JP6790713B2 - Fuel cell vehicle - Google Patents

Description

The present specification discloses a fuel cell vehicle that runs by driving a motor with the electric power of either a fuel cell or a battery.

Patent Document 1 discloses an example of a fuel cell vehicle. In the fuel cell vehicle, the fuel cell and the main battery are connected in parallel. Since it is difficult for a fuel cell to change its output abruptly, a main battery is provided in case the output of a motor is changed abruptly. When the output of the motor is rapidly increased, the output of the main battery is added to the output of the fuel cell. When the output of the motor is drastically reduced, the surplus power of the fuel cell is stored in the main battery.

The fuel cell is connected in parallel with the main battery via a voltage converter that converts its output voltage into the drive voltage of the traction motor. The fuel cell vehicle is also equipped with an auxiliary battery that supplies electric power to the auxiliary equipment group that is lower than the drive voltage of the traveling motor. The output voltage of the main battery and the fuel cell is 100 volts or more, and the output voltage of the auxiliary battery is 10 to 40 volts. The fuel cell vehicle of Patent Document 1 also includes a voltage converter that steps down the voltage of the output of the main battery or the output of the fuel cell and supplies the voltage to the auxiliary battery.

Auxiliary equipment includes important auxiliary equipment and non-important auxiliary equipment. A typical example of the former is an auxiliary device related to traveling such as a shift-by-wire device, and a typical example of the latter is an auxiliary device not involved in traveling such as audio equipment. It is desirable that the fuel cell vehicle be equipped with a power backup means so that the power supply to the important auxiliary equipment related to driving is not interrupted when the auxiliary battery fails. In the fuel cell vehicle of Patent Document 1, even if the auxiliary battery fails, electric power can be supplied from the main battery or the fuel cell to the important auxiliary machine via the voltage converter. That is, the main battery or fuel cell and the voltage converter function as power backup means to important auxiliary equipment.

Japanese Unexamined Patent Publication No. 2016-092893

In the technique of Patent Document 1, the above-mentioned power backup means may not be used depending on the location of failure. For example, if the auxiliary battery (or other auxiliary) fails due to a short circuit, the power supply end of the important auxiliary is held at the ground potential, and power cannot be supplied from the main battery or the fuel cell. In a fuel cell vehicle in which a main battery and a fuel cell are connected in parallel, there is room for improvement in power backup means to important auxiliary equipment.

The fuel cell vehicle disclosed in the present specification includes a main battery, a fuel cell, an auxiliary battery, an auxiliary power line, a bypass power line, a first voltage converter, a second voltage converter, a changeover switch, a first and second die, and the like. It also has a controller. The main battery stores the electric power supplied to the traction motor. The fuel cell is connected in parallel with the main battery via the FC voltage converter 31. The FC voltage converter is, for example, a multiplex converter in which a plurality of chopper-type boost converters are connected in parallel, and converts the output voltage of the fuel cell into the drive voltage of the traveling motor.

The auxiliary battery is a battery having a lower output power than the main battery and is a rechargeable battery. The auxiliary power line is a power line that connects the auxiliary battery and the first auxiliary and the second auxiliary that operate on the output power of the auxiliary battery.

The first voltage converter steps down the output voltage of the fuel cell and supplies it to the auxiliary power line. The second voltage converter steps down the output voltage of the main battery and supplies it to the auxiliary power line. The changeover switch switches the connection and disconnection between the second voltage converter and the auxiliary power line. The bypass power line is a power line that supplies power from the second voltage converter to the first auxiliary machine without going through the changeover switch and the auxiliary power line.

The first diode is provided to prevent a current backflow from the first auxiliary machine to the auxiliary power line. The second diode is provided to prevent a current backflow from the first auxiliary machine to the auxiliary power line through the bypass power line. When the auxiliary power line is short-circuited, the controller opens the changeover switch and operates the second voltage converter to supply power to the first auxiliary device via the bypass power line . When the fuel cell is inoperable, the controller closes the changeover switch, stops the first voltage converter, operates the second voltage converter, and supplies electric power to the first and second auxiliary machines. When the second voltage converter is inoperable, the controller operates the first voltage converter to supply electric power to the first and second auxiliary machines. Note that "closing the changeover switch" means conducting the devices connected to both ends of the changeover switch, and "opening the changeover switch" means electrically connecting the devices connected to both ends of the changeover switch. It means to shut off.

The first auxiliary machine is a representative of important auxiliary machines that require a backup of the power supply, such as auxiliary machines involved in driving, and the second auxiliary machine is an auxiliary machine that does not require a backup of the power supply, such as an audio device. It is a representative of the machine. Each of the "first auxiliary machine" and the "second auxiliary machine" may include a plurality of auxiliary machines.

The above fuel cell vehicle is important in all cases: (1) when the auxiliary power line is short-circuited, (2) when the fuel cell is inoperable, and (3) when the second voltage converter is inoperable. Power can be supplied to the auxiliary machine (first auxiliary machine). The case where the second voltage converter cannot operate includes the case where the second voltage converter itself cannot supply power to the auxiliary battery due to other factors even if the second voltage converter itself is normal. Other factors include, for example, a case where an abnormality occurs in the main battery and the power supply to the second voltage converter is stopped, and a short circuit failure occurs on the high voltage side of the second voltage converter. Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is a block diagram of the electric power system of the fuel cell vehicle of an Example. It is a figure which shows the circuit structure of the 2nd voltage converter.

The fuel cell vehicle 100 of the embodiment will be described with reference to the drawings. FIG. 1 shows a block diagram of the electric power system of the fuel cell vehicle 100. In FIG. 1, the solid line indicates the power line, and the broken line of the arrow indicates the signal line.

The fuel cell vehicle 100 runs on the motor 7. The motor 7 is driven by the electric power of the fuel cell 30 or the electric power of the main battery 3. Although the fuel cell 30 is shown by a simple rectangle in FIG. 1, the “fuel cell 30” here is a hydrogen tank for storing hydrogen, a fuel cell stack in which a plurality of fuel cell cells are stacked, and a fuel cell stack. It is an assembly of a plurality of devices such as an oxide gas supply device that supplies an oxide gas to a fuel cell and a fuel gas supply device that supplies a fuel gas to a fuel cell stack.

In general, automobiles are required to have the ability to rapidly change the driving force from zero to the maximum driving force in response to the driver's accelerator work. On the other hand, it is difficult for a fuel cell to change its output rapidly. Therefore, the fuel cell vehicle is equipped with a battery in addition to the fuel cell. The fuel cell vehicle 100 of the embodiment also includes a main battery 3. The main battery 3 is a rechargeable secondary battery, for example, a lithium ion battery or a nickel hydrogen battery.

The output voltage of the fuel cell 30 is, for example, 200 to 300 volts. The output voltage of the main battery 3 is, for example, 300 volts. On the other hand, the maximum drive voltage of the traveling motor 7 is 600 volts. The bidirectional DC-DC converter 5 boosts the DC power voltage of the main battery 3 to a voltage suitable for driving the motor and supplies it to the inverter 6. The FC voltage converter 31 boosts the DC power voltage of the fuel cell 30 to a voltage suitable for driving the motor and supplies it to the inverter 6. The main battery 3 and the fuel cell 30 are connected in parallel via voltage converters (bidirectional DC-DC converter 5, FC voltage converter 31), respectively.

The FC voltage converter 31 is a multiplex converter in which a plurality of chopper-type boost converter circuits using switching elements are connected in parallel. The letters "FDC" in FIG. 1 mean a voltage converter for FC. The FC voltage converter 31 adjusts the number of boost converter circuits to be operated according to the output of the fuel cell 30. For a multiplex converter that adjusts the number of boost converter circuits that operate according to the output of the fuel cell 30, refer to, for example, Japanese Patent Application Laid-Open No. 2014-014235.

The inverter 6 converts the boosted DC power of the main battery 3 and / or the boosted DC power of the fuel cell 30 into AC power suitable for driving the motor 7 and supplies it to the motor 7.

The bidirectional DC-DC converter 5 has a boosting function that boosts the power supplied from the main battery 3 and supplies it to the inverter 6, regenerative power supplied from the inverter 6, or the output of the fuel cell 30. It has both a step-down function of stepping down the voltage of surplus power not used for driving the main battery 3 and charging the main battery 3.

A system main relay 4 is connected between the main battery 3 and the bidirectional DC-DC converter 5. The symbol "SMR" in FIG. 1 represents a system main relay. When the main switch of the vehicle is turned on, the system main relay 4 is closed by the system controller 11, and the main battery 3 and the bidirectional DC-DC converter 5 are connected. When the main switch of the vehicle is turned off, the system controller 11 opens the system main relay 4, and the main battery 3 and the bidirectional DC-DC converter 5 are electrically cut off.

The fuel cell vehicle 100 includes a group of auxiliary machines that operate at a voltage lower than the output voltage of the main battery 3 and the fuel cell 30. Auxiliary equipment groups can be divided into two types: important auxiliary equipment that is an important device involved in the running of the vehicle and is required not to stop while driving, and non-important auxiliary equipment that is not involved in the running of the vehicle. .. Examples of important accessories are the shift-by-wire device 14 and the system controller 11. An example of a non-important auxiliary device is an audio device 15. Although not shown, some important accessories are connected in addition to the shift-by-wire device 14 and the system controller 11. In addition to the audio device 15, various non-important auxiliary devices are connected. In this embodiment, the shift-by-wire device 14 and the system controller 11 are representatives of important auxiliary equipment, and the audio device 15 is representative of non-important auxiliary equipment.

In addition to the above devices, the power system of the fuel cell vehicle 100 includes an auxiliary battery 13, a first voltage converter 10, a second voltage converter 20, a changeover switch 12, an auxiliary power line 35, a first bypass power line 33, and a second. It includes a bypass power line 34 and diodes 9a, 9b, 9c. Although details will be described later with reference to FIG. 2, a diode 9d having the same role as the diode 9b is provided inside the second voltage converter 20.

The auxiliary battery 13 is a battery for supplying electric power to an auxiliary group such as a shift-by-wire device 14, an audio device 15, and a system controller 11, and its output voltage is, for example, 12 volts. The shift-by-wire device 14, the audio device 15, and the system controller 11 are connected to the auxiliary battery 13 via the auxiliary power line 35. The negative electrode of the shift-by-wire device 14, the audio device 15, the system controller 11, and the auxiliary battery 13 conduct with each other via the ground G. The ground G is a conductive body of the vehicle. The auxiliary power line 35 is widely stretched in the vehicle, and various auxiliary devices are connected in addition to the shift-by-wire device 14, the audio device 15, and the system controller 11. In FIG. 1, the auxiliary power line 35 is represented by a thick solid line.

A diode 9a is attached to the shift-by-wire device 14 which is a representative of the important auxiliary equipment. The diode 9a passes a current from the auxiliary power line 35 to the shift-by-wire device 14, but does not pass a reverse current. The diode 9a is provided to prevent backflow of current from the shift-by-wire device 14 to the auxiliary power line 35 when the auxiliary power line 35, the auxiliary battery 13 or the audio device 15 is short-circuited with the ground G.

The first voltage converter 10 is connected between the output end of the fuel cell 30 and the auxiliary power line 35. The first voltage converter 10 steps down the output voltage of the fuel cell 30 and supplies it to the auxiliary power line 35. The letters "DDC1" in FIG. 1 mean "first voltage converter". The negative electrode of the output of the first voltage converter 10 is connected to the ground G in the first voltage converter 10.

The second voltage converter 20 is connected between the output end of the main battery 3 and the auxiliary power line 35. The letters "DDC2" in FIG. 1 mean "second voltage converter". The input end 20c of the second voltage converter 20 is connected to the main battery 3, and the first output end 20a is connected to the auxiliary power line 35 via the changeover switch 12. The second voltage converter 20 steps down the voltage of the output power of the main battery 3 and supplies it to the auxiliary power line 35 (that is, the auxiliary battery 13). A changeover switch 12 is connected between the first output terminal 20a of the second voltage converter 20 and the auxiliary power line 35. The changeover switch 12 is normally closed and is opened when the auxiliary power line 35 is short-circuited to disconnect the second voltage converter 20 from the auxiliary power line 35. The changeover switch 12 is controlled by the system controller 11. The negative electrode of the output of the second voltage converter 20 is connected to the ground G in the second voltage converter 20.

A first bypass power line 33 is also connected to the first output terminal 20a of the second voltage converter 20. The first bypass power line 33 is connected to the shift-by-wire device 14. The first bypass power line 33 is a power line for supplying power from the second voltage converter 20 to the shift-by-wire device 14 without going through the auxiliary power line 35. A diode 9b is connected in the middle of the first bypass power line 33. The diode 9b passes a current from the second voltage converter 20 toward the shift-by-wire device 14 and does not pass a current in the opposite direction. The diode 9b is provided to prevent a current backflow from the shift-by-wire device 14 to the auxiliary power line 35 through the first bypass power line 33.

The second voltage converter 20 includes a second output terminal 20b in addition to the first bypass power line 33 and the first output terminal 20a connected to the auxiliary power line 35. Power of a voltage obtained by stepping down the output voltage of the main battery 3 is output from either output end. The second output terminal 20b of the second voltage converter 20 is connected to the system controller 11 via the second bypass power line 34. The system controller 11 receives power from both the auxiliary power line 35 and the second bypass power line 34. A diode 9c is connected between the system controller 11 and the auxiliary power line 35. The diode 9c conducts a current from the auxiliary power line 35 to the system controller 11, but does not pass a reverse current. The diode 9c is provided to prevent a backflow of current from the system controller 11 to the auxiliary power line 35 when the auxiliary power line 35 is short-circuited with the ground G.

When a failure occurs in the power system of the auxiliary equipment group, the system controller 11 controls the changeover switch 12 and the first and second voltage converters 10 and 20 so that the power supply to the important auxiliary equipment is continued. In this embodiment, the shift-by-wire device 14 and the system controller 11 itself are examples of important auxiliary machines. When a short-circuit failure occurs in the auxiliary battery 13 or the audio device 15, the auxiliary power line 35 is short-circuited with the ground G. When the power supply through the auxiliary power line 35 is interrupted, the system controller 11 determines that the auxiliary power line 35 is short-circuited and opens the changeover switch 12. As a result, the second voltage converter 20 is disconnected from the short-circuited auxiliary power line 35. Since the system controller 11 receives power from the second voltage converter 20 via the second bypass power line 34 in addition to the auxiliary power line 35, the system controller 11 continues even if the power supply from the auxiliary power line 35 is interrupted. Can work. Since the backflow prevention diode 9c is connected between the auxiliary power line 35 and the system controller 11, even if the auxiliary power line 35 is short-circuited, the current does not flow back from the system controller 11 to the auxiliary power line 35. Absent.

Even if the auxiliary power line 35 is short-circuited, the current does not flow back from the shift-by-wire device 14 to the auxiliary power line 35 due to the backflow prevention diode 9a. When the auxiliary power line 35 is short-circuited, the first output terminal 20a of the second voltage converter 20 and the first bypass power line 33 are also short-circuited for a short time until the changeover switch 12 is opened. Since the backflow prevention diode 9b is connected to the first bypass power line 33, a current flows back from the shift-by-wire device 14 to the auxiliary power line 35 via the first bypass power line 33 and the changeover switch 12 before opening. There is no such thing. However, the shift-by-wire device 14 is cut off from power supply for a short time until the changeover switch 12 is opened. When the system controller 11 detects a short circuit in the auxiliary power line 35, the system controller 11 opens the changeover switch 12 and then operates the second voltage converter 20. When the changeover switch 12 is opened, the output voltage of the first output terminal 20a of the second voltage converter 20 is restored, and the power supply to the shift-by-wire device 14 is resumed via the first bypass power line 33.

As described above, even if the auxiliary power line 35 is short-circuited, power is continuously supplied to the shift-by-wire device 14. Further, even if the auxiliary power line 35 is short-circuited, the power supply to the system controller 11 is continued. As described above, when the auxiliary power line 35 is short-circuited, the power supply to the shift-by-wire device 14 is stopped for a short time until the changeover switch 12 is opened. On the other hand, inside the second voltage converter 20, a circuit is configured in which the power supply from the second output terminal 20b is continued even if the first output terminal 20a is short-circuited. Next, the circuit configuration of the second voltage converter 20 will be described with reference to FIG.

FIG. 2 is a diagram showing a circuit configuration of the second voltage converter 20. The second voltage converter 20 includes a conversion main circuit 22 including a power transistor, a control circuit 23 for controlling the power transistor of the conversion main circuit 22, a diode 9d, and a capacitor 25. The conversion main circuit 22 steps down the voltage of the output power of the main battery 3 input from the input terminal 20c and outputs the voltage to the first output terminal 20a and the second output terminal 20b. The negative electrode of the output of the conversion main circuit 22 is connected to the ground G. A diode 9d is connected between the positive electrode output end 22a and the second output end 20b of the conversion main circuit 22. As described above with reference to FIG. 1, the auxiliary power line 35 is connected to the first output terminal 20a via the changeover switch 12, and the auxiliary power line 35 is connected to the second output terminal 20b via the second bypass power line 34. The system controller 11 is connected. When the auxiliary power line 35 is short-circuited, the first output terminal 20a of the second voltage converter 20 is also short-circuited until the changeover switch 12 is opened. The diode 9d passes a current from the positive electrode output end 22a of the conversion main circuit 22 toward the second output end 20b, but cuts off the current in the opposite direction. The diode 9d prevents the current from flowing back from the system controller 11 to the auxiliary power line 35 via the second bypass power line 34 and the changeover switch 12 when the first output terminal 20a is short-circuited.

The capacitor 25 and the control circuit 23 are connected to the side of the second output end 20b with respect to the backflow prevention diode 9d. Although not shown, the control circuit 23 also receives power from the auxiliary battery 13 via the auxiliary power line 35. Before the auxiliary power line 35 is short-circuited, the control circuit 23 receives power from the auxiliary battery 13 via the auxiliary power line 35 and operates. Another diode that prevents current backflow from the control circuit 23 to the auxiliary power line 35 is also connected between the control circuit 23 and the auxiliary power line 35. Therefore, when the auxiliary power line 35 is short-circuited, the current does not flow back from the control circuit 23 to the auxiliary power line 35.

Since the capacitor 25 is connected to the cathode side of the diode 9d, no current flows from the capacitor 25 to the side of the first output terminal 20a when the first output terminal 20a is short-circuited. Power is stored in the capacitor 25 before the auxiliary power line 35 is short-circuited. When the auxiliary power line 35 is short-circuited and the voltage at the first output end 20a (and the positive electrode output end 22a of the conversion main circuit 22) drops to the potential of ground G, power is supplied from the capacitor 25 to the control circuit 23. The control circuit 23 can continue to operate. Further, the system controller 11 is connected to the second output terminal 20b via the second bypass power line 34. When the auxiliary power line 35 is short-circuited and the voltage at the first output end 20a (and the positive electrode output end 22a of the conversion main circuit 22) drops to the ground potential, power is also supplied from the capacitor 25 to the system controller 11. That is, the diode 9d and the capacitor 25 continue to supply power to the control circuit 23 and the system controller 11 from the short circuit of the auxiliary power line 35 to the opening of the changeover switch 12. The system controller 11 can continue to operate even when the auxiliary power line 35 is in a short-circuited state, and opens the changeover switch 12. When the changeover switch 12 is opened, the short-circuit state of the first output end 20a (and the positive electrode output end 22a of the conversion main circuit 22) is resolved. Then, the power supply from the conversion main circuit 22 to the shift-by-wire device 14 and the system controller 11 through the auxiliary power line 35 is restarted.

As described above, the fuel cell vehicle 100 can continue to supply power to important auxiliary equipment (shift-by-wire device 14 and system controller 11) even if the auxiliary power line 35 is short-circuited. In the fuel cell vehicle 100, when the auxiliary power line 35 is short-circuited, the power supply to the shift-by-wire device 14 is temporarily stopped until the changeover switch 12 is opened. On the other hand, the power supply to the system controller 11 continues until the changeover switch 12 is opened.

The circuit system of FIG. 1 continues to supply power to important auxiliary equipment (that is, shift-by-wire device 14 and system controller 11) even when an abnormality other than the short circuit of the auxiliary power line 35 described above occurs in the auxiliary equipment system. be able to. The changeover switch 12 is normally (normally) kept closed. When the fuel cell 30 is inoperable, the system controller 11 stops the first voltage converter 10 and operates the second voltage converter 20 while keeping the changeover switch 12 closed. Since the changeover switch 12 is closed, the output power of the second voltage converter 20 is supplied to all the auxiliary machines via the auxiliary power line 35.

When the second voltage converter 20 is inoperable, the system controller 11 operates the first voltage converter 10. The output power of the first voltage converter 10 is supplied to all the auxiliary machines via the auxiliary power line 35. The case where the second voltage converter 20 cannot operate includes a case where the power supply to the second voltage converter 20 is stopped for some reason in addition to the failure of the second voltage converter 20.

When the system controller 11 detects a short circuit in the auxiliary power line 35, the system controller 11 opens the changeover switch 12 and turns on a warning light indicating that an abnormality has occurred in the auxiliary equipment system. Even if an abnormality occurs in the auxiliary equipment system, the fuel cell vehicle 100 can continue to run because the power supply to the important auxiliary equipment (first auxiliary equipment) is continued. At this time, the system controller 11 may shift to a special traveling mode (evacuation traveling mode) when an abnormality occurs, such as suppressing the maximum output of the motor 7.

When the system controller 11 detects an abnormality other than a short circuit of the auxiliary power line 35, the system controller 11 keeps the changeover switch 12 in the closed state and turns on a warning light notifying that an abnormality has occurred in the auxiliary equipment system. Further, the system controller 11 opens the system main relay 4 when a short circuit occurs on the side of the main battery 3 with respect to the system main relay 4. By doing so, the running can be continued using the output power of the fuel cell 30. Even in that case, the system controller 11 may shift to a special traveling mode (evacuation traveling mode) when an abnormality occurs, such as suppressing the maximum output of the motor 7.

Further, for example, even when a short-circuit failure occurs inside the bidirectional DC-DC converter 5, the system controller 11 opens the system main relay 4. This is to prevent overcurrent of the main battery 3.

The fuel cell vehicle 100 of the embodiment can continue to supply electric power to important auxiliary devices (shift-by-wire device 14, system controller 11) even when the following abnormality occurs. (1) When the auxiliary power line 35 is short-circuited. (2) When the fuel cell 30 is inoperable. (3) When the second voltage converter 20 cannot operate. In the case of (1), the system controller 11 opens the changeover switch 12 and operates the second voltage converter 20 to continue supplying power to the shift-by-wire device 14 and the system controller 11. In the case of (2), the system controller 11 keeps the changeover switch 12 closed, stops the first voltage converter 10 and operates the second voltage converter 20 to continue supplying power to all auxiliary machines. Let me. In the case of (3), the system controller 11 operates the first voltage converter 10 to continue supplying power to all the auxiliary machines.

The points to be noted regarding the technique described in the examples will be described. The shift-by-wire device 14 and the system controller 11 of the embodiment correspond to an example of the "first auxiliary machine" of the claim. In addition to the shift-by-wire device 14 and the system controller 11, a first auxiliary device that should continue to supply power even after the auxiliary power line 35 is short-circuited may be connected. The first bypass power line 33 and the second bypass power line 34 of the embodiment correspond to an example of the "bypass power line" of the claim. The audio device 15 of the embodiment corresponds to an example of the "second auxiliary machine" of the claim. As a second auxiliary device that may be stopped when the auxiliary machine power line 35 is short-circuited, a device other than audio such as a room lamp may be connected. The system controller 11 of the embodiment corresponds to an example of the "controller" of the claim.

The diodes 9a and 9c of the embodiment correspond to an example of the "first diode" of the claim. The diodes 9b and 9d of the embodiment correspond to an example of the "second diode" of the claim. The diodes 9a and 9b may be incorporated in the shift-by-wire device 14. The diode 9c may be incorporated in the system controller 11.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

3: Main battery 4: System main relay 5: Bidirectional DC-DC converter 6: Inverter 7: Motor 9a-9d: Diode 10: First voltage converter 11: System controller 12: Changeover switch 13: Auxiliary battery 14: Shift By-wire device 15: Audio device 20: Second voltage converter 20a: First output end 20b: Second output end 20c: Input end 22: Conversion main circuit 22a: Positive output end 23: Control circuit 25: Capacitor 30: Fuel cell 31 : FC voltage converter 33: 1st bypass power line 34: 2nd bypass power line 35: Auxiliary power line 100: Fuel battery vehicle G: Ground

Claims (1)

The main battery that stores the electric power supplied to the traction motor,
A fuel cell connected in parallel with the main battery via a voltage converter for FC,
Auxiliary battery with lower output power than main battery,
An auxiliary power line connecting the auxiliary battery and the first auxiliary and the second auxiliary that operate on the output power of the auxiliary battery.
A first voltage converter that steps down the output voltage of the fuel cell and supplies it to the auxiliary power line.
A second voltage converter that steps down the output voltage of the main battery and supplies it to the auxiliary power line.
A changeover switch for switching connection and disconnection between the second voltage converter and the auxiliary power line,
A bypass power line that supplies power from the second voltage converter to the first auxiliary machine without going through the changeover switch and the auxiliary power line.
A first diode that prevents current backflow from the first auxiliary machine to the auxiliary power line,
A second diode that prevents current backflow from the first auxiliary machine to the auxiliary power line through the bypass power line, and
It has a controller and
The controller
When the auxiliary power line is short-circuited, the changeover switch is opened and the second voltage converter is operated to supply power to the first auxiliary device via the bypass power line .
Wherein when the fuel cell is inoperable closing said changeover switch, supplies power the to first the first accessory by operating the second voltage converter stops the voltage converter and the second accessory,
It said supplying power to said first auxiliary and second auxiliary by operating the first voltage converter when the second voltage converter is inoperable,
Fuel cell vehicle.

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