JP6048163B2 - Fuel cell system for electric vehicles - Google Patents

Description

  The present invention relates to a fuel cell system that supplies electric power for charging a secondary battery at the same time as operating a motor included in an electric vehicle.

  There are already fuel cell vehicles that use a fuel cell (hereinafter referred to as FC) to generate electric power and drive the motor using the electric energy.

  A general fuel cell vehicle is equipped with a small-capacity secondary battery along with the FC, but basically relies on the output from the FC for most of the energy required for traveling. The fuel cell vehicle uses the output from the secondary battery when energy is instantaneously insufficient due to acceleration of the accelerator fully open. In addition, the rechargeable battery is basically charged with regenerative energy during deceleration.

  On the other hand, it has a large-capacity battery, and has a function of charging (plug-in) from an AC commercial power supply to this battery. It basically runs as an electric vehicle (EV) and uses FC as a range extender. A car is expected. In other words, a low-power FC is mounted on the FC mounted on a general fuel cell vehicle, and this FC is activated / power-generated only when the battery SOC (State Of Charge) is lowered to charge the battery. And / or supply of running energy to the motor.

  For example, Patent Literature 1 and Patent Literature 2 disclose a system using both FC and a battery.

JP 2002-141073 A Japanese Patent No. 4686842

  In FC, the coarsening / elution of catalyst particles proceeds due to the potential fluctuation accompanying the large fluctuation in output, and the output performance deteriorates.

  In other words, when rapid and excessive fluctuations in the output voltage of the FC are repeated, there is a problem that the period during which the FC can maintain the expected performance is shortened.

  An object of this invention is to provide the fuel cell system which can extend the period which can maintain the expected performance of a fuel cell (FC).

  A fuel cell system according to a first aspect of the present invention is mounted on an electric vehicle including a motor that generates a driving force, a fuel cell, and a secondary battery, and the output power of the fuel cell. In the operation state in which the secondary battery is charged at the same time when the motor is operated using the output of the fuel cell, the output power of the fuel cell is calculated based on the change amount and change rate of the output voltage of the fuel cell due to the output fluctuation of the motor Control means for controlling.

In the fuel cell system of the invention set forth in claim 1, before Symbol control means it is in the operating state and the amount of change in the output voltage of the fuel cell with an output variation of the motor becomes equal to or greater than the first predetermined value In addition, the output power of the fuel cell is controlled during a period in which the change speed of the output voltage of the fuel cell accompanying the output fluctuation is equal to or higher than a second predetermined value.

In the fuel cell system of the invention set forth in claim 1, before Symbol control means, in said period, the actual state change in the output voltage is less than said first predetermined value of the fuel cell, the fuel There is a possibility that the fuel cell cannot be controlled so that at least one of the change rate of the actual output voltage of the battery is less than the second predetermined value is satisfied, and the second If the remaining amount of the next cell is a third or more default values, controls the fuel cell to rest and be so that the power output from the fuel cell.

The fuel cell system according to a second aspect of the present invention is the fuel cell system according to the first aspect , wherein the control means outputs power from the secondary battery to the motor, and is requested in accordance with output fluctuations of the motor. controlling the actual of the fuel cell amounts to so that a small change in the output voltage of the fuel cell than the amount of change in the output voltage of the fuel cell.

A fuel cell system according to a third aspect of the present invention is the fuel cell system according to the first or second aspect , wherein the control means is in a state where the actual output voltage change amount of the fuel cell is less than the first predetermined value. controlling the actual of the fuel cell so that to establish at least one is of the state change speed is lower than said second predetermined value of the output voltage of the fuel cell.

A fuel cell system according to a fourth aspect of the present invention is the fuel cell system according to any one of the first to third aspects, wherein the control means has completed the period in which the power output from the fuel cell is the pause. Thereafter, a state in which the actual output voltage change amount of the fuel cell is less than the first predetermined value, and a state in which the actual output voltage change rate of the fuel cell is less than the second predetermined value. The fuel cell is controlled to increase the power output from the fuel cell so that at least one of the above is established.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell system which can extend the period which can maintain desired performance of FC can be provided.

1 is a block diagram of an electric vehicle equipped with a fuel cell system according to an embodiment of the present invention. The figure which shows an example of the output characteristic of the fuel cell in FIG. The flowchart of the control unit with which the fuel cell system in FIG. 1 is provided. The figure which shows an example of the relationship between an accelerator opening and motor request | requirement electric power Pm. The figure which shows the relationship between the change speed of the detected value of an accelerator position sensor, and the delay time of the output of a fuel cell. The figure which shows the relationship between the variation | change_quantity of the output voltage of a fuel cell, and the surface area of platinum in a fuel cell. The figure which shows the relationship between the change speed of the output voltage of a fuel cell, and the surface area of platinum in a fuel cell. The figure which compares and represents an example of each time change of the detected value of an accelerator position sensor, the target output of a fuel cell, the correction output of a fuel cell, and the output voltage of a fuel cell. The figure showing the operation | movement area | region where deterioration of a catalyst is accelerated | stimulated especially.

  An electric vehicle equipped with a fuel cell system (hereinafter referred to as an FC system) according to an embodiment of the present invention will be described with reference to FIGS. The electric vehicle is typically an automobile.

  FIG. 1 is a block diagram of the electric vehicle 100. In FIG. 1, only some elements related to the present invention among the elements constituting the electric vehicle 100 are shown. The electric vehicle 100 appropriately includes various well-known elements included in the existing electric vehicle.

  The electric vehicle 100 includes an FC system 1, a secondary battery (hereinafter referred to as a battery) 2, an inverter 3, a motor 4, a control unit 5, an integrated control unit 6, an accelerator position sensor (hereinafter referred to as APS) 7, an AC- A DC converter 8, a power plug 9 and a diode 10 are included.

  The FC system 1 includes a fuel tank 11, a fuel cell (hereinafter referred to as FC) 12, a DC-DC converter 13, a diode 14, and a control unit 15.

  The fuel tank 11 stores hydrogen gas as fuel.

  The FC 12 generates DC power by an electrochemical reaction using hydrogen gas. As FC12, various known structures can be used as appropriate. The FC 12 typically includes a stack in which a number of cells each causing an electrochemical reaction are stacked in an electrically connected state. The output power as this stack is the output power of FC12. In the following description, the power, voltage, and current output by the FC 12 are referred to as FC power, FC voltage, and FC current, respectively.

  The DC-DC converter 13 increases or decreases the output voltage of the FC 12.

  The diode 14 prevents the backflow of current to the DC-DC converter 13.

  Under the instruction from the integrated control unit 6, the control unit 15 controls the FC 12 and the DC-DC converter 13 so that the output power of the FC system 1 becomes a required power.

  The battery 2 generates DC power by a chemical reaction and can be charged. As the battery 2, various known types can be used as appropriate, but a lithium ion battery is typically used. In the following, the power and voltage output by the battery 2 will be referred to as battery power and battery voltage, respectively.

  The inverter 3 converts DC power supplied from at least one of the FC system 1 and the battery 2 into AC power suitable for operating the motor 4.

  The motor 4 is operated by AC power supplied from the inverter 3 and generates a driving force for causing the electric vehicle 100 to travel.

  The control unit 5 controls the inverter 3 so that the motor 4 generates the required driving force instructed from the integrated control unit 6.

  The integrated control unit 6 determines the required driving force based on vehicle state information detected by various sensors such as the APS 7. The integrated control unit 6 instructs the control unit 15 to adjust the FC power and the step-up ratio with the notification of the APS value output from the APS 7. The integrated control unit 6 instructs the control unit 5 to control the inverter 3 to obtain the required driving force.

  The APS 7 detects the position of an accelerator pedal (not shown), and outputs a value representing the accelerator opening as an APS value.

  The AC-DC converter 8 converts AC power supplied from an AC commercial power supply via the power plug 9 into DC power. The DC power obtained by the AC-DC converter 8 is used for charging the battery 2.

  The diode 10 prevents reverse current flow to the AC-DC converter 8.

  Next, the operation of the electric vehicle 100 configured as described above will be described.

  The electric vehicle 100 has the following three states as traveling states in which driving force is generated by the motor 4. These three states are switched by changing the secondary voltage of the DC-DC converter 13 under the control of the control unit 15.

  In FIG. 1, Vfc_b is the output voltage of the FC 12, Vfc is the secondary voltage of the DC-DC converter 13, Vbo is the no-load voltage of the battery 2, Pfc is the output energy of the FC system 1, and Pbc is the charge of the battery 2. The electric power, Pbdc represents the output electric power Pm of the battery 2, and the motor required electric power.

(First state)
This is a state where Vfc is smaller than Vbo and Pm is smaller than the maximum value of Pbdc. In this case, Pbdc is equal to Pm, and Pfc is 0. That is, all the energy required by the motor 4 is supplied from the battery 2.

(Second state)
This is a state in which Vfc is larger than Vbo and Pm is smaller than the maximum value of Pfc. In this case, Pfc is equal to the sum of Pm and Pdc. That is, all the energy required by the motor 4 is supplied from the FC 12 and the battery 2 is charged by the energy supplied from the FC 12.

(Third state)
This is a state where Vfc is larger than Vbo and Pm is larger than the maximum value of Pfc. In this case, the sum of Pfc and Pbdc is equal to Pm. That is, the energy required by the motor 4 is supplied from both the battery 2 and the FC 12.

  That is, the electric vehicle 100 basically travels as an electric vehicle (EV) and uses the FC 12 as a range extender.

  FIG. 2 is a diagram illustrating an example of output characteristics of the FC 12.

  As shown in FIG. 2, the FC voltage decreases as the FC current (net current) increases, but the FC power (net power) increases.

  The integrated control unit 6 repeatedly determines the required driving force based on vehicle state information detected by various sensors such as the APS 7 at intervals of a predetermined unit time dt. The integrated control unit 6 instructs the control unit 15 to adjust the FC power and the step-up ratio with the notification of the APS value output from the APS 7 every time the required driving force is determined. Thus, the instruction is repeatedly performed at intervals of the unit time dt.

  When the electric vehicle is in the second state, the control unit 15 starts the process shown in FIG. 3 each time an instruction is issued from the integrated control unit 6 as described above. Note that the content of the processing described below is an example, and various processing that can obtain the same result can be used as appropriate.

  In step Sa1, the control unit 15 sets the APS value notified from the integrated control unit 6 as the value of the variable Pc. Note that the variable Pc represents the current APS value.

  In step Sa2, the control unit 15 checks whether or not the value of the variable F is zero. The variable F is a flag indicating whether or not it is in a charging suspension state described later, and its value is zero when it is not in a charging suspension state. If it is determined YES because the value of the variable F is zero, the control unit 15 proceeds to step Sa3.

  In step Sa3, the control unit 15 calculates the change amount ΔAPS of the accelerator opening and the change rate ΔAPS / dt. ΔAPS is calculated as the absolute value of the difference between the variable Pc and the value of the variable Pp updated as will be described later. The change rate ΔAPS / dt is calculated by dividing ΔAPS by the unit time dt. Note that the value of the variable Pp represents an APS value in the past by a unit time dt from the present.

  In step Sa4, the control unit 15 calculates a FC power target value (hereinafter referred to as FC target output) based on the value of the variable Pc. The FC target output is the output power of the FC 12 such that the power corresponding to the sum of the motor required power Pm and the reference value M of the charging power Pbc is obtained as the output power Pfc after being boosted by the DC-DC converter 13. Calculate as a quantity. The motor required power Pm is, for example, as shown in FIG. 4, based on the relationship between a predetermined accelerator opening and the motor required power Pm, the motor required power Pm corresponding to the accelerator opening represented by the value of the variable Pc. Is determined by obtaining The reference value M is determined in advance by a designer or the like, for example, as a constant value in consideration of the characteristics of the battery 2.

  In step Sa5, the control unit 15 estimates the change amount ΔV and change rate ΔV / dt of the FC voltage Vfc_b. The change amount ΔV is the change amount of the FC voltage per unit time when the FC 12 is operated to obtain the FC target output. The FC 12 causes a delay in the change of the FC power with respect to the control by the control unit 15. This delay changes as shown in FIG. 5, for example, according to the change speed of the APS value (acceleration opening change speed). Therefore, the control unit 15 estimates the FC voltage change amount ΔV in the period from the current time until the unit time dt elapses in consideration of this delay. Further, the change speed ΔV / dt is estimated as a value obtained by dividing the estimated change ΔV by the unit time dt.

  In step Sa6, the control unit 15 confirms whether or not the change amount ΔV is equal to or greater than the predetermined value X and the change rate ΔV / dt is equal to or greater than the predetermined value Y. The predetermined value X is predetermined by a designer or the like in consideration of the relationship between the FC voltage change amount and the Pt surface area.

  The Pt surface area is the surface area of a platinum (Pt) catalyst incorporated in FC12. The catalyst particles are coarsened / eluted due to the oxidation / reduction caused by the change in the FC voltage, so that the Pt catalyst is deteriorated and the Pt surface area is reduced. The decrease in the Pt surface area increases as the amount of change ΔV increases, and the relationship has characteristics as shown in FIG. 6, for example. Therefore, for example, the characteristics shown in FIG. 6 are obtained by a test or the like, and the predetermined value X is determined as the value of the change ΔV at which the Pt surface area becomes the allowable value AL. The allowable value AL may be arbitrarily determined by a designer or the like based on experiments, simulations, empirical rules, or the like according to a period in which the desired performance of the FC 12 is desired to be maintained. Further, the decrease in the Pt surface area increases as the change rate ΔV / dt increases, and the relationship is, for example, a characteristic as shown in FIG. Therefore, for example, the characteristic shown in FIG. 7 is obtained by a test or the like, and the predetermined value Y is determined as the value of the change rate ΔV / dt at which the Pt surface area becomes the allowable value AL.

  If it is determined NO in step Sa6 because the above condition is not satisfied, the control unit 15 proceeds to step Sa7.

  In step Sa7, the control unit 15 controls the FC 12 so that the FC target output calculated in step Sa4 is obtained.

  In step Sa8, the control unit 15 sets the value of the variable Pc as the value of the variable Pp. Thereby, when the process of FIG. 3 is executed next after the unit time dt has elapsed, the current APS value can be referred to as the past APS value.

  When step Sa8 is completed, the control unit 15 ends the process of FIG.

  By the way, if it determines with YES in said step Sa6 because said conditions are satisfied, the control unit 15 will progress to step Sa9.

  In step Sa9, the control unit 15 confirms whether or not the APS increase amount obtained by subtracting the value of the variable Pp from the value of the variable Pc is equal to or greater than the predetermined value Z. The default value Z will be described later. Then, if it is determined NO because the APS increase amount is less than the predetermined value Z, the control unit 15 proceeds to step Sa10.

  In step Sa10, the control unit 15 calculates the FC correction output. The FC correction output is FC power obtained such that ΔV or ΔV / dt is smaller than the FC target output. More preferably, the FC correction output is FC power obtained by correcting the FC target output so that ΔV is less than the predetermined value X or ΔV / dt is less than the predetermined value Y.

  In step Sa11, the control unit 15 controls the FC 12 so as to obtain an FC correction output. Thereafter, the control unit 15 ends the process of FIG. 3 through step Sa8.

  FIG. 8A shows an example of changes in the APS value.

  FIG. 8B shows an example of the FC target output corresponding to the change in the APS value shown in FIG. As shown in FIG. 8B, the FC target output is obtained by superimposing the required motor power Pm that changes in accordance with the change of the APS value on the reference value M of the charge power amount Pbc.

  The solid line in FIG. 8C shows an example of the FC correction output corresponding to the change in the APS value shown in FIG. In FIG. 8C, the FC correction output in the period PA shows the value calculated in Step Sa10 described above, and is reduced compared to the FC target output indicated by the broken line.

  In the period PA, the electric energy Pfc is smaller than the sum of the reference value M of the charging electric energy Pbc and the motor required power Pm, but the motor required power Pm is not changed. Accordingly, the charging power amount Pbc is a value obtained by subtracting the motor required power Pm from the FC correction output, and becomes smaller than the reference value M as shown by a one-dot chain line in FIG.

  That is, at this time, the control unit 15 reduces the FC power by reducing the charge power amount Pbc.

  A solid line in FIG. 8D shows an example of a change in the FC voltage when the FC 12 is controlled so as to obtain an FC correction output. In the period PA, since the FC power is reduced, the change is smaller than the FC voltage indicated by the broken line when the FC target output is set.

  By the way, when the accelerator is stepped on rapidly and in large quantities, the change amount ΔV and the change speed ΔV / dt are less than the predetermined values X and Y even if the charge power amount Pbc is zero and the power amount Pfc is only the motor required power Pm. There is a risk of not becoming.

  In a situation where the APS value increases sharply, the above situation may occur. Therefore, if the APS increase obtained by subtracting the value of the variable Pp from the value of the variable Pc is equal to or greater than the predetermined value J, if the determination is YES in Step Sa9, the control unit 15 proceeds to Step Sa12. The smaller the predetermined value J is, the higher the possibility that the change amount ΔV and the change speed ΔV / dt can be prevented from being equal to or higher than the predetermined values X and Y, but the risk that the SOC of the battery 2 will decrease increases. Therefore, the predetermined value J may be determined in advance by a designer or the like in consideration of the balance between the prevention of deterioration of the FC 12 and the stability of the SOC of the battery 2.

  In step Sa12, the control unit 15 confirms whether the SOC (State Of Charge) of the battery 2 is equal to or greater than a predetermined value K. If YES is determined here, the control unit 15 proceeds to step Sa13.

  In step Sa13, the control unit 15 sets the FC correction output to zero.

  In step Sa14, the control unit 15 sets 1 to the variable F.

  Thereafter, the control unit 15 performs Step Sa11 and Step Sa8 in the same manner as described above. Thereby, the electric energy Pfc is set to zero, and the output electric power Pbdc of the battery 2 becomes equal to the motor required electric power Pm. That is, all of the motor required power Pm is covered by the output power from the battery 2, and the charging suspension state is started. Then, the value of the variable F is set to 1 in response to the start of the charging suspension state. However, the power amount Pfc in the charging suspension state does not necessarily have to be zero, and may be in a “substantially zero” state where the power amount is extremely small.

  If the SOC of the battery 2 is not equal to or greater than the predetermined value K, the control unit 15 proceeds from step Sa12 to step Sa10, and performs step Sa10 and subsequent steps in the same manner as described above. That is, even if the APS value increases rapidly, the FC correction output calculated as described above in step Sa10 is obtained in the state where the SOC of the battery 2 has decreased to less than the predetermined value K. .

  As described above, when the process shown in FIG. 3 is started in a state where all of the motor required power Pm is covered by the output power from the battery 2, the variable F is 1, so that the control unit 15 performs step Sa2. Is NO and the process proceeds to step Sa15.

  In step Sa15, the control unit 15 checks whether or not the value of the variable Pc is less than the value of the variable Pp. That is, it is confirmed whether or not the accelerator opening is lowered. If the determination is YES because the accelerator opening is decreasing and the value of the variable Pc is less than the value of the variable Pp, the control unit 15 proceeds to step Sa16.

  In step Sa16, the control unit 15 determines a value obtained by increasing a certain amount from the FC correction output determined when the process shown in FIG. 3 was performed last time as a new FC correction output. The increment of the FC correction output here is a value at which the amount of change ΔV and the rate of change ΔV / dt due to this increase are less than the predetermined values X and Y, and is determined as a value of an integral number of the standard value M. deep. The standard value M is FC power when the output power amount Pfc is equal to the charging power amount Pbc.

  In step Sa17, the control unit 15 checks whether or not the FC correction output matches the standard value M. If it is determined YES because the FC correction output matches the standard value M, the control unit 15 proceeds to step Sa18.

  In step Sa18, the control unit 15 sets a variable F to zero. Thereafter, the control unit 15 proceeds to Step Sa11. If the determination is NO in step Sa17 because the FC correction output does not match the standard value M, the control unit 15 proceeds to step Sa11 without executing step Sa18. If NO in step Sa15 because the value of variable Pc is greater than or equal to the value of variable Pp, control unit 15 proceeds to step Sa11 without executing steps Sa16-18. Thus, after the FC correction output is set to zero in step Sa13, the FC correction output is increased to the standard value M by a certain amount as the accelerator opening decreases.

  Thereafter, the control unit 15 performs step Sa11 and subsequent steps in the same manner as described above. Thus, from the state where all the motor required power Pm is covered by the output power from the battery 2, as the accelerator opening decreases, the output power amount Pfc gradually increases to a magnitude corresponding to the charge power amount Pbc by a certain amount. It will be done. When the output power amount Pfc becomes equal to the charging power amount Pbc, the variable F becomes zero and the process returns to the second state. Thereby, the charging suspension state ends.

  In FIG. 8C, the change in the FC correction output during the period PB indicated by the solid line is set to zero in the above step Sa13 and then gradually increased by repeating step Sa16.

  In the period PB, the FC power is smaller than the reference value of the charging power amount Pbc, and all of the energy shown by the broken line is insufficient. The energy as indicated by the broken line is covered by the output power from the battery 2.

  The change in the FC voltage indicated by the solid line in FIG. 8D is smaller than the FC voltage indicated by the broken line when the FC target output is obtained because the FC power is reduced in the period PB. It has become.

As described above, according to the FC system 1, the output energy of the FC 12 for charging the battery 2 is reduced in a situation where any of the following conditions <A><B><C> is satisfied.
<A> Battery 2 is being charged.
<B> The change amount ΔV of the output voltage of the FC 12 is equal to or greater than the predetermined value X.
<C> The change rate ΔV / dt of the output voltage of the FC 12 is equal to or greater than the predetermined value Y.
As a result, in the FC system 1, the maximum value of the FC voltage change amount ΔV and the change rate ΔV / dt is reduced, and the deterioration of the catalyst mounted on the FC 12 is suppressed, and the expected performance of the FC 12 is maintained. It is possible to extend the possible period.

Further, according to the FC system 1, the output energy amount of the FC 12 for charging the battery 2 is adjusted so that the change amount ΔV and the change speed ΔV / dt do not exceed the predetermined values X and Y. The expected performance of FC12 can be maintained, and energy for charging battery 2 can be supplied to the maximum extent possible. According to FC system 1, the above conditions <A><B><C> In addition, in the situation where the following condition <D> is satisfied, there is a possibility that the change amount ΔV and the change speed ΔV / dt cannot be less than the predetermined values X and Y.
<D> The amount of increase in the accelerator opening per unit time is equal to or greater than a specified amount (ΔAPS is equal to or greater than a specified value J).
Therefore, the FC power is set to zero on condition that the following condition <E> is further satisfied.
<E> The SOC is not less than the specified value K.
Thus, it is possible to reliably prevent the change amount ΔV and the change speed ΔV / dt from exceeding the predetermined values X and Y. It should be noted that the amount of increase in the accelerator opening per unit time exceeds the specified amount in the case of rapid acceleration, its duration is short, and the frequency of occurrence of such situations is also common in general driving situations Few. For this reason, if the SOC is equal to or greater than the predetermined value K, it is possible to cover all of the motor required power Pm with the output power from the battery 2.

  If the FC power is suddenly increased when releasing the state where all of the motor required power Pm is covered by the output power from the battery 2, the change amount ΔV and the change speed ΔV / dt may become equal to or greater than the predetermined values X and Y. is there. However, according to the FC system 1, the FC power is increased by increasing a certain amount every unit time dt, that is, by so-called tailing. As a result, the change amount Δ and the change rate ΔV / dt do not become equal to or greater than the predetermined values X and Y, and the catalyst can be prevented from being deteriorated due to the increase in FC power at this time.

  As described above, according to the FC system 1, the FC12 operates so that the output voltage does not change in a region where the deterioration of the catalyst as shown in FIG. 9 is particularly accelerated, and the performance of the FC12 is maintained. it can.

  In general, the initial catalyst amount or the electrode area × the number of stacked layers in the FC 12 is set so that the target performance can be maintained under the assumed use condition / period. If the deterioration of the catalyst due to the output fluctuation can be suppressed as in the FC system 1, the initial catalyst amount or the electrode area × the number of stacked layers can be reduced, which leads to cost reduction while maintaining the performance.

  This embodiment can be variously modified as follows.

  If the FC correction output is smaller than the FC target output by ΔV or ΔV / dt, the deterioration of the catalyst when the FC correction output is FC power is reduced compared to the case where the FC target output is FC power. be able to. Therefore, the FC correction output does not have to be a small value until ΔV becomes less than the predetermined value X or ΔV / dt becomes less than the predetermined value Y.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above. Furthermore, you may combine the component covering different embodiment suitably.
The invention described in the scope of claims at the beginning of the filing of the present application will be appended.
[1]
A fuel cell system mounted on an electric vehicle including a motor that generates a driving force, a fuel cell, and a secondary battery, wherein the motor is operated using output power of the fuel cell and the second And a control means for controlling the output power of the fuel cell based on a change amount and a change speed of the output voltage of the fuel cell in accordance with an output fluctuation of the motor in an operation state in which the secondary battery is charged. Fuel cell system.
[2]
The control means has a change amount of the output voltage of the fuel cell that is equal to or greater than a first predetermined value in the operating state and that accompanies the output fluctuation of the motor, and a change in the output voltage of the fuel cell that accompanies the output fluctuation. The fuel cell system according to [1], wherein the output power of the fuel cell is controlled during a period when the speed is equal to or higher than a second predetermined value.
[3]
The control means outputs electric power from the secondary battery to the motor, and the change in the actual output voltage of the fuel cell is more than the amount of change in the output voltage of the fuel cell required in accordance with the output fluctuation of the motor. The fuel cell system according to [2], wherein the fuel cell is controlled so as to reduce the amount.
[4]
The control means includes a state in which the change amount of the actual output voltage of the fuel cell is less than the first predetermined value, and a change speed of the actual output voltage of the fuel cell is less than the second predetermined value. The fuel cell system according to [2] or [3], wherein the fuel cell is controlled so that at least one of the states is established.
[5]
In the period, the control means has a state in which the change amount of the actual output voltage of the fuel cell is less than the first predetermined value, and the change rate of the actual output voltage of the fuel cell is the second predetermined value. When it is possible that the fuel cell cannot be controlled so that at least one of a state of less than the value is satisfied and the remaining amount of the secondary battery is equal to or greater than a third predetermined value The fuel cell system according to any one of [2] to [4], wherein the fuel cell is controlled to stop power output from the fuel cell.
[6]
The control means has a state in which the change amount of the actual output voltage of the fuel cell becomes less than the first predetermined value after the period when the power output from the fuel cell is stopped is completed. The fuel cell so as to increase the power output from the fuel cell so that at least one of the change rate of the actual output voltage of the fuel cell is less than the second predetermined value is established. The fuel cell system according to [5], wherein the fuel cell system is controlled.

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell (FC) system, 2 ... Secondary battery (battery), 3 ... Inverter, 4 ... Motor, 5 ... Control unit, 6 ... Integrated control unit, 7 ... Accelerator position sensor (APS), 11 ... Fuel tank DESCRIPTION OF SYMBOLS 12 ... Fuel cell (FC), 13 ... DC-DC converter, 14 ... Diode, 15 ... Control unit, 100 ... Electric vehicle.

Claims (4)

A motor that generates driving force;
A fuel cell;
A fuel cell system mounted on an electric vehicle equipped with a secondary battery,
In an operation state in which the motor is operated using the output power of the fuel cell and the secondary battery is charged at the same time, based on the change amount and the change speed of the output voltage of the fuel cell due to the output fluctuation of the motor. Control means for controlling the output power of the fuel cell ,
The control means includes
In the operating state, the amount of change in the output voltage of the fuel cell due to the output fluctuation of the motor is equal to or greater than a first predetermined value, and the rate of change in the output voltage of the fuel cell due to the output fluctuation is a second value. Controlling the output power of the fuel cell during a period exceeding the predetermined value;
A state in which the amount of change in the actual output voltage of the fuel cell is less than the first predetermined value and a state in which the change rate of the actual output voltage of the fuel cell is less than the second predetermined value during the period If the fuel cell may not be controlled so that at least one of the above is established, and the remaining amount of the secondary battery is greater than or equal to a third predetermined value, the fuel A fuel cell system , wherein the fuel cell is controlled to stop power output from the battery. The control means outputs electric power from the secondary battery to the motor, and the change in the actual output voltage of the fuel cell is more than the amount of change in the output voltage of the fuel cell required in accordance with the output fluctuation of the motor. the fuel cell system according to claim 1, wherein the controller controls the fuel cell so that the amount is reduced. The control means includes a state in which the change amount of the actual output voltage of the fuel cell is less than the first predetermined value, and a change speed of the actual output voltage of the fuel cell is less than the second predetermined value. the fuel cell system according to claim 1 or 2, characterized in that at least one of the state to control the fuel cell to stand. The control means has a state in which the change amount of the actual output voltage of the fuel cell becomes less than the first predetermined value after the period when the power output from the fuel cell is stopped is completed. The fuel cell so as to increase the power output from the fuel cell so that at least one of the change rate of the actual output voltage of the fuel cell is less than the second predetermined value is established. The fuel cell system according to any one of claims 1 to 3, wherein the fuel cell system is controlled.

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