JP3453375B2 - Power generation control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation control system using a fuel cell as power generation means.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional fuel cell power generator shown in Japanese Patent Laid-Open No. 7-57753.
In FIG. 5, reference numeral 31 denotes a fuel cell main body, which is a hydrogen supply means 3
Hydrogen supplied from 2 reacts with oxygen in the air supplied from the air supply means 33 to generate DC power, which is converted into AC power by the power converter 34 and output. The power control unit 35 controls the flow rate control unit 36 and the power converter 34 based on the external load command, and the flow rate control unit 36 sets the supplied hydrogen flow rate of the hydrogen supply unit 32 and the supplied air flow rate of the air supply unit 33 to appropriate values. The electric power converter 34 can control the electric power value output from the fuel cell main body 31, and as a result, can control the electric power output. In addition,
Between the fuel cell main body 31 and the power converter 34, an overpower prevention unit 39 including a power detector 37 and a calculation unit 38 is provided to suppress the power value when there is a sudden increase in the power value. Controlled by.

In this fuel cell power generator, when the external load command changes drastically in a short time, the power control unit 35 controls to increase or decrease the power output in a short time, and the power is delayed due to the control delay. There is a problem that the output may be hunting, the operation of the fuel cell power generation device is not stable, the efficiency is deteriorated, and the durability life is shortened.

FIG. 6 is a block diagram of another conventional fuel cell power generator shown in JP-A-6-325774. In FIG. 6, reference numeral 41 denotes a fuel cell main body, in which hydrogen supplied from the hydrogen supply means 42 reacts with oxygen in the air supplied from the air supply means 43 to generate DC power, and AC power is generated by the power converter 44. Is converted to and output. The control device 45 includes the charging / discharging device 46 and the power converter 4.
4 to control the discharge from the charging / discharging device 46 or the discharging / charging device 4 even if the power value output from the fuel cell body 41 is constant.
By charging 6 the electric power output according to the external load can be controlled.

In this fuel cell power generator, when the electric power output is controlled according to the external load that changes greatly, the electric power value output from the fuel cell main body 41 is constant, so the charging / discharging device 46.
However, there is a problem in that the charge or discharge device 46 having a large capacity is required, resulting in a high cost and a large installation space for the device.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the prior art.

[0007]

In order to solve the above-mentioned problems, the power generation control system of the present invention comprises a power detection means for detecting the power required by a load, and an electric power to be supplied to the load. A predetermined power generation means for generating all or a part of the power is generated by using a command value generated every second predetermined period based on the average value of the detected power in the first predetermined period. And a power generation control means for controlling, and the command value created for each of the second predetermined periods is an average value in the first predetermined period whose end time is the start time of the second predetermined period. Based on the above
The electric power generation means of the
Air supply means, and the hydrogen supply means and air-air supply means
A fuel that generates electricity using hydrogen and air supplied from
Is a fuel cell power generator including a charge cell,
To do .

[0008]

[0009]

[0010]

Further, the fuel cell power generator of the present invention is a reformer.
Hydrogen supply means having a container, air supply means, and the hydrogen
Hydrogen and air supplied from supply means and air supply means
And a fuel cell for generating electric power using the electric power of the present invention.
And a generation control system .

[0012]

Next, the power generation control method of the present invention comprises a step of detecting the power required by the load and a predetermined power generation for generating all or part of the power to be supplied to the load. Controlling the means using a command value generated every second predetermined period based on an average value of the detected electric power in the first predetermined period, and at every second predetermined period. The command value created on the basis of the average value in the first predetermined period with the start time of the second predetermined period as the end time is based on the predetermined power generation method.
The stage includes a hydrogen supply unit having a reformer and an air supply unit.
And supplied from the hydrogen supply means and the air-air supply means.
Fuel cell that generates electricity using hydrogen and air
The fuel cell power generator is provided .

[0014]

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, the configuration of the fuel cell power generator of the present embodiment will be described with reference to FIG. 1, which is a system configuration diagram of the fuel cell power generator of the first embodiment of the present invention. .

Reference numeral 1 denotes a fuel cell body, which is a hydrogen supply means 2 represented by a reformer, a hydrogen storage alloy, a hydrogen cylinder, etc., and an air supply means 3 represented by a blower fan, a blower pump, etc.
And are connected. Reference numeral 4 denotes an output control device, one of which is electrically connected to the fuel cell main body 1 and the other of which is electrically connected to the power conversion device 5. Reference numeral 6 is an output line electrically connected to the power conversion device 5, which is branched on the way, and one of which is a system power supply connection line 1
The electric power source 7 is electrically connected to the system power source 7 via the load detecting means 8 and the electric power load 9 via the other side. Reference numeral 10 is an output command device that issues an output command to the output control device 4, and 11 is a flow rate control device that controls the hydrogen supply means 2 and the air supply means 3.

Output control means 4 and output command device 1
0, and means including the flow control device 11 correspond to the power generation control means of the present invention, and the load detection means 8 corresponds to the power detection means of the present invention. Further, the fuel cell power generator of the present embodiment corresponds to a unit including the power generation control system of the present invention.

Next, the operation of the fuel cell power generator of this embodiment will be described. While the operation of the fuel cell power generation system of the present embodiment is described, an embodiment of the power generation control method of the present invention will also be described (the same applies hereinafter).

Hydrogen supplied from the hydrogen supply means 2 and oxygen in the air supplied from the air supply means 3 react in the fuel cell main body 1 to generate direct current power. The generated DC power is sent to the power conversion device 5 after the power value is controlled by the output control device 4, converted into AC power of the same voltage as the system power supply 7, and supplied to the power load 9 through the output line 6. It
At this time, the power conversion efficiency indicates how much the input power to the power conversion device 5 becomes the output power from the power conversion device 5. Here, if the output power of the fuel cell main body 1 is insufficient with respect to the load power of the power load 9, power is also supplied from the system power supply 7, and conversely, if the output power is excessive with respect to the load power, to the system power supply 7. The power is returned and so-called grid interconnection operation is performed.

One of the purposes of generating power in the fuel cell power generator is economic efficiency due to its high power generation efficiency. However, if the output power is insufficient with respect to the load power, purchase the power from the grid power supply 7, When the output power is excessive with respect to the load power, the power is returned to the system power supply 7 at a lower price than the purchased power, and thus economical efficiency is generally deteriorated. Therefore, it is desired to faithfully follow the change in the load power so that the output power does not have an excess or deficiency with respect to the load power.

As a means for following this, first, the load detection means 8 detects the load power of the power load 9,
Based on this, the output command device 10 commands an output command value to the power control device 4, and the output control device 4 controls the DC power generated from the fuel cell main body 1 to the required value, and the flow rate according to the DC power value. The controller 11 controls the flow rate of hydrogen supplied from the hydrogen supply means 2 and the flow rate of air supplied from the air supply means 3 to appropriate values. Here, the output power can be controlled only by controlling the DC power of the output control device 4, but for example, even when the DC power generated from the fuel cell body 1 is reduced, the flow rate of hydrogen supplied to the fuel cell body 1 is constant. In such a case, the ratio of hydrogen reacted in the fuel cell main body 1 (hydrogen utilization rate) is decreased, and a large amount of hydrogen is discarded, resulting in a marked deterioration in efficiency. Therefore, the flow rate control device 11 controls the hydrogen flow rate and the air flow rate to appropriate values, thereby always maintaining the optimum efficiency.

In this series of follow-up control, the load power may change drastically in a short time, and if the load power is used as an output command as it is, the control for raising or lowering the DC power is performed in a short time. There has been a problem that hunting may occur due to a delay and the operation of the fuel cell power generator may become unstable. Further, for example, when a reformer that generates hydrogen by a catalytic reaction from a hydrocarbon fuel is used as the hydrogen supply means 2, the catalytic reaction cannot respond to an instantaneous change in the output command value, which deteriorates the efficiency or the durability. However, there is a problem that the life is shortened.

Therefore, in the present embodiment, as shown in FIG. 3, which is an explanatory diagram of the control operation of the fuel cell power generator according to the first embodiment of the present invention, the output command device 10 keeps the load power during the time T1. (first predetermined period) mean value, the power conversion efficiency such as an output command value by calculating in consideration of, for each output in the command value of the output control device 4 time T2 (second predetermined period) The DC power value to be set is used, and the load power time T
By using the average value between 1 as the output command value, an appropriate output command that ignores the instantaneous change can be performed, and by performing the output command every time T2, the operation that matches the response performance of the device can be performed. Can be done (time T2
The command value created for each (second predetermined period) is based on the average value during the time T1 (first predetermined period) whose end time is the start time of the second predetermined period. ).

As an example, when the optimum control value when a solid polymer electrolyte fuel cell power generator with an output of 1.5 kW class is operated at a certain home is calculated, T1: T2 = approximately 3: 1, T1
= 3 minutes, T2 = 1 minute. That is, in this example, the result is obtained that the operation control in which the output command value based on the average load power for 3 minutes is commanded to the device every minute is optimal.

As described above, in the present embodiment, by using the average value of the load power during the time T1 as the output command value, it is possible to perform an appropriate output command ignoring the instantaneous change, and at each time T2. By issuing an output command, it is possible to perform operation that matches the response performance of the device.
The fuel cell power generator is operated stably, and at the same time, the efficiency is constantly maintained and the durable life is extended.

(Second Embodiment) FIG. 2 is a system configuration diagram of a fuel cell power generator according to a different embodiment of the present invention. The same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 21 denotes a power storage unit that branches from a connection line 22 that connects the output control device 4 and the power conversion device 5 and is connected via a power storage amount control device 23. Reference numeral 24 is a storage amount detection means connected to the storage means 21. The purpose of providing the power storage means 21 is to reduce the economical efficiency caused by the transfer of electric power to and from the system power supply 7 due to the excess or deficiency of the output power with respect to the load power in the system interconnection operation of the first embodiment. By using charge / discharge of the power storage means 21, the amount of power supplied from the system power supply 7 and the amount of power returned to the system power supply 7 are reduced as much as possible, and the economy is further improved (the power storage means 21 (storage battery) is , System power supply 7
Will be used in preference to).

Next, the operation of the fuel cell power generator of this embodiment will be described.

As shown in FIG. 4, which is an explanatory diagram of the control operation of the fuel cell power generator of Embodiment 2 of the present invention,
The output command device 10 calculates the average electric power W1 of the load electric power detected by the load detection means 8 during the time T1, and the calculated average electric power W1 detected by the electric storage amount detection means 24 and the target electric storage amount Q2. Insufficient storage Q3 (=
Electric power W2 (= Q3 / T) obtained by dividing Q2-Q1) by time T2
2) is added to obtain W3 (= W1 + W2), the power conversion efficiency is added to this W3 to obtain an output command value, and the DC power value power control device 4 of the fuel cell main body 1 corresponding to the output command value at each time T2 The output control device 4
Is the DC power value set every time T2.
Further, the storage shortage amount Q3 is controlled by the storage amount control device 23 to be stored in the storage means 21 (the command value is corrected in accordance with the difference between the storage amount and a predetermined target storage amount. ).

This series of operation control is the follow-up control in (Embodiment 1) with the charge amount control added. If the average power W1 is used as the output command value as it is, the charge amount control is not performed. Instead, the difference between the target power storage amount Q2 and the current power storage amount Q1 may be gradually accumulated. For example, when the discharged amount is larger than the charged amount and the stored amount of electricity gradually decreases, in order to prevent the stored amount of electricity from becoming zero, the storage means 21 having a large capacity is required in advance, resulting in high cost and installation space of the device. There was a problem that it would grow. Therefore, in the present embodiment, the shortage of storage Q3 (= Q2-Q) during T2, which is the interval time for commanding the output command value.
W3 obtained by adding power W2 (= Q3 / T2) that supplements 1)
By setting the output command value by adding the power conversion efficiency to (= W1 + W2), it is possible to control the storage amount to be always converged to the target storage amount Q2 and to minimize the required capacity of the storage unit 21. It is a thing.

In the first and second embodiments described above, the predetermined period T1 used for calculating the average power is used.
And the predetermined period T2 used for giving the command value to the output control means may satisfy the relationship of T1 ≧ T2 (T1 may be a period of 1 second or more and 1 hour or less). .

The present invention is a program for causing a computer to execute the functions of all or some of the means (or devices, elements, circuits, units, etc.) of the above-described power generation control system of the present invention. , A program that operates in cooperation with a computer. Of course, the computer described above is not limited to pure hardware such as a CPU, but may include formware, an OS, and peripheral devices.

Further, the present invention is a program for causing a computer to execute all or some of the steps (or steps, operations, actions, etc.) of the above-described power generation control method of the present invention. It is a program that works in cooperation with.

[0034]

A computer-readable recording medium in which the program of the present invention is recorded is also included in the present invention. Further, one usage form of the program of the present invention may be a mode of operating in cooperation with a computer. Also,
One usage form of the program of the present invention may be a mode in which the program is transmitted through a transmission medium, read by a computer, and operates in cooperation with the computer. The recording medium includes a ROM and the like, and the transmission medium includes a transmission medium such as the Internet and light, radio waves, sound waves and the like.

The configuration of the present invention may be realized by software or hardware.

[0037]

According to the present invention, by using the average value of the load power during the time T1 as the output command value, an appropriate output command can be issued ignoring the instantaneous change, and the output command can be issued every time T2. With this, it is possible to operate the fuel cell power generator in accordance with the response performance of the device, and it is possible to stably operate the fuel cell power generator, and at the same time, always maintain high efficiency and prolong the durable life.

Further, by constantly controlling the amount of stored electricity so as to converge to the target amount of stored electricity Q2, the required capacity of the storage means can be minimized, and the cost can be reduced and the device can be made compact. It is a thing.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a fuel cell power generator according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram of a fuel cell power generator according to a different embodiment of the present invention.

FIG. 3 is an explanatory diagram of a control operation of the fuel cell power generator according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a control operation of the fuel cell power generator according to the second embodiment of the present invention.

FIG. 5 is a system configuration diagram of a conventional fuel cell power generator.

FIG. 6 is a system configuration diagram of another conventional fuel cell power generator.

[Explanation of symbols]

1 Fuel cell body 2 Hydrogen supply means 3 Air supply means 4 Output control means 5 Power converter 6 output lines 7 system power supply 8 Load detection means 9 power load 10 Output command device 11 Flow control device 12-system power connection line 21 Storage means 22 connection line 23 Storage amount control device 24 Storage amount detection means

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-274233 (JP, A) JP-A-4-304126 (JP, A) JP-A-63-314768 (JP, A) JP-A-2- 291668 (JP, A) Actual Kaihei 4-58057 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 8/04 H01M 8/06 H02J 3/38

Claims (3)

(57) [Claims] 1. A power detection means for detecting electric power requested from a load, and a predetermined power generation means for generating all or a part of electric power to be supplied to the load.
And a power generation control means for controlling using a command value created every second predetermined period based on the average value of the detected power in the first predetermined period. The command value created for each period is based on an average value in the first predetermined period with the start time of the second predetermined period as the end time, and the predetermined power generation means has the hydrogen supply having a reformer. hand
Stage, air supply means, the hydrogen supply means and air air
Electricity is generated using hydrogen and air supplied from the supply means.
A fuel cell power generator including a live fuel cell
Power generation control system according to claim. A hydrogen supply means having a wherein reformer, a fuel cell which generates power using an air supply means, the hydrogen and air supplied from the hydrogen supply means and air supply means, according to claim 1, wherein and a power generation control system,
Fuel cell power generator. 3. A step of detecting the electric power requested from the load, and a predetermined electric power generation means for generating all or a part of the electric power to be supplied to the load, Control using a command value created every second predetermined period based on an average value in one predetermined period, the command value created every second predetermined period is Based on the average value in the first predetermined period with the start time of the second predetermined period as the end time, the predetermined power generation means is a hydrogen supplier having a reformer.
Stage, air supply means, the hydrogen supply means and air air
Electricity is generated using hydrogen and air supplied from the supply means.
A fuel cell power generator including a live fuel cell
A power generation control method characterized by :