COOPERATIVE CONTROL SYSTEM AND COOPERATIVE CONTROL METHOD
FOR IT DEVICE AND BATTERY
BACKGR.O-U ND OF THE INVENTION
5 (1) Field of the Invention
The present invention relates to a system including
an I T device and a large capacity battery, and, more
particulariy, to a cooperative control system for an IT
device and a battery, preferable to efficiently use the
l o battery and to stably operate the IT device for a long
period of time.
(2)Description of the Related Art
Power outages frequently occur i.n an. area without
suf f ic:i.ent infrastructure development of the power network.
15 A power generator is installed at buildings, and is
operated during a power outage to supply the bui.l.dings with
el.ectrica.:l power. In preparation for some lcind of trouble
in the power generator, the server room has s 1-ead battery
array for supplying the server. and a cl -ient PC wi~th the
20 electrical. power for severa:L hours for repa-il-ing the.
trouble of the power generator. The battery array
generally is formed with extended capacity of the lead
battery of a UPS (Uninterruptible Power Supply). The
battery array is provided as a backup up of the power
25 generator. Because the battery array is not frequently
used, an inexpensive lead battery is applied, and is large
in volume and weight.
Though the infrastructure of the power networlc has
been developed, electrical power is not sufficiently
5 supplied in some areas, due to the increased demand of
electrj-cal power in some reason, for example, by the usage
of air-conditioning system in summer. In this case, a
scheduled power outage is executed, and causes less damage
as compared with a sudden power outage. In the scheduled
lo power outage, the power outages are executed on schedule on
rotation and daily bases. The power generator can be
operated, if it is i-nstalled at the building. However, the
IT device is stopped, jf no power generator is i.nstal.l.ed..
To continue a business servi-ce, a lithium-ion battery array
15 may be install-ed. The 1j.thium-ion battery can quiclcly be
charged, and can be charged and discharged for many times
(cycle performance). Thus, the i-ithium-ion batteries can
be used also during the scheduled power outages.
Accordi.ngl.y, d-iifferent battery arrays are provi.ded,
20 deperrdi.ng on the cl?aracteristics of the power outage or
faci1.iti.e~ of the buildings, and can be used as a technique
for supplying electrical power during the power outages.
The schedule time of power outages is given by a
power company, so the demand-side can know the time. It is
25 desirable that the demand-side can know also unschedu1.ed
power outages. Japanese Patent Application Laid-Open
Publication No. 2004-355219 discloses an example of a
method for estimating occurrence of unscheduled power
outages. In Japanese Patent Application Laid-Open
5 Publication No. 2004-355219, disclosed is a technique for
estimating the chance of a power outage, and the power
generator is activated before a power outage and switched
from a commercial power supply, thereby reducing the
capacity of the battery for connection to the UPS or not
lo requiring the UPS. This estimation is to judge that the
commercial power supply has "a great chance of occurrence
of a power outage within a predetermined period of time",
and i.s calculated based on weather informati-on acqui-red
through the Internet and a. predetermined condition. 'That
15 is, the estimation of Patent document 1 is to estimate the
time in which a power outage occurs.
SUMMARY OF THE INVENTION
~~~ ~~~~ ~~~~~~ ~~~ ~ ~ ~ ~~~
The technique of Japanese Patent Appl.i.catzi.on 1,ai.d-
20 Open Puhli.cat.ion No. 2004-355219 aims at activating the
power generator before occurrence of a power outage, and is
desired to simply estimate the occurrence time of power
outages. Sever rooms and offices are globally investigated
as installation places of the IT device (router, switch,
25 server, storage and the like). As a result of the
investigation, it is proven that the battery array are
installed in many places together with the IT device. The
present invention focuses on a high efficient usage of the
battery array. In this case, the high efficient usage
5 includes, for example, extension of discharge time of the
battery, a margin reduction of the discharge capacity, and
a reduction of unnecessary yuiclc charging. In the case of
a lead battery array, the reduction of the battery capacity
can reduce the battery cost, and can reduce the weight. In
lo the case of a lithium-ion battery array, the battery array
reacts to frequent power outages, and is used as an
alternative power generator, thereby reducing the cost of
light oi.1. for the power generator. The light oil is more
expensive several ti.mes than the electricity. Accordingly,
15 there are various advantages with a high efficient use of
the battery array.
It is advantageous to estimate power outages in
advance for high effi.ci.ency of the battery array. For
exampl.e, if the jntervals of the power outages are lcnown,
20 chargi-ng 5.s pel-formed at the known ihterval~s. T11i.s
prevents unnecessary quick charging. At this time, the
item to be estimated for power outages differs from the
occurrence time of the power outages as disclosed in
Japanese Patent Appl.ication Laid-Open Publication No. 2004-
25 355219. Instead of using only the UPS having the battery
as one unit, the IT device and the UPS are cooperatively
controlled, thereby expecting the high efficiency.
An object of the present invention is to provide a
system for realizing high efficient charging/discharging of
5 a battery, by estimating characteristics (time, frequency,
interval and the like) of an expected power outage in
advance, and also by cooperatively controlling an IT device
and a UPS having a battery for the estimated power outage.
Efficiently controlling the discharge of the battery
lo increases the appeared capacity and also improves
performance of the IT device.
The above-described object of the present invention
and new features will be obvi.ous from the descriptions of
the specification and attached drawings of the present
15 invention.
To address the above problem, the present invention
employs the conf igurati-ons of the clai.~ns, for example.
As an example of a cooperative control system for an
IT device and a battery, according to the present i.nventi.011,
20 there is provided a cooperatj~ve control system Lor an IT
device and a plura.l.j.tyo f batteries, in.cl.udi.ng:a
commercial power supply; a voltage logger which measures a
voltage of the commercial power supply; an uninterruptible
power supply unit which is connected to the commercial
25 power supply, and to which the plurality of batteries are
connected; a power strip with power measurement mechanism
which is connected to the uninterruptible power supply
unit; and the IT device which includes a server connected
to the power strip with power measurement mechanism, and
5 wherein the voltage logger, the uninterruptible power
supply unit, the power strip with power measurement
mechanism, and the server are connected to a network, and a
control unit in the server estimates a continuous duration
of a power outage, obtains restriction of power consumption
lo of the IT device using the estimated continuous duration of
the power outage and residual capacity of the plurality of
batteries, and controls power of the IT device to satisfy
the restrj..ctj.on of power consumptj.on.
As an example of a cooperative control method for an
15 IT device and a battery, according to the present invention,
there is provided a coopera.ti.ve control method for an IT
device and batteries, for a. system including a commercial
power supply, a vol.ta.ge i.ogger which measures a voltage of
1:I:ie commerci a1 power suppl~y, ail uninterruptib1.e power
20 supp1.y 1ini.t whi.ch i.s connected to the commercial power
supply and to which the pl.ural.ity of batteries are
connected, a power strip with power measurement mechanism
which is connected to the uninterruptible power supply unit,
and an IT device which includes a server connected to the
2s power strip with power measurement mechanism, and wherein
the voltage logger, the uninterruptible power supply unit,
the power strip with power measurement mechanism, and the
server are connected to a network, the method including the
steps of: estimating a continuous duration of a power
5 outage; obtaining restriction of power consumption of the
IT device, using the estimated continuous duration of the
power outage and residual capacity of the batteries; and
controlling power of the IT device to satisfy the
restriction of power consumption.
10 Charging and discharging of a battery array can
efficiently be performed, by estimating the characteristics
(time, frequency, interval and the lilce) of power outages,
and by cooperati.vely co~ltrollillg an. IT device and the
battery in accordance w:i.th the power outage characteristics
15 so as to continue servi.ces of the IT device and to avoid
performance deteriorati-on as much as possible. This call
reduce the battery capacity of the battery. From a
different point of view, the performance of the IT device
car1 be i.mprovrd nsi ng the same battery capacity. Further,
20 a chargii~g metl~od of the battery array j~s controlled,
thereby contributing to rea.1.izj.n.lg ong life batteries.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram i1-lustrating an example of a
25 system configuration for performing cooperative control for
an IT device and a battery;
FIG. 2 is a diagram illustrating an example of a
network configuration including a plurality of points with
the system of the present invention;
5 FIG. 3 is a diagram illustrating an operational
example of charge scheduling based on an estimation of a
power outage interval;
FIG. 4 is a diagram illustrating an operational
example of discharge scheduling with a large restriction on
lo performance, based on an estimation of a power outage time;
FIG. 5 is a di-agram ill.ustrating an operational
example of discharge scheduling with a little restriction
on performance, based on an esti.mation of a power outage
t: irne ;
3.5 FIG. 6 is a diagram illustrating an operational
example of an estimation of power outage time and interval.,
when a power outage occurs for several times;
FIG. 7 is a diagram illustrati-ng an example of a
tab1 e ihcluding esl.:imati.on :i.tems of power outage;
FIG. 8 is a diagram illitstratirlg an uperatj.ona1
example of a reactj-on for when an estj.mati..ono f power
outage is incorrect;
FIG. 9 is a diagram illustrating an example of a
control unit which performs cooperative control for an IT
25 device and a battery;
FIG. 10 is a diagram illustrating an example of a
power outages estimation unit in the control unit;
FIG. 11 is a diagram illustrating an example of an IT
power consumption budget unit in the control unit;
5 FIG. 12 is a diagram illustrating an example of
discharge characteristics of a battery;
FIG. 13 is a diagram illustrating an example of an IT
low-power control unit in the control unit;
FIG. 14 is a diagram showing an operational examp1.e
lo of low-power control in the IT device; and
FIG. 15 is a diagram showing an example of a
flowchart for cooperatively controlling an IT device and a
battery.
15 DETAILED DESCRIPTION OF .... . .. .. T .H..E E.. .. MBOD. IMENT
An embodiment of the present invention will now be
described wi.th reference to the accompanying drawings. I11
the entire drawings for describing the embodiment of the
present invention, the same name and the same reference
20 syml?o:l.s are yi~veri to those elements llavilig the same
functions, and the same elements will not repeatedly be
described.
FIG. 1 illustrates the essential parts of a system
for performing cooperative control for an IT device and a
25 battery, according to an embodiment of the present
invention. The connections identify the power system. A
commercial power supply CPWR 10 is supplied from a power
plant, as electrical power. A voltage logger VLTLOG 20 is
put in a place where a voltage of the commercial power
5 supply can be measured. The voltage logger 20 can record
voltages in time series or at occurrence of an event, and
can measure the power outage in addition to the swell, dip,
and momentary stop, in accordance with the voltage value.
The commercial power supply 10 is connected to an
lo uninterruptible power supply system UPS 30. The UPS 30
includes various systems, such as a standby type, a. line
interactive type, a on-1.ine i-nverter type, and is not
parti.cu3.a.r:l.y1 -imited. In thi.s descri-pti.on,t he on-line
inverter type i.s described. The UPS 30 i.nc1.ud.e~a
15 rectifier and a. converter CNV 31 which converts AC to DC, a
battery array BAT 32, a battery control unit CHGCTL 33
which contro1.s the battery array, an inverter INV 34 whi.ch
inverts DC to AC, and a control unit UCTL 35 of the UPS.
The control unit 35 of the UPS has a function for
20 monitori~ng t-.he m:esi.dual capacity of a battery, a fullction
for corresponding to a network, a function for instructing
an IT device for shutdown, and a function for performing
the charge control in accordance with a normal charge mode
or a quick charge mode. The UPS 30 is connected to a power
25 strip with power measurement mechanism PDU 40. The power
strip with power measurement mechanism PDU 40 can measure a
current value and a voltage value at each electrical outlet,
and has a mechanism for remotely monitoring the power and
controlling ON/OFF of power supply through network
5 connection. The PDU 40 is connected to each IT device 50.
For example, the PDU 40 is connected to servers SVRl (51),
SVR2 (52), and a router RTR 53, but it may be connected to
a modem, a firewall, a switch, and a storage instead. The
server SVRI. (51) is equipped with a control unit CTL 55
lo which performs cooperative control for the IT device and
the battery, according to the present invention.
FIG. 2 illustrates a networlc bloclc diagram with a
plurality of points including the system of a fi.rst
embodiment of the present inventi.on. The connect:ioris
15 identify signals of the networlc. A cooperative control
system (Sysl) for the IT device and the battery, as
illustrated in FIG. 1, j.s connected to other systems (Sys2,
Sys3) through a WAN (Wide Area Network). Tn the system
(Sysl~,) a router (RTR) 53 connects an external WAN and a13
20 i.ilt.e~:nal LAN (Local Area Networlc) 60. In addition, a
pl..ural.j.tyo f servers (SVR1, SVR2), the UPS 30, and the
power strip with power measurement mechanism (PDU) 40 are
connected to the router (RTR) 53, thereby forming the LAN
60. Information of the UPS, PDU, router, voltage logger
25 (VLTLOG) , tetnperahure/humidity logger (TMPLOG) can be
communicated to the servers (SVR1, SVR2) through the LAN 60
This implies that an internal state of another device can
be monitored and controlled using the LAN. For example,
the sever monitors and controls the voltage logged by the
5 voltage logger, the temperature and humidity sensed by the
temperature/humidity sensor, the residual capacity of the
battery of the UPS, the terminal voltage of the battery,
the setting of mode to the UPS, the power value of each IT
device at the power strip with power measurement mechanism,
1.0 and the low-power control of the IT device (server, router,
etc. ) .
The present invention includes the characteristic
technique for performing cooperati.ve control for the IT
device and the battery, in accordance with characteristics
15 (time, frequency, interval and the like) of estimated power
outages. Now, below given are examples of some effects and
benefits as a resu1.t of the estj.mati.on of the power outage,
in combi-nation with descripti-ons of operational examples of
IT device and the battery. The characteristi~cs of the
20 power outage include the power outage interval/frequency
and the power outage durati-on, and will sequentially be
described below.
Estimating of the power outage interval shows that
charge scheduling of the battery array is possible. FIG. 3
25 illustrates an example of charge scheduling based on the
estimation of the power outage interval. During the power
outage (time: tl-t2), if an IT device is operated using a
battery, the battery is discharged, and the battery
capacity will approximately be zero at the time t2. If no
5 estimation is made, it is not understood when the next
power outage will occur. Thus, the battery is quickly
charged to be ready for the next power outage, and will
complete1.y be charged at a time t3. If estimation is made,
it can be understood that the next power outage starts at a
10 time t4. There is enough time until the end of the power
outage, thus slow charge can be performed for the battery.
When no estimation is made, excess quick charge is
performed. Th.i.s results in unreasonably shortening the
life of the battery, i.f a lead battery is applied. At the
15 next power outage, after the power outage ends at a time t5,
if no estimation is made, slow charge may be performed. In
this case, the battery is i n a poor charge state, if the
power outage occurs at a time t6, and the battery is
depleted at a time t ' 7 . As a. resul.t, tl-ie servi-ce of the IT
20 devj.ce may not be completed. 1:f the eslrimatioln is made,
quiclc charge is done, thereby complete1.y charging the
battery until the time t6. As a result, the charge
scheduling can be performed by estimating the power outage
interval, and avoiding unnecessary quick charge or poor
25 charge state due to the slow charge.
Now, a description will be made to an effect of
estimating the continuous duration of the power outage. In
an IT service, it is desired that the service continue even
during the power outage, and provides high performance as
5 much as possible. However, high performance usually
results in great consumption of the battery and also
depletion of the battery capacity. Therefore, there is a
tradeoff between the performance and the battery capacity.
It is shown how the performance has been improved based on
10 estimation of the continuous duration of the power outage,
according to the present invention. By estimating the
power outage time, the time to use the battery can be
esti-mated, thus enabling to perform discharge scheduling of
the battery. When no estimation is made, the continuous
15 duration of the power outage is not lcnown. In this case,
in a. conceivable method, the battery usage is limited to a
small amount so as to react to it even in a long power
outage ti-me, or in an alternative method, the battery usage
is qui.te high so as not to react to i.t i.n a lonq power
20 out-.age time. FIG. 4 illustrates an example of wl~erl the
battery usage is greatly limi-ted, while FIG. 5 illustrates
an example of when the battery usage is limited only a
little. In FIG. 4, a power outage occurs between the time
tl and the time t2. When no estimation is made on the
25 power outage time, the battery usage is greatly limited.
Thus, an IT service can be continued during the power
outage, but the performance is limited to prfl. When the
estimation is made on the power outage time, the battery
usage time is ltnown in advance. Thus, the performance can
5 be enhanced to prf2 in consideration of the residual
capacity of the battery. This is because the margin of the
residual capacity of the battery can be cut down, since the
power outage time is known. In FIG. 5, a power outage
occurs between the time t3 and the time t5. When no
lo estimation is made on the power outage time, the battery is
depleted at the time t4 during the power outage, because
the performance is high (prf4) and requires high battery
usage. As a result, the power of the IT device i.s zero in
the duration between the time t4 and the time t5, and the
15 IT service needs to be discontinued. This is not desirable
for a server on the assumption of a 24-hour operation.
When estimati-on on the power outage is made, the .usage time
of the battery is known in advance. Thus, the performance
is restrained to prf3, and the usaqe of the battery cou1.d.
20 be c!ontinued during the power outage tirne. Accordingly, by
esti-mating the power outage ti-me, discharge sch.edul.ing of
the battery can be performed, and thus enhancing the
performance of the IT device.
Further, shown is a new effect when estimating the
25 continuous duration and interval of the power outages. FIG.
4 and FIG. 5 shown an example in which a power outage
occurs once a day. When a power outage occurs a plural-ity
of times in a day, it is important to estimate both the
power outage time and the power outage interval, in
5 planning how to use the battery. Plans can be created on
how the battery is used a plurality of times and when the
battery is charged. FIG. 6 illustrates an example of when
a power outage occurs for a plurality of times,
particularly, the power outage occurs twice. When no
10 estimation is made, in the first power outage between the
ti-me t6 and the time t7, the performance is limited to prf7,
and the battery capacity is reduced from C3 to C1. I-Iowever,
the IT servi.ce could successfully be contjnued. in the
second power outage between a. ti.me t8 and a time tl0, if
15 the performance is lirni-ted to prf7 as the same as the first
power outage, the battery is depleted at a time t9, thus
resulting in that the iT service cannot be discontinued.
When estimating the power outage ti.me and the power outage
i.ntervai., t-here are two methods based on the type of the
20 battery, and will. he-reinafter be described. In one method,
the total time duration of a. plurality of power outages is
estimated, and the usage of the battery in each power
outage is defined in order to continue the IT service
during the corresponding time. This method is suitable for
25 lead batteries requiring a long time to be charged. In the
other method, each of the power outage times and each of
the power outage intervals are estimated, and quick
charging is performed between the power outages. This
real-izes continuation of the IT service and improves the
5 performance, on the assumption of recovery of the battery
capacity. This method is suitable for lithium-ion
batteries, whose life is not likely to be shortened due to
quiclc charging. In the first method, the performance is
limited to prf6. This enables that the battery can be used
lo even in the second power outage, and enables continuation
of the service. The battery capacity is reduced from C3 to
C2 in the first power outage, and will be zero from C2 in
the next power outage. In the second method, the
perfor~nance is enhanced to prf7 which j.s a higher level of!
15 performance than that of prf6, and quick chargi-ng is
performed between the power outages, thereby recovering the
battery capacity, and resulting i.n both conti.nuati.on of the
service and high performance. Because a power outage
occurs from the time t6 to ti.me t'7, the battery capacity j.s
20 reduced from C3 to C1. However, quick charging :i.s
performed until the next power outage at the time t8, and
thus the battery capacity is recovered to C3 so as to be
ready for the power outage from the time t8.
Accordingly, the continuous duration of the power
25 outage and the interval between the power outages are
estimated and calculated, thereby performing appropriate
charge/discharge scheduling of the battery. In addition to
this advantage, it is possible to continue the service of
the IT device and to improve the performance. Based on
5 these advantages, in the first embodiment of the present
invention, examples of items for estimating on a power
outage are illustrated in FIG. 7. The items are managed in
a unit of one day, but this management unit is not limited.
The table is divided into two parts: one is the summary;
lo and the other one is the specifications. The summary part
has items of "whether a power outage occurs", "number of
power outages i.n one day", "longest time of power outage",
"total t:i.me of power outages", "shortest and longest ti.me
of power outage interval". As specification data, in 24
15 hours, the start time and the end time of a power outage
are given. Alternatively, the table may be prepared for
each minute to record whether a power outage occurs. For
the power outage intervals, it is necessary to calculate
the intervals over the management uni.t (one day). On March
20 I"'., power outages are estimated three times respectively
between 9:00 and 12:00, between 16:OO and 18:00, and
between 20:OO and 21:OO. On this date, the longest time of
the power outage is three hours, the total time of power
outages is six hours, and the power outage intervals are
25 two hours at minimum and thirteen hours at maximum. The
longest time between the power outage intervals is thirteen
hours from 21: 00 on March lS%p to 10: 00 on March 2nd.
It is assumed that the characteristics (time,
frequency, interval and the like) of a power outage change
5 depending on the place, day, and the like.
Estimation on a power outage may be incorrect,
because it is only calculation. When the estimation is
incorrect, it is good in one sense, because the power
outage does not occur, and it is bad in the other sense,
10 because the power outage time and interval differ from
those of the actual time and interval. In the embodiment
of the present invention, descriptions will now be made to
a reaction method of when the esti-mation is incorrect.
Coopera.ti.ve control. for the IT device and the battery based
1.5 on an estimation of a power outage is feedforward control
for preventing depletion of the battery. When the
esti.ma.tj.on is incorrect, the control i.s switched to
"feedback control." based on a determination using the
resj~dual. capacity o:E the battery. Thi.s example is
20 i 3.l.ust-r-ateid n PIG. 8. For the sake of clear j~l~lustration,
the area between. the performance prfl and the performance
prf2 and the area between the battery capacity C1 and the
battery capacity C2 are reduced. The estimated power
outage time is from the time tl to the time t2. However,
25 the actual. power outage time is longer than the duration
from the time tl to the time t2, and occurs from the time
tl to the time t5. When the actual power outage time is
longer than the estimated time, the actual measurement of
the residual capacity of the battery is fed-back. When
5 there are no measures to the time extension, the battery is
depleted at the tj.me t3. Thus, the IT device cannot be
operated between the time t3 and the tirne t5. When the
power outage extends beyond the estimated time, the
performance of the IT device is strictly limited, based on
l o actual measurements of the residual capaci-ty of the battery
and the power value of the IT device. As the residual
capacity decreases, the lneasurelnents are more frequently
performed.. The intervals between the time t2 and the time
t3, between the time t3 and the tirne t4, and between the
I time t4 and the time t5 become short sequentially in this
order. Accordingly to this method, the actual measurements
of the resi.dua.1.c a.pa.ci.tyo f the battery are fed-back to
limit the performance so that the battery has enough
capaci t.y d11r:ing the power outage time. TI-1i.s can be a
20 sol.ut.jon for a case whe~?t he esti.mati..onw as incorrect.
The d.escri.ptions have so far been made to the
advantage of estimating the power outage, the operations of
the IT device and the battery, the example of cooperative
control, and the control example of the solution for when
25 the estimation of a power outage was incorrect.
Descriptions will now be made to a specific configuration
of a cooperative control unit for an IT device and a
battery, on the basis of an operational example of the
cooperative control for the IT device and the battery.
5 FIG. 9 illustrates a configuration of the control
unit CTL 55 which controls an IT device and a battery,
according to the first embodiment of the present invention.
The control unit CTL 55 operates on the server SVR. The
control unit 55 may be configured using the hardware, such
lo as a microcomputer and the like, or may be configured using
software. The control unit includes a Power Outages
Estimation unit POE 70 which has an interface with a
voltage monitor, an IT Power consumption Budget unit IPB 80
which has an interface wi.th the UPS 30, and an IT low-Power
15 Control unit IPC 90 which performs low power control to
satisfy specified restriction of power consumption of an IT
device, and. which has an interface with the power strip PDU
40. The POE unit 70 estimates the power outage time and
frequency to make a. p3.a.n of a. power outage pl~an, and
20 represents power outage ir~forrnation about wl?.ether a power
outage actually occurs at this tj.me. The IPB uni.t 80
specifies the restriction of power consumption of an IT
device, based on the power outage time and the residual
capacity of the battery of the UPS. The operational
25 overview of the control unit CTL 55 is as follows. The
control unit estimates the power outage time and interval,
and specifies the restriction of power consumption based on
the residual capacity of the battery, in order to operate
the IT device for the estimated power outage time. Then,
5 the control unit performs low-power control for the IT
devi-ce, to keep the power equal to or lower than the
specified restriction of power consumption of the IT device
Descriptions will now be made to a configuration of
each functional bloclc. FIG. 10 illustrates the power
10 outages estimation unit POE 70. The POE outputs actual
power outage information representing occurrence/completion
of a power outage and whether a power outage occurs now,
using the measurement values of the voltage logger 20. The
POE stores voltage data of the voltage logger in a data
1 extraction unit, and performs statistical analysis on the
stored voltage data to malce a plan of a power outage. The
voltage data of the voltage logger VLTLOG 20 i.s adjusted,
and date/time data is extracted from the OS using a data
extra.ct:i.on ur1i.t 73.. At this l:i.me, the data. may be
20 extracted in time series, or may be extracted with an event
of voltage vari.ati.on. The data extracted by the data
extraction unit 71 is stored in a data storage unit 72,
together with date/time information attached thereto in
time series. A statistical analysis unit 73 performs
25 statistical analysis on time-series data of the data
storage unit 72, and generates a time-series model. The
time-series model includes a moving average (MA) model, an
autoregressive (AR) model, an autoregressive moving average
(ARMA) model, and a generalized autoregressive conditional
5 heteroscedasticity (GARCH) model, but is not limited to
these. The statistical. analysis unit 73 updates the timeseries
model using everyday data. The statistical analysis
unit 73 may perform a general statistical process for the
time-series data, as estimation for Sunday, simply by
lo getting an average of Sundays. The accuracy may be
improved in combination with a machine learning technique.
A power outage calcul.ation uni.t 74 makes a plan of power
outages using the estimated frequency, time, and interval
of the power outages at a timer-setting sclledule time, for
15 example, at 0:00, stores the plan data, and notifies the
IPB unit 80 of the data.
FIG. 11 illustrates a configuration of the IT power
consumption budget unit IPB 80, according to the first
emhod'liment of t h e present i.nvent:-i.on. The TPB unit 80
zo speci.fi.es restrj~c!t.iono f power cons~impti.ono f IT device,
based on the power outage plan of the power outages
estimation unit 70 and the residual capacity of the battery
of the UPS 30, and has a function for determining a charge
mode based on the estimated interval of the power outages
25 included in the power outage plan. The unit calculates a
battery charge plan, for defining in which time zone and in
which mode the battery is charged using the battery usage
planning unit 82, and also the restriction of power
consumption of IT device. The calculation is made using
5 the input residual capacity and voltage of the battery from
the UPS 30, the power outage plan from the power outages
estimation unit POE 70, actual power outage information,
and battery array specifications 81. The unit informs the
UPS 30 of the charge mode in accordance with the battery
l o charge plan. The unit measures the residual capacity of
the battery of the UPS 30 on a regular or irregular basis
by a timer during the power outage, and obtains the
restricti-on of power consumption of IT device using the
continuous duration of the power outage represented in each
1.5 power outage plan and the residual capacity of the battery.
Descriptions will now be made to a method for
cal~cul.a.tingt he restriction of power consumption of IT
device. To continuously operate the IT device in the power
outage ti.rr~e estimated by the power o~it:ages esti-mation i ~ n i ~ t
20 POE '70, it is necessary to speci.fy how niucl? current flows
to the IT device 50 based on the residual capacity and the
terminal voltage of the UPS 30. At this time, it is
necessary to perform the calculation based on the discharge
characteristics of the battery. FIG. 12 illustrates an
25 example of discharge characteristics of a battery. For
simplification sake, one 12 V battery is used. The battery
array may be formed appropri.ately in parallel or in series.
The discharge time of the battery changes in accordance
with the amount of a discharge current CA, when the rated
5 capacity is identified as "C". The discharge time is forty
minutes with lCA, while the discharge time is twenty hours
with 0.05CA. The discharge current may be set in a range
of satisfying the estimated power outage time. This is the
restrj-ction of power consumptjon of IT device. For example,
l o to have a two-hour power outage time, the discharge current
may simply be set 0.25CA or lower.
FIG. 1.3 illustrates a confi.guration of the IT lowpower
control uni.t IPC 90. The IPC unit 90 performs :].ow--
power control. for each I'T device, using some inputs of
15 power consumption data of each IT device which is acqui-red
by the power strip with power measurement mechanism PDU 40
and the restri-ction of power consumption. of IT device
obtained by the IT power consumpti.on budget unit IPB 80.
FIG. 1.4 :i.l.:Lustrates an operational exa1npl.e for
zo performilly ].ow-power control of IT device, for the
restriction of power consumption of IT devi.ce during the
power outage. In this case, the low-power control is
performed to satisfy the restriction of power consumption
of IT device which is obtained using the residual capacity
25 of the battery and the estimated power outage time. The
restriction of power consumption of IT device is reviewed
in a manner that the residual capacity of the battery
reaches zero at the end of the remaining estimated power
outage time. The restriction of power consumption of I?'
5 device is set using the actual measurement power value.
Accordingly, the descriptions have been made to the
configuration of the control. 1jnj.t CTL 55 which performs
cooperative control for the IT device and the battery. Now,
descriptions will be made to how the entire control is made
10 using control software of the control unit, using a
flowchart. FIG. 15 illustrates this flowchart. The unit
estimates a power outage time(s) of a day and the
frequency/interval of the power outages (S2), at a sch.edul.e
time (Sl) , for exampl-e, at 0 : 00. If a power outage occurs
15 (S3), the unit matches between the actual. power outage and
the power outage estimated at the schedule time, and reads
the continuous d.ura.ti.ona nd i.11terval.so f the power outages.
The unit measures the residual capacity of the battery (S4),
and sets restri.c:ti~or of J?OW~Ic:o nsuniptj.on o:E IT device
20 using the continuous duration ot the power outages ( S 5 ) .
The unit compares the restriction of power consumption of
IT device with the minimum value (full power restriction)
at which the IT device consumes the lowest power in a full
power restriction state (S10). When the restriction of
25 power consumption of IT device is high, the unit performs
the low-power control of IT device. The unit compares the
restriction of power consumption of IT device with the
actual power consumption of the IT device (Sll). When the
restriction of power consumpti.on of IT device is high, the
5 budget is satisfied. Thus, the unit does not perform lowpower
control of the IT device. When the restriction of
power consumption of IT device i.s low, the budget is not
satisfied. Thus, the unit performs low-power control in a
manner that the IT power is equal to or lower than the
lo restriction of power consumption of IT device (512). As an
exceptional process, if the minimum value of the IT device
is greater (S10) as a comparison between the minimum power
val.ue of the IT device and the restrictj-on.o f power
consumpti.on of IT devi.ce, the battery capacity i.s
15 insufficient, and the IT service can not be contj-nued. In
this case, the unit informs another site about this (S13),
and shuts (low11 the device ( 5 1 4 ) . The 1jni.t peri.odj.cal1.y
measures the residual capacity of the battery (57) by a
time:r: i.nterrupti.on ( 5 6 ) , and resets the restri.ct:.i.oonf
20 power collsumption ot IT device ( S 5 ) . As a resul-t, the IT
performance can be performed while using the battery to the
maximum during the power outage. Upon recovery of the
power (SE), the unit cancels the low-power control of the
IT device during the power outage (S9). In accordance with
25 the estimated outage interval.^, in the case of short outage
intervals, the unit sets the quick charging, and in the
case of long outage intervals, the unit sets a normal
charging mode (S15), and continues the process. These are
a series of operations in the flowchart.
5 While periodically measuring the residual capacity of
the battery, the restriction of power consumption of IT
device is set. Further, when low-power control. i.s
necessary, a loop with procedures from S6, 57, S5, S8, S10,
S11, 512, and to S6 again is formed. On the contrary, when
l o low-power control is not necessary, a loop with procedures
S6, S7, 5 5 , 58, SIO, S11, and S6 is formed. The trigger of
the loop is periodical actual measurement of the residual
capacity of the battery. Accordingly, the low-power
corltrol for the IT device is performed to meet with the
15 residual capacity, by estimating the power outage time,
thereby avoiding performance deterioration of the IT device
during the outage time and continuing the service.
WHAT IS CLAIMED IS:
1. A cooperative control system for an IT device and a
plurality of batteries, comprising:
5 a commercial power supply;
a voltage logger which measures a voltage of the
commercial power supply;
an uninterruptible power supply unit which is
connected to the commercial power supply, and to which the
10 plurality of batteries are connected;
a power strip with power measurement mechanism which
is connected to the uninterruptible power supply unit; and
the :IT d.evi.ce which i-ncludes a server connected to
the power strip with power n~easurement mechanism, and
1s wherein
the voltage logger, the uninterruptible power supply
unit, the power strip with power measurement mechanism, and
the server are connected to a network, and
a cont:rol 111.1i.t :i.ri the server estj.mat:es a cont:i.i?uous
20 duration of- a power outage, obtains restriction of power
consumption of the IT devi.ce using the estimated conti.nuous
durati-on of the power outage and residual capacity of the
plurality of batteries, and controls power of the IT device
to satisfy the restriction of power consumption of IT
25 device.
2. The cooperative control system for the IT device and
the batteries according to claim 1, wherein
the control unit periodically or non-periodically
5 measures the residual capacity of the batteries, obtains
the restriction of power consumption of the IT device using
the estimated continuous duration of the power outage and
the measured residual capacity of the batteries in
association with each power outage, and controls power of
l o the IT device to satisfy the restriction of power
consumption of the IT device.
3. The cooperative control system for the IT' device and
the batteries according to claim 1, wherein the control
15 unit comprises:
a power outages estimation unit which stores voltage
data of the voltage logger, and estimates a continuous
duration of a power outage based on the stored voltage
data ;
an TT power c!onsumptjon budgel: unit whi.ch obtains the
restriction of power consumption of the IT device using the
estimated continuous duration of the power outage and the
measured residual capacity of the batteries; and
an IT low-power control unit which performs low-power
25 control, based on power data of the IT device which is
acquired by the power strip with power measurement
mechanism and the restriction of power consumption of the
IT device.
5 4. The cooperative control system for the IT device and
the batteries according to claim 3, wherein
the power outages estimation unit performs
statistical analysis on stored time-series data, and
generates a time-series model.
10
5. The cooperative control system for the IT device and
the batteries, according to claim 1, wherein
the control unit performs feedback control for
limiting performance of the IT device, based on actual
15 measurement of the residual capacity of the batteries, when
a power outage duration is longer than the estimated power
outage duration.
6. The cooperat:i.ve cont:rol. system for the IT device and
20 the batteries according to c.l.aim 1, wherein
the control unit further estimates an interval of
power outages, and controls a charge mode of the batteries
based on the estimated interval of the power outages.
25 7. The cooperative control system for the IT device and
the batteries according to claim 6, wherein
the control unit stores voltage data of the voltage
logger, and estimates an interval of power outages based on
the stored voltage data.
5
8. A cooperative control method for an IT device and
batteries, for a system including a commercial power supply,
a voltage logger whj.ch measures a voltage of the commercial
power supply, an uninterruptible power supply unit which is
10 connected to the commercial power supply and to which the
plurality of batteries are connected, a power strip with
power measurement mechanism which is connected to the
uninterruptib1.e power supply unj.t, and an. IT device which
includes a server connected to the power strip with power
15 measurement mechanism, and wherein the voltage logger, the
uninterruptible power supply unit, the power strip with
power measurement mechanism, and the server are connected
to a network, the method comprisj.ng the steps of:
est:ima.ting a continuous durati~on of a power outage;
obtaillirly restriction of power coi?sump>t-.i.on of the T'T
device, using the estimated continuous duration of the
power outage and residual capacity of the batteries; and
controlling power of the IT device to satisfy the
restriction of power consumption of the IT device.
9. The cooperative control method for the IT device and
the batteries accordi-ng to claim 8, further comprising the
steps of:
periodically or non-periodically measuring residual
5 capacity of the batteries;
obtai-ning the restriction of power consumption of the
I?' device, using the estimated continuous duration of the
power outage and the measured residual capacity of the
batteries, in association with each power outage; and
10 controlling power of the IT device to satisfy the
restriction of power consumption.
10. The cooperative control metl~od for the IT devi.ce and
the batteri-es according to c1.aj.m 8, wherei-n
15 the estimating the continuous duration of the power
outage includes storing voltage data of the voltage logger
and estj..mati.ng the continuous duration of the power outage
based on the stored voltage data.
z0 11. The cooperative control method for the IT device and
the batteries according to claim 8, further comprising the
steps of:
estimating an interval of power outages; and
controlling a charge mode of the batteries, based on
25 the estj-mated interval of the power outages.
12. The cooperative control method for the IT device and
the batteries according to claim 11, wherein
the estimating the interval of thc power outages
5 includes storing voltage data of the voltage S.ogger and
estimating the interval of the power outages based on the
stored voltage data.