U.S. patent application number 11/051836 was filed with the patent office on 2005-06-23 for power generation control system, power generation control method, program, and medium.
Invention is credited to Miyauchi, Shinji, Ogawa, Osamu, Suzuki, Jiro, Ueda, Tetsuya.
Application Number | 20050136311 11/051836 |
Document ID | / |
Family ID | 26601440 |
Filed Date | 2005-06-23 |
United States Patent
Application |
20050136311 |
Kind Code |
A1 |
Ueda, Tetsuya ; et
al. |
June 23, 2005 |
Power generation control system, power generation control method,
program, and medium
Abstract
It has been difficult to reduce a waste of energy in a fuel cell
power generating process when, for example, a temporary rise or
drop of a power load occurs. A fuel cell power generation system
includes: load detection means of detecting power requested by a
load; and output control means of accumulating a time at which a
detected power requested by the load is equal to or larger than a
predetermined value when a fuel cell body does not generate power
to be supplied to the load, and allowing the fuel cell body to
start generating power to be supplied to the load according to a
predetermined rule based on an accumulation result.
Inventors: |
Ueda, Tetsuya; (Kasugai-shi,
JP) ; Ogawa, Osamu; (Kyoto-shi, JP) ; Suzuki,
Jiro; (Nara-shi, JP) ; Miyauchi, Shinji;
(Shikigun, JP) |
Correspondence
Address: |
RATNERPRESTIA
P O BOX 980
VALLEY FORGE
PA
19482-0980
US
|
Family ID: |
26601440 |
Appl. No.: |
11/051836 |
Filed: |
February 4, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11051836 |
Feb 4, 2005 |
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10148845 |
Nov 13, 2002 |
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10148845 |
Nov 13, 2002 |
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PCT/JP01/08620 |
Oct 1, 2001 |
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Current U.S.
Class: |
700/297 ;
429/423; 429/430; 700/287 |
Current CPC
Class: |
Y02E 60/50 20130101;
H01M 8/04604 20130101; H02J 3/14 20130101; H02J 7/34 20130101; H02J
3/00 20130101; H01M 16/006 20130101; H02J 2310/58 20200101; H01M
8/0494 20130101; H01M 8/04947 20130101; Y02E 60/10 20130101; H01M
8/04626 20130101; H01M 8/04955 20130101; H02J 2300/30 20200101;
H02J 3/144 20200101; H01M 8/04992 20130101; H02J 3/38 20130101 |
Class at
Publication: |
429/030 ;
700/287 |
International
Class: |
H01M 008/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 3, 2000 |
JP |
2000-303349 |
May 23, 2001 |
JP |
2001-154585 |
Claims
1-35. (canceled)
36. A power generation control system for use with a predetermined
power generator, comprising: a power detector detecting power in at
least a first predetermined period requested by a load; and a power
generation controller controlling the predetermined power generator
generating all or a part of power to be supplied to the load, by
using a command value generated during every second predetermined
period based on an average value of the detected power in the first
predetermined period, except for a case where the second
predetermined period coincides with the first predetermined period,
wherein the command value generated during every second
predetermined period is generated based on the average value in the
first predetermined period having an end time equal to a starting
time of the second predetermined period, and said predetermined
power generator is a fuel cell power generator which comprises a
hydrogen supplier having a reformer, an air supplier, and a fuel
cell generating power by using hydrogen supplied by said hydrogen
supplier and oxygen supplied by said air supplier.
37. The power generation control system according to claim 36,
wherein excess or shortfall of the generated power relative to the
requested power is adjusted by using system power and/or a
battery.
38. The power generation control system according to claim 37,
wherein: the excess or shortfall of the generated power is adjusted
by using system power and the battery; and the battery is used by
priority over the system power.
39. The power generation control system according to claim 37,
wherein control is performed by amending the command value
corresponding to a difference between an amount of accumulation of
the battery and a predetermined target amount of accumulation of
the battery.
40. A fuel cell power generator, comprising: a hydrogen supplier
having a reformer; an air supplier; a fuel cell generating power by
using hydrogen supplied by said hydrogen supplier and oxygen
supplied by said air supplier and the power generation control
system according to claim 36.
41. A power generation control method, comprising the steps of:
detecting power in at least a first predetermined period requested
by a load; and controlling a predetermined power generator
generating all or a part of power to be supplied to the load, by
using a command value generated during every second predetermined
period based on an average value of the detected power in the first
predetermined period, except for a case where the second
predetermined period coincides with the first predetermined period,
wherein the command value generated during every second
predetermined period is generated based on the average value in the
first predetermined period having an end time equal to a starting
time of the second predetermined period, and said predetermined
power generator is a fuel cell power generator which comprises a
hydrogen supplier having a reformer, an air supplier, and a fuel
cell generating power by using hydrogen supplied by said hydrogen
supplier and oxygen supplied by said air supplier.
42. A computer program product for directing a computer to function
as the power generation controller of the power generation control
system according to claim 36, by: controlling a predetermined power
generator generating all or a part of power to be supplied to the
load, by using a command value generated during every second
predetermined period based on an average value of the detected
power in the first predetermined period, except for the case where
the second predetermined period coincides with the first
predetermined period.
43. A computer-processible medium storing a computer program
product according to claim 42.
Description
TECHNICAL FIELD
[0001] The present invention relates to a power generation control
system, a power generation control method, a program and a medium
for supply of power to, for example, a domestic power load using a
fuel cell, etc.
BACKGROUND ART
[0002] (A) FIG. 11 shows a configuration of a conventional fuel
cell power generation device (conventional technology 1) disclosed
in Japanese Patent Laid-Open No. 7-57753. In FIG. 11, a fuel cell
body 31 generates DC power by reaction between hydrogen supplied by
hydrogen supply means 32 and oxygen in the air supplied by air
supply means 33, and a power converter 34 outputs AC power after
converting the DC power into the AC power. At an external load
command, a power control unit 35 controls a flow rate control unit
36 and the power converter 34, the flow rate control unit 36
controls the flow rate of the hydrogen supply by the hydrogen
supply means 32 and the flow rate of the air supply by the air
supply means 33 such that the flow rates can be the optimum values,
and the power converter 34 controls the amount of electricity
output by the fuel cell body 31, thereby successfully controlling
the output power. An excess power prevention means 39 including a
power detector 37 and an arithmetic unit 38 is provided between the
fuel cell body 31 and the power converter 34 so that the amount of
electricity can be appropriately suppressed when there is a steep
rise in electricity output.
[0003] FIG. 12 shows the configuration of the fuel cell power
generation device (conventional technology 2) disclosed in Japanese
Patent Laid-Open No. 6-325774. In FIG. 12, a fuel cell body 41
generates DC power by reaction between hydrogen supplied by
hydrogen supply means 42 and oxygen in the air supplied by air
supply means 43, and a power converter 44 outputs AC power after
converting the DC power into the AC power. A control device 45
controls a charge/discharge device 46 and the power converter 44,
and can control the power output depending on an external load by
the discharge from the charge/discharge device 46 or the charge to
the charge/discharge device 46 although the amount of electricity
from the fuel cell body 41 is constant. In the fuel cell power
generation device, since the amount of electricity from the fuel
cell body 41 is constant when the power output is controlled
depending on a fluctuating external load, the amount of charge or
discharge of the charge/discharge device 46 becomes considerably
large. Therefore, a large capacity charge/discharge device 46 is
required, and the entire device is costly and needs a large
installation space.
[0004] (B) The configuration of the conventional fuel cell power
generation system (conventional technology 3) disclosed in Japanese
Patent Laid-Open No. 5-182675 and others is described below by
referring to FIG. 13 showing the configuration of the conventional
fuel cell power generation system (conventional technology 3).
[0005] In FIG. 13, a fuel cell (body) 131 is connected to a load
134 through a battery 132 and an output control means 133 including
an inverter.
[0006] The operations of the conventional fuel cell power
generation system (conventional technology 3) are described below
by referring to FIG. 14 which is a graph for explanation of an
example of an operation pattern of the conventional fuel cell power
generation system (conventional technology 3).
[0007] In FIG. 14, the horizontal and vertical axes respectively
indicate the time and power, and reference numerals 141 and 142
respectively denote a load power and output power.
[0008] The load power 141 is rated power of W8c of the fuel cell
body 131 from t2 to t3, and is W8d smaller than the rated power of
the fuel cell body 131 from t1 to t2.
[0009] On the other hand, in the fuel cell body 131 (FIG. 13), the
output control means 133 performs a continuous operation by the
rated power W8c from t2 to t3, and performs an intermittent
operation by the rated power W8c from t1 to t2 so that the same
amount of electricity as the load power 141 can be obtained.
[0010] Therefore, the battery 132 (FIG. 13) puts on charge and
discharge the redundant power and the insufficient power in the
period from t1 to t2.
[0011] Since the fuel cell body 131 cannot continue generating
power unless a high temperature can be constantly maintained, the
energy such as the power for heating the fuel cell body 131 before
generating power during power-up is required. Furthermore, since a
stopping operation is performed by safely emitting hydrogen
remaining in the path while cooling it, the energy such as power,
etc. is also required.
[0012] Since an intermittent operation is performed in the above
mentioned conventional fuel cell power generation system
(conventional technology 3), energy is wasted each time power-up
and power-down operations are performed.
[0013] Although the configuration of the fuel cell power generation
system (conventional technology 4) is similar to that of the above
mentioned fuel cell power generation system (conventional
technology 3), the waste of the conventional technology can be
avoided to a certain extent by changing the output power by
following the load power as shown in FIG. 15 which is a graph for
explanation of an example of an operation pattern of the
conventional fuel cell power generation system (conventional
technology 4).
[0014] In FIG. 15, the horizontal and vertical axes respectively
indicate the time and the power. Reference numerals 143 and 144
respectively denote load power and output power. The load power 143
is high in the morning 143b, afternoon 143c, and evening 143d, and
is low at midnight 143e and in the early morning 143a.
[0015] The operation of the fuel cell body is controlled by the
output power 144 following the load power 143 between the maximum
output power W9c and the minimum output power W9d. Since the fuel
cell body 1 has a continuously increasing amount of charge of the
battery 132 with excess power when the load power 143 is smaller
than the minimum output power W9d at midnight 143e and in the early
morning 143a, the operation is stopped.
[0016] Thus, the conventional fuel cell power generation system
(conventional technology 4) is generally activated and stopped once
a day, thereby more successfully reducing the waste energy during
the power-up and power-down than the above mentioned fuel cell
power generation system (conventional technology 3).
[0017] (A) However, in the conventional fuel cell power generation
device (conventional technology 1), when an external load command
largely changes within a short time, the power control unit 35 has
to control the output power by raising and dropping it within a
short time, thereby possibly causing the hunting of output power
because of the delay of control. As a result, there can arise the
problem that the operation of the fuel cell power generation device
becomes unstable, the efficiency of the device is lowered, and the
durability is shortened.
[0018] (B) Additionally, there has been the problem that the fuel
cell power generation system (conventional technology 4) wastes
energy when the operation as shown in FIG. 16 which is a graph for
explanation of an example of another operation pattern of the
conventional fuel cell power generation system (conventional
technology 4) is performed.
[0019] To be more practical, in the conventional fuel cell power
generation system (conventional technology 4), when there is a
temporary rise 145b of load power 145 when the operation is
stopped, for example, at midnight 145e or in the early morning
145a, the system is started but stopped soon. Furthermore, in the
fuel cell power generation system (conventional technology 4), the
stopping process is started but the activating process is soon
performed when there is a temporary drop 145d of the load power 145
during the operation, for example, in the afternoon 145c, etc.
Thus, energy is wasted in the originally unnecessary activating and
stopping operations.
DISCLOSURE OF THE INVENTION
[0020] The present invention has been achieved to solve the
abovementioned problems with the conventional technology, and aims
at providing a power generation control system, a power generation
control method, a program, and a medium for preventing the
reduction of the durability by, for example, stabilizing the
operation of the fuel cell power generation device and improving
the efficiency.
[0021] The present invention has also been achieved to solve the
problem with the conventional technology, and aims at providing a
power generation control system, a power generation control method,
a program, and a medium capable of minimizing the waste of energy
even when there arise a temporary rise or drop of power load.
[0022] The 1st invention of the present invention (corresponding to
claim 1) is a power generation control system comprising:
[0023] power detection means of detecting power requested by a
load; and
[0024] power generation control means of controlling predetermined
power generation means of generating all or a part of power to be
supplied to the load using a command value generated in each second
predetermined period based on an average value of the detected
power in a first predetermined period.
[0025] The 2nd invention of the present invention (corresponding to
claim 2) is the power generation control system according to the
1st invention of the present invention, wherein the command value
generated in each second predetermined period is generated based on
an average value in the first predetermined period with a starting
time of the second predetermined period as an end time of the first
predetermined period.
[0026] The 3rd invention of the present invention (corresponding to
claim 3) is the power generation control system according to the
1st or 2nd invention of the present invention, wherein:
[0027] said predetermined power generation means is a fuel cell;
and
[0028] excess or shortfall of the generated power relative to the
requested power is adjusted using system power and/or battery.
[0029] The 4th invention of the present invention (corresponding of
claim 4) is the power generation control system according to the
3rd invention of the present invention, wherein:
[0030] the excess or shortfall of the generated power can be
adjusted using system power and battery; and
[0031] said battery is used by priority over said system power.
[0032] The 5th invention of the present invention (corresponding to
claim 5) is the power generation control system according to the
3rd invention of the present invention, wherein said control is
performed with amount of accumulation of the battery taken into
account.
[0033] The 6th invention of the present invention (corresponding of
claim 6) is the power generation control system according to the
5th invention of the present invention, wherein said taking an
amount of accumulation of the battery into account means amending
the command value corresponding to the difference between the
amount of accumulation and a predetermined target amount of
accumulation.
[0034] The 7th invention of the present invention (corresponding to
claim 7) is a power generation control method, comprising the steps
of:
[0035] detecting power requested by a load; and
[0036] controlling predetermined power generation means of
generating all or a part of power to be supplied to the load using
a command value generated in each second predetermined period based
on an average value of the detected power in a first predetermined
period.
[0037] The 8th invention of the present invention (corresponding to
claim 8) is a power generation control system, comprising:
[0038] power detection means of detecting power requested by a
load;
[0039] time accumulation means of accumulating a time at which the
detected power requested by the load equal to or larger than a
predetermined value when predetermined power generation means does
not generate power to be supplied to the load; and
[0040] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0041] The 9th invention of the present invention (corresponding to
claim 9) is the power generation control system according to the
8th invention of the present invention, wherein said predetermined
rule refers to allowing said power generation means to start
generating power to be supplied to the load when (1) a total period
of the time continuously accumulated in a predetermined period or
(2) a total period of the time discontinuously accumulated in a
predetermined period exceeds a predetermined threshold.
[0042] The 10th invention of the present invention (corresponding
to claim 10) is the power generation control system according to
the 9th invention of the present invention, wherein said time
accumulation means outputs (1) the total period of the time
continuously accumulated in the predetermined period or (2) the
total period of the time discontinuously accumulated in the
predetermined period as a result of the accumulation.
[0043] The 11th invention of the present invention (corresponding
to claim 11) is the power generation control system according to
the 8th invention of the present invention, wherein said
predetermined rule refers to allowing said power generation means
to start generating power to be supplied to the load when a total
period of continuously accumulated time exceeds a predetermined
threshold.
[0044] The 12th invention of the present invention (corresponding
to claim 12) is a power generation control system, comprising:
[0045] power detection means of detecting power requested by a
load;
[0046] time accumulation means of accumulating a time at which the
detected power requested by the load equal to or smaller than a
predetermined value when predetermined power generation means
generates power to be supplied to the load; and
[0047] power generation control means of allowing said power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0048] The 13th invention of the present invention (corresponding
to claim 13) is a power generation control system, comprising:
[0049] power detection means of detecting power requested by a
load;
[0050] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means does not generate power to be supplied to the
load; and
[0051] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0052] The 14th invention of the present invention (corresponding
to claim 14) is the power generation control system according to
the 13th invention of the present invention, wherein said
predetermined rule refers to allowing said power generation means
to start generating power to be supplied to the load when the
accumulated power exceeds a predetermined threshold.
[0053] The 15th invention of the present invention (corresponding
to claim 15) is a power generation control system, comprising:
[0054] power detection means of detecting power requested by a
load;
[0055] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means generates power to be supplied to the load;
and
[0056] power generation control means of allowing the power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0057] The 16th invention of the present invention (corresponding
to claim 16) is a power generation control system, comprising:
[0058] record accumulation means of accumulating a record of power
requested by a load when predetermined power generation means
generates power to be supplied to the load according to a
predetermined rule; and
[0059] power generation control means of allowing the power
generation means to start or stop generating power to be supplied
to the load according to the accumulated record by priority over
the rule.
[0060] The 17th invention of the present invention (corresponding
to claim 17) is the power generation control system according to
the 16th invention of the present invention, wherein:
[0061] a time at which said power generation means is allowed to
start or stop generating power to be supplied to the load is
computed based on the accumulated record; and
[0062] said power generation means is allowed to start or stop
generating power to be supplied to the load practically at the
computed time.
[0063] The 18th invention of the present invention (corresponding
to claim 18) is a power generation control method, comprising the
steps of:
[0064] detecting power requested by a load;
[0065] accumulating a time at which the detected power requested by
the load indicates a value equal to or larger than a predetermined
value when predetermined power generation means does not generate
power to be supplied to the load; and
[0066] allowing said power generation means to start generating the
power to be supplied to the load using a predetermined rule based
on the accumulation result.
[0067] The 19th invention of the present invention (corresponding
to claim 19) is a power generation control method, comprising the
steps of:
[0068] detecting power requested by a load;
[0069] accumulating a time at which the detected power requested by
the load indicates a value equal to or smaller than a predetermined
value when predetermined power generation means generates power to
be supplied to the load; and
[0070] allowing said power generation means to stop generating the
power to be supplied to the load using a predetermined rule based
on the accumulation result.
[0071] The 20th invention of the present invention (corresponding
to claim 20) is a power generation control method, comprising the
steps of:
[0072] detecting power requested by a load;
[0073] accumulating power requested by the load in a predetermined
period when predetermined power generation means does not generate
power to be supplied to the load; and
[0074] allowing said power generation means to start generating the
power to be supplied to the load using a predetermined rule based
on the accumulation result.
[0075] The 21st invention of the present invention (corresponding
to claim 21) is a power generation control method, comprising the
steps of:
[0076] detecting power requested by a load;
[0077] accumulating power requested by the load in a predetermined
period when predetermined power generation means generates power to
be supplied to the load; and
[0078] allowing the power generation means to stop generating the
power to be supplied to the load using a predetermined rule based
on the accumulation result.
[0079] The 22nd invention of the present invention (corresponding
to claim 22) is a power generation control method, comprising the
steps of:
[0080] accumulating a record of power requested by a load when
predetermined power generation means generates power to be supplied
to the load according to a predetermined rule; and
[0081] allowing the power generation means to start or stop
generating power to be supplied to the load according to the
accumulated record by priority over the rule.
[0082] The 23rd invention of the present invention (corresponding
to claim 23) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to the 1st invention of the present invention,
comprising:
[0083] power detection means of detecting power requested by a
load; and
[0084] power generation control means of controlling predetermined
power generation means of generating all or a part of power to be
supplied to the load using a command value generated based on an
average value of the detected power in a first predetermined period
in each second predetermined period.
[0085] The 24th invention of the present invention (corresponding
to claim 24) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to the 8th invention of the present invention,
comprising:
[0086] power detection means of detecting power requested by a
load;
[0087] time accumulation means of accumulating a time at which the
detected power requested by the load indicates a value equal to or
larger than a predetermined value when predetermined power
generation means does not generate power to be supplied to the
load; and
[0088] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0089] The 25th invention of the present invention (corresponding
to claim 25) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to the 12nd present invention, comprising:
[0090] power detection means of detecting power requested by a
load;
[0091] time accumulation means of accumulating a time at which the
detected power requested by the load indicates a value equal to or
smaller than a predetermined value when predetermined power
generation means generates power to be supplied to the load;
and
[0092] power generation control means of allowing said power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0093] The 26th invention of the present invention (corresponding
to claim 26) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to the 13th present invention, comprising:
[0094] power detection means of detecting power requested by a
load;
[0095] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means does not generate power to be supplied to the
load; and
[0096] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0097] The 27th invention of the present invention (corresponding
to claim 27) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to the 15th invention of the present invention,
comprising
[0098] power detection means of detecting power requested by a
load;
[0099] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means generates power to be supplied to the load;
and
[0100] power generation control means of allowing the power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0101] The 28th invention of the present invention (corresponding
to claim 28) is a program being used to direct a computer to
function as all or a part of the power generation control system
according to claim 16, comprising:
[0102] record accumulation means of accumulating a record of power
requested by a load when predetermined power generation means
generates power to be supplied to the load according to a
predetermined rule; and
[0103] power generation control means of allowing the power
generation means to start or stop generating power to be supplied
to the load according to the accumulated record by priority over
the rule.
[0104] The 29th invention of the present invention (corresponding
to claim 29) is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 1st invention of
the present invention, comprising:
[0105] power detection means of detecting power requested by a
load; and
[0106] power generation control means of controlling predetermined
power generation means of generating all or a part of power to be
supplied to the load using a command value generated based on an
average value of the detected power in a first predetermined period
in each second predetermined period.
[0107] The 30th invention of the present invention (corresponding
to claim 30),is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 8th invention of
the present invention, comprising:
[0108] power detection means of detecting power requested by a
load;
[0109] time accumulation means of accumulating a time at which the
detected power requested by the load indicates a value equal to or
larger than a predetermined value when predetermined power
generation means does not generate power to be supplied to the
load; and
[0110] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0111] The 31st invention of the present invention (corresponding
to claim 31) is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 12th invention of
the present invention, comprising:
[0112] power detection means of detecting power requested by a
load;
[0113] time accumulation means of accumulating a time at which the
detected power requested by the load indicates a value equal to or
smaller than a predetermined value when predetermined power
generation means generates power to be supplied to the load;
and
[0114] power generation control means of allowing said power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0115] The 32nd invention of the present invention (corresponding
to claim 32) is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 13th invention of
the present invention, comprising:
[0116] power detection means of detecting power requested by a
load;
[0117] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means does not generate power to be supplied to the
load; and
[0118] power generation control means of allowing said power
generation means to start generating the power to be supplied to
the load using a predetermined rule based on the accumulation
result.
[0119] The 33rd invention of the present invention (corresponding
to claim 33) is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 15th invention of
the present invention, comprising:
[0120] power detection means of detecting power requested by a
load;
[0121] power accumulation means of accumulating power requested by
the load in a predetermined period when predetermined power
generation means generates power to be supplied to the load;
and
[0122] power generation control means of allowing the power
generation means to stop generating the power to be supplied to the
load using a predetermined rule based on the accumulation
result.
[0123] The 34th invention of the present invention (corresponding
to claim 34) is a computer-processible medium storing a program
being used to direct a computer to function as all or a part of the
power generation control system according to the 16th invention of
the present invention, comprising:
[0124] record accumulation means of accumulating a record of power
requested by a load when predetermined power generation means
generates power to be supplied to the load according to a
predetermined rule; and
[0125] power generation control means of allowing the power
generation means to start or stop generating power to be supplied
to the load according to the accumulated record by priority over
the rule.
BRIEF DESCRIPTION OF THE DRAWINGS
[0126] FIG. 1 shows a configuration of a system of a fuel cell
power generation device according to a first embodiment of the
present invention;
[0127] FIG. 2 shows a configuration of a system of a fuel cell
power generation device according to a second embodiment of the
present invention;
[0128] FIG. 3 shows a controlling operation of the fuel cell power
generation device according to the first embodiment of the present
invention;
[0129] FIG. 4 shows a controlling operation of the fuel cell power
generation device according to the second embodiment of the present
invention;
[0130] FIG. 5 is a graph for explanation of an example of an
operation pattern of a fuel cell power generation system according
to a third embodiment of the present invention;
[0131] FIG. 6 is a graph for explanation of an example of an
operation pattern of a fuel cell power generation system according
to a fourth embodiment of the present invention;
[0132] FIG. 7 is a graph for explanation of an example of an
operation pattern of a fuel cell power generation system according
to a fifth embodiment of the present invention;
[0133] FIG. 8 is a graph for explanation of an example of an
operation pattern of a fuel cell power generation system according
to a sixth embodiment of the present invention;
[0134] FIG. 9 is a graph for explanation of an example of an
stopping pattern of a fuel cell power generation system according
to a seventh embodiment of the present invention;
[0135] FIG. 10 shows a configuration of the system of the fuel cell
power generation system according to the third embodiment of the
present invention;
[0136] FIG. 11 shows a configuration of a system of a conventional
fuel cell power generation device (conventional technology 1);
[0137] FIG. 12 shows a configuration of a system of a conventional
fuel cell power generation device (conventional technology 2);
[0138] FIG. 13 shows a configuration of a system of a conventional
fuel cell power generation system (conventional technology 3);
[0139] FIG. 14 is a graph for explanation-of an example of an
operation pattern of a conventional fuel cell power generation
system (conventional technology 3);
[0140] FIG. 15 is a graph for explanation of an example of an
operation pattern of a conventional fuel cell power generation
system (conventional technology 4); and
[0141] FIG. 16 is a graph for explanation of another example of an
operation pattern of a conventional fuel cell power generation
system (conventional technology 4).
DESCRIPTION OF SYMBOLS
[0142] 1 fuel cell body
[0143] 2 hydrogen supply means
[0144] 3 air supply means
[0145] 4 output control means
[0146] 5 power conversion device
[0147] 6 output line
[0148] 7 system power
[0149] 8 load detection means
[0150] 9 power load
[0151] 10 output command device
[0152] 11 flow rate control device
[0153] 12 system power connection line
[0154] 21 accumulation means
[0155] 22 connection line
[0156] 23 accumulation amount control device
[0157] 24 accumulation amount detection means
BEST MODE FOR CARRYING OUT THE INVENTION
[0158] The embodiments according to the present invention will be
described below by referring to the attached drawings.
EMBODIMENT 1
[0159] First, a configuration of a fuel cell power generation
device according to a first embodiment of the present invention
will be described below by referring to FIG. 1 showing the
configuration of the system of the fuel cell power generation
device according to the first embodiment of the present
invention.
[0160] To a fuel cell body 1, hydrogen supply means 2 represented
by a reformer, a hydrogen storage alloy, a hydrogen bomb, etc., and
air supply means 3 represented by an air blower, a blower pump,
etc. are connected. One terminal of output control means 4 is
electrically connected to the fuel cell body 1, and another
terminal is electrically connected to a power conversion device 5.
An output line 6 is electrically connected to the power conversion
device 5, branched in the line, one terminal is electrically
connected to a system power 7 through a system power connection
line 12 while another terminal is electrically connected to load
detection means 8 and a power load 9. Output command device 10
issues an output command to the output control means 4, and a flow
rate control device 11 controls the hydrogen supply means 2 and the
air supply means 3.
[0161] The output control means 4, the output command device 10,
and the means including the flow rate control device 11 correspond
to the power generation control means according to the present
invention, and the load detection means 8 corresponds to power
detection means according to the present invention. The fuel cell
power generation device according to the first embodiment of the
present invention corresponds to means including the power
generation control system according to the present invention.
[0162] Described below will be the operation of the fuel cell power
generation device according to the first embodiment of the present
invention. While describing the operation of the fuel cell power
generation system according to the first embodiment of the present
invention, an embodiment of the power generation control method
according to the present invention is also described (as in the
following descriptions).
[0163] The hydrogen supplied by the hydrogen supply means 2 reacts
with the oxygen in the air supplied by the air supply means 3 in
the fuel cell body 1 to generate DC power. The amount of
electricity of the generated DC power is controlled by the output
control means 4, then transmitted to the power conversion device 5,
converted into AC power having the same voltage as the system power
7, and supplied to the power load 9 through the output line 6. At
this time, power conversion efficiency indicates how the input
power into the power conversion device 5 is converted into the
output power from the power conversion device 5. If the output
power of the fuel cell body 1 is short relative to the load power
of the power load 9, the power is also supplied by the system power
7. On the other hand, if the output power is excessive relative to
the load power, then the power is returned to the system power 7,
thereby performing a system linkage operation.
[0164] An object of the power generation by a fuel cell power
generation device is to obtain the economical efficiency by the
high efficiency. However, when the output power is short relative
to the load power, power is purchased from the system power 7. On
the other hand, when the output power is excessive relative to the
load power, the purchased power is returned at a low price to the
system power 7, thereby normally lowering the economical
efficiency. Therefore, it is demanded that the output power can
closely follow the change of the load power such that the output
power can be prepared in proper quantities relative to the load
power.
[0165] As means of following the load power, the load detection
means 8 first detects the load power of the power load 9. Based on
the detection result, the output command device 10 issues an output
command value to the output control means 4, the output control
means 4 controls the DC power generated by the fuel cell body 1 at
the request value. Depending on the DC power value, the flow rate
control device 11 controls the hydrogen flow rate from the hydrogen
supply means 2 and the air flow rate from the air supply means 3 at
the appropriate value. The output power can be controlled only by
the output control means 4 performing the DC power control.
However, if the hydrogen flow rate to the fuel cell body 1 is
constant, and a smaller amount of DC power is generated by the fuel
cell body 1, then the ratio of the hydrogen (hydrogen utilization
rate) reacting in the fuel cell body 1 is reduced and a large
volume of hydrogen is wasted, thereby exceedingly lowering the
efficiency. Thus, by the flow rate control device 11 controlling
the hydrogen flow rate and the air flow rate at the appropriate
value, the efficiency can be optimally maintained.
[0166] In a series of following controlling processes, the load
power can incessantly change within a short time. If the load power
is used as an output command as is, the DC power rises or drops
within a short time, thereby causing the trouble that the delay of
control induces hunting and an unstable operation of the fuel cell
power generation device. Furthermore, when a reformer for
generating hydrogen from a hydrocarbon fuel by catalysis is used as
the hydrogen supply means 2, the process by catalysis cannot follow
an instant change of an output command value, thereby causing the
problem of lowered efficiency and reduced durability.
[0167] According to an embodiment of the present invention, as
shown in FIG. 3 showing the fuel cell power generation device
according to the first embodiment of the present invention, the
output command device 10 computes an output command by obtaining an
average value of the load power in the period of time T1 (first
predetermined period) with the power conversion efficiency taken
into account, and sets the output command value as a DC power value
to be set by the output control means 4 every time T2 (second
predetermined period). Using the average value of the load power in
the time T1 for an output command value, an appropriate output
command can be issued regardless of an instant change, and using an
output command every time T2, the device can be operated depending
on its response time (time T2 (second predetermined period) (The
command value generated each time T2 (second predetermined period)
is based on the average value in the period of the time T1 (first
predetermined period) ending at the starting time of the second
predetermined period.
[0168] As an example, when the optimum control value in the
domestic operation of a solid polymer fuel cell power generation
device of 1.5 KW output is obtained, a result of T1=3 minutes and
T2=1 minute indicating T1:T2=approximately 3:1 is output. That is,
in this example, the optimum operation control can be performed by
issuing an output command value based on an average load power in 3
minutes to a device each minute.
[0169] Thus, according to the first embodiment of the present
invention, the optimum output command can be issued regardless of
an instant change by applying an average value in the period of the
time T1 of the load power to an output command value, and an
operation of a device can be optimally performed corresponding to
the response time of the device by issuing an output command each
time T2. As a result, the fuel cell power generation device can be
stably operated with high efficiency and longer durability.
EMBODIMENT 2
[0170] The configuration of the fuel cell power generation device
according to a second embodiment of the present invention will be
described below by referring to FIG. 2 showing the configuration of
the system of the fuel cell power generation device according to a
second embodiment of the present invention. The means also
appearing in the above mentioned first embodiment is assigned the
same reference numeral, and the explanation is omitted here.
[0171] Accumulation means 21 is branched from a connection line 22
connecting the output control means 4 to the power conversion
device 5, and connected through an accumulation amount control
device 23. Accumulation amount detection means 24 is connected to
the accumulation means 21. An object of providing the accumulation
means 21 is to solve the problem with the first embodiment that the
economical efficiency is reduced in the system linkage operation by
adjusting the power relating to the system power 7 due to the
excess or deficient output power relative to the load power. That
is, using the charge/discharge of the accumulation means 21, the
amount of power supply from the system power 7 and the amount of
return power to the system power 7 can be minimized, thereby
improving the economical efficiency (the accumulation means 21
(battery) is used by priority over the system power 7).
[0172] Described below will be the operation of the fuel cell power
generation device according to the second embodiment of the present
invention. As shown in FIG. 4, the output command device 10
operates an average power W1 in the period of time T1 of the load
power detected by the load detection means 8. The power W2 (=Q3/T2)
is obtained by dividing the shortage of accumulation Q3 (=Q2-Q1)
which is a difference between the current amount of accumulation Q1
detected by the accumulation amount detection means 24 and the
target amount of accumulation Q2 by the time T2. The power W2 is
added to the average power W1 to obtain W3 (=W1+W2). Then, an
output command value is obtained from the W3 with the power
conversion efficiency taken into account, and the DC power value of
the fuel cell body 1 corresponding to the output command value is
issued to the output control means 4 each time T2. The output
command value is defined as the DC power value set each time T2 by
the output control means 4. In addition, the shortage of
accumulation Q3 is controlled to be accumulated in the accumulation
means 21 by the accumulation amount control device 23 (a command
value is amended depending on the difference between an amount of
accumulation and a predetermined target amount of
accumulation).
[0173] The series of the above mentioned controlling operations are
performed by adding the accumulation amount control to the
following control (refer to FIG. 3) according to the first
embodiment of the present invention. When the average power W1 is
defined as an output command value as is, then the amount of
accumulation is not controlled, thereby possibly accumulating the
difference between the target amount of accumulation Q2 and the
current amount of accumulation Q1 gradually. For example, when the
amount of accumulation gradually decreases with the amount of
discharge exceeding the amount of charge, the accumulation means 21
of a large capacity is to be prepared not to reduce the amount of
accumulation down to zero, thereby requiring the higher cost and
larger device installation space. Therefore, according to the
second embodiment of the present invention, an output command value
is obtained by taking the power conversion efficiency into account
for W3 (=W1+W2) obtained by adding the power W2 (=Q3/T2)
compensating for the shortage of accumulation Q3 (=Q2-Q1) in the
time period T2 for specification of the output command value. Thus,
the amount of accumulation is controlled to constantly converge
into the target amount of accumulation Q2, thereby minimizing the
requirements for the accumulation means 21.
[0174] Thus, according to the second embodiment of the present
invention, the requirements for the accumulation means 21 can be
minimized by controlling the amount of accumulation to converge
into the target amount of accumulation Q2, thereby reducing the
cost and size of the device.
[0175] In the above mentioned first and second embodiments of the
present invention, the predetermined period T1 used for obtaining
the average power W1 and the predetermined period T2 used for
issuing a command value to the output control means can satisfy the
expression of T1.gtoreq.T2 (where T1 can be a period equal to or
longer than 1 second, and equal to or shorter than 1 hour).
EMBODIMENT 3
[0176] Then, the configuration of the fuel cell power generation
system according to a third embodiment of the present invention is
described below by referring to FIG. 10 showing the configuration
of the fuel cell power generation system of the third embodiment of
the present invention.
[0177] In FIG. 10, the host 101, output control means 102, and load
detection means 103 are serially connected in this order, a load
104 wastes the power connected to the load detection means 103, and
a battery 105 is branched and connected from the connection portion
between the output control means 102 and the load detection means
103.
[0178] The fuel cell body 101 corresponds to means including the
power generation means according to the present invention, the load
detection means 103 corresponds to means including the power
detection means according to the present invention, the output
control means 102 corresponds to means including the power
generation control means and the time accumulation means according
to the present invention. The fuel cell power generation system
according to the third embodiment of the present invention
corresponds to means including the power generation control system
according to the present invention.
[0179] Then, the operations of the fuel cell power generation
system according to the third embodiment of the present invention
are described below by referring to FIG. 5 showing a graph for
explanation of an example of an operation pattern of the fuel cell
power generation system according to the third embodiment of the
present invention.
[0180] The output control means 102 controls the activation stop of
the system, and the output power of the fuel cell body 101 so that
the power of the load 104 detected by the load detection means 103
can be followed (when the output power of the fuel cell body 101
cannot follow the power of the load 104, the excess power and
shortfall power are buffered by the charge and discharge of the
battery 105).
[0181] An example of an operation pattern shown in FIG. 5 is a
model of an operation pattern of a common home in a day. The
horizontal and vertical axes respectively indicate time and power.
Reference numerals 111 and 112 respectively denote load power and
output power.
[0182] Load power 111 is high in the morning 111b, afternoon 111c,
and evening 111d, and low at midnight 111e and in the early morning
111a.
[0183] On the other hand, the operation of the fuel cell body 101
is controlled by the output control means 102 such that the output
power 112 following the load power 111 can be obtained between
maximum output power W1c and minimum output power W1d.
[0184] According to the third embodiment of the present invention,
when the load power 111 transfers, for example, from the low level
in the early morning 111a, etc. to the high level in the morning
111b, etc., and when the load power not less than a predetermined
value W1a is maintained for not less than a predetermined time T1a,
the system is activated. In contrast, when the load power 111
transfers, for example, from the high level in the evening 111d,
etc. to the low level at midnight 111e, etc., and, for example,
when the load power lower than a predetermined value W1b is
maintained for not less than a predetermined time T1b, the system
is stopped.
[0185] Although there arises an instant rise or drop of a power
load, an unnecessary activating (stopping) operation can be
prevented by the control of the operation in which power generation
is started (or stopped) when continuously accumulated time exceeds
(or falls below) a predetermined threshold, thereby successfully
performing one activating (stopping) operation in one day. That is,
the waste of energy during the activating/stopping operation can be
minimized.
EMBODIMENT 4
[0186] The configuration and the operation of the fuel cell power
generation system according to the fourth embodiment of the present
invention is described below by referring to FIG. 6 which is a
graph for explanation of an example of an operation pattern of the
fuel cell power generation system according to the fourth
embodiment of the present invention.
[0187] The configuration and the operations of the fuel cell power
generation system according to the fourth embodiment of the present
invention are similar to the configuration and the operations of
the fuel cell power generation system according to the third
embodiment of the present invention. In FIG. 6, the horizontal and
vertical axes respectively indicate time and power. Reference
numerals 113 and 114 respectively denote load power and output
power. The load power 113 is high in the morning 113b, afternoon
113c, and evening 113d, and is low at midnight 113e and in the
early morning 113a.
[0188] However, according to the fourth embodiment of the present
invention, the operation of the fuel cell body is controlled by the
output control means such that the output power 114 following the
load power 113 can be obtained between maximum output power W2c and
minimum output power W2d.
[0189] When the load power 113 transfers from the low level in the
early morning 113a, etc. to the high level in the morning 113b,
etc., and when the load power not less than a predetermined value
W2a is generated at a predetermined or higher ratio R2a in a
predetermined time T2a, the system is activated. When the load
power 113 transfers from the high level in the evening 113d, etc.
to the low level at midnight 113e, and when the load power at or
below a predetermined value W2b is generated at a predetermined or
higher ratio R2b in a predetermined time T2b, the system is
stopped.
[0190] For example, when R2a=70%, the system is activated when the
load power at or over the predetermined value W2a is generated over
70% in the predetermined time T2a in the activating operation.
Therefore, an instant value of the load power 113 falls not more
than W2a in the activation discrimination time (T2a) in 113f, it is
ignored (little influenced). In contrast, when R2b=70%, the system
is stopped when the load power at or below the predetermined value
W2b is generated over 70% in the predetermined time T2b in the
stopping operation. Therefore, an instant value of the load power
113 falls not less than W2b in the stop discrimination time (T2b)
in 113g, it is ignored.
[0191] As described above, by controlling the operation of starting
(stopping) generation of power when (1) the total period of
continuously accumulated time or (2) the total period of
discontinuously accumulated time exceeds (falls below) a
predetermined threshold, an unnecessary activating (stopping)
operation can be prevented, and one activating (stopping) operation
can be performed in one day. That is, the waste of energy during
the activating/stopping operation can be minimized (it is obvious
that the output of the time accumulation means (corresponding to
the means included in the output control means according to the
fourth embodiment) according to the present invention can be a
total time in a predetermined period, or can be each time before
computing the total value).
[0192] Furthermore, as compared with the above mentioned third
embodiment of the present invention, the required amount of
accumulation of the battery can be reduced by reducing the
shortfall of the power due to the delay of activation or the excess
power due to the delay of a stopping operation, thereby realizing a
lower cost system.
EMBODIMENT 5
[0193] The configuration and the operation of the fuel cell power
generation system according to a fifth embodiment of the present
invention will be described below by referring to FIG. 7 which is a
graph for explanation of an example of an operation pattern of the
fuel cell power generation system according to the fourth
embodiment of the present invention.
[0194] The configuration and the operations of the fuel cell power
generation system according to the fourth embodiment of the present
invention are similar to the configuration and the operations of
the fuel cell power generation system according to the third
embodiment of the present invention (the output control means
according to the fifth embodiment corresponds to the power
generation control means and power accumulation means according to
the present invention). In FIG.7, the horizontal and vertical axes
respectively indicate time and power. Reference numerals 115 and
116 respectively denote load power and output power. The load power
115 is high in the morning 115b, afternoon 115c, and evening 115d,
and is low at midnight 115e and in the early morning 115a.
[0195] However, according to the fourth embodiment of the present
invention, the operation of the fuel cell body is controlled by the
output control means such that the output power 116 following the
load power 115 can be obtained between maximum output power W3c and
minimum output power W3d.
[0196] When the load power 115 transfers from the low level in the
early morning 115a, etc. to the high level in the morning 115b,
etc., and when the average load power obtained by dividing a load
power accumulation amount by a time exceeds a predetermined value
W3a in a predetermined time T3a, the system is activated. When the
load power 115 transfers from the high level in the evening 115d,
etc. to the low level at midnight 115e, and when the average load
power obtained by dividing a load power accumulation amount by a
time falls not more than a predetermined value W3b in a
predetermined time T3b, the system is stopped.
[0197] Therefore, a value of the load power 115 falls for a moment
in the activation discrimination time (T3a) in 115f, it is ignored.
Likewise, a value of the load power 115 rises for a moment in the
stop discrimination time (T3b) in 115g, it is ignored.
[0198] Thus, by controlling the operation of starting (stopping)
generation of power when the accumulated power exceeds (falls
below) a predetermined threshold, an unnecessary activating
(stopping) operation can be prevented, and one activating
(stopping) operation can be performed in one day. That is, the
waste of energy during the activating/stopping operation can be
minimized.
[0199] Furthermore, the delay of activation and stop can be reduced
as compared with the cases according to the above mentioned third
embodiment and the required amount of accumulation of the battery
can be reduced by reducing the shortfall of the power due to the
delay of activation or the excess power due to the delay of a
stopping operation, thereby realizing a lower cost system.
EMBODIMENT 6
[0200] The configuration and the operation of the fuel cell power
generation system according to the fourth embodiment of the present
invention is described below by referring to FIG. 8 which is a
graph for explanation of an example of an operation pattern of the
fuel cell power generation system according to the fourth
embodiment of the present invention.
[0201] The configuration and the operations of the fuel cell power
generation system according to the fourth embodiment of the present
invention are similar to the configuration and the operations of
the fuel cell power generation system according to the third
embodiment of the present invention (the output control means
according to the fifth embodiment corresponds to the power
generation control means and means including record accumulation
means according to the present invention). In FIG. 8, the
horizontal and vertical axes respectively indicate time and
power.
[0202] However, the output control means according to the present
invention computes the optimum daily activation time B with the
time at which system was to be activated taken into account, and
when predetermined number of days in the stored optimum activation
time B enters the range of a predetermined time T4a, it computes an
average time B0 of the optimum activation times B, and activates
the system (reference numerals 117 and 118 respectively denote load
power including values for the days, and output power also
including values for the days).
[0203] By performing, with advantage over a predetermined rule (for
example, a rule in one of the above mentioned conventional
technologies can be used) for generating power, the control of the
start of generating power based on the accumulated record, the
delay of activation can be reduced as compared with the cases
according to the above mentioned third through fifth embodiments,
and the required amount of accumulation of the battery can be
further reduced.
EMBODIMENT 7)
[0204] The configuration and the operation of the fuel cell power
generation system according to the fourth embodiment of the present
invention is described below by referring to FIG. 9 which is a
graph for explanation of an example of a stopping pattern of the
fuel cell power generation system according to the fourth
embodiment of the present invention.
[0205] The configuration and the operations of the fuel cell power
generation system according to the fourth embodiment of the present
invention are similar to the configuration and the operations of
the fuel cell power generation system according to the third
embodiment of the present invention. In FIG. 9, the horizontal and
vertical axes respectively indicate time and power.
[0206] However, the output control means according to the present
invention computes the optimum daily stop time D with the time at
which system was to be stopped taken into account, and when
predetermined number of days in the stored optimum stop time D
enters the range of a predetermined time T5b, it computes an
average time DO of the optimum stop times D, and stops the system
(reference numerals 119 and 120 respectively denote load power
including values for the days, and output power also including
values for the days).
[0207] By performing, with advantage over a predetermined rule for
generating power, the control of the end of generating power based
on the accumulated record, the delay of stop can be reduced as
compared with the cases according to the above mentioned third
through fifth embodiments, and the requirements for the battery can
be further reduced.
[0208] Described above are the first to seventh embodiment of the
present invention.
[0209] In short, the present invention includes a power generation
control system which comprises power detection means of detecting
power requested by a load and power generation control means of
controlling predetermined power generation means of generating all
or a part of power to be supplied to a load using a command value
generated based on an average value of the detected power in a
first predetermined period in each second period (it is obvious
that the predetermined power generation means is a fuel cell, and
the excess or shortfall of the generated power relative to the
requested power is adjusted using system power and/or battery).
[0210] The present invention also includes a power generation
control system which comprises power detection means of detecting
power requested by a load, time accumulation means of accumulating
a time at which power requested by the detected load indicates a
value equal to or larger than a predetermined value when
predetermined power generation means does not generate power to be
supplied to the load, and power generation control means of
allowing the power generation means to start generating the power
to be supplied to the load using a predetermined rule based on an
accumulation result.
[0211] The present invention also includes a power generation
control system which comprises power detection means of detecting
power requested by a load, time accumulation means of accumulating
a time at which power requested by the detected load indicates a
value equal to or smaller than a predetermined value when
predetermined power generation means generates power to be supplied
to the load, and power generation control means of allowing the
power generation means to stop generating the power to be supplied
to the load using a predetermined rule based on an accumulation
result.
[0212] The present invention also includes a power generation
control system which comprises power detection means of detecting
power requested by a load, power accumulation means of accumulating
power requested by the load in a predetermined period when
predetermined power generation means does not generate power to be
supplied to the load, and power generation control means of
allowing the power generation means to start generating the power
to be supplied to the load using a predetermined rule based on an
accumulation result.
[0213] The present invention also includes a power generation
control system which comprises power detection means of detecting
power requested by a load, power accumulation means of accumulating
power requested by the load in a predetermined period when
predetermined power generation means generates power to be supplied
to the load, and power generation control means of allowing the
power generation means to stop generating the power to be supplied
to the load using a predetermined rule based on an accumulation
result.
[0214] The present invention further includes a power generation
control system which comprises record accumulation means of
accumulating a record of power requested by the load when
predetermined power generation means generates power to be supplied
to the load according to a predetermined rule, and power generation
control means of allowing the power generation means to start or
stop generating power to be supplied to the load according to the
accumulated record by priority over the rule.
[0215] The present invention can also be a program used to direct a
computer to perform the functions of all or a part of means (or
devices, elements, circuits, units, etc.) of the power generation
control system according to the present invention, and a program
cooperating with the computer. It is obvious that the computer
according to the present invention can include not only purely
hardware such as a CPU but also firmware, an OS, and peripheral
units.
[0216] Furthermore, the present invention can also be a program
used to direct a computer to perform the operations of all or apart
of steps (or processes, operations, effects, etc.) of the power
generation control method according to the present invention, and a
program cooperating with the computer.
[0217] A part of the means (or devices, elements, circuits, unit,
etc.) of the present invention, and a part of the steps (or
processes, operations, effects, etc.) indicate some means or steps
in the plurality of means or steps, or a part of the functions or a
part of the operations in one means or step.
[0218] A part of the devices (or elements, circuit, units, etc.) of
the present invention indicate some devices in the plurality of
devices, or a part of the means (or elements, circuits, units,
etc.) in one device, or indicate a part of the functions in one
means.
[0219] The present invention further includes a computer-readable
storage medium storing a program according to the present
invention. An embodiment of the program according to the present
invention can be stored in a computer-readable storage medium, and
coordinate with the computer. An embodiment of the program
according to the present invention can also be transmitted through
a transmission medium, read by the computer, and cooperate with the
computer. A storage medium can be ROM, etc., and a transmission
medium can be a transmission medium such as Internet, etc., light,
electric wave, sound wave, etc.
[0220] The configuration of the present invention can be realized
by either software or hardware.
[0221] The present invention can also be a storage medium storing
program used to direct a computer to perform the functions of all
or a part of means of all or a part of the power generation control
system according to the present invention, and a computer-readable
storage medium, and the program can cooperate with the computer to
perform the above mentioned functions.
[0222] The present invention can also be a storage medium storing
program used to direct a computer to perform the operations of all
or a part of steps of all or a part of the power generation control
method according to the present invention, and a computer-readable
storage medium, and the program can cooperate with the computer to
perform the above mentioned operations.
[0223] Thus, the present invention is a fuel cell power generation
system comprising, for example, a fuel cell body, and output
control means of activating/stopping the system and controlling
output power of the fuel cell body such that the load power
detected by load detection means can be followed, activates the
system when the load power not less than a predetermined value W1a
continues longer than a predetermined time T1a, and stops the
system when the load power lower than a predetermined value W1b
continues longer than a predetermined time T1b.
[0224] Additionally, the present invention is a fuel cell power
generation system comprising, for example, a fuel cell body, and
output control means of activating/stopping the system and
controlling output power of the fuel cell body such that the load
power detected by load detection means can be followed, activates
the system when load power not less than a predetermined value W2a
is generated at a ratio higher than a predetermined ratio R2a in a
predetermined time T2a, and stops the system when load power not
more than a predetermined value W2b is generated at a ratio higher
than a predetermined ratio R2b in a predetermined time T2b.
[0225] Furthermore, the present invention is a fuel cell power
generation system comprising, for example, a fuel cell body, and
output control means of activating/stopping the system and
controlling output power of the fuel cell body such that the load
power detected by load detection means can be followed, activates
the system when the average load power obtained by dividing a load
power accumulation amount by a time exceeds a predetermined value
W3a in a predetermined time T3a, and stops the system when the
average load power obtained by dividing a load power accumulation
amount by a time falls below a predetermined value W3b in a
predetermined time T3b.
[0226] The present invention is the fuel cell power generation
system which sets an optimum activation time at a daily activation
time, and activates the system at an average time of the optimum
activation time when the difference among the optimum activation
times stored every day becomes in the range of a predetermined time
T4a.
[0227] The present invention is the fuel cell power generation
system which sets an optimum stop time at a daily stop time, and
stops the system at an average time of the optimum stop time when
the difference among the optimum stop times stored every day
becomes in the range of a predetermined time T5b.
[0228] Furthermore, the present invention is a fuel cell power
generation device characterized by a configuration of, for example,
a fuel cell stack for generating DC power by having the hydrogen
supplied by hydrogen supply means react with oxygen in the air
supplied by air supply means, a power control device for
controlling the DC power generated by the fuel cell stack, a
flowrate control device for controlling the hydrogen flow rate
supplied by the hydrogen supply means depending on the DC power
value set by the power control device, and the air flow rate
supplied by air supply means, a power conversion device for
converting the DC power generated by the fuel cell stack into the
AC power of substantially the same voltage as the system power, an
output line for connecting the power conversion device with an
external power load, load power detection means of detecting
external load power, a system power connection line for connecting
the output line with the system power, and an output command device
connected to the power control device and the load power detection
means. With the configuration, the output command device computes
the average power W1 in the time period T1 of the load power
detected by the load power detection means, adds the power
conversion efficiency, etc. to the W1 to obtain an output command
value, and sets the output command value as a DC power value set
each time T2 by the power control device.
[0229] Furthermore, the present invention is a fuel cell power
generation device characterized by a configuration of, for example,
a fuel cell stack for generating DC power by having the hydrogen
supplied by hydrogen supply means react with oxygen in the air
supplied by air supply means, a power control device for
controlling the DC power generated by the fuel cell stack, a flow
rate control device for controlling the hydrogen flow rate supplied
by the hydrogen supply means depending on the DC power value set by
the power control device, and the air flow rate supplied by air
supply means, a power conversion device for converting the DC power
generated by the fuel cell stack into the AC power of substantially
the same voltage as the system power, an output line for connecting
the power conversion device with an external power load, load power
detection means of detecting external load power, a system power
connection line for connecting the output line with the system
power, a accumulation amount control device branched and connected
from the connection line connecting the power control device with
the power conversion device, accumulation amount detection means,
accumulation means, and an output command device connected to the
power control device, the load power detection means, the
accumulation amount control device, and the accumulation amount
detection means. With the configuration, the accumulation amount
control device controls the output command device to compute the
average power W1 in the time period T1 of the load power detected
by the load power detection means, obtain W3 (=W1+W2) by adding the
power W2 (=Q3/T2) obtained by dividing the shortage of accumulation
Q3 (=Q2-Q1), which is the difference between the current amount of
accumulation Q1 detected by the accumulation amount detection means
and the target amount of accumulation Q2 by the time T2, to the W1,
add the power conversion efficiency, etc. to the W3 as an output
command value, and accumulate the shortage of accumulation Q3 in
the accumulation means.
[0230] Thus, although there arises an instant rise or drop of a
power load, an unnecessary activating/stopping operation can be
prevented, thereby successfully performing one activating and
stopping operation in one day. That is, the waste of energy during
the activating/stopping operation can be minimized.
[0231] Additionally, the required amount of accumulation of the
battery can be reduced by reducing the shortfall of the power due
to the delay of activation or the excess power due to the delay of
a stopping operation, thereby realizing a lower cost system.
[0232] The entire disclosure of the above mentioned documents are
incorporated herein by reference in its entirety.
[0233] INDUSTRIAL APPLICABILITY
[0234] As described above, it is apparent that the present
invention has the merit of improving the efficiency and suppressing
the reduction of the durability by, for example, guaranteeing a
stable operation of a fuel cell power generation device.
[0235] Furthermore, the present invention has also a merit of
minimizing the waste of energy in generating a fuel power although
there arises an instant rise or drop of a power load.
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