JP4456197B2 - Fuel cell power generation control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell power generation control method, and more particularly, to a fuel cell power generation control method in a so-called hybrid fuel cell power supply system including a fuel cell and a transient response-compliant electric energy buffer.
[0002]
[Prior art]
In recent years, so-called fuel cell electric vehicles equipped with fuel cells have been actively developed. As one of the fuel cell electric vehicles, a so-called hybrid type fuel cell electric vehicle is known which has a transient response-compatible electric energy buffer such as a fuel cell and a battery as a power source. In this hybrid type fuel cell electric vehicle, current is supplied by the fuel cell when it is within the fuel cell response speed range. In addition, if the fuel cell alone cannot supply a sufficient current or cannot follow the required speed due to a delay in the fuel supply system, the current is supplied from the transient response-compatible electrical energy buffer during a transition such as acceleration. The supplied output current is controlled.
[0003]
However, in this output current control, since a constant current is supplied from the fuel cell, when the external load is small, surplus power is consumed by a resistance load provided separately, which is wasted. An electric current was generated.
[0004]
In order to prevent such waste, Japanese Patent Laid-Open No. 5-151983 discloses a fuel cell power supply system that controls the output current of the fuel cell.
As shown in FIG. 5, the fuel cell power supply system M ′ includes a fuel cell 51, a DC / DC converter 52, and a battery 53 that is a transient response-compliant electric energy buffer. Further, a control device 55 is provided for controlling the current supply amount of the fuel cell 51 and the output limit value of the DC / DC converter 52 in accordance with the required external load (required load) 54. Further, an ammeter 56 for measuring the output current of the fuel cell 51 and an ammeter 57 for measuring the output current of the battery 53 are provided. Furthermore, the output circuit of the DC / DC converter 52 is provided with a voltmeter 58 for measuring the output voltage.
[0005]
In this fuel cell power supply system M ′, an output current to the fuel cell 51 is measured by an ammeter 56 and an output current of the battery 53 is measured by an ammeter 57. Further, the output voltage of the DC / DC converter 52 is controlled based on the measured value of the voltmeter 58 and the measured value of a thermometer (not shown) provided in the battery 53.
[0006]
When the external load 54 increases rapidly, the DC / DC converter 52 limits the output of current based on the measured values of these ammeters 56 and 57, and the fuel cell 51 limits the output current of the fuel cell 51. It is changed at a speed that can be followed. On the other hand, a shortage of current with respect to the external load 54 is supplied from the battery 53. In this way, control is performed so that current can be stably supplied even when the external load 54 rapidly increases. These controls are all performed by the control device 55.
[0007]
[Problems to be solved by the invention]
However, the conventional technology does not deal with cases where the external load suddenly decreases, such as when the hybrid fuel cell electric vehicle suddenly decelerates or stops, or when power is regenerated from there. Absent. In this way, when the external load is suddenly reduced, if the current generated in the fuel cell is reduced corresponding to the reduction in the external load, the amount of hydrogen supplied from the hydrogen storage alloy (not shown) to the fuel cell is also reduced. Of course, it must be reduced.
[0008]
However, a certain delay is inevitable when reducing the hydrogen supply. For this reason, excess hydrogen is supplied to the fuel cell, and hydrogen under pressure remains inside the fuel cell. As a result, the pressure balance with the oxygen system may be lost, pressure balance may not be achieved, and the fuel cell may be brought to an emergency stop. Furthermore, the reaction membrane of the fuel cell may be damaged.
[0009]
Therefore, an object of the present invention is to safely consume the residual hydrogen inside the fuel cell and perform an emergency stop not only when the external load suddenly increases, but also when the external load suddenly decreases or regenerates. In other words, the power generation control of the fuel cell is performed so that stable power can be always supplied to the external load.
[0010]
[Means for Solving the Problems]
  The present invention that solves the above problems(1) When the fuel cell output current target value determined according to the required load of the fuel cell power supply system decreases, the invention according to claim 1 responds to the decrease in the fuel cell output current target value. ReducedFuel cell output current command valueThe decrease rate of the fuel cell output current target value is made smaller than the decrease rate of the fuel cell output current target value to cause the fuel cell to generate a large amount of power to process surplus fuel gas, and the generated power when the surplus fuel gas is processed, Storing in the electrical energy buffer;A fuel cell power generation control method.
(2) The invention according to claim 2The fuel cell output current target value determined according to the required load of the fuel cell power system isWhen decreasing beyond a predetermined threshold, the rate of decrease of the fuel cell output current command value that is decreased in accordance with the decrease in the target value of the fuel cell output current is made smaller than when the predetermined threshold is not exceeded. By causing the fuel cell to generate a large amount of power and processing surplus fuel gas, the power generated when the surplus fuel gas is processed is stored in the electric energy buffer.A fuel cell power generation control method.
[0011]
  In the present invention, BurningThe residual hydrogen under pressure in the fuel cell can be suppressed.
  Here, the “predetermined reduction rate” means a rapid decrease that causes excess hydrogen to be generated when the fuel cell output current command value is decreased following the decrease.
In the embodiment described later,The “decreasing rate determined according to the decreasing rate of the target value of the fuel cell output current” means a decreasing rate within a range where surplus hydrogen does not remain in the fuel cell.
  further,In the embodiment described later,The “specified value” to be subtracted from the fuel cell output current limit value is a margin that is given so that the fuel cell output command value does not exceed the fuel cell output current value. Specifically, it can be set to about 1 A, for example. it can.
[0012]
(3) Further, the invention according to claim 3 is a fuel in which the control device is a limit value of a current to be extracted from the fuel cell when the fuel cell output current target value decreases beyond the predetermined threshold value. The battery output current limit value is set to a value larger than the fuel cell output current target value and to decrease in accordance with a decrease in the fuel cell output current target value, and the fuel cell output current command value is The fuel cell power generation control method is characterized in that it is determined so as to decrease within a range not exceeding the fuel cell output current limit value.
(4) In the invention according to claim 4, in the case where the control device determines the fuel cell output current command value so as to decrease within a range not exceeding the fuel cell output current limit value, the fuel cell When the output current command value is equal to or greater than the value obtained by subtracting the specified value from the fuel cell output current limit value, the fuel cell output current command value is made to coincide with the value obtained by subtracting the specified value from the fuel cell output current limit value. This is a featured power generation control method.
(5) The invention according to claim 5 is characterized in that the control device controls the fuel cell output current command value to decrease until it matches the fuel cell output current target value. This is a power generation control method.
(6) Further, in the invention according to claim 6, when the control device determines that the fuel cell output current target value is in a regenerative state, the fuel cell output is a limit value of a current to be extracted from the fuel cell. When the current command value is equal to or greater than a value obtained by subtracting a specified value from the fuel cell output current limit value, the fuel cell output current command value is made to coincide with a value obtained by subtracting the specified value from the fuel cell output current limit value. A fuel cell power generation control method. Claim 6Even when the fuel cell output current target value is in the regenerative state as in the invention according to the above, the same problem as in the case where the fuel cell output current target value rapidly decreases can occur. Therefore, it is preferable to perform the same control when the fuel cell output current target value is in the regenerative state.
[0013]
  In additionWhen the fuel cell output current command value exceeds the fuel cell output current target value, the fuel cell output current command value exceeds a value obtained by subtracting a specified value from the fuel cell output current limit value, When the fuel cell output current command value matches the value obtained by subtracting the specified value from the fuel cell output current limit value, and the fuel cell output current command value is equal to or less than the value obtained by subtracting the specified value from the fuel cell output current limit value The control is performed to decrease the fuel cell output current command value until the fuel cell output current command value coincides with the target value of the fuel cell output current while decreasing the fuel cell output current command value at the predetermined decrease rate.You can also
[0014]
BurningEven when the fuel cell output current command value exceeds the fuel cell output current target value, the same problem as in the case where the fuel cell output current target value rapidly decreases can occur. Therefore, it is preferable to perform the same control when the fuel cell output current command value exceeds the fuel cell output current target value.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram of an electric system in a fuel cell power supply system in which power generation control according to the present invention is performed, and FIG. 2 is a block diagram of the fuel supply system. Since the fuel cell power supply system M is used mounted on, for example, a fuel cell electric vehicle, an example in which the fuel cell power supply system M is mounted on a fuel cell electric vehicle (not shown) will be described here.
[0016]
As shown in FIG. 1, the electric system M <b> 1 in the fuel cell power supply system M includes a fuel cell 1. The fuel cell 1 is connected via a DC / DC converter 2 to a battery 3 that is an electrical energy buffer for transient response. Further, a current required according to an external load 4 including a required load of a main motor and auxiliary devices not shown is supplied from the fuel cell 1 and the battery 3 to the main motor and auxiliary devices not shown. The external load 4 is calculated based on the current value detected by the ammeter 8.
[0017]
Further, a control device 5 is provided for controlling the current supply amount of the fuel cell 1 and controlling the output limit value of the DC / DC converter 2. Further, ammeters 6 and 7 that measure output currents from the fuel cell 1 and the battery 3 and an ammeter 8 that measures an external load current are provided. A voltmeter 9 for measuring the output voltage from the DC / DC converter 2 is also provided. The current values and voltage values measured by these ammeters 6, 7, 8 and voltmeter 9 are sent to the control device 5. In the control device 5, the output current value of the fuel cell 1, the output limit value of the DC / DC converter 2, and the output voltage value of the DC / DC converter 2 are controlled based on these current values and voltage values. .
[0018]
As shown in FIG. 2, in the fuel supply system M2, hydrogen is supplied to the fuel cell 1 from a hydrogen supply source 11 made of, for example, an occluded hydrogen alloy via a regulator 12 and an ejector 13. In the regulator 12, the supply amount of supplied hydrogen is controlled, and hydrogen is directly ejected to the fuel cell 1 by the ejector 13.
[0019]
Furthermore, oxygen-rich air is supplied to the fuel cell 1. Air is supplied to the fuel cell 1 by the action of the air pump 14, but before the air is sucked by the air pump 14, dust is captured by the air filter 15, and after being discharged from the air pump 14, the heat exchanger Air is cooled by 16. The subsequent air is supplied to the fuel cell 1 via the filter 17.
[0020]
Hydrogen and air (oxygen) are supplied to the fuel cell 1 to the hydrogen electrode and the oxygen electrode, respectively, and the inside of the fuel cell 1 is humidified by the humidifier 18 to promote the electrochemical reaction between hydrogen and oxygen in the air. To do. In the fuel cell 1, hydrogen and oxygen in the air react electrochemically to generate an electric current. Although an electric current is generated by the electrochemical reaction and surplus water is generated, the surplus water generated here is removed through the demister 19. The surplus water contains hydrogen mixed with impurities, and this hydrogen is released into the atmosphere via the demister 19 and the purge valve 20.
[0021]
Further, in the fuel cell 1, the pressure balance is properly maintained by the air pressure regulating valve 21 so that the pressure balance of the differential pressure between the hydrogen electrode and the oxygen electrode does not collapse. When the pressure balance in the fuel cell 1 is likely to collapse, the pressure is adjusted by appropriately opening the air pressure regulating valve 21 with air.
[0022]
Next, a power generation control method for a fuel cell according to the present invention will be described.
FIG. 3 is a graph showing an example of a change in current value when power generation control in the present invention is performed.
Here, as shown by a solid line in FIG. 3, a fuel cell output current target value (hereinafter referred to as “target value”) I corresponding to the external load 4._CMDA description will be given of the control in the case where the change occurs. This target value I_CMDIs calculated by the control device 5 based on the current value of the ammeter 8 that detects the external load 4.
[0023]
In the idling state (region A) before the start of running of the fuel cell electric vehicle, the target value I_CMDIs 0. Next, when the accelerator is stepped on and the fuel cell electric vehicle starts running, the external load 4 rapidly increases and the target value I_CMDIncreases instantaneously and then reaches a certain value I₁(Region B) and the required load is stable.
[0024]
Subsequently, for example, when the fuel cell electric vehicle decelerates rapidly and the external load 4 rapidly decreases, the target value I_CMDDecreases rapidly at a reduction rate exceeding a predetermined reduction rate (region C), and eventually enters a negative region to enter a regenerative state (region D). Thereafter, when the accelerator is depressed again and the external load 4 increases again, the target value I_CMDIncreases to escape from the regenerative state (region E), and the traveling speed becomes constant, the external load 4 becomes stable and the target value I_CMDIs also a constant value I₂It stabilizes at. And target value I_CMDIs a constant value I₂(Region F).
[0025]
Thus, when the external load 4 fluctuates, first, the fuel cell output current limit value (hereinafter referred to as “limit value”) I._LMTThe control will be described. Limit value I calculated here_LMTIs transmitted to the DC / DC converter 2 and this limit value I_LMTIs the current limit value of the DC / DC converter 2.
[0026]
Target value I_CMDIn region A where is 0, the limit value I_LMTIs a target value I to give a little margin_CMDSlightly higher value I_ThreeSet to Next, the accelerator is depressed and the target value I_CMDIn the subsequent region B, the limit value I is considered in consideration of the delay of the current generated from the fuel cell 1._LMTIncrease. At this time, the target value I_CMDLike limit I_LMTCan be increased instantaneously, but the limit value I_LMTThe increase rate is limited by the performance of the hydrogen supply source 11 and the like. Therefore, the limit value I_LMTCannot be increased instantaneously, and the limit value I has the maximum size in the performance of the hydrogen source 11._LMTIncrease. With the maximum increase rate, the limit value I_LMTIs the target value I_CMDIncrease the value to a slightly higher value than that value I_FourTo maintain.
[0027]
Thereafter, in a region C where the external load 4 decreases rapidly, the target value I_CMDLimit value I according to the decrease of_LMTAlso reduce. Here, the target value I_CMDThe magnitude of the reduction rate when reducing the value does not depend on the performance of the hydrogen supply source 11 in particular. Further, in the region D where the external load 4 is regenerated, the target value I_CMDLimit value I according to the decrease of_LMTAnd the target value I_CMDLimit value I with increasing_LMTAlso increase. After the regenerative state is removed, the external load 4 is stabilized and the target value I_CMDIs also a constant value I₂In region E until the target value I_CMDLimit value I with increasing_LMTIncrease the target value I_CMDIs a constant value I₂In the stable region F, the limit value I_LMTIs the target value I_CMDConstant value I of₂Value I slightly larger than_FiveStabilize with.
[0028]
Thus, the target value I_CMDAnd limit value I_LMTIs set in the fuel cell output current command value (hereinafter referred to as “command value”) I._REFThe control will be described. This command value I_REFIs transmitted to the fuel cell 1 where the command value I_REFThe current of the value given by is output.
[0029]
Target value I_CMDIn the region A where is 0, the command value I_REFIs also set to 0. Next, the target value I_CMDIn region B after the instantaneous increase, command value I_REFIt is desirable to increase the_REFIs the limit value I_LMTExceeding this causes adverse effects such as generation of surplus hydrogen. On the other hand, the command value I_REFIs the limit value I_LMTIf it is increased while being matched with the command value I_REFIs the limit value I_LMTIt is feared that Therefore, the command value I_REFIs the limit value I_LMTIf it matches the value obtained by subtracting the specified value α from the command value I_REFIs the limit value I_LMTThe value is increased while keeping the value equal to the value obtained by subtracting the specified value α from the value. The prescribed value α can be set to 1A, for example, as described above.
In this region B, the command value I_REFOver time, the target value I_CMDIs the value I₁Until reaching the limit I_LMTIt continues to increase in a state that matches the value obtained by subtracting the prescribed value α from (region B1). In this region B1, the command value I_REFIs the target value I_LMTTherefore, only the fuel cell 1 cannot supply the current required by the external load 4. The current shortage at this time can be covered by taking out from the battery 3.
[0030]
Then the command value I_REFIs the target value I_CMDIs the value I₁After reaching the command value I_REFIs the target value I_CMDIs the value I₁Is maintained (region B2). Command value I_REFIs the target value I_CMDIs the value I₁In a state that matches, the current required by the external load 4 can be supplied only from the fuel cell 1.
[0031]
Thereafter, in a region C where the external load 4 decreases rapidly, the target value I_CMDCommand value I_REFAlso reduce. At this time, the target value I_CMDCommand value I at the same rate as_REFIs reduced, surplus hydrogen remains in the fuel cell 1 due to a delay in control of the hydrogen gas supplied from the hydrogen supply means 11 to the fuel cell 1. In order to prevent the surplus hydrogen from remaining, the target value I_CMDIs smaller than the decrease rate of the target value I_CMDCommand value I with a reduction rate determined according to_REFIs reduced (region C1). Thus, the command value I_REFBy reducing the decrease rate of the residual hydrogen, it is possible to significantly reduce or eliminate surplus hydrogen remaining due to control delay.
[0032]
The command value I_REFAs the value decreases, the limit value I_LMTSince the decrease rate is larger, the command value I_REFAnd limit value I_LMTWill meet. With this decrease, the command value I_REFDecreases the command value I_REFIs the limit value I_LMTThis also causes surplus hydrogen to remain in the fuel cell 1. Therefore, the command value I_REFIs the limit value I_LMTCommand value I_REFIs the limit value I_LMTIt is conceivable to match. However, the command value I_REFIs the limit value I_LMTCommand value I_REFIs the limit value I_LMTCommand value I_REFAnd limit value I_LMTIt is feared that it will exceed. Therefore, the command value I_REFIs the limit value I_LMTWhen the specified value α is subtracted from the command value I_REFIs the limit value I_LMTThe value is decreased while being matched with the value obtained by subtracting the specified value from (region C2). In this way, surplus hydrogen can be prevented from remaining.
[0033]
Thereafter, the target value I in the region D where the external load 4 is regenerated._CMDIn the region D1 where the decrease is in the limit value I_LMTHas also decreased. Here, the command value I_REFIs the limit value I_LMTIs consistent with the limit value I_LMTCommand value I_REFDecrease. Subsequently, in the regenerative state, the target value I is generated by causing acceleration or the like._CMDThe limit value I_LMTAccordingly increases (area D2). At this time, the command value I in the region C1 again._REFCommand value I with the same reduction rate as_REFDecrease.
[0034]
Thereafter, the vehicle is again in the required load stable state (area E), but the command value I is maintained even in this required load stable state._REFIs the target value I_CMDDoes not agree with the command value I_REFIs the target value I_CMDBigger than. Here, the command value I_REFIs the target value I_CMDCommand value I in the region C1 until_REFCommand value I with the same reduction rate as_REFDecrease. And the command value I_REFIs the target value I_CMDCommand value I when_REFIs the target value I_CMD(Region F).
[0035]
In the region C to the region E, the command value I_REFIs the target value I_CMDIs over. Therefore, an extra current is generated with respect to the current required for the external load 4, and the battery 3 can be charged with this extra current.
[0036]
Next, the power generation control procedure so far will be described based on the flowchart shown in FIG. This power generation control is performed in the control device 5.
First, when power generation control is started (S1), the target value I_CMDIn order to determine whether or not the current value is decreasing rapidly, this target value I_CMDAnd previous target value I_CMDOLDIt is determined whether or not the difference is smaller than a predetermined regulation value β (S2). The specified value β at this time can be set, for example, in a range of approximately −700 A / sec to −1300 A / sec. Here, if the absolute value of the specified value β is too large, the pressure cannot be compensated and the ion exchange membrane of the fuel cell may be damaged. On the other hand, if the absolute value of the specified value β is too small, the efficiency of the entire system is lowered. Here, this target value I_CMDAnd previous target value I_CMDOLDIs determined to be smaller than the predetermined regulation value β, the target value I_CMDIs in a state of rapidly decreasing, the process proceeds to step S6 described later. On the other hand, this target value I_CMDAnd previous target value I_CMDOLDIf it is determined that the difference between the target value I is not smaller than the predetermined regulation value β,_CMDIs not in a state of rapidly decreasing. In this case, the target value I is determined in order to determine whether or not the engine is in a regenerative charging state, such as when the so-called engine brake is applied or the vehicle is running down a steep hill._CMDIs determined to be less than 0 (S3).
[0037]
Here, the target value I_CMDIs determined to be less than 0, the battery is in a regenerative charge state, and the process proceeds to step S6 described later. On the other hand, the target value I_CMDIs determined not to be less than 0, it is not in the regenerative charge state. In this case, in order to determine whether or not surplus hydrogen treatment is being performed, the command value I_REFIs the target value I_CMDIt is judged whether it is larger than (S4). And the command value I_REFIs the target value I_CMDIf it is determined that the value is larger than that, the surplus hydrogen treatment is being performed, and the process proceeds to step S6 described later. On the other hand, the command value I_REFIs the target value I_CMDIf it is determined that the value is not larger than that, it is not in the state of decreasing transient, but is in either the required load stable state or the rising transient state.
[0038]
Here, in order to determine whether the required load is stable or in an up-transition state, the limit value I_LMTIs the target value I_CMDIt is determined whether it is larger (S5). And the limit value I_LMTIs the target value I_CMDIs larger than the target value I because it is in the required load stable state._CMDCommand value I_REF(S5-1). On the other hand, the limit value I_LMTIs the target value I_CMDIf it is determined that the value is not larger than the limit value I, since it is in an up-transition state such as during acceleration, the limit value I_LMTThe value obtained by subtracting the specified value α from the command value I_REF(S5-2).
[0039]
In step S2, the current target value I_CMDAnd previous target value I_CMDOLDIn step S3, the target value I is smaller than the predetermined regulation value β._CMDIs less than 0, in step S4, the command value I_REFIs the target value I_CMDIn step S6, which is proceeded to when it is determined that the value is larger than each, it is in a decreasing transition state. In the case of this decreasing transition state, the command value I_REFIf the A is rapidly reduced, surplus hydrogen remains in the fuel cell 1. Therefore, the command value I_REFMust be reduced at a predetermined rate. On the other hand, the target value I_CMDWith the rapid decrease of the limit value I_LMTAlso decreases rapidly. At this time, the command value I_CMDIf the rate of decrease of the_CMDIs the limit value I_LMTWill be exceeded. Command value I_CMDIs the limit value I_LMTExceeding this causes excess hydrogen to be fed into the fuel cell 1 and cause excess hydrogen. Therefore, the limit value I_LMTIs the command value I_CMDIt is determined whether or not the following is true (S6).
[0040]
In step S6, the limit value I_LMTThe value obtained by subtracting the specified value α from the command value I_CMDIn the following cases, the command value I_CMDIs the limit value I_LMTLimit value I in order not to exceed_LMTThe value obtained by subtracting the specified value α from the command value I_CMD(S6-1). On the other hand, the limit value I_LMTIs the command value I_CMDIf not, the previous command value I_CMDOLDThe value obtained by subtracting the predetermined specified value γ from the command value I_CMD(S6-2). Here, the specified value γ can be set within a range of −300 A / sec to −100 A / sec, for example, −200 A / sec. If the absolute value of the specified value γ is too large, the pressure cannot be compensated and the ion exchange membrane of the fuel cell 1 may be damaged. On the other hand, if the absolute value of the specified value γ is too small, there is a problem that the efficiency of the entire system is lowered.
[0041]
Thus, in each step S5-1, S5-2, S6-1, S6-2, the command value I_CMDIs set, it is determined whether or not the operation is continued (S7). And when driving | running is continued, it returns to step S2 and the same control is repeated. On the other hand, control is complete | finished when driving | operation is not continued and it stops (S8).
[0042]
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be applied, for example, when the fuel cell electric vehicle stops and does not regenerate.
[0043]
【The invention's effect】
As described above, according to the present invention, when the external load is suddenly reduced or regenerated, the residual hydrogen inside the fuel cell is safely consumed and the power is always stably supplied to the external load without emergency stop. Thus, it is possible to perform power generation control of the fuel cell.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electrical system of a fuel cell power supply system in which power generation control according to the present invention is performed.
FIG. 2 is a block diagram of a fuel system of a fuel cell power supply system in which power generation control according to the present invention is performed.
FIG. 3 is a graph showing an example of a change in current value when power generation control is performed in the present invention.
FIG. 4 is a flowchart showing a procedure for performing power generation control according to the present invention.
FIG. 5 is a block diagram of a conventional hybrid fuel cell power supply system.
[Explanation of symbols]
1 Fuel cell
2 DC / DC converter
3 Battery (electric energy buffer for transient response)
4 External load (required load)
5 Control device
6,7,8 Ammeter
9 Voltmeter
M Fuel cell power system

Claims (6)

A fuel cell that generates power using hydrogen supplied from a fuel supply source , oxygen in the air supplied from an air pump, an electric energy buffer capable of storing the generated power of the fuel cell, and a control device, It is configured to be able to supply power to an external load from the fuel cell and the electric energy buffer,
The control device is
The fuel cell output current target value determined according to the required load of the fuel collector Ikeshi stem,
A fuel cell output current command value is determined according to the determined fuel cell output current target value,
In the fuel cell power generation control method in the fuel cell system for outputting a current corresponding to the determined fuel cell output current command value from the fuel cell,
The controller is
When the fuel cell output current target value decreases and surplus hydrogen remains in the fuel cell due to the hydrogen control delay, the target value is decreased according to the decrease in the fuel cell output current target value. wherein the reduction rate of the fuel cell output current command value, the fuel most were generated in the battery to process the surplus hydrogen to be smaller than the reduction rate of the fuel cell output current target value that,
A power generation control method for a fuel cell, wherein generated electric power when the surplus hydrogen is processed is stored in the electric energy buffer. A fuel cell that generates electricity using fuel gas supplied from a fuel supply source, an electric energy buffer capable of storing electric power generated by the fuel cell, and a control device, and includes an external load from the fuel cell and the electric energy buffer. Configured to be able to supply power
The control device is
The fuel cell output current target value determined according to the required load of the fuel collector Ikeshi stem,
A fuel cell output current command value is determined according to the determined fuel cell output current target value,
In the fuel cell power generation control method in the fuel cell system for outputting a current corresponding to the determined fuel cell output current command value from the fuel cell,
The controller is
Determining whether the rate of decrease of the fuel cell output current target value decreases beyond a predetermined threshold determined in consideration of the generation of surplus fuel gas;
When the fuel cell output current target value decreases when the fuel cell output current target value decreases by exceeding the predetermined threshold, the fuel cell output current command value decrease rate is reduced from the fuel cell output current target value decrease rate . To make the fuel cell generate a lot of power to reduce excess fuel gas,
A power generation control method for a fuel cell, wherein generated electric power when the surplus fuel gas is processed is stored in the electric energy buffer. In the case where the control device decreases the fuel cell output current target value beyond the predetermined threshold,
The fuel cell output current limit value, which is the limit value of the current extracted from the fuel cell, is set to a value larger than the fuel cell output current target value, and decreases in accordance with a decrease in the fuel cell output current target value. As well as
Wherein the fuel cell output current command value, the power generation control method for a fuel cell according to 請 Motomeko 2 you, characterized in that defined as decreases in the range not exceeding the fuel cell output current limit. In the case where the control device determines the fuel cell output current command value to decrease within a range not exceeding the fuel cell output current limit value,
When the fuel cell output current command value is equal to or greater than a value obtained by subtracting a specified value from the fuel cell output current limit value, the fuel cell output current command value matches the value obtained by subtracting the specified value from the fuel cell output current limit value. The power generation control method for a fuel cell according to claim 3, wherein: The controller is
5. The power generation control of the fuel cell according to claim 2, wherein the control is performed such that the fuel cell output current command value is decreased until the fuel cell output current target value is matched. Method. The controller is
When it is determined that the fuel cell output current target value is in a regenerative state,
Before Ki燃 fee when the above value obtained by subtracting the specified value from the cell output current command value is the fuel cell output current limit value, a value that the fuel cell output current command value obtained by subtracting the specified value from the fuel cell output current limit The power generation control method for a fuel cell according to claim 3 , wherein

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