JP4154997B2 - Control device for fuel cell vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a fuel cell vehicle using a fuel cell as a power source.
[0002]
[Prior art]
In a fuel cell, a fuel gas such as hydrogen gas and an oxidizing gas containing oxygen are electrochemically reacted through an electrolyte, and electric energy is directly taken out between electrodes provided on both surfaces of the electrolyte. In recent years, a fuel cell vehicle that uses this fuel cell as a vehicle drive source has attracted attention.
[0003]
That is, a hydrogen storage device such as a high-pressure hydrogen tank, a liquid hydrogen tank, or a hydrogen storage alloy tank is installed in a vehicle, and hydrogen supplied from the hydrogen storage device and air containing oxygen are sent to the fuel cell to react with each other. It is an ultimate clean vehicle that drives the motor connected to the drive wheels with the extracted electric energy, and the only exhaust material is water.
[0004]
In a fuel cell vehicle, the amount of power generated by the fuel cell is basically determined according to the driving force required by the driver. Since the driving power for driving the vehicle is calculated momentarily according to the operation amount of the accelerator pedal, the vehicle speed, etc., the power generation amount of the fuel cell also changes accordingly.
[0005]
As described above, the fuel cell takes out electric energy by reacting the fuel gas and the oxidant gas, and it is efficient to change the gas supply amount to the fuel cell according to the power generation amount. For example, in order to realize an idle stop function similar to that of a conventional internal combustion engine vehicle, when the fuel cell vehicle is temporarily stopped, the supply of fuel gas and oxidant gas to the fuel cell is temporarily stopped and the fuel cell is If the extraction of the electric power is stopped, the fuel efficiency is further improved (for example, Patent Document 1).
[0006]
In addition, many fuel cells used in fuel cell vehicles are solid polymer fuel cells. This is because the operating temperature is relatively low from room temperature to 100 ° C., the start-up time is short, the size and weight can be reduced, and the output density is high.
[0007]
The solid polymer electrolyte membrane constituting this polymer electrolyte fuel cell conducts hydrogen ions ionized at the fuel electrode to the oxidizer electrode, but has a characteristic that the conductivity decreases if the electrolyte membrane is not sufficiently wet. Have. Therefore, in order to prevent the electrolyte membrane from being dried, the gas supplied to the fuel cell is humidified with a humidifier.
[0008]
When the operation of such a fuel cell system is stopped, the temperature of the fuel cell is lowered, so that the temperature of the humidified gas is also lowered and water vapor is condensed. If the water vapor in the pipe from the humidifier to the fuel cell stack or in the fuel cell is condensed, the electrolyte membrane and the electrode in contact with it are excessively wetted, and the diffusion of hydrogen and oxygen is hindered.
[0009]
As a countermeasure against such condensation of water vapor, a technique for preventing condensation of water vapor by maintaining the temperature of the pipe from the humidifier to the fuel cell stack higher than the temperature of the humidifier is known (for example, patents). Reference 2).
[0010]
[Patent Document 1]
Japanese Patent Application No. 2002-178882
[0011]
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-251912 (5th page)
[0012]
[Problems to be solved by the invention]
However, even if the technique described in Patent Document 2 is applied to a fuel cell vehicle, if the temperature of the fuel cell stack decreases during idling stop, it is unavoidable that condensed water is generated inside the fuel cell stack and the pipes before and after the fuel cell stack. Absent. For this reason, when the fuel cell system is restarted from the power generation stop state, there is a problem that the power generation efficiency of the fuel cell is lowered due to the influence of condensed water, and in some cases, the fuel cell may be deteriorated.
[0013]
In addition, it is necessary to increase the amount of gas supplied to the fuel cell and discharge the condensed water condensed inside the fuel cell to the outside of the fuel cell. In this case, the time for restarting the fuel cell system is required. There was a problem of prolonged.
[0014]
Furthermore, when the gas supply amount is increased for discharging condensed water, there is a problem that problems such as operation noise of the air compressor and gas discharge sound occur.
[0015]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a control device for a fuel cell vehicle using a fuel cell as a power source, vehicle motion control means for controlling driving and braking of the vehicle, and required power generation from the vehicle motion control means. The power generation amount control means for controlling the power generation amount of the fuel cell based on the amount, and the temperature of the fuel cell Condensate does not occur When the power generation request from the vehicle motion control means disappears when the predetermined value is exceeded, the power generation amount control means stops the power generation of the fuel cell, while the temperature of the fuel cell Above A power generation continuation determining means for continuing the power generation for keeping the temperature of the fuel cell in the power generation amount control means even when there is no power generation request from the vehicle motion control means when the predetermined value or less, The gist.
[0016]
【The invention's effect】
According to the present invention, when the temperature of the fuel cell is equal to or lower than the predetermined value, the power generation for maintaining the temperature of the fuel cell is continued even if there is no power generation request for the fuel cell. Therefore, it is possible to realize a fuel cell vehicle that suppresses this to a minimum.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system configuration diagram illustrating a configuration of a fuel cell vehicle including a control device for a fuel cell vehicle according to the present invention.
[0018]
In FIG. 1, a fuel cell vehicle 1 includes a fuel cell system 3 as a power source of the vehicle, a power manager 5 that converts electric power generated by the fuel cell system 3, and a secondary battery 7 that is charged and discharged by the power manager 5. A drive motor 9 that is driven by the generated power of the fuel cell system 3 or the power of the secondary battery 7 to drive the vehicle, a differential device 11 that distributes the driving force of the drive motor to the left and right, a drive shaft 13, and a drive Wheel 15, driven wheel 17, brake 19, wheel rotation sensor 21 provided for each wheel for detecting wheel rotation speed, accelerator sensor 23 for detecting accelerator pedal depression amount, and brake pedal depression amount are detected. Brake sensor 25, steering sensor 27 for detecting the rotation angle of the steering wheel, and yaw ray for detecting the angular velocity around the vertical axis passing through the center of gravity of the vehicle A sensor 29, a G sensor 31 that detects the longitudinal and lateral accelerations of the vehicle, a temperature sensor 33 that detects the temperature of the fuel cell system 3, and a control device 35 that controls the entire fuel cell vehicle 1 are provided. Yes.
[0019]
The control device 35 includes vehicle motion control means 37 that controls driving and braking of the fuel cell vehicle 1, and power generation amount control means 41 that controls the power generation amount of the fuel cell based on the required power generation amount from the vehicle motion control means 37. When the temperature of the fuel cell detected by the temperature sensor 33 exceeds a predetermined value, when there is no power generation request from the vehicle motion control means 37, the power generation amount control means 41 stops the power generation of the fuel cell, while the temperature sensor When the fuel cell temperature detected by the fuel cell 33 is equal to or lower than a predetermined value, even if there is no power generation request from the vehicle motion control means 37, the power generation amount control means 41 continues the power generation for keeping the fuel cell system 3 warm. Continuation determination means 39.
[0020]
The control device 35 is not particularly limited, but is configured as a microprocessor having a CPU, a memory, and an I / O interface in the present embodiment.
[0021]
The fuel cell system 3 is a fuel cell system that controls the power generation amount based on the required power generation amount instructed by the power generation amount control means 41 of the control device 35 and sends the fuel cell temperature detected by the temperature sensor 33 to the control device 35. is there.
[0022]
Then, when the target vehicle behavior calculated based on the operation amount of the driver and the actual vehicle behavior calculated based on the detection value of each sensor exceed the error range, the control device 35 determines the actual vehicle behavior. The driving force and the braking force of each wheel are controlled so as to approximate the target vehicle behavior. For this control, a power generation amount signal is sent to the power generation amount control means 41, and the braking force of each wheel is controlled by the brake 19 via a brake control device (not shown).
[0023]
At this time, depending on the behavior state of the vehicle, the power generation amount control means 41 issues a power generation amount cut command to the fuel cell system 3 and stops the power supply from the power manager 5 to the drive motor 9 to drive rapidly. The shaft torque is reduced and the vehicle is stabilized.
[0024]
Further, as specific control of driving and braking of the fuel cell vehicle 1 by the vehicle motion control means 37 of the present embodiment, driving force control (traction control system, which suppresses driving force when slipping of driving wheels is detected) (Hereinafter referred to as TCS), anti-lock braking system (hereinafter referred to as ABS) that prevents wheel lock during braking, vehicle attitude control (vehicle stability control, hereinafter referred to as VSC) that stabilizes the vehicle attitude during turning, and the inter-vehicle distance from the preceding vehicle The vehicle following control (active cruise control, hereinafter referred to as ACC) is included.
[0025]
For these controls, the control device 35 includes a wheel rotation sensor 21, an accelerator sensor 23, a brake sensor 25, a steering sensor 27, a yaw rate sensor 29, a G sensor 31, a temperature sensor 33, and a front vehicle for each wheel. The inter-vehicle distance measuring radar device (not shown) for measuring the inter-vehicle distance is connected.
[0026]
The vehicle motion control means 37 of the control device 35 inputs the detection signals of the four wheel rotation sensors 21, calculates the estimated vehicle speed from the rotation speed for each wheel, and compares the rotation speed of each wheel with the estimated vehicle speed. Thus, the slip ratio of each wheel is calculated.
[0027]
The TCS control by the vehicle motion control means 37 performs driving force reduction or driving force cutting if there is a driving wheel 15 in which the calculated slip ratio of each wheel falls outside the range of the appropriate slip ratio. If necessary, the drive wheel 15 is braked by the brake 19.
[0028]
The ABS control by the vehicle motion control means 37 is based on the calculated slip ratio of each wheel. If there is a wheel having a slip ratio that is too large, the braking force of the wheel is weakened. If there is, the control is performed to increase the braking force of the wheel, thereby preventing the wheel from being locked and maintaining the steering performance and the directional stability of the vehicle.
[0029]
The VSC control by the vehicle motion control means 37 detects the driver's accelerator operation amount from the accelerator sensor 23, the driver's brake operation amount from the brake sensor 25, and the driver's steering operation amount from the steering sensor 27. The degree of understeer and oversteer in the turning state of the vehicle is determined from the sensor 29, the G sensor 31, the wheel rotation sensor 21, etc., and the braking force for each wheel of the brake 19 and the driving force of the drive motor 9 are controlled to Improve stability.
[0030]
In the ACC control by the vehicle motion control means 37, the inter-vehicle distance measurement radar device (not shown) measures the inter-vehicle distance from the preceding vehicle and maintains the inter-vehicle distance appropriately within the set vehicle speed range. And the braking force of the brake 19 are controlled.
[0031]
FIG. 2 is a configuration diagram illustrating details of the fuel cell system 3. The fuel cell system 3 includes a hydrogen tank 51 that stores hydrogen at a high pressure, a hydrogen pressure sensor 53 that detects the pressure of the hydrogen tank 51, a hydrogen pressure adjustment valve 55 that adjusts the hydrogen gas pressure from the hydrogen tank 51, Ejector 57 that mixes exhaust from pole 79 and hydrogen from hydrogen pressure regulating valve 55, compressor 59 that pressurizes air, humidifier 65 that humidifies air and hydrogen from air humidifier 67 and hydrogen humidifier 69, A fuel cell stack 75 having an air electrode 77 and a hydrogen electrode 79 and generating electric power using humidified hydrogen and air supplied from the humidifier 65, and an air pressure adjusting valve for adjusting the exhaust pressure from the outlet of the air electrode 77 81, a hydrogen purge valve 83 for releasing hydrogen from the outlet of the hydrogen electrode 79 to the outside, an air pressure sensor 71 for detecting the inlet pressure of the air electrode 77, and an inlet pressure of the hydrogen electrode 79. And the hydrogen pressure sensor 73, a temperature sensor 33 for detecting a cooling water temperature of the fuel cell stack 75, and a fuel cell system controller 85.
[0032]
The air is pressurized from the atmosphere by the compressor 59 and humidified by the air humidifying unit 67 and then supplied to the air electrode 77 of the fuel cell stack 75. The unused air in the fuel cell stack 75 is air pressure regulating valve 81. To the atmosphere.
[0033]
The flow rate and pressure of air supplied to the air electrode 77 of the fuel cell stack 75 are controlled by the rotational speed of the compressor 59 and the opening of the air pressure adjustment valve 81.
[0034]
The compressor 59 is driven by the compressor motor 61, and the fuel cell system control device 85 refers to the motor rotation sensor 63 to control the compressor motor 61 so as to have a target rotation speed.
[0035]
Further, the fuel cell system controller 85 refers to the air pressure sensor 71 and adjusts the target rotational speed of the compressor 59 and the air pressure so that the pressure of the air supplied to the air electrode 77 of the fuel cell stack 75 becomes the target pressure. The opening degree of the valve 81 is controlled.
[0036]
Hydrogen, which is a fuel gas, is humidified with pure water (not shown) from the hydrogen tank 51 via the hydrogen pressure adjustment valve 55 and the ejector 57, and then supplied to the hydrogen electrode 79 of the fuel cell stack 75. The hydrogen unused in the fuel cell stack 75 is circulated to the hydrogen electrode 79 of the fuel cell stack 75 by the ejector 57. The pressure of hydrogen supplied to the hydrogen electrode 79 of the fuel cell stack 75 is controlled by the opening degree of the hydrogen pressure adjustment valve 55. The fuel cell system control device 85 refers to the hydrogen pressure sensor 73 and controls the hydrogen pressure adjustment valve 55 so that the pressure of hydrogen supplied to the hydrogen electrode 79 of the fuel cell stack 75 becomes a target pressure.
[0037]
The hydrogen purge valve 83 opens and closes depending on the state of the fuel cell stack 75, thereby reducing output and efficiency due to water inside the fuel cell stack 75, that is, air leakage from the air electrode 77 to the hydrogen electrode 79. Used to prevent.
[0038]
The fuel cell system control device 85 receives the required power generation amount from the control device 35 of the fuel cell vehicle, and controls the hydrogen pressure and the air pressure so that the required power generation amount can be generated. Further, when the fuel cell system control device 85 receives a command of the required power generation amount 0 or a power generation amount cut command from the power generation amount control means 41, the fuel cell system control device 85 closes the hydrogen pressure regulating valve 55 to cut fuel and stops the rotation of the compressor 59. I do. Further, the fuel cell system 3 sends the temperature detected by the temperature sensor 33 as the fuel cell temperature to the control device 35 of the fuel cell vehicle.
[0039]
The fuel cell vehicle control device 35 in FIG. 1 and the fuel cell system control device 85 in FIG. 2 may be integrated.
[0040]
The fuel cell vehicle 1 shown in FIG. 1 can be used with a conventional hydraulic control brake. However, even if a negative pressure type brake booster that assists the brake pedal depression force is provided, the engine intake negative pressure can be used. Can not. For this reason, an electric brake in which the brake itself is motorized is more suitable than an electric negative pressure pump that is a negative pressure supply source that replaces the intake negative pressure. Further, the electric brake has an advantage that anti-lock control for each wheel can be easily realized only by an electric operation by an electronic control unit.
[0041]
FIG. 3 is a configuration diagram showing an example of an electric brake that can be used as the brake 19, and is an example in which a floating caliper brake is electrified. In FIG. 3, the forward / reverse rotation of the motor 540 is converted into a linear reciprocating motion by the ball screw 530, and by this linear reciprocating motion, the two pads 510 are pressed against or released from both surfaces of the brake disc 520. It is supposed to be.
[0042]
FIG. 4 is a condensation characteristic diagram showing a change ΔT in the decrease in fuel cell temperature after stopping the power extraction in the fuel cell stack 75 of FIG. 2 and the amount of condensed water W in the fuel cell stack 75. As shown in FIG. 4, after the power generation is stopped, the temperature of the fuel cell stack decreases, and the amount of condensed water W increases as the temperature decrease width ΔT increases with time.
[0043]
[First Embodiment]
FIGS. 5 and 6 are flowcharts for explaining the control operation in the first embodiment of the control apparatus for the fuel cell vehicle shown in FIG. 1. FIG. 5 shows the operation of the vehicle motion control means 37. 6 shows the operation of the power generation continuation determining means 39 and the power generation amount control means 41. These flowcharts are called from the main routine and executed every predetermined time (for example, 10 msec). For example, the main routine calculates the driving force and required power generation amount of the vehicle or the braking force of the vehicle based on the detection values of the accelerator sensor 23 and the brake sensor 25.
[0044]
In FIG. 5, the vehicle motion control means 37 first reads detected values of the accelerator sensor 23, the brake sensor 25, and the steering sensor 27 in step (hereinafter, step is abbreviated as S) 10. Subsequently, the rotational speed sensor 21 of each wheel is read in S12. Next, in S14, it is determined whether or not an idling stop condition is satisfied. The idling stop condition is, for example, the case where the vehicle is stopped when the accelerator is off, the amount of electric power used by the fuel cell auxiliary machine or the electric brake is not so large, and the secondary battery 7 does not need to be charged.
[0045]
If the idling stop condition is satisfied in the determination in S14, the process proceeds to S24. If the idling stop condition is not satisfied in S14, it is determined in S16 whether or not the drive wheel 19 has a spin. The slip ratio of each wheel is calculated based on the detected rotational speed of the four-wheel wheel rotation sensor 21 and the vehicle speed calculated from these, and it is determined that the drive wheel 19 exceeding the predetermined slip ratio is spinning. If there is a driving wheel spin in the determination of S16, the process proceeds to S24. In S24, the required power generation amount Pr is set to 0, and the process returns to the main routine.
[0046]
If it is determined in S16 that there is no drive wheel spin, it is determined in S18 whether or not the vehicle is turning based on the detection value of the yaw rate sensor 29. If it is determined in S18 that the vehicle is not turning, the process proceeds to S26. If the vehicle is turning in S18, it is determined in S20 whether or not the vehicle posture is appropriate. In determining whether the vehicle posture is appropriate, the driver's operation amount input from the accelerator sensor 23, the brake sensor 25, and the steering sensor 27, the yaw rate sensor 29, the G sensor 31, and the wheel rotation sensors 21 are input. Based on the information, the degree of understeer and oversteer is determined. If the degree of understeer and oversteer is within a predetermined range, the vehicle posture is determined to be appropriate.
[0047]
If it is determined in S20 that the vehicle posture is appropriate, the process proceeds to S26. If it is determined in S20 that the vehicle posture is not appropriate, it is determined in S22 whether or not the vehicle is oversteered. If it is determined in S22 that it is not oversteer, the process proceeds to S26. In S26, the required power generation amount Pr corresponding to the accelerator opening and the vehicle speed is calculated, and the process returns to the main routine.
[0048]
If it is determined in S22 that the vehicle is oversteered, the required power generation amount Pr with reduced driving force is calculated in S28, and the process returns to the main routine.
[0049]
FIG. 6 shows the power generation control operation of the fuel cell system 3 by the power generation continuation determining means 39 and the power generation amount control means 41 in response to the calculation of the required power generation amount Pr by the vehicle motion control means 37 described above.
[0050]
First, the required power generation amount Pr is read in S30. In S32, it is determined whether Pr = 0. If Pr = 0 is not satisfied, the process proceeds to S38, where the required power generation amount Pr is sent to the fuel cell system controller 85 to generate the required power generation amount Pr.
[0051]
If Pr = 0 in the determination at S32, then at S34, the fuel cell temperature Tw is read from the temperature sensor 33, and at S36, it is determined whether Tw is equal to or less than a predetermined value T0.
[0052]
If it is determined in S36 that the fuel cell temperature Tw is not equal to or lower than the predetermined value T0 (if the fuel cell temperature Tw exceeds the predetermined value T0), the required power generation amount Pr = 0 is set to the fuel cell in order to stop power generation in S40. Output to system 3. Receiving the required power generation amount Pr = 0, the fuel cell system controller 85 closes the hydrogen pressure adjustment valve 55 to cut the fuel, and stops the rotation of the compressor 59 to stop the air supply.
[0053]
If it is determined in S36 that the fuel cell temperature Tw is equal to or less than the predetermined value T0, the fuel cell system 3 is set to, for example, the minimum power generation amount Pmin as the required power generation amount Pr in S42 so that the fuel cell system 3 can continue the power generation for keeping warm. Send the required power generation to 3. This minimum power generation amount Pmin may be determined, for example, according to the difference between the detected value of an outside air temperature sensor (not shown) and the fuel cell temperature Tw.
[0054]
With the above control, when the fuel cell temperature is equal to or lower than the predetermined value, the fuel cell system 3 continues to generate power for keeping the fuel cell 3 even if the required power generation amount from the vehicle motion control means 37 is zero. Water clogging due to condensed water in the battery system can be prevented.
[0055]
[Second Embodiment]
Next, a second embodiment of the control apparatus for a fuel cell vehicle according to the present invention will be described. In the second embodiment, the determination temperature at which power generation can be stopped is provided with a hysteresis characteristic, and when the required power generation amount is 0, the frequent stoppage of power generation and restart of power generation for fuel cell heat retention are prevented. It is.
[0056]
FIG. 7A is a flowchart for explaining the control operation in the second embodiment of the control apparatus for the fuel cell vehicle whose configurations and characteristics are shown in FIGS. This flowchart is called from the main routine and executed every predetermined time (for example, 10 msec). Note that the operation of the vehicle motion control means 37 of the control device 35 is the same as that of FIG. 5 described in the first embodiment, and therefore, a duplicate description is omitted.
[0057]
FIG. 7B is a control map of the power generation stoppage enable flag used in the flowchart of FIG. In FIG. 7 (b), the current fuel cell temperature Tw and the previous fuel cell temperature Tw-1 have a first predetermined value T1 and a second predetermined value T2 (<T1) as threshold values, respectively. For the combination of streets, the set (SET), reset (RESET), or hold (HOLD) of the power generation stoppage enable flag is defined as shown in the figure. This is because the first predetermined value T1 and the second predetermined value T2 (<T1) realize the hysteresis characteristic of the fuel cell temperature determination, and the power generation stop of the fuel cell and the power generation restart for keeping the fuel cell temperature are performed. This prevents frequent repetition.
[0058]
That is, in FIG. 7B, when the current fuel cell temperature Tw exceeds the first predetermined value T1 (T1 <Tw), the power generation stoppage possible flag is set regardless of the previous fuel cell temperature Tw-1. When the current fuel cell temperature Tw is lower than the second predetermined value T2 (Tw <T2), control is performed to reset the power generation stoppage possible flag regardless of the previous fuel cell temperature Tw-1. However, when the current fuel cell temperature Tw is between the second predetermined value T2 and the first predetermined value T1 (T2 <Tw ≦ T1), depending on the previous range of the fuel cell temperature Tw−1, If T1 <Tw-1, the power generation stoppage possible flag is set, if T2 <Tw-1≤T1, the power generation stoppage possible flag is held, and if Tw-1 <T2, the power generation stoppage possible flag is reset. .
[0059]
In FIG. 7A, the power generation continuation determining means 39 first reads the fuel cell temperature Tw from the temperature sensor 33 in S50. Next, in S52, the required power generation amount Pr is read from the vehicle motion control means 37, and in S54, it is determined whether the required power generation amount Pr is zero. If the required power generation amount Pr is not 0 in S54, the process proceeds to S62, and the required power generation amount Pr is commanded from the power generation amount control means 41 to the fuel cell system 3 to generate the required power generation amount Pr.
[0060]
If the required power generation amount Pr is 0 in the determination of S54, the process proceeds to S56, and the previous fuel cell temperature Tw-1 is read. Next, in S58, the power generation stoppage possible flag is set (SET), reset (RESET) or held from the current fuel cell temperature Tw and the previous fuel cell temperature Tw-1 with reference to the control map of FIG. The power generation stop flag to be (HOLD) is updated.
[0061]
Next, in S60, it is determined whether or not the value of the power generation stoppage possible flag is 1. If the value of the power generation stoppage enable flag is 1, the process proceeds to S64, and the required power generation amount Pr = 0 is output to the fuel cell system 3 in order to stop the power generation of the fuel cell system 3. If the value of the power generation stoppage enable flag is not 1 in the determination of S60, the process proceeds to S66, and the required power generation amount Pr is set to the minimum power generation amount Pmin in order to continue (or restart the power generation) to keep the fuel cell system 3 warm. Is output to the fuel cell system 3.
[0062]
Here, the steps of S60, S62, and S66 correspond to the power generation continuation determination means 39.
[0063]
According to this embodiment described above, there is an effect that it is possible to provide a control device for a fuel cell vehicle that prevents control hunting.
[0064]
[Third Embodiment]
Next, as a third embodiment, a description will be given of a third embodiment in which power generation is not stopped unless the fuel cell temperature becomes a predetermined value or more during startup of the fuel cell system. The configuration of the fuel cell vehicle 1 and the configuration and characteristics of the fuel cell system 3 are the same as those of the first embodiment shown in FIGS.
[0065]
For example, when the fuel cell system 3 of FIG. 2 is started, the fuel cell stack 75 may be cooled down. In particular, during cold weather, even if the coolant temperature detected by the temperature sensor 33 becomes equal to or higher than the first predetermined value T1, the inside of the separator constituting the fuel cell stack 75, the surface of the fuel cell stack 75, etc. It is conceivable that the value has not increased to T1.
[0066]
Therefore, when the fuel cell temperature Tw exceeds the temperature T1 when the fuel cell system is started up, if the required power generation amount becomes 0 and the power generation is stopped, moisture may be condensed in a relatively short time. In order to avoid this phenomenon, in the present embodiment, a third predetermined value T3 (T1 <T3) higher than the first predetermined value T1 is set, and the fuel cell temperature Tw is set to the first value during startup of the fuel cell system. Until the predetermined value T3 of 3 is exceeded, even if the required power generation amount Pr is 0, power generation is continued so that the inside and the surface of the fuel cell stack are sufficiently warmed up.
[0067]
FIG. 8 shows operations of the power generation continuation determining means 39 and the power generation amount control means 41 of the control device 35 in the third embodiment. This flowchart is called from the main routine and executed every predetermined time (for example, 10 msec). Note that the operation of the vehicle motion control means 37 of the control device 35 is the same as that of FIG. 5 described in the first embodiment, and therefore, a duplicate description is omitted.
[0068]
In FIG. 8, the power generation continuation determining means 39 first reads the required power generation amount Pr in S70. Next, in S72, it is determined whether or not the required power generation amount Pr is zero. If the required power generation amount Pr is not 0, the process proceeds to S84, where the required power generation amount Pr is output to the fuel cell system 3 via the power generation amount control means 41, and the power generation according to the required power generation amount Pr is performed.
[0069]
If the required power generation amount Pr is 0 in the determination in S72, the process proceeds to S74, the running flag is read, and the fuel cell temperature Tw is read in S76. Next, in S78, it is determined whether or not the running flag is 1. If the running flag is not 1, the process proceeds to S80.
[0070]
In S80, since the engine is not being started, it is determined whether or not the fuel cell temperature Tw is equal to or lower than the first predetermined value T1 according to the same normal temperature determination standard as in the first embodiment. If the fuel cell temperature Tw is equal to or lower than the first predetermined value T1, the process proceeds to S88, continues power generation for keeping the fuel cell temperature, and returns to the main routine. If it is determined in S80 that the fuel cell temperature Tw is not equal to or lower than the first predetermined value T1, the process proceeds to S90 to stop power generation and return to the main routine.
[0071]
If the startup flag is 1 in S78, it is next determined in S82 whether the fuel cell temperature Tw is equal to or higher than a third predetermined value T3 (T1 <T3). If the fuel cell temperature Tw is equal to or higher than the third predetermined value T3, the activation flag is reset in S86, and the process proceeds to S90. If it is determined in S82 that the fuel cell temperature Tw is not equal to or higher than the third predetermined value T3, the process proceeds to S88 to continue power generation.
[0072]
According to the third embodiment described above, when the fuel cell system is started, power generation can be continued until the inside and the surface of the fuel cell stack are sufficiently warmed up, which promotes warming up and prevents control hunting. There is an effect that a control device for a fuel cell vehicle can be provided.
[0073]
[Fourth Embodiment]
Next, an embodiment of a fuel cell vehicle in which the brake system has an energy regeneration function will be described as a fourth embodiment. The configuration of the fuel cell vehicle 1 and the configuration and characteristics of the fuel cell system 3 are the same as those of the first embodiment shown in FIGS.
[0074]
In the fourth embodiment, the power manager 5 of FIG. 1 realizes an energy regeneration function by regenerative braking in cooperation with the control device 35. For this reason, when the fuel cell vehicle 1 is braked, the rotational force of the drive wheels 15 rotates the drive motor 9 via the drive shaft 13 and the differential device 11, and the drive motor 9 serves as a generator to reduce the travel energy of the vehicle. Convert to regenerative power. The electric power generated by the drive motor 9 is voltage-converted and rectified by the power manager 5 and is charged in the secondary battery 7 or consumed by an auxiliary device of the fuel cell.
[0075]
FIG. 9 shows the operation of the control device 35 in the fourth embodiment. This flowchart is called from the main routine and executed every predetermined time (for example, 10 msec).
[0076]
In FIG. 9, first, in S100, it is determined whether or not the secondary battery 7 can be charged. It is assumed that the power manager 5 constantly monitors the charge / discharge state of the secondary battery 7, grasps the remaining capacity or SOC of the secondary battery 7, and notifies the control device 35 of the value. If the secondary battery 7 is not rechargeable, nothing is done and the process returns to the main routine.
[0077]
If it is determined in S100 that the secondary battery 7 can be charged, the process proceeds to S102 to determine whether there is an energy regeneration request, that is, whether braking of the fuel cell vehicle 1 is necessary. This energy regeneration request is a case where braking force is required when the brake sensor 25 detects that the driver has operated the brake pedal, or when the control device 35 performs TRC control, VSC control, or ACC control. If there is no energy regeneration request in S102, the process returns to the main routine without doing anything.
[0078]
If there is an energy regeneration request in S102, the process proceeds to S104, and the fuel cell temperature Tw is read from the temperature sensor 33. Next, in S106, it is determined whether or not the fuel cell temperature Tw is equal to or lower than a first predetermined value T1. If the fuel cell temperature Tw is equal to or lower than the first predetermined value T1, the process proceeds to S112, where power generation is continued to keep the fuel cell warm, and the secondary battery 7 is charged with the power generated by the fuel cell stack 75.
[0079]
If it is determined in S106 that the fuel cell temperature Tw is not equal to or less than the first predetermined value T1, the process proceeds to S108, where the required power generation amount Pr = 0 for the fuel cell system 3 is stopped and the power generation of the fuel cell is stopped. Next, in S110, energy regeneration by regenerative braking is performed, and the power manager 5 charges the secondary battery 7 with the regenerative power generated by the drive motor 9.
[0080]
According to the present embodiment, when the temperature of the fuel cell system is equal to or lower than a predetermined value, even if the secondary battery can be charged with regenerative energy, energy regeneration is not performed and power generation is continued to secure a heat source. There is an effect that it is possible to provide a fuel cell vehicle in which the influence of condensed water is minimized.
[0081]
[Fifth Embodiment]
Next, a fifth embodiment of the control apparatus for a fuel cell vehicle according to the present invention will be described. In the fifth embodiment, when the temperature of the fuel cell exceeds a predetermined value, the first control map in which the required power generation amount for the fuel cell is 0 is selected, while when the temperature of the fuel cell is equal to or lower than the predetermined value, the fuel cell This is an embodiment of a control device for a fuel cell vehicle that switches the control map so that the second control map in which the required power generation amount for the vehicle always exceeds 0 is selected. The configuration of the fuel cell vehicle 1 and the configuration and characteristics of the fuel cell system 3 are the same as those of the first embodiment shown in FIGS. In the present embodiment, switching of a braking torque map for controlling an inter-vehicle distance control (ACC) function of a fuel cell vehicle will be described as an example.
[0082]
FIG. 10 is a flowchart for explaining the operation of the control device 35 in the fifth embodiment. This flowchart is called from the main routine and executed every predetermined time (for example, 10 msec).
[0083]
In FIG. 10, it is first determined in S120 whether or not there is a braking torque request. If there is no braking torque request, the process returns to the main routine without doing anything. If there is a braking torque request in the determination of S120, the process proceeds to S122, and the fuel cell temperature Tw is read from the temperature sensor 33. Next, in S124, it is determined whether or not the fuel cell temperature Tw is equal to or lower than the first predetermined value T1, and if the fuel cell temperature Tw exceeds the first predetermined value T1, the process proceeds to S126, where the fuel cell temperature Tw is the first predetermined value T1. If it is equal to or less than the predetermined value T1, the process proceeds to S128. In S126, the first braking torque map which is the first control map including the required power generation amount for the fuel cell including 0 is selected, and the process proceeds to S130. In S128, the second braking torque map which is the second control map in which the required power generation amount for the fuel cell always exceeds 0 is selected, and the process proceeds to S130. In S130, braking control is performed using the selected torque map.
[0084]
FIG. 11 is a diagram for explaining an example of the first and second braking torque maps, and is a map for calculating the target braking G from the distance from the preceding vehicle and the reciprocal of the relative speed with the preceding vehicle. The first braking torque map is a normal braking torque map selected when the fuel cell temperature exceeds a predetermined value, and is shown by a mesh in FIG. The second braking torque map is a braking torque map that performs braking stronger than normal, which is selected when the fuel cell temperature is equal to or lower than a predetermined value, and is indicated by an arrow in FIG.
[0085]
Instead of switching the control map, for example, when calculating using mathematical formulas, it is also possible to change the mathematical formulas, or to change the schedule when braking is determined on a schedule basis.
[0086]
According to the present embodiment, by performing the above-described control, the generation of condensed water is prevented in advance, the power is taken out from the fuel cell before it significantly affects the fuel cell, and the water clogging of the fuel cell is prevented. It becomes possible.
[0087]
[Sixth Embodiment]
Next, a sixth embodiment of the control apparatus for a fuel cell vehicle according to the present invention will be described. The sixth embodiment is an embodiment in which the power generation for keeping the temperature of the fuel cell is resumed if a predetermined time elapses after the power generation of the fuel cell is stopped by the torque cut that stabilizes the vehicle behavior. The configuration of the fuel cell vehicle 1 and the configuration and characteristics of the fuel cell system 3 are the same as those of the first embodiment shown in FIGS.
[0088]
FIG. 12 is a flowchart for explaining the operation of the control device according to the sixth embodiment. This flowchart is called from the main routine and executed every predetermined time (for example, 10 msec).
[0089]
In FIG. 12, first, in S140, it is determined whether vehicle behavior control is present (ON) / not present (OFF). If the vehicle behavior control is present, the process returns to S142. If the vehicle behavior control is not present, the process returns to the main routine without doing anything.
[0090]
In S142, it is determined whether or not there is a torque cut request for stabilizing the vehicle behavior. If there is no torque cut request, the process returns to the main routine without doing anything.
[0091]
If there is a torque cut request in the determination in S142, the process proceeds to S144, and the fuel cell temperature Tw is read from the temperature sensor 33. Next, in S146, it is determined whether or not the torque cut flag is 1. If it is 1, the process proceeds to S148, and if it is 0, the process proceeds to S150.
[0092]
In S148, it is determined whether or not the fuel cell temperature Tw is equal to or lower than a predetermined value T1, and if it is equal to or lower than the predetermined value T1, the process proceeds to S152. If it is determined in S148 that the fuel cell temperature Tw exceeds the predetermined value T1, the process proceeds to S158, where the torque cut timer for measuring the torque cut time is updated, and the torque cut time indicated by the torque cut timer in S160 is equal to or longer than the predetermined time. It is determined whether or not. If the torque cut time is equal to or longer than the predetermined time, the torque cut is interrupted, and the process proceeds to S152 to restart power generation for keeping the fuel cell system 3 warm.
[0093]
If it is determined in S160 that the torque cut time is less than the predetermined time, the process proceeds to S162 to continue the torque cut, the required power generation amount Pr = 0 for the fuel cell system 3 is continued, and the process returns to the main routine.
[0094]
In S150, it is determined whether or not the fuel cell temperature Tw is equal to or lower than a predetermined value T1, and if it is equal to or lower than the predetermined value T1, the process proceeds to S152. If it is determined in S150 that the fuel cell temperature Tw exceeds the predetermined value T1, the process proceeds to S164, and a torque cut flag indicating that torque cut is in progress is set. Next, in order to integrate the torque cut time in S166, the torque cut timer is started, and in S168, the required power generation amount Pr for the fuel cell system 3 is set to 0, and the process returns to the main routine.
[0095]
In S152, the torque cut flag is reset, and in S154, the torque cut timer is reset. In S156, the required power generation amount Pr for the fuel cell system 3 is set as the minimum power generation amount for keeping the temperature, and the process returns to the main routine.
[0096]
According to the present embodiment described above, the power generation is resumed even if the required power generation amount is 0 when a predetermined time has elapsed after the power generation of the fuel cell is stopped by torque cut. There is an effect that water clogging due to the condensation of water can be prevented.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an overall configuration of a fuel cell vehicle including a control device for a fuel cell vehicle according to the present invention.
FIG. 2 is a configuration diagram showing a configuration of a fuel cell system.
3 is a configuration diagram of an electric brake suitable for the fuel cell vehicle of FIG. 1. FIG.
4 is a characteristic diagram showing the relationship between a decrease amount ΔT of the fuel cell temperature and the amount of condensed water W in the fuel cell system shown in FIG. 2;
FIG. 5 is a flowchart showing the operation of the control device for the fuel cell vehicle in the first embodiment.
FIG. 6 is a flowchart showing the operation of the control device for the fuel cell vehicle in the first embodiment.
7A is a flowchart showing the operation of the control device for a fuel cell vehicle according to the second embodiment, and FIG. 7B is an update control table of a power generation stoppage enable flag used in the second embodiment.
FIG. 8 is a flowchart showing the operation of a control device for a fuel cell vehicle in a third embodiment.
FIG. 9 is a flowchart showing an operation of a control device for a fuel cell vehicle according to a fourth embodiment.
FIG. 10 is a flowchart showing an operation of a control device for a fuel cell vehicle in a fifth embodiment.
FIG. 11 is a diagram showing an example of a braking torque map used by the control device for a fuel cell vehicle according to the fifth embodiment.
FIG. 12 is a flowchart showing an operation of a control device for a fuel cell vehicle in a sixth embodiment.
[Explanation of symbols]
1 ... Fuel cell vehicle
3. Fuel cell system
5. Power manager
7 ... Secondary battery
9 ... Drive motor
11 ... differential device
13 ... Drive shaft
15 ... Driving wheel
17 ... driven wheel
19 ... Brake
21 ... Wheel rotation sensor
23 ... Accelerator sensor
25 ... Brake sensor
27 ... Steering sensor
29 ... Yaw rate sensor
31 ... G sensor
33 ... Temperature sensor
35 ... Control device
37 ... Vehicle motion control means
39 ... Power generation continuation determination means
41 ... Power generation amount control means

Claims (10)

In a control device for a fuel cell vehicle using a fuel cell as a power source,
Vehicle motion control means for controlling driving and braking of the vehicle;
Power generation amount control means for controlling the power generation amount of the fuel cell based on the required power generation amount from the vehicle motion control means;
When the temperature of the fuel cell exceeds a predetermined value at which no condensed water is generated , when there is no power generation request from the vehicle motion control unit, the power generation amount control unit stops power generation of the fuel cell. If the temperature is below the predetermined value, even if no power request from the vehicle motion control unit, a power generation continuation judgment means for continuing the power generation for the thermal insulation of the fuel cell to the power generation amount control means,
A control apparatus for a fuel cell vehicle, comprising: The power generation continuation determining means is
After the fuel cell is started, until the temperature of the fuel cell exceeds a predetermined value at which no condensed water is generated, even if there is no power generation request from the vehicle motion control unit, the power generation amount control unit is allowed to warm up the fuel cell. control apparatus for a fuel cell vehicle according to claim 1 for generating electricity, wherein the benzalkonium allowed to continue for. The vehicle motion control means includes
If the temperature of the fuel cell exceeds a predetermined value condensed water does not occur, while the required power generation amount with respect to the fuel cell to select a first control map containing 0, when the temperature of the fuel cell is less than the predetermined value, the fuel cell by switching the control maps as required generation amount is always selects the second control map of more than 0 with respect to the control of the fuel cell vehicle according to claim 1, wherein the benzalkonium controls the driving and braking of the vehicle apparatus. The vehicle motion control means includes
4. The control device for a fuel cell vehicle according to claim 1, further comprising: a driving force control unit that temporarily suppresses the driving force when a slip of the driving wheel is detected. 5. The vehicle motion control means includes
The control apparatus for a fuel cell vehicle according to any one of claims 1 to 3, further comprising vehicle attitude control means for stabilizing the vehicle attitude during turning. The vehicle motion control means includes
4. The control device for a fuel cell vehicle according to claim 1, further comprising an ABS control means for preventing wheel lock during braking. The vehicle motion control means includes
The control apparatus for a fuel cell vehicle according to any one of claims 1 to 3, further comprising an inter-vehicle tracking control means for controlling an inter-vehicle distance from the preceding vehicle.   4. The fuel cell vehicle control according to claim 1, wherein the power generation amount control means restarts the power generation of the fuel cell when a predetermined time elapses after the power generation is stopped. 5. apparatus. In a control device for a fuel cell vehicle, comprising a brake system capable of energy regeneration, a fuel cell, and a secondary battery, and using at least one of the fuel cell and the secondary battery as a power source,
When the temperature of the fuel cell exceeds a predetermined value, when regenerative power is obtained from the brake system, the power generation of the fuel cell is temporarily stopped and the secondary battery is charged with the regenerative power, while the temperature of the fuel cell is Charging control means for charging the secondary battery with the generated power of the fuel cell without performing energy regeneration in the brake system when the predetermined value or less;
A control apparatus for a fuel cell vehicle, comprising:   In a control device for a fuel cell vehicle using a fuel cell as a power source,
  Vehicle motion control means for controlling driving and braking of the vehicle;
  A power generation amount control for controlling the power generation amount of the fuel cell based on the required power generation amount from the vehicle motion control means. Means and
  When the temperature of the fuel cell exceeds a first predetermined value at which no condensed water is generated, when there is no power generation request from the vehicle motion control means, the power generation amount control means stops the power generation of the fuel cell, When the temperature of the fuel cell is lower than the second predetermined value which is smaller than the first predetermined value, the power generation amount control means is used to keep the fuel cell warm even if there is no power generation request from the vehicle motion control means. Power generation continuation determining means for continuing the power generation of
  A control apparatus for a fuel cell vehicle, comprising:

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