to UPS. ！
Server Racks
Copyright © 2011 NTT DATA INTELLILINK CORP.
１．Energy-saving design － Efficiency comparison
－
UPS system (current)
IT equip.（Server, etc.）
UPS
AC
ＩＣＴ
ＵＰＳ
Alternating current
Switching board
AC
AC
DC AC
AC
DC
DC12V
CPU
Direct current
AC incoming
HVDC HVDC PS Rack
IT equip.（Server, etc.） ＩＣＴ
ＨＶＤＣ
AC
DC
DC340V
DC
AC incoming
Two conversions are eliminated. Significant energy saving. Further improved reliability.
DC
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DC12V
CPU
１．Energy-saving design － Efficiency comparison
－
PDU （AC）
UPS system (current) 80~85%
98%
～
Transformer
AC
UPS
Server Rack
75~85%
98.5% S/B
AC/DC
AC
Server
58～70％ HVDC
12V systems is
２０～３５％ power reduction.
PDU （DC）
HVDC 98% Transformer
AC
98% PS Rack
Server Rack
95% DC/DC
DC340V
Approx.９１％
Compensating circuit of Bus for stabilizing
～
※The air conditioning power reduction also added!
Centralized power.
DCｄｃ DC12V w/o power supply
Server
※ Efficiency calculation is the reference on 50% load. ※ Value about the efficiency varies depending on the configuration.
Copyright © 2011 NTT DATA INTELLILINK CORP.
4
２． High-reliability design －
ｎ＋1 The merit of redundancy －
The Spare always backs up with n+1. System does not down even the failure of multiple locations!
ＨＶＤＣ Power Supply Rack
ＤＣ server
ｎ＋2
ＤＣ server
Trouble Rectifier
Rectifier
ＤＣ server
Rectifier
Rectifier
ＤＣ server
ｎ＋１
Rectifier
Rectifier
Trouble
Rectifier
２０kVA ２０kVA
AC incoming
Transformer
Commercial power supply A
Transformer Commercial power supply B
Spare
Server Rack ４kW
Non-stop system
Transformer
２０kVA ２０kVA
２０kVA ２０kVA ２０kVA
DC
Rectifier
Distribution board
２０kVA
Rectifier
Rectifier
Rectifier
Rectifier
２０kVA
２０kVA
DC340V
ＤＣ server DC12V Trouble
DC/DC DC/DC DC/DC ２kW ２kW ２kW
２０kVA ２０kVA
Central Power Supply（ｎ＋１）
Spare
Spare
It is possible to be extended without stopping the system！
ｎ＋１ ｎ＋１ (Spare)
(Spare)
Copyright © 2011 NTT DATA INTELLILINK CORP.
３． Safety design
We achieved "Safety" by our new technology , HVDC ！
① ARC Restraint Technology
②Middle point ground Anti-electric shock ・ earth measure
・By setting the arc control circuit, suppress the generation of the arc.
Arc outbreak at the time of the direct current interception had been a problem.
・An electric shock, an earth fault with high voltage are limited on a secure current value by the high resistivity of 47kΩ.
Danger associated with the high voltage had been pointed out.
Copyright © 2011 NTT DATA INTELLILINK CORP.
Electric shock and earth fault protection － Middle point ground － There is no influence on the system feeding power by the leakage (electric shock) and the earth fault.
47kΩ E 340V
R1 47kΩ -170V
380V x 47kΩ 47kΩ×(47kΩ+2kΩ)+47kΩ×2kΩ
= 7.5 mA
I3
E×R2 R1
･･･
When the leakage( electric shock ) detected, turn off the switch and interrupting the route of leakage, and the electric shock is instantaneously stopped. ◆ When getting an electric shock, the current that flows to " a human is 2( kΩ ) of resistance ".
I3 = Calculating formula
E
I3
0V
at equivalent circuit. R3
Middle point ground
Server
R2
Leakage (electrical shock)
R2
Human R3:2kΩ
Server
rectification
+170V
I3 ＝
R1×(R2＋R3 )＋R2 ×R3
※In an actual device, short time peak current flows by the load. However, we solved in discharge circuit.
◆ We developed high-resistance grounding method aimed at high-voltage electric shock accident prevention. Copyright © 2011 NTT DATA INTELLILINK CORP.
ＨＶＤＣ
－ Basic system configuration －
ΔＹ transformers
SERVER RACK
PS RACK
AC
DC340V
DC/DC
340V→12V
Server Server Server
During a power outage. DC/DC 340V→48V
Server Server Server
Battery Three-phase Δ結線 Delta Connection
３相交流
six-phase full wave rectification DC340V
. Phase shift ３０°
Three-phase Y結線 Star Connection ３相交流
Battery voltage DC288V
Copyright © 2011 NTT DATA INTELLILINK CORP.
Floor Configuration
Conventional AC ・UPS systems
－
HVDC systems Floor layout １
A/C 空調
A/C 空調
A/C 空調
空調 A/C
高圧 High-voltage transformers トランス
A/C 空調
各種SW S.B UPS UPS UPS Battery バッテリー A/C 空調
A/C
A/C 空調
A/C A/C 空調
A/C
A/C 空調
Electrical room 電力室
特 高 受 電
非常用
Generator エンジン
特 高 受 電
PS PS
高圧
Rack ラック
High-voltage transformers トランス
Battery バッテリー 空調 A/C
A/C 空調
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非常用 エンジン
Generator
高圧 High-voltage transformers トランス
A/C
A/C A/C 空調
バ ッ テ リ ー
A/C
A/C 空調
バ ッ テ リ ー
サ ー バ ラ ッ ク
バ ッ テ リ ー
Battery
サ ー バ ラ ッ ク
Battery
バ ッ テ リ ー
Server rack
バ ッ テ リ ー
PS Battery
サ ー バ ラ ッ ク
Server rack
バ ッ テ リ ー
Battery
バ ッ テ リ ー
※構成例
PS Battery
サ ー バ ラ ッ ク
バ ッ テ リ ー
A/C 空調
PS Battery
バ ッ テ リ ー
Battery
サ ー バ ラ ッ ク
Battery
Battery
バ ッ テ リ ー
PS
Server rack
PS
A/C A/C 空調
A/C 空調
空調 A/C
空調 A/C
非常用
Generator エンジン
A/C 空調
Electrical room 電力室 Special-high power receiving
A/C 空調
Electrical 電力室 room Special-high power receiving
サ ー バ ラ ッ ク
サ ー バ ラ ッ ク
PDU A/C 空調
特 高 受 電
サ ー バ ラ ッ ク
Special-high power receiving
PDU
サ ー バ ラ ッ ク
A/C A/C 空調
Server rack
PDU
A/C 空調
A/C 空調
Server rack
PDU
サ ー バ ラ ッ ク
A/C 空調
Server rack
PDU
サ ー バ ラ ッ ク
Server rack
サ ー バ ラ ッ ク
Server room サーバー室
Server rack
A/C 空調
A/C 空調
Server rack
PDU
サ ー バ ラ ッ ク
A/C 空調
Server rack
PDU
サ ー バ ラ ッ ク
Server rack
PDU
A/C 空調
Server rack
A/C 空調
Server room サーバー室
Server rack
Server room サーバー室
Floor layout ２
Battery
－
Server rack
ＨＶＤＣ
Result of JAPAN
Major data center company A This company constructs the data center of 4000 racks scale in the autumn of this year.
Major data center company B
This company is examining the introduction at the beginning of next year .
Major carrier
C
The evaluation machine was introduced.
Copyright © 2011 NTT DATA INTELLILINK CORP.
Suggestions The photovoltaic generation Installation.
General method of Japan
HVDC
photovoltaic panel
AC
340V
UPS
AC/DC
AC/DC
12V
ACRectification
340V
Efficiency 97%
AC/DC
12V
Unnecessary
DC/AC Unnecessary
Battery
Battery
HVDC can be used without converting the power of the photovoltaic generation. DC200～400V
HVDC Supply AC incoming
Server, Router, etc.
DC/DC
Converter
Server, Router, etc.
Power controller
Converter
DC/AC
photovoltaic panel
MTTP with control operation DC/DC Converter
DC400V DC340V
Non-priority
Priority
Unnecessary
（AC） （DC）
The output of the photovoltaic panel is a high voltage, So the HVDC data centre is a good combination ! ・No power controller Highly effective, high reliability, and low price ! ・As running out of the photovoltaic generation power, the electric power is automatically supplied from the AC system side. ・HVDC does not flow back to the AC system in waveform troubled!
If you have any interest in our products, please feel free to contact the following address. Thank you for your attention.
[email protected] Green Consulting Business Unit Green Consulting Business Division NTT DATA INTELLILINK CORPORATION
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