JP2003168453A - Power generation amount control equipment of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent that a fuel cell deteriorates by the pressure difference of hydrogen gas and air excessively increased at the time of the falling of a target amount of power generation, and it deteriorates by over-charging an electricity accumulating means. <P>SOLUTION: Based on the target amount of power generation of the fuel cell by the target amount calculating means 101 of power generation, an operating point control means 102 controls at least either of pressure or flow rate of the fuel gas and the air to the target operating point. A recoverable amount detection means 103 calculates a recoverable amount recoverable from the output of the fuel cell for the electricity accumulating means. Based on the operation state of the fuel cell, such as gas pressure, and the like, which an operation state detection means 104 has detected, an output demand value calculating means 105 calculates the demand value of the output taken out from the fuel cell. A gas pressure difference detection means 107 detects the pressure difference of air electrode pressure and fuel electrode pressure. A power generation control means 106 outputs the instruction value, which controls power generation of the fuel cell, based on the output of 101, 103, 104, 105, and 107. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation amount control device for a fuel cell system including a fuel cell and a storage means for storing surplus power generated by the fuel cell.

[0002]

2. Description of the Related Art In a fuel cell, the amount of power generation is controlled by the pressure and flow rate of fuel gas (hydrogen) and air supplied to the fuel electrode and the air electrode, respectively. When the external load of the fuel cell suddenly decreases, the output of the fuel cell also needs to be reduced accordingly. In that case, it is necessary to reduce the hydrogen supply in accordance with the decrease in the output of the fuel cell, but it is generally unavoidable that there is some delay in the decrease in the hydrogen supply. Therefore, in this case, if the output of the fuel cell is drastically reduced, the hydrogen supply is delayed and the hydrogen supply becomes excessive, the pressure balance between the hydrogen system and the air system is disrupted, and the fuel cell stops in an emergency or It is conceivable that the reaction film of will deteriorate.

To prevent this, Japanese Patent Laid-Open No. 8-4
The technique described in Japanese Patent No. 5527 (hereinafter referred to as the first conventional technique) is known. This first conventional technique keeps the pressure balance between the hydrogen system and the air system within a certain level by continuing the air supply in response to the delay in the decrease of the hydrogen supply when the power generation is stopped, and the stress due to the pressure difference is applied to the electrolyte membrane. It is to prevent the hanging.

Further, in Japanese Patent Laid-Open No. 2000-348748, when the reduction rate of the current target value exceeds a predetermined reduction rate, the current command value is slower than the reduction rate of the target value, and the reduction rate of the target value is slower. There is disclosed a technique (hereinafter, referred to as a second conventional technique) in which the current limit value, which is the upper limit value of the command value, is determined in accordance with the target value by decreasing the reduction rate according to the target value.

[0005]

In the first prior art, however, the pressure balance between the hydrogen system and the air system can be maintained, but the pressure of the hydrogen already supplied does not decrease quickly, and the air system compressor is not accelerated. However, there is a problem in that the power consumption is continued and the energy is wasted.

In the second prior art, it is stated that the reduction rate of the command value determined from the reduction rate of the current target value means the reduction rate within the range where surplus hydrogen does not remain in the fuel cell. It cannot be said that this is uniquely determined by the rate of decrease. In other words, the target pressure with respect to the target output (current) is not necessarily linear, and the required characteristics thereof differ depending on the type of fuel cell, so that the target output current is changed from 250 [A] to 200 [A].
It cannot be said that the rate of decrease of the command value for lowering the pressure is the same if it changes from [A] to 1 [s] and from 150 [A] to 100 [A] in 1 [s]. . Therefore, even if the reduction rate of the command value is determined from the reduction rate of the current target value, the pressure cannot always be sufficiently reduced. Here, for the same target value decrease rate, the value at which the command value decrease rate is maximum can be used in all operating ranges, but in this case, the pressure drops sharply in a certain operating range. There is a problem that it passes.

Although it is stated that the current limit value is determined according to the target value, this does not take into consideration whether or not there is sufficient free space in the energy buffer such as the battery, so the free space is insufficient. In this case, there is a problem that the battery may be deteriorated due to overcharge or the like.

In view of the above problems, it is an object of the present invention to prevent the fuel cell from deteriorating due to an excessive pressure difference between hydrogen gas pressure and air pressure when the target power generation amount of the fuel cell decreases. It is an object of the present invention to provide a power generation amount control device for a fuel cell, which can prevent the power storage means from being deteriorated by overcharging the power storage means from the fuel cell.

[0009]

In order to achieve the above object, the invention according to claim 1 is a target power generation amount calculating means for calculating a target power generation amount of a fuel cell and a part of the power generation amount of the fuel cell. Possible power storage means, recoverable amount calculation means for calculating the recoverable amount of the power storage means, operating state detection means for detecting the operating state of the fuel cell, and power generation control for computing a command value of output taken out from the fuel cell A power generation control device for a fuel cell, the power generation control means, when the target power generation amount is lowered, the output of the target power generation amount calculation means, the output of the operating state detection means, It is a means for calculating a command value of the output taken out from the fuel cell based on the output of the recoverable amount calculating means, and causing the fuel cell to generate power with a power generation amount larger than the target power generation amount within a range in which the power storage means can be recovered. That is the summary.

In order to achieve the above object, the invention according to claim 2 is the fuel cell power generation amount control device according to claim 1, wherein the recoverable amount calculation means is the amount of electricity stored in the electricity storage means, and the electricity storage means. The gist is to calculate the recoverable amount based on the deterioration state and the temperature of the power storage unit.

In order to achieve the above object, the invention according to claim 3 is the power generation amount control device for a fuel cell according to claim 1 or 2, wherein the fuel cell is based on the output of the target power generation amount calculation means. An output request for calculating the value of the output to be taken out from the fuel cell based on the output of the operating point control means for controlling the pressure of the gas supplied to the target operating point and the operating state detection means for detecting the gas pressure of the fuel cell. Value calculation means, and the power generation control means, while reducing the gas pressure when the target power generation amount decreases, the sum of the target power generation amount and the recoverable amount, and the output of the output request value calculation means. The gist is to compare and use the smaller one of them as the output command value of the fuel cell.

In order to achieve the above object, the invention according to claim 4 is the fuel cell power generation amount control device according to claim 3, wherein the operating point control means is based on the output of the target power generation amount calculation means. , At least a target value of the gas pressure is calculated from a predetermined relationship, and the output request value calculation means is based on the output of the operation state detection means, and a relationship opposite to the predetermined relationship used in the operating point control means. The gist is to calculate the required output value from

In order to achieve the above object, the invention according to claim 5 is the fuel cell power generation amount control device according to any one of claims 1 to 4, wherein the power generation control means is an output command value. In addition to the function of calculating, a function of opening and closing a purge valve that connects the passage of the fuel gas discharged from the fuel cell and the atmosphere is provided, and the target power generation amount when the target power generation amount decreases, the operating state, and the The gist is to open and close the purge valve based on the recoverable amount.

In order to achieve the above object, the invention according to claim 6 is the power generation control device for a fuel cell according to claim 5, wherein the opening area of the purge valve supplies both fuel gas and oxidant gas. The gist is that the area is set so that the gas pressure difference between the oxidant electrode and the fuel electrode does not exceed the limit value when the pressure decreases when both are stopped at the same time and the oxidant gas passage is opened to the atmosphere at the same time.

In order to achieve the above object, the invention according to claim 7 is the power generation amount control device for a fuel cell according to claim 5 or 6, wherein the output of the output required value calculating means and the target power generation amount are The gist is to open and close the purge valve based on the value of the sum of the recoverable amount and

To achieve the above object, the invention according to claim 8 is the fuel cell power generation amount control device according to claim 7, wherein the output of the output required value calculation means, the target power generation amount, and the recoverable amount. The gist of the invention is to open the purge valve when the difference between the amount and the sum is greater than or equal to a predetermined value.

In order to achieve the above object, a ninth aspect of the present invention is the fuel cell power generation amount control device according to the seventh aspect, wherein the output required value is the sum of the target power generation amount and the recoverable amount. The gist is to open the purge valve when the value is equal to or more than a value obtained by multiplying the value by a predetermined ratio larger than 1.

In order to achieve the above object, the invention according to claim 10 is the fuel cell power generation amount control device according to claim 1, wherein the operating state detecting means is configured to continue the power generation by the fuel cell to the power storage means. It is a means for detecting whether or not the power can be supplied, and when the operation is stopped, when the fuel cell detects that the fuel cell continues to generate power and can supply the power to the power storage means when the operation is stopped. The gist of the present invention is to calculate a command value of the output to be taken out from the fuel cell in the power storage means based on the recoverable amount and continue power generation.

In order to achieve the above object, the invention according to claim 11 is the fuel cell power generation amount control device according to claim 10, wherein the power generation control means has a function of calculating an output command value, It has a function to open and close a purge valve that connects the passage of the fuel gas discharged from the cell and the atmosphere, and when power generation is continued when the operation is stopped, the purge valve is closed and power generation is continued when the operation is stopped. If not, the gist is to open the purge valve.

In order to achieve the above object, the invention according to claim 12 is the power generation control device for a fuel cell according to claim 10 or claim 11, wherein the operating state detecting means is
Gas pressure detection means for detecting the pressure of the gas supplied to the fuel cell is provided, and it is possible to detect whether or not the power generation can be continued depending on whether or not the pressure of the gas has reached the minimum pressure value required for power generation. Use as a summary.

In order to achieve the above object, the invention according to claim 13 is the power generation control apparatus for a fuel cell according to claim 11, which is a gas for detecting a gas pressure difference between an oxidizing gas electrode and a fuel gas electrode. Even in the case of having a pressure difference detection means and continuing power generation when the operation is stopped, the purge valve is opened immediately before the gas pressure difference increases to reach a limit value or more, and power generation is continued. Use as a summary.

In order to achieve the above object, the invention according to claim 14 is the power generation amount control device for a fuel cell according to claim 12 or claim 13, wherein the gas pressure detecting means or the gas pressure difference detecting means is: The gist is to estimate the gas pressure or the gas pressure difference based on the gas pressure at the time of operation stop.

[0023]

According to the present invention, the target power generation amount calculation means for calculating the target power generation amount of the fuel cell, the power storage means capable of collecting a part of the power generation amount of the fuel cell, and the power storage means. Of the fuel cell including a recoverable amount calculating means for calculating the recoverable amount of the fuel cell, an operating state detecting means for detecting the operating state of the fuel cell, and a power generation control means for calculating a command value of the output taken out from the fuel cell. In the power generation amount control device, the power generation control unit outputs the output of the target power generation amount calculation unit, the output of the operation state detection unit, and the output of the recoverable amount calculation unit when the target power generation amount decreases. Based on the calculation of the command value of the output to be taken out from the fuel cell based on this, the fuel cell is made to generate power with a power generation amount larger than the target power generation amount within the range in which the power storage means can recover the target power generation amount. Sometimes fuel gas pressure rises The differential pressure between the air pressure Te is an effect that can be prevented to degrade the electrical storage means such as a battery due to or becomes excessive, too taken out output.

Note that the term "when the target power generation amount is decreased" means that the target power generation amount becomes 0 when the operation is stopped as well as when the power generation amount is decreased during operation, and the present invention is applied. be able to.

According to a second aspect of the present invention, in the fuel cell power generation amount control device according to the first aspect, the recoverable amount calculation means includes a stored amount of the storage means, a deterioration state of the storage means, and Since the recoverable amount is calculated based on the temperature of the power storage unit, in addition to the effect of the invention of claim 1, the recoverable amount can be calculated even if the power storage unit changes with time or the ambient temperature changes. This has the effect of enabling accurate calculation.

According to a third aspect of the present invention, in the fuel cell power generation amount control device according to the first or second aspect, based on the output of the target power generation amount calculation means, the gas supplied to the fuel cell is controlled. An operating point control means for controlling the pressure to a target operating point, an output request value calculating means for calculating the value of the output to be taken out from the fuel cell based on the output of the operating state detecting means for detecting the gas pressure of the fuel cell, The power generation control means, while reducing the gas pressure when the target power generation amount is reduced, the sum of the target power generation amount and the recoverable amount,
In addition to the effect of the invention according to claim 1 or claim 1, it is the means for comparing the output of the output request value calculation means and using the smaller value as the output command value of the fuel cell. The optimum output can be obtained according to the operating state of the fuel cell and the recoverable amount. As a result, when the output decreases, the fuel gas pressure rises and the pressure difference with the air pressure becomes excessive, or the output is extracted too much. As a result, it is possible to prevent deterioration of the power storage means such as the battery.

According to a fourth aspect of the present invention, in the fuel cell power generation amount control device according to the third aspect, the operating point control means is based on the output of the target power generation amount calculation means.
At least a target value of the gas pressure is calculated from a predetermined relationship, and the output request value calculation means is based on the output of the operating state detection means, and from the relationship opposite to the predetermined relationship used by the operating point control means. Since the output request value is calculated, in addition to the effect of the invention described in claim 3, there is an effect that an optimum output corresponding to the operating state of the fuel cell can be obtained.

According to the invention of claim 5, in the fuel cell power generation amount control device of any one of claims 1 to 4, the power generation control means has a function of calculating an output command value. In addition, it has a function of opening and closing a purge valve that communicates the passage of the fuel gas discharged from the fuel cell with the atmosphere, and when the target power generation amount falls, the target power generation amount, the operating state, and the recoverable amount are set. Since the purge valve is opened and closed based on the above, in addition to the effect of the invention according to claims 1 to 4, the fuel gas which exceeds the recoverable amount of the power storage means and cannot be consumed by power generation is discharged from the purge valve. Since the fuel gas can be discharged, the fuel gas pressure can be reduced at an early stage while recovering the recoverable output, and the pressure difference between the fuel gas pressure and the air pressure can be prevented from becoming excessive.

According to a sixth aspect of the present invention, in the fuel cell power generation amount control device according to the fifth aspect, the opening area of the purge valve is such that both the supply of the fuel gas and the supply of the oxidant gas are stopped simultaneously, and at the same time. By setting the area where the gas pressure difference between the oxidant electrode and the fuel electrode does not exceed the limit value when the pressure drops when the oxidant gas passage is opened to the atmosphere,
In addition to the effect of the invention as set forth in claim 5, it is possible to prevent the differential pressure between the fuel gas pressure and the air pressure from becoming excessively large only by operating the purge valve even when the power storage means cannot recover the target power generation amount when it is reduced. The effect is that you can do it.

According to the invention of claim 7, in the fuel cell power generation amount control device of claim 5 or 6, the output of the output required value calculation means, the target power generation amount and the recoverable amount. Since the purge valve is opened / closed based on the value of the sum of the above, in addition to the effect of the invention of claim 5 or 6, the fuel gas pressure is reduced early while recovering the recoverable output. As a result, it is possible to prevent the differential pressure between the fuel gas pressure and the air pressure from becoming excessive.

According to the eighth aspect of the present invention, in the fuel cell power generation amount control device according to the seventh aspect, the output of the output required value computing means and the sum of the target power generation amount and the recoverable amount are calculated. Since the purge valve is opened when the difference from the value is a predetermined value or more, in addition to the effect of the invention according to claim 7, the output of the output command value and the purge valve can be performed easily and reliably. There is an effect that it is possible to make a decision to execute both of the opening.

According to a ninth aspect of the present invention, in the fuel cell power generation amount control device according to the seventh aspect, the required output value is greater than 1 in the sum of the target power generation amount and the recoverable amount. Since the purge valve is opened when the value is equal to or more than the value obtained by multiplying the predetermined ratio, in addition to the effect of the invention according to claim 7, the output of the required output value and the opening of the purge valve can be performed easily and reliably. There is an effect that it is possible to make a decision to execute both.

According to the invention of claim 10, claim 1
In the fuel cell power generation amount control device described above, the operating state detection means is a means for detecting whether or not the fuel cell is in a state in which power generation is continued and power can be supplied to the power storage means. When it is detected by the state detecting means that the fuel cell continues to generate electric power and is capable of supplying electric power to the power storage means, the power storage means calculates the command value of the output taken out from the fuel cell based on the recoverable amount. Since the power generation is continued, in addition to the effect of the invention described in claim 1, wasteful discharge of the fuel gas remaining in the fuel gas passage is suppressed, and the fuel gas pressure is reduced early. The effect is that you can.

According to the invention of claim 11, claim 1
In the fuel cell power generation amount control device according to 0, in addition to the function of calculating the output command value, the power generation control means opens and closes a purge valve that connects the passage of the fuel gas discharged from the fuel cell and the atmosphere. The purge valve is provided with a function, and when the power generation is continued when the operation is stopped, the purge valve is closed, and when the power generation is not continued when the operation is stopped, the purge valve is opened. In addition to the effects of the invention described, there is an effect that wasteful emission of fuel gas can be suppressed to a minimum and fuel consumption can be improved.

According to the invention of claim 12, claim 1
0 or the fuel cell power generation amount control device according to claim 11, wherein the operating state detection means includes a gas pressure detection means for detecting the pressure of the gas supplied to the fuel cell, and the pressure of the gas is necessary for power generation. Since it is detected whether or not the power generation can be continued depending on whether or not the minimum pressure value is reached, in addition to the effect of the invention according to claim 10 or 11, the power generation is forcibly continued and the fuel is continuously generated. This has the effect of preventing deterioration of the battery.

According to the invention of claim 13, claim 1
1. The fuel cell power generation amount control device according to 1, further comprising gas pressure difference detection means for detecting a gas pressure difference between the oxidizing gas electrode and the fuel gas electrode, wherein power generation is continued when the operation is stopped. Also, when the gas pressure difference increases, the purge valve is opened immediately before the gas pressure difference exceeds the limit value so that power generation is continued. Therefore, in addition to the effect of the invention according to claim 11, Even when the decrease in fuel gas pressure is not expected and the differential pressure becomes large, there is an effect that power generation is performed as much as possible and useless fuel discharge from the purge valve can be minimized.

According to the invention of claim 14, claim 1
In the fuel cell power generation amount control device according to claim 2 or 13, the gas pressure detection means or the gas pressure difference detection means estimates the gas pressure or the gas pressure difference based on the gas pressure at the time of operation stop. Therefore, in addition to the effect of the invention of claim 12 or claim 13, even when the operation of the fuel cell is stopped due to a failure of the gas pressure detecting means, the oxidizing gas electrode and the fuel gas electrode are There is an effect that power generation can be continued within a range in which the gas pressure difference between and does not exceed the limit value.

[0038]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a basic configuration of a fuel cell power generation amount control device according to the present invention, which is common to first to fifth embodiments described later. In FIG. 1, a fuel cell power generation amount control apparatus includes a target power generation amount calculation means 101 for calculating a target power generation amount of a fuel cell, and a gas pressure of a fuel gas and an oxidant gas based on an output of the target power generation amount calculation means 101. Alternatively, an operating point control means 102 that controls at least one of the flow rates to a target operating point, a recoverable amount detection means 103 that calculates a recoverable amount that can recover the output of the fuel cell to a power storage means (not shown), a gas pressure, etc. An operating condition detecting means 104 for detecting an operating condition of the fuel cell; an output request value calculating means 105 for calculating a request value of the output taken out from the fuel cell based on the output of the operating condition detecting means 104;
Gas pressure difference detection means 107 for detecting the pressure difference between the pressure of the oxidant electrode (air electrode) and the pressure of the fuel electrode, target power generation amount calculation means 101, recoverable amount calculation means 103, operating state detection means 104, and output Power generation control means 106 for outputting a command value for controlling the power generation of the fuel cell based on the outputs of the required value calculation means 105 and the gas pressure difference detection means 107.

The operating point control means 102 is, for example, as shown in FIG.
(A) thru | or the control table as shown in FIG.3 (c) is built in, and the target gas pressure which is target hydrogen pressure and target air pressure, target air flow rate, and target hydrogen flow rate are calculated from the target power generation amount, respectively, The gas pressure and the gas flow rate at the air electrode 201a and the fuel electrode 201b are controlled so as to reach their respective target values.

FIG. 2 is a system configuration diagram showing a configuration example of a fuel cell system to which the fuel cell power generation amount control apparatus according to the present invention is applied. In FIG. 2, a fuel cell system to which the present invention is applied includes a fuel cell stack 201 including an air electrode (oxidant electrode) 201a and a fuel electrode 201b,
A humidifier 202 for humidifying the fuel gas and air supplied to the fuel electrode 201b and the air electrode 201a, a compressor 203 for supplying air to the humidifier 202, and a high-pressure hydrogen tank 215 for storing high-pressure hydrogen gas as fuel. ,
A variable valve 204 that controls the flow rate of high-pressure hydrogen supplied from the high-pressure hydrogen tank 215, a throttle 205 that is provided at the outlet of the air electrode 201a and that controls the air pressure and flow rate of the air of the air electrode, and hydrogen from the outlet of the fuel electrode 201b. A purge valve 206 that exhausts to the outside, a pure water pump 207 that supplies pure water for humidification to the humidifier 202, an ejector 208 that recirculates unused hydrogen discharged from the fuel electrode 201b upstream, and a fuel Drive unit 20 that extracts output from the battery
9, an air pressure sensor 210 that detects the air pressure at the inlet of the air electrode 201a, a hydrogen pressure sensor 211 that detects the hydrogen pressure at the inlet of the fuel electrode 201b, and an air flow rate sensor 212 that detects the air flow rate flowing into the air electrode 201a. A hydrogen flow rate sensor 213 for detecting the flow rate of hydrogen flowing into the fuel electrode 201b, a controller 214 for fetching a signal from each sensor and driving each actuator based on the built-in control software, and a drive unit 209. A battery 2 as a power storage unit that collects recoverable electric power from the fuel cell stack 201 and discharges it when necessary.
16 are provided.

The controller 214 is the power generation control device for the fuel cell shown in FIG. 1 and controls the entire fuel cell system.

In the compressor 203, the air is compressed and sent to the humidifier 202, and in the humidifier 202, the pure water pump 2
The pure water supplied at 07 humidifies the air, and the humidified air is sent to the air electrode 201a of the fuel cell stack 201. The flow rate of the high-pressure hydrogen in the high-pressure hydrogen tank 215 is controlled by the variable valve 204, merges with the recirculation amount by the ejector 208, and is then sent to the humidifier 202, which then humidifies the humidifier 202.
Then, like the air, the pure water supplied by the pure water pump 207 humidifies the hydrogen, and the humidified hydrogen releases the fuel cell stack 20.
1 is sent to the fuel electrode 201b.

In the fuel cell stack 201, the sent air and hydrogen are caused to react with each other to generate electric power, and an electric current (electric power) is supplied to the drive unit 209. If the fuel cell is a power source for an electric vehicle, the drive unit 209 includes an inverter, a vehicle drive motor, and the like.

If the fuel cell stack 201 cannot cover all the electric power required by the drive unit 209,
The shortage is satisfied by discharging the battery 216. If the battery 216 has a chargeable capacity, the battery 216 is charged with at least a part of the electric power generated by the fuel cell stack 201 depending on the operating condition.

The remaining air used for the reaction in the fuel cell stack 201 is discharged to the outside of the fuel cell, and the throttle 20
After pressure control is performed in 5, the gas is discharged to the atmosphere. Also,
The remaining hydrogen used in the reaction is discharged to the outside of the fuel cell, but is returned to the upstream of the humidifier 202 by the ejector 208 and reused for power generation.

As means for detecting the state of the gas supplied to the fuel cell stack 201, the fuel cell stack 201
, A pressure sensor 210 for detecting the air pressure at the inlet of the air electrode 201a, a flow sensor 212 for detecting the air flow rate, a pressure sensor 211 for detecting the hydrogen pressure at the inlet of the fuel electrode 201b, and a flow sensor 213 for detecting the hydrogen flow rate. Is detected by the controller 214. The controller 214 controls the compressor 2 so that each read value becomes a predetermined target value determined from the target power generation amount at that time.
03, the throttle 205, the variable valve 204 is controlled, and the pressure that is actually achieved with respect to the target value,
The output (current value) taken out from the fuel cell stack 201 to the drive unit 209 is commanded and controlled according to the flow rate.

The opening area of the purge valve 206 in this embodiment is such that when the supply of hydrogen as the fuel gas and the air as the oxidant gas are both stopped at the same time and the oxidant gas passage is opened to the atmosphere at the same time, the pressure drops. , Air electrode 201a
The area is set such that the gas pressure difference between the fuel electrode 201b and the fuel electrode 201b does not exceed the limit value.

FIG. 5 shows (a) gas pressure at the time of power generation reduction when the technique for preventing the differential pressure between the hydrogen pressure and the air pressure from becoming excessive due to the continued operation of the compressor described as the prior art is used. , (B) output command value and actual output,
(C) A time chart showing the relationship between opening and closing of the purge valve. Now, assuming that the target power generation amount of the fuel cell sharply decreases as shown in FIG. 5B due to the driver's deceleration operation, the target gas pressure for realizing the power generation amount is, for example, as shown in FIG. In the same manner, it decreases based on the control table for obtaining the target gas pressure for the target power generation amount.

Now, the hydrogen pressure and the air pressure are controlled toward the target gas pressure, but there is some delay in the response of the variable valve 204 for controlling the hydrogen pressure. Therefore, when the command value of the output taken out from the fuel cell is sharply reduced like the target power generation amount as shown in FIG. 5B, the amount of hydrogen consumed due to the reduction in output sharply decreases, but the hydrogen supply is reduced. Has a response delay, the hydrogen gas pressure becomes excessive as shown in FIG. If left as it is, the gas pressure will continue to be excessive with respect to the target value, and the differential pressure between the hydrogen pressure and the air pressure will be excessive, resulting in an emergency stop or deterioration of the reaction film of the fuel cell stack 201. And so on.

In this conventional technique, as a countermeasure, the pressure is controlled by the compressor so that the air pressure follows the hydrogen pressure. However, the reduction in hydrogen pressure itself is not promoted, and the power consumption of the air-based compressor 203 increases, resulting in wasting energy.

Therefore, in the first to fourth embodiments corresponding to claims 1 to 9, it is sufficient within the range of the total sum of the target power generation amount and the electric power that can be absorbed by the battery at each time. By taking out the output, the gas pressure becomes excessive and the system stops, the reaction film deteriorates,
Prevent wasting energy.

The state is shown in FIG. 6 (a) gas pressure, (b)
The output command value and (c) open / close state of the purge valve are shown. Similar to the case of FIG. 5, the target power generation amount is suddenly reduced, and the target gas pressure obtained from the table of FIG. 3A based on it is rapidly reduced.

In this case, from the hydrogen pressure at that time, as shown in FIG.
The output required value to be taken out is calculated based on the reverse table of (a), that is, from FIG. Here, FIG.
In (a), the gas pressure for generating a certain target amount of power generation may be set with a control target value and upper and lower limit values as a permissible range of fluctuations. In this case, in the reverse table of FIG. 4, in the sense of the maximum output that can be taken out at that pressure, the table data is obtained based on the data corresponding to the pressure lower limit value for the same target power generation amount in FIG. It is created and the required output value according to the actual pressure of hydrogen is calculated based on the data.

Next, this output required value and the target power generation amount at that time plus the recoverable amount that is the power that can be absorbed as the residual hydrogen recoverable amount in the battery, the total power generation amount (the target power generation amount and the recoverable amount). Of the total power generation amount) and the output demand value is smaller than the total power generation amount, the output demand value is the output command value, and when the output demand value is larger than the total power generation amount, the total power generation amount is the output command value. .

As a result, it becomes possible to take out the maximum output that should be (can be taken out) at that time.
It is possible to prevent the hydrogen pressure from becoming excessive as in (a),
The air pressure can also be quickly reduced. Therefore, the compressor 20 is quickly reduced at the same time.
The driving power consumption of No. 3 can be reduced promptly, waste of energy can be suppressed, and the fuel consumption of the fuel cell can be improved.

If the required output value is greater than the predetermined value or larger than the predetermined value with respect to the total power generation amount, the pressure cannot be sufficiently reduced even if the total power generation amount is taken out as the output. Eventually, there is a case where the air pressure has to be excessively large and the power consumption of the compressor 203 has to be discarded.

In this case, the hydrogen pressure that cannot be lowered even if the total amount of power that can be generated is reduced by opening the purge valve 206, or by opening the purge valve 206 and dropping hydrogen to lower the pressure. The air pressure is reduced accordingly. Then, by taking out the maximum output according to the pressure at that time, it is possible to suppress the wasteful consumption of energy in the compressor 203.

An example of this is shown in FIG. FIG. 7 shows (a) when the power generation amount decreases when the purge valve is opened in the present embodiment.
FIG. 6 is a time chart explaining the gas pressure, (b) output command value and actual output, and (c) opening / closing state of the purge valve, FIG.
Similar to the case of FIG. 6, the target power generation amount is suddenly decreased, and the target gas pressure obtained from the table of FIG.

In this case, since the required output value is larger than the total power generation capacity by a predetermined amount or more, the purge valve 206 is opened and hydrogen is discharged to the outside. Then, the required output value to be taken out is calculated from the hydrogen pressure at that time based on FIG. 4, which is the reverse table of FIG. 3 (a), and compared with the total power generation amount at that time,
When the output demand value is smaller than the total power generation amount, the output demand value is the output command value, and when the output demand value is larger than the total power generation amount, the total power generation amount is the output command value. As a result, by taking out the maximum output that should be taken out (can be taken out) at that time, it is possible to prevent the hydrogen pressure from becoming excessive as shown in FIG. 7A, and it is possible to quickly reduce the air pressure. For this reason, the rotation of the compressor 203 can be promptly reduced, so that the power consumption thereof can be promptly reduced, and waste of energy can be more effectively suppressed.

In the case of this method, the predetermined value for determining the difference between the total power generation amount and the output required value or the ratio of the two is the difference between the output required value exceeding the total generated amount or the output required value. If the ratio to the total power generation is less than a specified value, it is more efficient to consume energy with the compressor without opening the purge valve even if the pressure is somewhat high, and if it is more than the specified value, the energy is wasted with the compressor. Rather than opening the purge valve and discarding hydrogen, it is more efficient to check the value in advance and set it.

Next, the operation of the embodiment of the fuel cell power generation amount control apparatus of the present invention having the above-mentioned configuration will be described in detail with reference to the flowcharts.

<First Embodiment> The operation of the power generation control device for a fuel cell according to the first embodiment will be described with reference to FIGS.
0, shown in the flow chart of FIG.

FIG. 8 is a general flowchart, which is executed by the controller 214 of FIG. 2 at predetermined time intervals (for example, every 10 [ms]).

First, in step S801, the driver operation amount such as the accelerator operation amount of the driver is detected, and step S801
At 802, the target power generation amount TP of the fuel cell is calculated based on the driver operation amount. In step S803, the target power generation amount TP
Based on the table data shown in FIGS. 3A to 3C, the target gas pressure TPR, the target air flow rate TQATR, and the target hydrogen flow rate TQ are obtained.
H2 is calculated, and in step S804, the compressor 20
3. The variable valve 204 and the throttle 205 are controlled to control the gas pressure and flow rate. In step S805, a flag FP indicating whether the pressure / flow rate is in a decreasing transient state.
DOWN is calculated, and the flag FPDOWN is set to 1 in step S806.
Determine if

If it is determined in step S806 that the pressure / flow rate is on the decreasing side transient (FPDOWN = 1), step S806
Proceed to 807 to calculate the required output value PDEMPH2, and step S
The output command value TPM is calculated in 808, and the output control of the fuel cell is executed in step S810, and the process ends.

If it is determined in step S806 that the pressure / flow rate is not a transient on the decreasing side (FPDOWN = 0), step S806
In step S810, normal control is performed, and in step S810, output control of the fuel cell is performed and the process ends.

FIG. 9 shows the contents of the procedure in step S805 of FIG. 8 for determining whether the pressure / flow rate is in the transient state on the decreasing side and setting the flag FPDOWN.

First, in step S901, the previous value FPDOWNz of the flag FPDOWN indicating whether the pressure / flow rate is in the transient state on the decrease side and the previous value TPz of the target power generation amount are read, and it is determined in step S902 whether FPDOWNz is 1 or not. To do.
If FPDOWNz is 1 in step S902, the process proceeds to step S903, and in step S903 it is determined whether the target power generation amount previous value TPz-target power generation amount TP is larger than the predetermined value dTP1. If it is determined to be large in step S903, the flag FPDOWN = 1 is set in step S906, and if it is not determined to be large in step S903, flag FPDOWN = 0 is set in step S905, and the process ends.

If FPDOWNz is not 1 in step S902, the process proceeds to step S904 and step S904.
Then, it is determined whether TPz-TP is larger than the predetermined value dTP2. If it is determined to be large in step S904, the flag FPDOWN is set to 1 in step S907, and then step S90
When it is not judged to be large in step 4, step S908
Then, the flag FPDOWN is set to 0, and the process ends. Where dTP1 <d
Set it to TP2 and set the ON / OFF hysteresis of the flag FPDOWN with this width.

FIG. 10 shows the contents of the procedure of the output request value PDEMPH2 calculation in step S807 of FIG.

First, in step S1001, the actual pressure of hydrogen at the fuel electrode inlet detected by the hydrogen pressure sensor 211 of FIG.
PH2 is read, and in step S1002, step S
Based on PH2 read in 1001, output required value PDEMPH2 corresponding to the actual hydrogen gas pressure from the table in FIG.
Is calculated and the process ends.

FIG. 11 shows the contents of the calculation procedure of the output command value TPM in step S808 of FIG.

First, in step S1101, the electric power PBATLMT that can be absorbed by the battery is calculated, and in step S1102.
Then, the total power generation amount TPALL, which is the sum of the target power generation amount TP and the battery absorbable power PBATLMT, is calculated. Step S1
In 003, it is determined whether or not the total power generation amount TPALL> the required output value PDEMPH2, and in step S1103, TPALL> P
If it is determined to be DENPH2, step S110
At 4, the output command value TPM = PDEMPH2 is set, and the process ends. If it is not determined in step S1103 that TPALL> PDEMPH2, the output command value TPM = TPA in step S1005.
LL and finish.

<Second Embodiment> A second embodiment is shown in the flowcharts of FIGS. 8, 10, 11, and 12.

Since FIGS. 8, 10 and 11 are similar to those of the first embodiment, only FIG. 12 will be described.

FIG. 12 shows the contents of the procedure in step S805 of FIG. 8 for determining whether the pressure / flow rate is in the decreasing transient state and setting the flag FPDOWN.

In step S903 of FIG. 9 of the first embodiment, instead of comparing the previous value of the target power generation amount with the target power generation amount (TPz-TP) and a predetermined value, in step S1203, the target power generation amount is changed. TP, which is the ratio of the previous value to the target power generation
It is determined whether z / TP is larger than the predetermined value rTP1, and in step S1204, step S9 in FIG. 9 of the first embodiment is performed.
Instead of 04, determine if TPz / TP is greater than rTP2. The other steps are the same as those in FIG. 9, and thus description thereof will be omitted. Here, rTP1 <rTP2 is set, and the ON / OFF hysteresis of the flag FPDOWN is set with this width.

<Third Embodiment> A third embodiment will be described.
This embodiment uses FIG. 13 instead of FIG. 11 of the first and second embodiments, so only FIG. 13 will be described.

FIG. 13 shows the contents of the procedure for calculating the output command value TPM in step S808 of FIG.

In step S1301, the battery absorbable power PBATLMT, which is the power that can be absorbed by the battery, is calculated, and in step S1302, the total power generation amount TPALL, which is the sum of the target power generation amount TP and the battery absorbable power PBATLMT, is calculated. In step S1303, it is determined whether the required output value PDEMPH2> TPALL * α (α> 1) corresponding to the actual hydrogen pressure is satisfied.

PDEMPH2> TPALL * in step S1303
If it is determined to be α, the process proceeds to step S1304, a command to open the purge valve 206 is output, and the process proceeds to step S1304.
Proceed to 1305. In step S1305, TPALL> PDEMP
If it is determined that it is H2, and if it is determined that TPALL> PDEMPH2, in step S1307 the output command value TPM
= PDEMPH2 and finish. TPAL in step S1305
When it is not determined that L> PDEMPH2, step S13
At 08, the output command value TPM = TPALL is set, and the process ends.

PDEMPH2> TPALL * in step S1303
If it is not determined to be α, the process proceeds to step S1306, it is determined whether TPALL> PDEMPH2, and TPALL>
If it is determined to be PDEMPH2, step S1309
Then, set the output command value TPM = PDEMPH2 and finish. If it is not determined in step S1306 that TPALL> PDEMPH2, the output command value TPM = TPALL is set in step S1310, and the process ends.

Here, the coefficient α satisfying α> 1 is determined by the purge valve 2
While the hydrogen gas pressure is high with 06 closed, the compressor 203 is continuously operated to consume energy in order to maintain the air pressure corresponding to the hydrogen gas pressure.
This is a value for determining which is more efficient, which is to open 6 to drop hydrogen to reduce the pressure and also reduce the rotation of the compressor 203, and it should be obtained in advance.
In this embodiment, the efficiency is determined by the TPALL ratio.

<Fourth Embodiment> A fourth embodiment will be described.
This embodiment uses FIG. 14 instead of FIG. 13 of the third embodiment, so only FIG. 14 will be described.

FIG. 14 shows the contents of the procedure for calculating the output command value TPM in step S808 of FIG.

In step S1403, PDEMPH2> TP instead of step S1303 in FIG. 13 of the third embodiment.
Judge whether ALL + β. The other steps are the same as those in FIG. 13, so description thereof will be omitted.
Where β> 0, which is more efficient, the energy is consumed by the compressor 203 in a high pressure state with the purge valve 206 closed, or the pressure is reduced by opening the purge valve 206 and discarding hydrogen. Is a value for judging, and shall be obtained in advance. In the present embodiment, this efficiency determination is performed based on the difference value with respect to TPALL.

In these embodiments, FIG. 9 or FIG.
The target power generation amount TP and its previous value TPz were used when judging the pressure / flow rate decrease side transient in 2. However, this is the actual hydrogen pressure instead of the target hydrogen pressure TPRH2, TPz instead of TP. It is also possible to use PRH2 and judge the transient on the decrease side of pressure / flow rate by the difference or ratio of TPRH2 and PRH2.

Further, in these embodiments, the command value for the output control of the fuel cell is the output TPM, but this also holds true for the current I as in the conventional example.

In the control method of the power generation amount control device of the present invention, if the differential pressure between the hydrogen gas pressure and the air pressure still remains, conventional techniques for continuing the operation of the compressor may be used in combination.

<Fifth Embodiment> Next, a fifth embodiment corresponding to claims 10 to 14 will be described with respect to control when the operation of the fuel cell is stopped.

In this embodiment, the battery 2
The recoverable amount is calculated from the charge state of 16 and the like, the chargeability is determined, the operation of the purge valve 206 and the power generation state of the fuel cell stack 201 are determined, and the fuel cell stack 201 remains downstream of the ejector 208 even after the fuel gas supply is stopped. Power generation is continued by using the fuel gas that is generated, and the gas pressure of the fuel cell is rapidly reduced.

FIG. 15 shows the variable valve 204 when the operation is stopped.
The control main flow of the fifth embodiment executed after closing the fuel cell and stopping the supply of the fuel gas is shown.

First, in step S1501, the state of charge of the battery 216 is detected, and in step S1502 it is determined whether or not charging is possible based on the state of charge of the battery. This determination is YES if there is room for further charging from the state of charge of the battery (for example, state of charge SOC = less than 80%) and there is no failure in the charging system, and the process proceeds to step S1503. If NO, the process moves to step S1509 to control the purge valve.

Next, in step S1503, a battery chargeable power value (recoverable amount) is calculated. The details will be described in detail with reference to FIG. In step S1504, the air electrode 201a
And the gas pressure value of the fuel electrode 201b are obtained.
Details will be described in detail with reference to FIG.

In step S1505, if the gas pressure of the air electrode 201a and the gas pressure of the fuel electrode 201b maintain the pressure required for power generation, and there is no failure in the power generation system or the power transmission system to the battery 216, YES is determined, The process moves to step S1506. If NO, the process moves to step S1509 to control the purge valve.

Steps S1506 and S15
In 07, the amount of power generation is determined based on the battery chargeable power value, power is generated, and the battery is charged. It should be noted that the fuel gas pressure can be reduced more quickly by operating at the maximum value within the range of rechargeable power.

In step S1508, step S15
From the gas pressure value of the air electrode and the gas pressure value of the fuel electrode obtained in 04, the differential pressure between both electrodes is calculated, and it is determined whether or not it exceeds the limit value.

In the purge valve control of step S1509,
When the power cannot be recovered by the battery (step S15)
02), if power generation by the fuel cell is impossible (step S)
1505), the purge valve 206 is opened, and the purge valve is opened immediately before the estimated differential pressure value increases in step S1508 even if it may exceed the limit value. .

Next, an example of the calculation of the recoverable amount which is the battery chargeable power value in step S1503 of FIG. 15 will be described. First, as shown in FIG. 16, the relationship between the state of charge SOC [%] and the charging power E _P [kw] at a battery temperature of room temperature and a deterioration state close to 0 is obtained in advance, and the relationship is used as a reference. Of charging power E _P =
Find f (SOC).

Next, as shown in FIG. 17A, the relationship between the battery deterioration state and the internal resistance R [Ω] is investigated in advance,
Based on this, the relationship between the internal resistance R and the deterioration coefficient α (≦ 1) is obtained (FIG. 17B). Further, the influence of the battery temperature on the battery charge is also investigated in advance, and
The temperature coefficient β (≦ 1) is obtained ((FIG. 17 (c)). From these, the recoverable amount E _P ′ is

## EQU1 ## E _P '= α × β × E _P (1) It can be calculated by the equation (1).

The above-described battery chargeable power value calculation processing will be described with reference to the flowchart of FIG. In FIG. 18, first, the battery internal resistance (R) is detected in step S1801, and the internal resistance (R) is detected in step S1802.
The deterioration coefficient (α) is calculated by searching a table as shown in FIG. Next, in step S1803, the battery temperature (T) is detected, and in step S1803.
FIG. 17C based on the battery temperature (T) at 1804.
Temperature coefficient (β) by searching a table like
Is calculated. Then, the deterioration coefficient (α) and the temperature coefficient (β) are read in step S1805, and step S180
In step 6, the battery chargeable power, that is, the recoverable amount E _P ′ is calculated by the equation (1), and the process returns.

Next, an example of calculation of the gas pressure value in step S1504 of FIG. 15 will be described with reference to the flowchart of FIG.

First, in step S1901, the air electrode 201
The detected value immediately before the operation stop of the air pressure sensor 210 that detects the pressure on the side a is read, and in step S1902, the pressure decrease on the air electrode side based on the pressure on the air electrode side immediately before the operation stop and the opening degree of the throttle 205. Estimate the state. Next, in step S1903, the output voltage V [V] of the fuel cell
Is detected and the extraction current Ic [c / sec] is calculated from the charging power E _P '[kW] calculated in S1503 and the output voltage V [V] of the fuel cell in step S1904,

## EQU00002 ## Ic = E _P '/ V [c / sec] (2) Equation (2) is obtained. When this Ic [c / sec] is taken out from the fuel cell, the fuel gas flow rate Q _H2 consumed in the fuel cell
When [mol / sec] is obtained, the following equation (3) is obtained.

[0104]

## EQU00003 ## QH2 = Ic / 2 / F.times.Ncell [mol / sec] (3) where F = 96485 [c / mol] (Faraday constant), Ncell [pieces] (total number of fuel cell cells) Is.

Further, this fuel gas flow rate Q _{H2 is set} to the fuel electrode 2
Fuel electrode pressure Pk [kPa] when consumed in 01b
Ask for. First, the equation of state of gas in equation (4)

## EQU00004 ## PV _H2 = nR _H2 T _H2 4 From (4), V _H2 is the fuel gas system volume (constant), R _H2 is the gas constant of the fuel gas (constant), and T _H2 is the temperature in the fuel gas electrode. If it is a detected value, both sides of the state equation (4) are differentiated by t,

## EQU00005 ## dP / dt = (R _H2 T _H2 / V _H2 ) × dn / dt (5) Equation (5) is obtained, and dn / dt = Q _H2 (6) = (R _H2 T _H2 / V _H2 ) × Q _H2 (7) Formula (7) is obtained. When the previous estimated value of the fuel gas electrode pressure Pk [kPa] is P _k-1 ,

[Equation 6] P _k = P _k−1 + dP / dt × Δt [kPa] (8) Equation (8) is obtained. The previously estimated value uses the detected value immediately before the operation stop for the first time.

As the temperature detection value, it is possible to detect the temperature in the fuel gas electrode immediately before the operation is stopped and use it as a constant value. The temperature in the fuel gas electrode after the operation is stopped is detected by the temperature sensor. It is also possible to always detect and use it by the above.

FIG. 20 shows changes in (a) gas pressure and (b) purge valve open / closed state under the control of the fifth embodiment. Even when the operation is stopped, the fuel cell stack 201 continues to generate electric power using the fuel remaining downstream of the ejector 208 according to the state of charge of the battery 216, and the compressor 20
It is possible to quickly reduce the pressure of the fuel cell by preventing the pressure difference on the fuel electrode side from the pressure difference on the air electrode side from becoming excessive in the state where 3 is stopped and the throttle 205 is opened. It is possible to suppress wasteful consumption of energy and wasteful exhaust of residual fuel gas due to driving of the compressor 203.

Power generation is stopped at a place where the gas pressure is lower than the pressure necessary for power generation, and the power generation is continued more than necessary to prevent deterioration of the fuel cell.

At this time, in order to more effectively reduce the pressure on the fuel gas electrode side, it is advisable to generate the maximum value of the electric power that can be charged by the battery 216 with the fuel cell.

Further, in the prior art, even if power is generated by the fuel cell with the residual fuel gas when the operation is stopped,
There is a possibility that the differential pressure value between the fuel electrode and the air electrode rises, and as a result, it exceeds the limit differential pressure value and deteriorates the fuel cell. However, in the present invention, this is prevented by obtaining the differential pressure value, comparing it with the limit differential pressure, and opening the purge valve immediately before the limit is exceeded.

FIG. 21 shows this example. FIG. 21 shows (a)
6 is a time chart showing gas pressure, (b) purge valve open / closed state, and (c) battery charged state. It is assumed that the gas supply is stopped by closing the variable valve 204 and stopping the compressor 203 from the operating state of the fuel cell at time t0. Since the battery charge state is not the upper limit at time t0, the power generation is continued with the purge valve closed, and the hydrogen gas remaining downstream of the variable valve 204 continues the power generation. However, when the difference between the fuel electrode pressure and the air electrode pressure reaches the limit pressure difference value during continuous power generation, the purge valve 206 is opened at time t1 to protect the reaction film, and power generation is continued. Then, the power generation is stopped at time t2 when the air electrode pressure is reduced to the required lower limit value which is the lower limit of the pressure required for power generation.
As a result, it is possible to recover as much residual hydrogen as electric power to the battery as possible while maintaining the pressure difference applied to the reaction film at or below the limit differential pressure value.

Further, depending on the state of charge of the battery, it may be impossible to charge the battery. In that case, power generation is stopped, the purge valve is opened, and thereafter, the gas pressure is reduced only by the action of the purge valve. The opening area of the purge valve is the gas pressure between the oxidant gas electrode and the fuel gas electrode when the pressure drops when both the supply of fuel gas and oxidant gas are stopped simultaneously and the oxidant gas passage is opened to the atmosphere at the same time. If the area is set so that the difference does not exceed the limit value, the pressure difference will not exceed the limit value even in such a case.

An example of this is shown in FIG. FIG. 22 shows (a)
6 is a time chart showing gas pressure, (b) purge valve open / closed state, and (c) battery charged state. Time t
The gas supply is stopped at 0 as in FIG. After time to, power generation is continued while the purge valve is closed, and the residual hydrogen is recovered as electric power in the battery.
It is assumed that the battery charge state reaches the upper limit at time t1. Therefore, at the time t1, the power generation is stopped and the charging of the battery is terminated, and at the same time, the purge valve 206 is opened. This allows
It is possible to recover as much residual hydrogen as electric power to the battery while avoiding overcharging of the battery.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a power generation control device for a fuel cell according to the present invention.

FIG. 2 is a system configuration diagram illustrating an example of a fuel cell system to which the fuel cell power generation control device according to the present invention is applied.

3 is an example of a control table used by the operating point control means 102 of FIG. 1 or the controller 214 of FIG.
(A) Target gas pressure for target power generation, (b) Target air flow rate for target power generation, (c) Target hydrogen flow rate for target power generation, respectively.

FIG. 4 is an example of a table showing output required values corresponding to detected gas pressure values, which is a reverse table of the table of FIG.

FIG. 5 is a time chart for explaining (a) gas pressure, (b) output command value and actual output, and (c) open / close state of a purge valve when the amount of power generation is reduced in the conventional example.

FIG. 6 is a time chart for explaining (a) gas pressure, (b) output command value and actual output, and (c) open / close state of the purge valve when the amount of power generation is reduced when the purge valve is not opened in the present invention. .

FIG. 7 (a) gas pressure, (b) output command value and actual output when the amount of power generation decreases when the purge valve is opened in the present invention,
(C) It is a time chart explaining the opening / closing state of the purge valve.

FIG. 8 is a schematic flowchart common to the first to fourth embodiments.

FIG. 9 is a detailed flowchart in the first embodiment.

FIG. 10 is a detailed flowchart in the first embodiment.

FIG. 11 is a detailed flowchart in the first embodiment.

FIG. 12 is a detailed flowchart of the second embodiment.

FIG. 13 is a detailed flowchart of the third embodiment.

FIG. 14 is a detailed flowchart of the fourth embodiment.

FIG. 15 is a main flowchart in the fifth embodiment.

FIG. 16 is a battery charging state in the fifth embodiment [S
It is a graph which shows the charging electric power to OC].

FIG. 17A is a graph showing an example of the internal resistance value of the battery with respect to the deterioration state of the battery, and FIG. 17B is a graph showing an example of the deterioration coefficient of the battery with respect to the internal resistance value of the battery.
(C) A graph showing an example of the temperature coefficient of the battery recoverable power with respect to the battery temperature.

FIG. 18 is a battery absorption (charging) in the fifth embodiment.
It is a detailed flowchart for calculating a possible power value.

FIG. 19 is a detailed flowchart for calculating a gas pressure value in the fifth embodiment.

FIG. 20 (a) when the power generation amount is reduced in the fifth embodiment.
It is a time chart which shows gas pressure and (b) opening and closing of a purge valve.

FIG. 21 (a) Gas pressure when the differential pressure value of gas pressure reaches a limit value when the amount of power generation is reduced in the fifth embodiment,
It is a time chart which shows (b) opening and closing of a purge valve and (c) battery charge state.

FIG. 22 (a) Gas pressure when the battery charge state reaches the upper limit when the amount of power generation is reduced in the fifth embodiment,
It is a time chart which shows (b) opening and closing of a purge valve, and (c) charge state of a battery.

[Explanation of symbols]

101 ... Target power generation amount calculation means 102 ... Operating point control means 103 ... Recoverable amount detecting means 104 ... Operating state detection means 105 Output required value calculation means 106 ... Power generation control means 107 ... Gas pressure difference detection means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 8/00 H01M 8/00 Z H02J 7/00 303 H02J 7/00 303E // B60L 11/18 B60L 11 / 18 G F term (reference) 5G003 AA05 CA01 CA11 CB01 EA08 FA04 5H027 AA02 BA13 DD00 DD03 KK01 KK11 KK21 KK52 MM02 MM08 5H115 PA08 PC06 PG04 PI18 PI29 PO06 PU01 PU08 PV09 QN25 SE03 SE06 TI02 TI19 TI14 TO05 TO06 TI14 TO14 TO14 TO14

Claims (14)

[Claims] 1. A target power generation amount calculation means for calculating a target power generation amount of a fuel cell, a power storage means capable of recovering a part of the power generation amount of the fuel cell, and a recoverable amount for calculating a recoverable amount of the power storage means. A power generation amount control device for a fuel cell, comprising: a calculating unit; an operating state detecting unit that detects an operating state of the fuel cell; and a power generation control unit that calculates a command value of an output taken out from the fuel cell. The control means, when the target power generation amount is low, the command value of the output taken out from the fuel cell based on the output of the target power generation amount calculation means, the output of the operating state detection means, and the output of the recoverable amount calculation means. And a power generation amount control device for the fuel cell, wherein the power generation amount of the fuel cell is greater than the target power generation amount within a range in which the power storage means can recover. 2. The recoverable amount calculating means calculates the recoverable amount based on a stored amount of the storage means, a deterioration state of the storage means, and a temperature of the storage means. Item 1. A power generation control device for a fuel cell according to Item 1. 3. Operating point control means for controlling the pressure of the gas supplied to the fuel cell to a target operating point based on the output of the target power generation amount calculating means, and the operating state detection for detecting the gas pressure of the fuel cell. Output required value calculation means for calculating the value of the output to be taken out from the fuel cell based on the output of the means, the power generation control means, while reducing the gas pressure when the target power generation amount is reduced, the target power generation amount. And a sum of the recoverable amount and the output of the output request value calculation means, and the smaller one of them is used as the output command value of the fuel cell. Item 2. A fuel cell power generation amount control device according to item 2. 4. The operating point control means calculates at least a target value of gas pressure from a predetermined relationship on the basis of the output of the target power generation amount calculation means, and the output required value calculation means calculates the operating state. 4. The fuel cell power generation amount control device according to claim 3, wherein the output demand value is calculated from the relationship opposite to the predetermined relationship used by the operating point control means, based on the output of the detection means. 5. The power generation control means has, in addition to a function of calculating an output command value, a function of opening and closing a purge valve that communicates a passage of a fuel gas discharged from a fuel cell with the atmosphere. The fuel cell according to any one of claims 1 to 4, wherein the purge valve is opened / closed based on the target power generation amount, the operating state, and the recoverable amount at the time of decrease. Power generation control device. 6. The opening area of the purge valve is such that when the supply of fuel gas and oxidant gas is both stopped at the same time and the oxidant gas passage is open to the atmosphere at the same time, the oxidant electrode and the fuel electrode 6. The fuel cell power generation amount control device according to claim 5, wherein the gas pressure difference between the two is set to an area not exceeding a limit value. 7. The purge valve is opened and closed based on the output of the output required value calculation means and the value of the sum of the target power generation amount and the recoverable amount. The fuel cell power generation amount control device described in 1. 8. The purge valve is opened when the difference between the output of the output request value calculation means and the sum of the target power generation amount and the recoverable amount is a predetermined value or more. The fuel cell power generation amount control device according to claim 7, which is characterized in that. 9. The purge valve is opened when the output required value is equal to or more than a value obtained by multiplying a value of a sum of the target power generation amount and the recoverable amount by a predetermined ratio larger than 1. The fuel cell power generation amount control device according to claim 7. 10. The operating state detecting means is means for detecting whether or not the fuel cell is in a state where it continues to generate electric power and can supply electric power to the power storage means, and when the operation is stopped, the operating state detecting means detects the fuel cell. When it is detected that the power generation means continues to generate power and is capable of supplying power to the power storage means, the power storage means calculates a command value of the output taken out from the fuel cell based on the recoverable amount, and continues power generation. The power generation amount control device for a fuel cell according to claim 1, wherein: 11. The power generation control means has a function of calculating an output command value and a function of opening and closing a purge valve that connects a passage of a fuel gas discharged from a fuel cell and the atmosphere, and the operation stop. 11. The fuel cell power generation according to claim 10, wherein the purge valve is closed when the power generation is continued occasionally, and the purge valve is opened when the power generation is not continued when the operation is stopped. Quantity control device. 12. The operating state detecting means includes a gas pressure detecting means for detecting the pressure of gas supplied to the fuel cell, and generates power depending on whether or not the pressure of the gas has reached a minimum pressure value required for power generation. 12. The fuel cell power generation amount control device according to claim 10 or 11, wherein it is detected whether or not the fuel cell can continue. 13. A gas pressure difference detecting means for detecting a gas pressure difference between an oxidizing gas electrode and a fuel gas electrode, wherein the gas pressure difference of the gas pressure difference is detected even when power generation is continued when the operation is stopped. Just before the limit value is exceeded when increasing,
The fuel cell power generation amount control device according to claim 11, wherein the purge valve is opened and power generation is continued. 14. The gas pressure detecting means or the gas pressure difference detecting means estimates the gas pressure or the gas pressure difference based on the gas pressure when the operation is stopped. The fuel cell power generation amount control device described.