JP6161338B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system that performs voltage fixing and variable current control for making the output current of a fuel cell variable by fixing the output voltage of the fuel cell and adjusting the supply amount of a reaction gas.

  Patent Document 1 discloses four types of control as fuel cell output control, that is, first and second normal modes for normal time and first and second idle power generation suppression modes for idle power generation suppression mode. (FIGS. 11 and 12).

  Among these controls, the first idle power generation suppression mode is mainly used when the battery 22 needs to be charged in the idle power generation suppression mode, and the target cell voltage Vcelltgt (= target FC voltage Vfctgt / number of cells) is set. In this control, the potential is fixed at a potential outside the redox region R3 and the FC current Ifc is kept constant ([0115]).

  The second idle power generation suppression mode is mainly used when the battery 22 does not need to be charged in the idle power generation suppression mode, and the target cell voltage Vcelltgt (= target FC voltage Vfctgt / number of cells) is In this control, the FC current Ifc is made variable by fixing the potential to the oxidation-reduction region R3 or higher and making the target oxygen concentration Cotgt variable ([0118]).

  Note that the idle power generation suppression mode described above means that the FC 16 actively stops power generation when the main switch 158 is on, and the active power generation refers to the FC 16 performed based on a command from the ECU 32. It is said that power generation by residual gas is not included ([0082]).

  In addition, the target cell voltage Vcelltgt in the first and second idle power generation suppression modes may be set so that the cell voltage Vcell becomes a value in the reduction region R2 or the oxidation region R4 ([0164]). .

JP 2012-252998 A

  As described above, in Patent Document 1, the target cell voltage Vcelltgt in a state where active power generation by the fuel cell is stopped (in the first and second idle power generation suppression modes) is the cell voltage Vcell in the reduction region R2 or the oxidation region. It should be set so as to be a value within R4. That is, the target voltage is set in consideration of deterioration of the fuel cell or its cell. For this reason, Patent Document 1 does not focus on the energy efficiency of the vehicle or the entire fuel cell system.

  For example, when the output voltage of the fuel cell is transformed by a DC / DC converter and supplied to the auxiliary machine, when the difference between the output voltage of the fuel cell and the target input voltage to the auxiliary machine is large during idling, It is conceivable that the power loss in the DC / DC converter increases. However, Patent Literature 1 does not consider such a point.

  The above talk is not limited to fuel cell vehicles, nor is it limited to idling.

  The present invention has been made in consideration of the above-described problems, and an object thereof is to provide a fuel cell system capable of improving the overall energy efficiency.

A fuel cell system according to the present invention includes:
A first load that is a traveling motor;
A fuel cell for supplying power to the first load;
A gas supply device for supplying a reaction gas to the fuel cell;
A power storage device connected in parallel with the fuel cell to supply power to the first load;
A first voltage converter disposed between the first load and the power storage device;
A second load which is an auxiliary machine connected between the first load and the fuel cell or between the first load and the power storage device via a second voltage converter;
A fuel cell vehicle comprising: the gas supply device; the control device for controlling the first voltage conversion device and the second voltage conversion device;
The controller is
When the power consumption of the second load is greater than the power consumption of the first load,
By adjusting the input voltage to the second voltage conversion device by the first voltage conversion device, the input voltage to the second voltage conversion device is a constant value that makes voltage conversion in the second voltage conversion device unnecessary. Or a first energy efficiency improvement value that is a constant value that suppresses the transformation rate in the second voltage converter,
A total value of required powers of the first load and the second load while the input voltage to the second voltage converter is maintained at the first energy efficiency improvement value which is a constant value by the first voltage converter. The supply amount of the reaction gas is adjusted by the gas supply device so as to follow the above.

  According to the present invention, when the power consumption of the second load, which is an auxiliary machine, is larger than the power consumption of the first load, which is a traveling motor, the second voltage conversion device (the voltage conversion device on the second load side) is supplied. The input voltage is adjusted to eliminate the need for voltage conversion in the second voltage converter or suppress the transformation rate in the second voltage converter. Thereby, it becomes possible to reduce the loss of a 2nd voltage converter. At this time, even if adjustment to the input voltage to the second voltage converter is performed, desired power is supplied to the first load and the second load by adjusting the supply power from the fuel cell with the supply amount of the reaction gas. Supply can be performed.

A fuel cell system according to the present invention includes:
A first load;
A fuel cell for supplying power to the first load;
A gas supply device for supplying a reaction gas to the fuel cell;
A power storage device connected in parallel with the fuel cell to supply power to the first load;
A first voltage converter disposed between the first load and the power storage device;
A second load connected between the first load and the fuel cell or between the first load and the power storage device;
Arranged on the wiring connecting the second load and the wiring between the first load and the fuel cell or between the first load and the power storage device, or on the wiring between the first load and the fuel cell A second voltage converter arranged in
A control device for controlling the gas supply device, the first voltage conversion device, and the second voltage conversion device;
The controller is
When the power consumption of the second load is greater than the power consumption of the first load,
The input voltage to the second voltage converter is adjusted to the second voltage converter by adjusting the input voltage to the second voltage converter by at least one of the first voltage converter and the second voltage converter. A constant value that eliminates the need for voltage conversion in the device or a first energy efficiency improvement value that is a constant value that suppresses the transformation rate in the second voltage conversion device;
A total value of required powers of the first load and the second load while the input voltage to the second voltage converter is maintained at the first energy efficiency improvement value which is a constant value by the first voltage converter. The supply amount of the reaction gas is adjusted by the gas supply device so as to follow the above.

  According to the present invention, when the power consumption of the second load is larger than the power consumption of the first load, voltage conversion in the second voltage conversion device is not required or the transformation rate in the second voltage conversion device is suppressed. The input voltage to the second voltage converter is adjusted. Thereby, it becomes possible to reduce the loss of a 2nd voltage converter. At this time, even if adjustment to the input voltage to the second voltage converter is performed, desired power is supplied to the first load and the second load by adjusting the supply power from the fuel cell with the supply amount of the reaction gas. Supply can be performed.

  When the power consumption of the second load is larger than the power consumption of the first load, the control device oxidizes the input voltage to the second voltage conversion device by the cell voltage of each cell constituting the fuel cell. A value that falls outside the reduction potential range may be set. Thereby, it is possible to suppress the deterioration of the fuel cell while reducing the loss of the second voltage conversion device.

  When the power consumption of the second load is larger than the power consumption of the first load, the fuel cell vehicle may be idle. Thereby, it becomes possible to improve the energy efficiency at the time of idling of the fuel cell vehicle.

  The fuel cell system includes a third load that is an auxiliary machine connected between the first load and the fuel cell or between the first load and the power storage device, and the control device includes the third load. When the power consumption is larger than the power consumption of the first load and the second load, the input voltage to the third load is adjusted by adjusting the input voltage to the third load by the first voltage converter. To a second energy efficiency improvement value that is a value that makes voltage conversion unnecessary in the first voltage conversion device or a value that suppresses the transformation rate in the first voltage conversion device, and the first load, the second The supply amount of the reaction gas may be adjusted by the gas supply device so as to follow the total value of the required power of the load and the third load.

  According to the above, when the power consumption of the third load is larger than the power consumption of the first load and the second load, the voltage conversion in the first voltage converter is not required or the transformation rate in the first voltage converter is suppressed. The input voltage to the third load is adjusted as follows. Thereby, it becomes possible to reduce the loss of a 1st voltage converter. At this time, even if adjustment to the input voltage to the third load is performed, desired power is supplied to the first to third loads by adjusting the supply power from the fuel cell with the supply amount of the reaction gas. It becomes possible.

  According to the present invention, it is possible to improve the energy efficiency of the entire fuel cell system.

1 is a schematic overall configuration diagram of a fuel cell vehicle as a fuel cell system according to a first embodiment of the present invention. It is a basic flowchart regarding the output control of the fuel cell stack in the first embodiment. It is a flowchart which sets the target FC voltage in the 2nd mode (CVVC control) of 1st Embodiment. It is a figure which shows the example of the time chart at the time of using the various control which concerns on 1st Embodiment. It is a schematic whole block diagram of the fuel cell vehicle as a fuel cell system concerning a 2nd embodiment of the present invention. It is a flowchart which sets a target FC voltage in the 2nd mode (CVVC control) of 2nd Embodiment. It is a figure which shows the example of the time chart at the time of using the various control which concerns on 2nd Embodiment. It is a schematic whole block diagram of the fuel cell vehicle as a fuel cell system which concerns on 3rd Embodiment of this invention. It is a flowchart which sets a target FC voltage in the 2nd mode (CVVC control) of 3rd Embodiment.

A. First Embodiment 1. FIG. Explanation of overall configuration [1-1. overall structure]
FIG. 1 is a schematic overall configuration diagram of a fuel cell vehicle 10 (hereinafter referred to as “FC vehicle 10” or “vehicle 10”) as a fuel cell system according to a first embodiment of the present invention. As shown in FIG. 1, the FC vehicle 10 includes a travel motor 12, an inverter 14, a fuel cell stack 16, a gas supply device 18 including an air pump 20, a high-voltage battery 22 (power storage device), and a battery-side voltage. It has a control device 24, an air conditioner 26, a 12V system 28, an air pump side voltage control device 30, and an electronic control device 32.

  For ease of understanding, the traveling motor 12 is also referred to as “motor 12”, the fuel cell stack 16 is referred to as “FC stack 16” or “FC16”, and the air pump 20 is also referred to as “A / P20”. The high voltage battery 22 is also referred to as “battery 22”, the battery side voltage control device 24 is referred to as “BAT-VCU 24”, and the air conditioner 26 is also referred to as “A / C 26”. Further, the air pump side voltage control device 30 is referred to as “A / P-VCU 30”, and the electronic control device 32 is referred to as “ECU 32”.

[1-2. Drive system]
The motor 12 generates a driving force based on the electric power supplied from the FC 16 and the battery 22, and rotates a wheel (not shown) through a transmission (not shown) by the driving force. Further, the motor 12 outputs electric power (regenerative power Preg) [W] generated by performing regeneration to the battery 22 or the like.

  The inverter 14 is configured as a three-phase bridge type, performs DC / AC conversion, converts DC to three-phase AC and supplies it to the motor 12, and supplies the DC after AC / DC conversion accompanying the regenerative operation. Supply to the battery 22 and the like.

[1-3. FC system]
(1-3-1. FC stack 16)
The FC stack 16 has, for example, a structure in which fuel cell cells (hereinafter referred to as “FC cells”) formed by sandwiching a solid polymer electrolyte membrane from both sides between an anode electrode and a cathode electrode are stacked.

(1-3-2. Gas supply device 18)
The gas supply device 18 supplies a reaction gas to the FC stack 16. The gas supply device 18 includes an anode system that supplies and discharges hydrogen (fuel gas) to and from the anode of the FC stack 16, and a cathode system that supplies and discharges air (oxidant gas) containing oxygen to the cathode of the FC stack 16. And a cooling system for cooling the FC stack 16.

  The air pump 20 is included in the cathode system, compresses outside air (air) and sends it to the cathode side, and its intake port communicates with the outside of the vehicle (outside) via a pipe (not shown). As shown in FIG. 1, the A / P 20 is connected to the wiring 100 between the FC 16 and the inverter 14 via the A / P-VCU 30.

  As a specific configuration of the gas supply device 18, for example, the one described in Patent Document 1 (see FIG. 3 in Patent Document 1) can be used.

[1-4. High voltage battery 22]
The battery 22 is a power storage device (energy storage) including a plurality of battery cells. For example, a lithium ion secondary battery, a nickel hydride secondary battery, or a capacitor can be used. In this embodiment, a lithium ion secondary battery is used.

[1-5. BAT-VCU24]
The BAT-VCU 24 includes power from the FC 16 (hereinafter referred to as “FC power Pfc” or “FC generated power Pfc”), power from the battery 22 (hereinafter referred to as “battery power Pbat”) [W], and the motor 12. The supply destination with regenerative power Preg from is controlled.

  The BAT-VCU 24 is a voltage converter that performs step-up / step-down on both sides. That is, the voltage (primary voltage V1) [V] on the battery 22 side (hereinafter referred to as “primary side”) is changed to the voltage (secondary voltage V2) [V] on the motor 12 side (hereinafter referred to as “secondary side”). And the secondary voltage V2 is stepped up and down to the primary voltage V1. Depending on the required specifications, the BAT-VCU 24 may not be a voltage converter that performs step-up / step-down on both sides.

[1-6. Air conditioner 26]
The A / C 26 adjusts the temperature in the passenger compartment of the vehicle 10. As shown in FIG. 1, the A / C 26 is connected in parallel to the 12V system 28 with respect to the wiring 102 between the battery 22 and the BAT-VCU 24.

[1-7.12V system 28]
The 12V system 28 is a system including equipment that operates at a relatively low voltage. For example, the 12V system 28 includes a 12V battery, accessories (audio equipment, navigation device, etc.), ECU 32, and the like. As shown in FIG. 1, the 12V system 28 is connected in parallel with the A / C 26 to the wiring 102 between the battery 22 and the BAT-VCU 24.

  The 12V system 28 uses a step-down voltage converter (not shown) when receiving the output voltage of the battery 22 (hereinafter referred to as “battery voltage Vbat”) or the like. For ease of understanding, the first embodiment does not consider the influence of the voltage converter.

[1-8. A / P-VCU30]
The A / P-VCU 30 is a voltage converter that performs step-up / step-down from the input side (FC16, BAT-VCU24 side) to the output side (A / P20 side). As shown in FIG. 1, the A / P-VCU 30 is connected to the wiring 100 between the FC 16 and the inverter 14. Depending on the required specifications, the A / P-VCU 30 may be a voltage conversion device that performs only step-up or step-down from the input side toward the output side.

[1-9. ECU32]
The ECU 32 is connected to the motor 12, the inverter 14, the FC 16, the gas supply device 18 (including the air pump 20), the battery 22, the BAT-VCU 24, the air conditioner 26, and the 12V system 28 via the communication line 104 (FIG. 1 and the like). And the AP-VCU 30 is controlled. In the control, a program stored in a memory (ROM) is executed, and detection values of various sensors (not shown) are used.

  The ECU 32 includes a microcomputer and has an input / output interface such as a timer, an A / D converter, and a D / A converter as necessary. Note that the ECU 32 can be composed of a plurality of ECUs for each part, instead of only one ECU.

2. Control of First Embodiment Next, control in the ECU 32, particularly output control of the FC stack 16 will be described.

[2-1. Basic control]
FIG. 2 shows a basic flowchart relating to output control of the FC stack 16 in the first embodiment. In step S1, the ECU 32 determines whether or not the FC vehicle 10 (FC system) is in a low load state. Specifically, it is determined whether the required load (system required load Psys_req) of the entire FC vehicle 10 (FC system) is below a threshold value (low load determination threshold value) for determining a low load. The system required load Psys_req is calculated in the same manner as in Patent Document 1 (see FIG. 6 in Patent Document 1).

  When the vehicle 10 is not in a low load state (S1: NO), the ECU 32 executes the first mode in step S2. The first mode is variable voltage / current variable control in which both the output voltage of FC 16 (hereinafter referred to as “FC voltage Vfc”) and the output current (hereinafter referred to as “FC current Ifc”) are variable. The first mode is mainly used when the system required load Psys_req is relatively high, and the target of the FC voltage Vfc is maintained in a state where the target gas concentration is fixed (or the reaction gas is maintained in a rich state). The FC current Ifc is controlled by adjusting a value (hereinafter referred to as “target FC voltage Vfc_tar”).

  When the vehicle 10 is in a low load state (S1: YES), in step S3, the ECU 32 performs the second mode. The second mode is constant voltage and variable current (CVVC) control in which the FC current Ifc is variable while the FC voltage Vfc is fixed. The second mode is mainly used when the system required load Psys_req is relatively low. The FC current Ifc is made variable by fixing the target FC voltage Vfc_tar and making the target gas concentration variable. .

  Accordingly, the ECU 32 in the second mode supplies desired power to the first load and the second load by adjusting the amount of reaction gas supplied from the FC 16 (FC power Pfc). A method of setting the target FC voltage Vfc_tar in the second mode will be described later with reference to FIG.

[2-2. Setting of target FC voltage Vfc_tar in the second mode]
FIG. 3 is a flowchart for setting the target FC voltage Vfc_tar in the second mode of the first embodiment. In step S11, the ECU 32 determines whether or not the vehicle 10 (FC system) is idle. The idle state means that the FC 16 actively stops power generation when the main switch (not shown) of the vehicle 10 is on. The positive power generation refers to power generation of the FC 16 based on a command from the ECU 32, and does not include power generation using residual gas.

  For example, when the load of the motor 12 falls below a predetermined threshold value (idle determination motor load threshold value), it is determined as an idle state. Alternatively, when the vehicle speed V [km / h] of the vehicle 10 is lower than a predetermined threshold (idle determination vehicle speed threshold), it may be determined that the vehicle is in an idle state. In the first embodiment, when the vehicle 10 is in an idle state, the power consumption Pmot of the motor 12 is smaller than the power consumption Pap of the air pump 20. Therefore, the idle state may be determined by comparing the power consumption Pmot of the motor 12 with the A / P power consumption Pap (hereinafter also referred to as “A / P power consumption Pap”).

  When the vehicle 10 is idling (S11: YES), in step S12, the ECU 32 uses the power consumption of the air conditioner 26 (hereinafter also referred to as “A / C power consumption Pac”) and the power consumption of the 12V system 28 ( Hereinafter, it is determined whether or not the total Pac + P12v of “12V system power consumption P12v” exceeds the power consumption Pap of the air pump 20.

  Such a determination is made because the A / P 20 as an auxiliary machine is connected to the wiring 100 between the FC 16 and the inverter 14, whereas the air conditioner 26 and the 12V system as an auxiliary machine are connected. 28 is connected to the wiring 102 between the battery 22 and the BAT-VCU 24.

  For example, in the first embodiment, the voltage in the entire system is controlled in consideration of the power loss (conversion loss) of each VCU 24, 30. For this reason, the power consumption Pap of the air pump 20 paired with the A / P-VCU 30 is a comparison object alone. Further, since the air conditioner 26 and the 12V system 28 are associated with the BAT-VCU 24 (or are in a position to receive power supply from the battery 22 without going through each VCU), the power consumption P12v and Pac of both of them are combined. Compare.

  When the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v exceeds the A / P power consumption Pap in step S12 of FIG. 3 (S12: YES), the ECU 32 outputs the output voltage of the battery 22 in step S13. It is determined whether (battery voltage Vbat) is a value outside the redox region.

  The redox region is a voltage range in which the cell voltage of each cell constituting the FC stack 16 is within the range of the redox potential. Details of the range of the oxidation-reduction potential are described in Patent Document 1 (see FIGS. 9 and 10 of Patent Document 1 and related descriptions thereof).

  When the battery voltage Vbat is a value outside the oxidation-reduction region (S13: YES), from the viewpoint of the FC voltage Vfc or the cell voltage, it is in a state where deterioration of the FC16 can be suppressed. Therefore, in step S14, the ECU 32 sets the battery voltage Vbat as the target FC voltage Vfc_tar.

  Accordingly, the ECU 32 stops the transformation operation of the BAT-VCU 24, and makes the secondary voltage V2 (the voltage on the FC16 side with respect to the BAT-VCU 24) equal to the battery voltage Vbat (direct connection process). That is, the FC current Ifc is determined according to the FC voltage Vfc due to the characteristics of the FC16. For this reason, when the BAT-VCU 24 electrically connects the primary side and the secondary side without performing voltage conversion, the FC voltage Vfc follows the secondary voltage V2. Accordingly, since the BAT-VCU 24 does not perform voltage conversion, the secondary voltage V2 and the FC voltage Vfc become substantially equal to the battery voltage Vbat.

  For the A / P-VCU 30, the secondary voltage V2 (≈battery voltage Vbat) is transformed so as to be equal to the target input voltage Vap_tar of the A / P20. Therefore, the air pump 20 can be operated by the battery power Pbat or the FC power Pfc.

  On the other hand, when the battery voltage Vbat is not a value outside the redox region (S13: NO), from the viewpoint of the FC voltage Vfc or the cell voltage, the deterioration of the FC16 is likely to proceed. Therefore, in step S15, the ECU 32 sets a value outside the redox region (for example, 0.9 V × number of cells) as the target FC voltage Vfc_tar.

  After setting the value outside the redox region as the target FC voltage Vfc_tar, the ECU 32 operates the BAT-VCU 24 to transform the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. That is, the FC current Ifc is determined according to the FC voltage Vfc due to the characteristics of the FC16. Therefore, the ECU 32 sets the transformation rate of the BAT-VCU 24 so that the secondary voltage V2 after the BAT-VCU 24 transforms the battery voltage Vbat becomes the target FC voltage Vfc_tar. Further, the A / P-VCU 30 is transformed so that the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24 transformation rate) is equal to the target input voltage Vap_tar of the A / P20.

  Returning to S12 of FIG. 3, when the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v does not exceed the A / P power consumption Pap (S12: NO), in step S16, the ECU 32 causes the air pump 20 to It is determined whether or not the required input voltage (hereinafter referred to as “A / P required voltage Vap_req”) is a value outside the redox region.

  When the A / P required voltage Vap_req is a value outside the redox region (S16: YES), from the viewpoint of the FC voltage Vfc or the cell voltage, it is in a state in which the deterioration of the FC16 can be suppressed. Therefore, in step S17, the ECU 32 sets the A / P request voltage Vap_req as the target FC voltage Vfc_tar.

  Accordingly, the ECU 32 operates the BAT-VCU 24 to transform the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. As described above, the FC current Ifc is determined according to the FC voltage Vfc due to the characteristics of the FC16. Therefore, the ECU 32 sets the transformation rate of the BAT-VCU 24 so that the secondary voltage V2 after the BAT-VCU 24 transforms the battery voltage Vbat becomes the target FC voltage Vfc_tar.

  Further, for the A / P-VCU 30, since the secondary voltage V2 that is the input voltage to the A / P-VCU 30 is the A / P required voltage Vap_req, there is no need for voltage transformation in the A / P-VCU 30. . Therefore, the ECU 32 instructs the A / P-VCU 30 to perform processing (direct connection processing) for connecting the input side (FC16 and battery 22 side) and the output side (air pump 20 side) without performing voltage conversion. As a result, the air pump 20 can be operated by the battery power Pbat or the FC power Pfc.

  On the other hand, when the A / P required voltage Vap_req is not a value outside the redox region (S16: NO), from the viewpoint of the FC voltage Vfc or the cell voltage, the deterioration of the FC16 is likely to proceed. Therefore, in step S18, the ECU 32 sets a value outside the redox region as the target FC voltage Vfc_tar, similarly to step S15.

  When the difference between the total Pap + Pac + P12v that can be obtained when the total Pac + P12v is larger than the A / P power consumption Pap and the value of the total Pap + Pac + P12v that can be taken when the total Pac + P12v does not exceed the A / P power consumption Pap is clear. The values of the target FC voltage Vfc_tar in steps S15 and S18 may be different.

  The processing after setting a value outside the redox region as the target FC voltage Vfc_tar in step S18 is the same as that in step S15.

  Returning to step S11, when the vehicle 10 is not idling (S11: NO), in step S19, the ECU 32 is a value outside the redox region and the FC power Pfc is increased (for example, 0.8V × number of cells). ) Is set as the target FC voltage Vfc_tar.

  Accordingly, the ECU 32 operates the BAT-VCU 24 to transform the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. Specifically, the ECU 32 sets the transformation rate of the BAT-VCU 24 so that the secondary voltage V2 after the BAT-VCU 24 transforms the battery voltage Vbat becomes the target FC voltage Vfc_tar. Further, the A / P-VCU 30 is transformed so that the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24 transformation rate) is equal to the target input voltage Vap_tar of the A / P20.

[2-3. Examples of various controls]
FIG. 4 shows an example of a time chart when various controls according to the first embodiment are used. The FC generated power Pfc in FIG. 4 indicates only the power consumption of the auxiliary machine, that is, those corresponding to the A / C power consumption Pac, the 12V system power consumption P12v, and the A / P power consumption Pap. Those corresponding to the power Pmot are not included. Further, the VCU total loss Ltotal in FIG. 4 is a total of power loss (conversion loss) of the BAT-VCU 24 and the A / P-VCU 30.

  Further, in FIG. 4, the solid line of the VCU total loss Ltotal corresponds to the control according to the first embodiment, and the broken line corresponds to the control according to the comparative example. The control according to the comparative example is, for example, the control disclosed in Patent Document 1.

  Until the time point t1, the vehicle is in a low load state (S1: YES in FIG. 2) and is not in an idle state (S11: NO in FIG. 3). Therefore, the ECU 32 sets a value (for example, 0.8 V × number of cells) that is outside the redox region and increases the FC power Pfc as the target FC voltage Vfc_tar (S19).

  At time t1, the vehicle 10 enters an idle state (S11: YES in FIG. 3), and the output (drive amount) of the air pump 20 increases. As the vehicle 10 enters the idle state, the ECU 32 compares the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v with the A / P power consumption Pap (S12). At time t1, the total Pac + P12v is larger than the A / P power consumption Pap (S12: YES), and the battery voltage Vbat is a value outside the redox region (S13: YES). Therefore, the ECU 32 sets the battery voltage Vbat as the target FC voltage Vfc_tar (S14).

  As a result, the VCU total loss Ltotal is reduced in the control according to the first embodiment as compared with the comparative example.

  At time t2, the output (drive amount) of the air pump 20 further increases. Accordingly, the FC power Pfc increases as the A / P power consumption Pap and the system required load Psys_req increase. At time t2, the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v is smaller than the A / P power consumption Pap (S12: NO). In addition, the A / P request voltage Vap_req is a value outside the redox region (S16: YES). Therefore, the ECU 32 sets the A / P request voltage Vap_req as the target FC voltage Vfc_tar (S17).

3. Effects of First Embodiment As described above, according to the first embodiment, the vehicle 10 is idle (S11 in FIG. 3: YES), and the power consumption of the air pump 20 (second load) that is an auxiliary machine. When Pap is larger than the power consumption Pmot of the traveling motor 12 (first load), the secondary voltage V2 that is the input voltage to the A / P-VCU 30 (second voltage converter) is adjusted to obtain A / P -The voltage conversion in VCU30 is made unnecessary (S17), or the transformation rate in A / P-VCU30 is suppressed (S18). Thereby, it becomes possible to reduce the loss of A / P-VCU30. At this time, even if adjustment to the input voltage (secondary voltage V2) to the A / P-VCU 30 is performed, the motor 12 can be obtained by adjusting the supply power (FC generated power Pfc) from the FC 16 with the supply amount of the reaction gas. In addition, it is possible to supply desired power to the air pump 20.

  Similarly, according to the first embodiment, the vehicle 10 is idle (S11 in FIG. 3: YES), and the 12V system 28 (third load) and the air conditioner 26 (third load), which are auxiliary machines, are used. When the total power consumption P12v + Pac of the power consumption P12v and Pac is larger than the power consumption Pmot of the travel motor 12 (first load) and the power consumption Pap of the air pump 20 (second load) (S12: YES), BAT-VCU24 (first The voltage conversion device) adjusts the input voltage to the air conditioner 26 (hereinafter referred to as “Vac_in”) and the input voltage to the 12V system 28 (hereinafter referred to as “V12v_in”) to be the battery voltage Vbat. Thereby, the input voltages Vac_in and V12v_in to the air conditioner 26 and the 12V system 28 are set to values (S14) that do not require voltage conversion in the BAT-VCU 24 or values (S15) that suppress the transformation rate in the BAT-VCU 24. . Thereby, it becomes possible to reduce the loss of BAT-VCU24. At this time, even if the input voltages Vac_in and V12v_in are adjusted as described above, the supply power from the FC 16 (FC generated power Pfc) is adjusted to adjust the supply amount of the reaction gas, so that the motor 12, the air pump 20, the air conditioner It becomes possible to supply desired power to the shoner 26 and the 12V system 28.

  According to the first embodiment, the vehicle 10 is idle (S11 in FIG. 3: YES), and the power consumption Pap of the air pump 20 (second load) that is an auxiliary machine is equal to that of the travel motor 12 (first load). When larger than the power consumption Pmot, the ECU 32 (control device) sets the input voltage Vap_in to the A / P 20 and A / P-VCU 30 to a value outside the redox region (the cell voltage of each cell constituting the FC stack 16 is The value is set to a value outside the oxidation-reduction potential range (S16 to S18 in FIG. 3). Thereby, it is possible to suppress the deterioration of the FC 16 while reducing the loss of the A / P-VCU 30.

  In 1st Embodiment, the process of FIG.3 S12-S18 is implemented at the time of idling of the FC vehicle 10 (S11: YES). Thereby, the energy efficiency at the time of idling of the FC vehicle 10 can be improved.

B. Second Embodiment 1. FIG. Description of overall configuration (difference from the first embodiment)
[1-1. overall structure]
FIG. 5 is a schematic overall configuration diagram of a fuel cell vehicle 10A (hereinafter referred to as “FC vehicle 10A” or “vehicle 10A”) as a fuel cell system according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment, the air conditioner 26 and the 12V system 28 are connected between the battery 22 and the BAT-VCU 24 (see FIG. 1). On the other hand, in 2nd Embodiment, the air conditioner 26 and 12V type | system | group 28 are connected between the motor 12 (inverter 14) or FC16, and BAT-VCU24 (refer FIG. 5).

  Accordingly, an air conditioner side voltage control device 34 (hereinafter also referred to as “A / C-VCU 34”) is disposed in front of the air conditioner 26, and a 12V system side voltage is disposed in front of the 12V system 28. A control device 36 (hereinafter also referred to as “12V system-VCU 36”) is arranged.

[1-2. A / C-VCU34]
The A / C-VCU 34 is a voltage converter that performs step-up / step-down from the input side (FC16, BAT-VCU24 side) to the output side (A / C26 side). As shown in FIG. 5, the A / C-VCU 34 is connected to the motor 100 (inverter 14) or the wiring 100 between the FC 16 and the BAT-VCU 24. Depending on the required specifications, the A / C-VCU 34 may be a voltage converter that performs only step-up or step-down from the input side toward the output side.

[1-3.12V system-VCU36]
The 12V system-VCU 36 is a voltage converter that performs step-up / step-down from the input side (FC16, BAT-VCU24 side) toward the output side (12V system 28 side). The 12V-VCU 36 is connected to the motor 100 (inverter 14) or the wiring 100 between the FC 16 and the BAT-VCU 24. Depending on the required specifications, the 12V-VCU 36 may be a voltage converter that performs only step-up or step-down from the input side toward the output side.

2. Control of Second Embodiment Next, control in the ECU 32, particularly output control of the FC stack 16 will be described. The basic control is the same as that in the first embodiment (FIG. 2).

[2-1. Setting of target FC voltage Vfc_tar in the second mode]
FIG. 6 is a flowchart for setting the target FC voltage Vfc_tar in the second mode of the second embodiment. In step S21, the ECU 32 determines whether or not the vehicle 10A (FC system) is idle. Specifically, this is the same as S11 in FIG.

  When vehicle 10A is idling (S21: YES), in step S22, ECU 32 compares the power consumption of each auxiliary machine. That is, the ECU 32 determines which of A / P power consumption Pap, A / C power consumption Pac, and 12V system power consumption P12v is the largest.

  Such determination is made by connecting the air pump 20, the air conditioner 26, and the 12V system 28 as auxiliary machines to the wiring 100 between the FC 16 or the motor 12 (inverter 14) and the BAT-VCU 24. Based on that.

  For example, in the second embodiment, the voltage in the entire system is controlled in consideration of the power loss (conversion loss) of each VCU 24, 30, 34, 36. For this reason, the power consumption Pap of the air pump 20 paired with the A / P-VCU 30 is a comparison object alone. Similarly, the power consumption Pap of the air conditioner 26 paired with the A / C-VCU 34 is a comparison object alone. Similarly, the power consumption P12v of the 12V system 28 paired with the 12V system-VCU 36 is a comparison object alone.

  When the 12V system power consumption P12v is the highest in step S22 of FIG. 6 (S22: P12v> Pap, Pac), the control voltage of the 12V system 28 (hereinafter referred to as “12V system control voltage V12v”) is a value outside the redox region. It is determined whether or not. As its name suggests, the 12V system control voltage V12v is about 12V.

  When the 12V system control voltage V12v is a value outside the redox region (S23: YES), in step S24, the ECU 32 sets the 12V system control voltage V12v as the target FC voltage Vfc_tar. Accordingly, the ECU 32 operates the BAT-VCU 24 to make the secondary voltage V2 equal to the target FC voltage Vfc_tar. Further, the transformation operation of the 12V system-VCU 36 is stopped, and the secondary voltage V2 is made equal to the 12V system control voltage V12v (direct connection process). For the A / P-VCU 30, the secondary voltage V2 (= 12V system control voltage V12v) is transformed so as to be equal to the target input voltage Vap_tar of the A / P20. For the A / C-VCU 34, the secondary voltage V2 (= 12V system control voltage V12v) is transformed so as to be equal to the target input voltage Vac_tar of the A / C26.

  On the other hand, when the 12V system control voltage V12v is not a value outside the redox region (S23: NO), in step S25, the ECU 32 sets the value outside the redox region (for example, 0.9V × number of cells) to the target FC voltage Vfc_tar. Set as.

  After setting the value outside the redox region as the target FC voltage Vfc_tar, the ECU 32 transforms the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. In other words, the FC current Ifc is determined according to the FC voltage Vfc due to the characteristics of the FC16. Therefore, the ECU 32 sets the transformation rate of the BAT-VCU 24 so that the secondary voltage V2 after transforming the battery voltage Vbat by the BAT-VCU 24 becomes the target FC voltage Vfc_tar.

  Further, the 12V system-VCU 36 is transformed so that the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24) is equal to the target input voltage V12v_tar of the 12V system 28. For the A / P-VCU 30, the secondary voltage V2 (= battery voltage Vbat × BAT-VCU 24) is transformed so as to be equal to the target input voltage Vap_tar of the A / P 20. For the A / C-VCU 34, the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24 transformation rate) is transformed to be equal to the target input voltage Vac_tar of the A / C26.

  Returning to step S22, when the A / C power consumption Pac is the highest (S22: Pac> P12v, Pap), the control voltage of the air conditioner 26 (hereinafter referred to as “A / C control voltage Vac”) is outside the redox region. It is determined whether it is the value of.

  When the A / C control voltage Vac is a value outside the redox region (S26: YES), in step S27, the ECU 32 sets the A / C control voltage Vac as the target FC voltage Vfc_tar. Accordingly, the ECU 32 operates the BAT-VCU 24 to make the secondary voltage V2 equal to the target FC voltage Vfc_tar.

  Further, the transformation operation of the A / C-VCU 34 is stopped, and the secondary voltage V2 (= A / C control voltage Vac) is directly used as the input voltage Vac_in to the A / C 26 (direct connection process). For the A / P-VCU 30, the secondary voltage V2 (= A / C control voltage Vac) is transformed so as to be equal to the target input voltage Vap_tar of A / P20. For the 12V system-VCU 36, the secondary voltage V2 (= A / C control voltage Vac) is transformed to be equal to the target input voltage V12v_tar of the 12V system 28.

  On the other hand, when the A / C control voltage Vac is not a value outside the redox region (S26: NO), from the viewpoint of the FC voltage Vfc or the cell voltage, the deterioration of the FC 16 is likely to proceed. Therefore, in step S28, the ECU 32 sets a value outside the redox region as the target FC voltage Vfc_tar, similarly to step S25.

  The processing after setting a value outside the redox region as the target FC voltage Vfc_tar in step S28 is the same as that in step S25.

  Returning to step S22, when the A / P power consumption Pap is the highest (S22: Pap> P12v, Pac), the process proceeds to step S29. Steps S29 to S31 are the same as steps S16 to S18 in FIG.

  Returning to step S21, if the vehicle 10A is not idle (S21: NO), in step S32, the ECU 32 is a value that is outside the redox region and the FC power Pfc becomes large (for example, 0.8 V × number of cells). ) Is set as the target FC voltage Vfc_tar. Accordingly, the ECU 32 controls the BAT-VCU 24 to transform the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. Specifically, the ECU 32 sets the transformation rate of the BAT-VCU 24 so that the secondary voltage V2 after the BAT-VCU 24 transforms the battery voltage Vbat becomes the target FC voltage Vfc_tar.

  Further, the A / P-VCU 30 is transformed so that the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24 transformation rate) is equal to the target input voltage Vap_tar of the A / P20. Further, the A / C-VCU 34 is transformed so that the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24 transformation rate) is equal to the target input voltage Vac_tar of the A / C26. For the 12V system-VCU 36, the secondary voltage V2 (= battery voltage Vbat × BAT-VCU24) is transformed so as to be equal to the target input voltage V12v_tar of the 12V system 28.

[2-2. Examples of various controls]
FIG. 7 shows an example of a time chart when various controls according to the second embodiment are used. In FIG. 7, it is assumed that the vehicle 10A is in an idle state (S21 in FIG. 6: YES) at all times. The FC generated power Pfc in FIG. 7 indicates only power consumption of the auxiliary machine, that is, A / C power consumption Pac, 12V system power consumption P12v, and A / P power consumption Pap, and the power consumption Pmot of the motor 12 is shown. Those corresponding to are not included. Further, the VCU total loss Ltotal in FIG. 7 is the total power loss of the BAT-VCU 24, A / P-VCU 30, A / C-VCU 34, and 12V system-VCU 36.

  Further, in FIG. 7, the solid line of the VCU total loss Ltotal corresponds to the control according to the second embodiment, and the broken line corresponds to the control according to the comparative example. The control according to the comparative example is, for example, the control disclosed in Patent Document 1.

  Until time t11, the vehicle is in a low load state (S1: YES in FIG. 2) and is in an idle state (S21: YES in FIG. 6). Therefore, the ECU 32 compares the A / C power consumption Pac, the 12V system power consumption P12v, and the A / P power consumption Pap (S22). Before time t11, the 12V system power consumption P12v is the largest (S22: P12v> Pap, Pac), and the 12V system control voltage V12v is a value outside the redox region (S23: YES). Therefore, the ECU 32 sets the 12V system control voltage V12v as the target FC voltage Vfc_tar (S24).

  At time t11, the outputs (drive amounts) of the air pump 20 and the air conditioner 26 increase. At time t11, the A / C power consumption Pac is the largest (S22: Pac> P12v, Pap), and the A / C control voltage Vac is a value outside the redox region (S26: YES). For this reason, the ECU 32 sets the A / C control voltage Vac as the target FC voltage Vfc_tar (S27).

  At time t12, the output (drive amount) of the air pump 20 further increases, but the largest power consumption remains the A / C power consumption Pac.

  At time t13, the output (drive amount) of the air conditioner 26 decreases. Accordingly, the A / P power consumption Pap becomes the largest (S22: Pap> P12v, Pac). At time t13, the A / P request voltage Vap_req is a value outside the redox region (S29: YES). Therefore, the ECU 32 sets the A / P request voltage Vap_req as the target FC voltage Vfc_tar (S30).

3. Effects of Second Embodiment According to the second embodiment as described above, the following effects can be obtained in addition to or instead of the effects of the first embodiment.

  That is, according to the second embodiment, when the vehicle 10A is idle (S21 in FIG. 6: YES), and the power consumption P12v of the 12V system 28 (second load) is the largest (S22 in FIG. 6: P12v>). Pap, Pac), the secondary voltage V2 that is the input voltage to the 12V system-VCU 36 (second voltage conversion device) is adjusted to eliminate the need for voltage conversion in the 12V system-VCU 36 (S24) or 12V system-VCU36. The transformation rate is suppressed (S25). As a result, the loss of the 12V-VCU 36 can be reduced. At this time, even if the input voltage (secondary voltage V2) to the 12V system-VCU 36 is adjusted, the motor 12 and the air pump can be adjusted by adjusting the supply amount of the reaction gas to the supply power (FC generated power Pfc) from the FC 16. 20, it is possible to supply desired power to the air conditioner 26 and the 12V system 28.

  When the power consumption Pac of the air conditioner 26 (second load) is the largest (S22 in FIG. 6: Pac> P12v, Pap) and when the power consumption Pap of the air pump 20 (second load) is the largest (S22: Pap The same applies to> P12v, Pac).

C. Third Embodiment 1. FIG. Description of overall configuration (difference from the first embodiment)
[1-1. overall structure]
FIG. 8 is a schematic overall configuration diagram of a fuel cell vehicle 10B (hereinafter referred to as “FC vehicle 10B” or “vehicle 10B”) as a fuel cell system according to a third embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The third embodiment includes an FC voltage control device 38 (hereinafter referred to as “FC-VCU 38”). In addition, the A / P-VCU 30 is included in the first embodiment, but the A / P-VCU 30 is not included in the third embodiment.

[1-2. FC-VCU38]
The FC-VCU 38 is a voltage conversion device that performs step-up / step-down from the input side (FC16 side) toward the output side (motor 12, BAT-VCU 24 side). As shown in FIG. 8, the FC-VCU 38 is disposed on the wiring 100 between the motor 12 (inverter 14) and the FC 16. Depending on the required specifications, the FC-VCU 38 may be a voltage conversion device that performs only step-up or step-down from the input side toward the output side.

2. Control of Third Embodiment Next, control in the ECU 32, particularly output control of the FC stack 16 will be described. The basic control is the same as that in the first embodiment (FIG. 2).

[2-1. Setting of target FC voltage Vfc_tar in the second mode]
FIG. 9 is a flowchart for setting the target FC voltage Vfc_tar in the second mode of the third embodiment. In step S41, the ECU 32 determines whether or not the vehicle 10B (FC system) is idle. Specifically, this is the same as S11 in FIG.

  If the vehicle 10B is idle (S41: YES), in step S42, the ECU 32 determines whether or not the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v exceeds the A / P power consumption Pap. judge. The reason for making such a determination is the same as in the first embodiment.

  When total Pac + P12v of A / C power consumption Pac and 12V system power consumption P12v exceeds A / P power consumption Pap (S42: YES), in step S43, ECU 32 determines that battery voltage Vbat is outside the redox region. It is determined whether or not there is.

  When the battery voltage Vbat is a value outside the redox region (S43: YES), from the viewpoint of the FC voltage Vfc or the cell voltage, it is in a state where deterioration of the FC16 can be suppressed. Therefore, in step S45, the ECU 32 sets the battery voltage Vbat as the target FC voltage Vfc_tar. Accordingly, the ECU 32 stops the transformation operation of the BAT-VCU 24 and the FC-VCU 38 and makes the secondary voltage V2 equal to the battery voltage Vbat (direct connection process).

  On the other hand, when the battery voltage Vbat is not a value outside the redox region (S43: NO), from the viewpoint of the FC voltage Vfc or the cell voltage, the deterioration of the FC16 is likely to proceed. Therefore, in step S45, the ECU 32 sets a value outside the redox region (0.9V × number of cells) as the target FC voltage Vfc_tar.

  After setting the value outside the redox region as the target FC voltage Vfc_tar, the ECU 32 controls the BAT-VCU 24 or the FC-VCU 38 so that the FC voltage Vfc becomes the target FC voltage Vfc_tar. For example, the battery voltage Vbat is transformed by operating the BAT-VCU 24 while the FC-VCU 38 is in a directly connected state.

  Returning to S42 in FIG. 9, when the total Pac + P12v of the A / C power consumption Pac and the 12V system power consumption P12v does not exceed the A / P power consumption Pap (S42: NO), in step S46, the ECU 32 determines that the A / P It is determined whether or not the required voltage Vap_req is a value outside the redox region.

  When the A / P required voltage Vap_req is a value outside the redox region (S46: YES), from the viewpoint of the FC voltage Vfc or the cell voltage, it is in a state where deterioration of the FC 16 can be suppressed. Therefore, in step S47, the ECU 32 sets the A / P request voltage Vap_req as the target FC voltage Vfc_tar. Accordingly, the ECU 32 operates the BAT-VCU 24 while bringing the FC-VCU 38 into a direct connection state, and transforms the battery voltage Vbat so that the FC voltage Vfc becomes the target FC voltage Vfc_tar.

  On the other hand, when the A / P required voltage Vap_req is not a value outside the redox region (S46: NO), from the viewpoint of the FC voltage Vfc or the cell voltage, the deterioration of the FC 16 is likely to proceed. Therefore, in step S48, the ECU 32 sets a value outside the redox region as the target FC voltage Vfc_tar, similarly to step S45. The processing after setting the value outside the redox region as the target FC voltage Vfc_tar in step S48 is the same as that in step S45.

  Returning to step S41, if the vehicle 10B is not idle (S41: NO), the process proceeds to step S49. Step S49 is the same as S19 of FIG.

3. Effects of Third Embodiment According to the third embodiment as described above, the following effects can be obtained in addition to or instead of the effects of the first embodiment.

  That is, according to the third embodiment, the vehicle 10B is idle (S41 in FIG. 9: YES), and the power consumption Pap of the air pump 20 (second load) is the power consumption of the travel motor 12 (first load). When larger than Pmot, the FC voltage Vfc, which is the input voltage to the FC-VCU 38 (second voltage converter) is adjusted by the BAT-VCU 24 (first voltage converter), and voltage conversion in the FC-VCU 38 is unnecessary. (S47, S48).

  As a result, the loss of the FC-VCU 38 can be reduced. At this time, even if the input voltage (FC voltage Vfc) to the FC-VCU 38 is adjusted by the BAT-VCU 24, the motor 12 can be obtained by adjusting the supply amount of the reaction gas from the supply power (FC generated power Pfc) supplied from the FC16. In addition, it is possible to supply desired power to the air pump 20.

  Similarly, according to the third embodiment, the vehicle 10B is idle (S41 in FIG. 9: YES), the power consumption Pac of the air conditioner 26 (third load) and the 12V system 28 (third load). When the total Pac + P12v of the power consumption P12v is larger than the power consumption Pmot of the travel motor 12 (first load) and the power consumption Pap of the air pump 20 (second load) (S42: YES), BAT-VCU24 (first voltage conversion) Device) and FC-VCU 38 (second voltage converter) adjust the input voltages Vac_in and V12v_in to the air conditioner 26 and the 12V system 28. This eliminates the need for voltage conversion in the BAT-VCU 24 and FC-VCU 38 for the input voltages Vac_in and V12v_in to the air conditioner 26 and 12V system 28 (S44), or suppresses the transformation rate in the BAT-VCU 24 and FC-VCU 38. (S45).

  Thereby, it becomes possible to reduce the loss of BAT-VCU24 and FC-VCU38. At this time, even if the input voltages Vac_in and V12v_in are adjusted as described above, the supply power from the FC 16 (FC generated power Pfc) is adjusted to adjust the supply amount of the reaction gas, so that the motor 12, the air pump 20, the air conditioner It becomes possible to supply desired power to the shoner 26 and the 12V system 28.

D. Modifications Note that the present invention is not limited to the above-described embodiments, and various configurations can be adopted based on the description of the present specification. For example, the following configuration can be adopted.

1. In the above embodiments, the FC vehicles 10, 10A, and 10B are used as the FC system. However, the present invention is not limited to this, and other than the FC vehicles 10, 10A, and 10B may be used as the FC system. For example, a moving body such as a ship or an aircraft can be used as the FC system. Alternatively, a robot, a manufacturing apparatus, a household power system, or a home appliance may be used as the FC system.

2. Configuration of Vehicle 10, 10A, 10B (FC System) In the above embodiments, the components shown in FIGS. 1, 5, and 8 are included. For example, auxiliary machines (air pump 20, air conditioners 26 and 12V) are included. The combination and arrangement of the system 28) can be arbitrarily set. For example, in FIGS. 1, 5, and 8, the A / P 20 is connected to the secondary side (wiring 100) of the BAT-VCU 24, but may be connected to the primary side (wiring 102).

  Although the gas supply apparatus 18 of each said embodiment illustrated the structure provided with the air pump 20 which supplies the air containing oxygen, it is good also as a structure provided with the hydrogen pump which supplies hydrogen instead of or in addition to this.

3. Power supply mode In each of the above embodiments, the vehicle 10, 10A, 10B is used on the condition that it is idle (S11 in FIG. 3, S21 in FIG. 6, S41 in FIG. 9), but the voltage in any VCU Control that makes conversion unnecessary or suppresses the transformation rate can be used in scenes other than idling. For example, the above control may be used during cruise traveling, slow acceleration, or creep traveling of the vehicles 10, 10A, 10B.

10, 10A, 10B ... Fuel cell vehicle (fuel cell system)
12 ... Traveling motor (first load) 16 ... Fuel cell stack (fuel cell)
18 ... Gas supply device 20 ... Air pump (second load)
22 ... High voltage battery (power storage device) 24 ... BAT-VCU (first voltage converter)
26 ... Air conditioner (2nd load, 3rd load)
28 ... 12V system (second load, third load) 30 ... AP-VCU (second voltage converter)
32 ... ECU (control device) 38 ... FC-VCU (second voltage converter)
Pmot: Power consumption of motor (first load) Pap: Power consumption of air pump (second load)

Claims (5)

A first load that is a traveling motor;
A fuel cell for supplying power to the first load;
A gas supply device for supplying a reaction gas to the fuel cell;
A power storage device connected in parallel with the fuel cell to supply power to the first load;
A first voltage converter disposed between the first load and the power storage device;
A second load which is an auxiliary machine connected between the first load and the fuel cell or between the first load and the power storage device via a second voltage converter;
A fuel cell system including a fuel cell vehicle comprising: the gas supply device; the control device that controls the first voltage conversion device and the second voltage conversion device;
The controller is
When the power consumption of the second load is greater than the power consumption of the first load,
By adjusting the input voltage to the second voltage conversion device by the first voltage conversion device, the input voltage to the second voltage conversion device is a constant value that makes voltage conversion in the second voltage conversion device unnecessary. Or a first energy efficiency improvement value that is a constant value that suppresses the transformation rate in the second voltage converter,
A total value of required powers of the first load and the second load while the input voltage to the second voltage converter is maintained at the first energy efficiency improvement value which is a constant value by the first voltage converter. A fuel cell system, wherein the supply amount of the reaction gas is adjusted by the gas supply device so as to follow the above. A first load;
A fuel cell for supplying power to the first load;
A gas supply device for supplying a reaction gas to the fuel cell;
A power storage device connected in parallel with the fuel cell to supply power to the first load;
A first voltage converter disposed between the first load and the power storage device;
A second load connected between the first load and the fuel cell or between the first load and the power storage device;
Arranged on the wiring connecting the second load and the wiring between the first load and the fuel cell or between the first load and the power storage device, or on the wiring between the first load and the fuel cell A second voltage converter arranged in
A fuel cell system comprising: the gas supply device; the control device that controls the first voltage conversion device and the second voltage conversion device;
The controller is
When the power consumption of the second load is greater than the power consumption of the first load,
The input voltage to the second voltage converter is adjusted to the second voltage converter by adjusting the input voltage to the second voltage converter by at least one of the first voltage converter and the second voltage converter. A constant value that eliminates the need for voltage conversion in the device or a first energy efficiency improvement value that is a constant value that suppresses the transformation rate in the second voltage conversion device;
A total value of required powers of the first load and the second load while the input voltage to the second voltage converter is maintained at the first energy efficiency improvement value which is a constant value by the first voltage converter. A fuel cell system, wherein the supply amount of the reaction gas is adjusted by the gas supply device so as to follow the above. The fuel cell system according to claim 1 or 2,
When the power consumption of the second load is larger than the power consumption of the first load, the control device oxidizes the input voltage to the second voltage conversion device by the cell voltage of each cell constituting the fuel cell. A fuel cell system, wherein the fuel cell system is set to a value outside the reduction potential range. The fuel cell system according to claim 1 or claim 3 dependent on claim 1,
When the power consumption of the second load is greater than the power consumption of the first load, the fuel cell vehicle is idle. In the fuel cell system according to claim 1 or claim 3 or 4 dependent on claim 1 or claim 4 dependent on claim 3 dependent on claim 1,
The fuel cell system includes a third load that is an auxiliary machine connected between the first load and the fuel cell or between the first load and the power storage device,
The controller is
When the power consumption of the third load is larger than the power consumption of the first load and the second load,
By adjusting the input voltage to the third load by the first voltage conversion device, the input voltage to the third load becomes a value that makes voltage conversion in the first voltage conversion device unnecessary, or the first voltage While making it the 2nd energy efficiency improvement value which is the value which controls the transformation rate in a converter,
The fuel cell system, wherein the supply amount of the reaction gas is adjusted by the gas supply device so as to follow a total value of required power of the first load, the second load, and the third load.

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