JP5776406B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  As a conventional fuel cell system, there is one that promotes warm-up by supplying electric power to an auxiliary machine when the fuel cell is warm-up (see Patent Document 1).

JP 2000-512068 A

  When the fuel cell is warmed up, the heat loss increases as the power generated by the fuel cell increases, and the warm-up performance improves. However, auxiliary machines that can be energized during warm-up are limited to cathode compressors and heaters that raise the temperature of cooling water, and cannot generate more power than the power consumed by these auxiliary machines. Therefore, there is a problem that sufficient warm-up performance cannot be obtained if power is supplied only to the auxiliary machine as in the conventional fuel cell system.

  The present invention has been made paying attention to such conventional problems, and an object of the present invention is to improve the warm-up performance by increasing the power generated by the fuel cell during warm-up.

  The present invention is a fuel cell system in which an anode gas and a cathode gas are supplied to a fuel cell to generate power, and the generated power is supplied to a drive motor of the vehicle. And when the fuel cell is warmed up, it is provided with a warm-up control means for promoting the warm-up by supplying generated power to the drive motor.

The present invention, the anode gas and the cathode gas and power is supplied to the fuel cell, a fuel cell system for supplying generated power to the drive motor of the vehicle. In addition, when the fuel cell is warmed up, it is provided with a warm-up control means for promoting the warm-up by supplying generated power to the drive motor, and the warm-up control means generates power to the drive motor so as to increase the output current of the fuel cell. It is characterized by supplying electric power .

1 is a schematic view of a fuel cell system according to an embodiment of the present invention. It is a figure which shows the relationship between the temperature of a fuel cell stack, and the current voltage characteristic of a fuel cell stack. It is a flowchart explaining the warm-up control by one Embodiment of this invention. It is a flowchart explaining a drive motor supply electric power calculation process. 7 is a map for calculating the amount of heat generated by the fuel cell stack per unit time based on the output power of the fuel cell stack and the average cell voltage. It is a map which calculates a 1st largest drive motor supply electric power sequentially based on warming-up completion prediction time and estimated drive motor temperature. It is a map which calculates a 2nd largest drive motor supply electric power sequentially based on warming-up completion prediction time and estimated inverter temperature. It is a flowchart explaining an estimated drive motor temperature calculation process. It is a table which calculates the rising temperature of a drive motor based on an electric power integrated value. It is a flowchart explaining an estimated inverter temperature calculation process. It is a table which calculates the temperature rise of an inverter based on an electric power integrated value.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In a fuel cell, an electrolyte membrane is sandwiched between an anode electrode (fuel electrode) and a cathode electrode (oxidant electrode), an anode gas containing hydrogen in the anode electrode (fuel gas), and a cathode gas containing oxygen in the cathode electrode (oxidant) Electricity is generated by supplying gas. The electrode reaction that proceeds in both the anode electrode and the cathode electrode is as follows.

Anode electrode: 2H ₂ → 4H ⁺ + 4e ⁻ (1)
Cathode electrode: 4H ⁺ + 4e ⁻ + O ₂ → 2H ₂ O (2)

  The fuel cell generates an electromotive force of about 1 volt by the electrode reactions (1) and (2).

  When a fuel cell is used as a power source for automobiles, a large amount of electric power is required. Therefore, the fuel cell is used as a fuel cell stack in which several hundred fuel cells are stacked. Then, a fuel cell system that supplies anode gas and cathode gas to the fuel cell stack is configured, and electric power for driving the vehicle is taken out.

  FIG. 1 is a schematic diagram of a fuel cell system 100 according to an embodiment of the present invention.

  The fuel cell system 100 includes a fuel cell stack 1, a cathode gas supply / discharge device 2, an anode gas supply / discharge device 3, a stack cooling device 4, a power system 5, a power system cooling device 6, and a park lock device 7. And a controller 8.

  The fuel cell stack 1 is formed by stacking several hundred fuel cells, and receives the supply of anode gas and cathode gas to generate electric power necessary for driving the vehicle. The fuel cell stack 1 includes an anode electrode side output terminal 11 and a cathode electrode side output terminal 12 as terminals for taking out electric power.

  The cathode gas supply / discharge device 2 is a device that supplies cathode gas to the fuel cell stack 1 and discharges cathode off-gas discharged from the fuel cell stack 1 to the outside air. The cathode gas supply / discharge device 2 includes a cathode gas supply passage 21, a filter 22, a cathode compressor 23, and a cathode gas discharge passage 24.

  The cathode gas supply passage 21 is a passage through which the cathode gas supplied to the fuel cell stack 1 flows. The cathode gas supply passage 21 has one end connected to the filter 22 and the other end connected to the cathode gas inlet hole of the fuel cell stack 1.

  The filter 22 removes foreign matters in the cathode gas taken into the cathode gas supply passage 21.

  The cathode compressor 23 is provided in the cathode gas supply passage 21. The cathode compressor 23 takes in air (outside air) as cathode gas through the filter 22 into the cathode gas supply passage 21 and supplies it to the fuel cell stack 1.

  The cathode gas discharge passage 24 is a passage through which the cathode off gas discharged from the fuel cell stack 1 flows. One end of the cathode gas discharge passage 24 is connected to the cathode gas outlet hole of the fuel cell stack 1, and the other end is an open end.

  The anode gas supply / discharge device 3 is a device that supplies anode gas to the fuel cell stack 1 and discharges anode off-gas discharged from the fuel cell stack 1 to the cathode gas discharge passage 24. The anode gas supply / discharge device 3 includes a high-pressure tank 31, an anode gas supply passage 32, a pressure reducing valve 33, an anode gas discharge passage 34, and a purge valve 35.

  The high pressure tank 31 stores the anode gas supplied to the fuel cell stack 1 in a high pressure state.

  The anode gas supply passage 32 is a passage for supplying the anode gas discharged from the high-pressure tank 31 to the fuel cell stack 1. The anode gas supply passage 32 has one end connected to the high pressure tank 31 and the other end connected to the anode gas inlet hole of the fuel cell stack 1.

  The pressure regulating valve 33 is provided in the anode gas supply passage 32. The pressure regulating valve 33 is controlled to be opened and closed by the controller 8 and adjusts the pressure of the anode gas flowing out from the high-pressure tank 31 to the anode gas supply passage 32 to a desired pressure.

  The anode gas discharge passage 34 is a passage through which the anode off gas discharged from the fuel cell stack 1 flows. The anode gas discharge passage 34 has one end connected to the anode gas outlet hole of the fuel cell stack 1 and the other end connected to the cathode gas discharge passage 24.

  The purge valve 35 is provided in the anode gas discharge passage 34. The purge valve 35 is controlled to be opened and closed by the controller 8 and controls the flow rate of the anode off gas discharged from the anode gas discharge passage 34 to the cathode gas discharge passage 24.

  The stack cooling device 4 is a device that cools the fuel cell stack 1 and maintains the fuel cell stack 1 at a temperature suitable for power generation. The stack cooling device 4 includes a cooling water circulation passage 41, a radiator 42, a bypass passage 43, a three-way valve 44, a circulation pump 45, a PTC heater 46, and a water temperature sensor 47.

  The cooling water circulation passage 41 is a passage through which cooling water for cooling the fuel cell stack 1 circulates.

  The radiator 42 is provided in the cooling water circulation passage 41. The radiator 42 cools the cooling water discharged from the fuel cell stack 1.

  The bypass passage 43 has one end connected to the coolant circulation passage 41 and the other end connected to the three-way valve 44 so that the coolant can be circulated by bypassing the radiator 42.

  The three-way valve 44 is provided in the cooling water circulation passage 41 on the downstream side of the radiator 42. The three-way valve 44 switches the cooling water circulation path according to the temperature of the cooling water. Specifically, when the temperature of the cooling water is relatively high, the cooling water circulation path is such that the cooling water discharged from the fuel cell stack 1 is supplied again to the fuel cell stack 1 via the radiator 42. Switch. On the contrary, when the temperature of the cooling water is relatively low, the cooling water discharged from the cooling water discharged from the fuel cell stack 1 flows through the bypass passage 43 without passing through the radiator 42 and is again returned to the fuel cell stack 1. The cooling water circulation path is switched so as to be supplied.

  The circulation pump 45 is provided in the cooling water circulation passage 41 on the downstream side of the three-way valve 44 and circulates the cooling water.

  The PTC heater 46 is provided in the cooling water circulation passage 41 between the three-way valve 44 and the circulation pump 45. The PTC heater 46 is energized when the fuel cell stack 1 is warmed up to raise the temperature of the cooling water.

  The water temperature sensor 47 is provided in the cooling water circulation passage 41 on the upstream side of the radiator 42. The water temperature sensor 47 detects the temperature of the cooling water discharged from the fuel cell stack 1 (hereinafter referred to as “stack cooling water temperature”). In the present embodiment, the stack cooling water temperature is used as the temperature of the fuel cell stack 1.

  The power system 5 includes a current sensor 51, a voltage sensor 52, a drive motor 53, an inverter 54, a battery 55, and a DC / DC converter 56.

  The current sensor 51 detects a current taken out from the fuel cell stack 1 (hereinafter referred to as “output current”).

  The voltage sensor 52 detects an inter-terminal voltage (hereinafter referred to as “output voltage”) between the anode electrode side output terminal 11 and the cathode electrode side output terminal 12.

  The drive motor 53 is a three-phase AC synchronous motor in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The drive motor 53 functions as an electric motor that is driven to rotate by receiving electric power supplied from the fuel cell stack 1 and the battery 55, and power generation that generates electromotive force at both ends of the stator coil during deceleration of the vehicle in which the rotor is rotated by external force. Function as a machine.

  The inverter 54 includes a plurality of semiconductor switches such as IGBTs (Insulated Gate Bipolar Transistors). The semiconductor switch of the inverter 54 is controlled to be opened and closed by the controller 8, whereby DC power is converted into AC power or AC power is converted into DC power. When the drive motor 53 functions as an electric motor, the inverter 54 converts the combined DC power of the generated power of the fuel cell stack 1 and the output power of the battery 55 into three-phase AC power and supplies the three-phase AC power to the drive motor 53. On the other hand, when the drive motor 53 functions as a generator, the regenerative power (three-phase AC power) of the drive motor 53 is converted into DC power and supplied to the battery 55.

  The battery 55 charges the surplus power generated by the fuel cell stack 1 (output current × output voltage) and the regenerative power of the drive motor 53. The electric power charged in the battery 55 is supplied to auxiliary equipment such as the cathode compressor 23 and the PTC heater 46 and the drive motor 53 as necessary.

  The DC / DC converter 56 is a bidirectional voltage converter that raises and lowers the output voltage of the fuel cell stack 1. By controlling the output voltage of the fuel cell stack 1 by the DC / DC converter 56, the output current of the fuel cell stack 1, and thus the generated power, is controlled.

  The power system cooling device 6 is a device that cools each electrical component of the power system 5, and includes a power system cooling water circulation passage 61, a power system radiator 62, and a power system circulation pump 63.

  The electric power system coolant circulation passage 61 is a passage through which coolant for cooling the drive motor 53, the inverter 54, the DC / DC converter 56 and the battery 55 circulates.

  The power system radiator 62 is provided in the power system cooling water circulation passage 61. The power system radiator 62 cools the cooling water circulating in the power system cooling water circulation passage 61.

  The power system circulation pump 63 is provided in the power system cooling water circulation passage 61 and circulates the cooling water.

  The park lock device 7 is provided on the output shaft 531 of the drive motor 53. The park lock device 7 mechanically moves the output shaft 531 of the drive motor 53 so that the output shaft 531 of the drive motor 53 does not rotate when the position of the shift lever selected by the driver is in the parking range (P range). It is a fixing device. The park lock device 7 mechanically fixes the output shaft 531 of the drive motor 53 by engaging a pawl member (parking pawl) with a parking gear that rotates integrally with the output shaft 531 of the drive motor 53.

  The controller 8 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). In addition to the water temperature sensor 47, current sensor 51, and voltage sensor 52, the controller 8 includes an outside air temperature sensor 81 that detects outside air temperature, a shift lever position detection sensor 82 that detects the position of the shift lever, and an accelerator pedal. Signals from various sensors necessary for controlling the fuel cell system 100 such as an accelerator stroke sensor 83 for detecting the amount of depression of the battery and an SOC sensor 84 for detecting the amount of charge of the battery 55 are input.

  The controller 8 performs warm-up control of the fuel cell stack 1 based on these input signals.

  FIG. 2 is a diagram showing the relationship between the temperature of the fuel cell stack 1 and the current-voltage characteristics (hereinafter referred to as “IV characteristics”) of the fuel cell stack 1.

  As shown in FIG. 2, the IV characteristic of the fuel cell stack 1 changes according to the temperature of the fuel cell stack 1, and the lower the temperature of the fuel cell stack 1, the more the output current of the same current value from the fuel cell. The output voltage when taken out is low. That is, the power generation efficiency of the fuel cell decreases as the temperature of the fuel cell decreases.

  If the vehicle is allowed to travel in a state where the power generation efficiency of the fuel cell stack 1 is lowered, the required power of the drive motor 53 becomes large during traveling and the output current of the fuel cell stack 1 increases. The output voltage of 1 may be lower than the minimum voltage. Here, the minimum voltage is a voltage value set in advance by experiments or the like, and is a voltage value that promotes deterioration of the electrolyte membrane of the fuel cell when the output voltage of the fuel cell stack 1 falls below this value.

  Therefore, after the fuel cell system 100 is started, the fuel cell stack 1 is warmed up early, and even if the IV characteristic of the fuel cell stack 1 increases the required power of the drive motor 53, the fuel cell stack 1 It is necessary to raise the temperature of the fuel cell stack 1 until the output voltage has an IV characteristic that does not fall below the minimum voltage.

  Here, in order to increase the warm-up speed of the fuel cell stack 1, it is effective to increase the output power of the fuel cell stack 1 during warm-up to increase the generated power. The reason will be described below.

  When all the chemical energy of hydrogen as the anode gas can be converted into electric energy, the output voltage of the fuel cell stack 1 becomes the theoretical voltage shown in FIG.

  However, since various losses such as resistance polarization, activation polarization, and diffusion polarization occur inside the fuel cell, it is not possible to convert all chemical energy into electrical energy, and part of the chemical energy is thermal energy. And then released to the outside. Therefore, as shown in FIG. 2, the output voltage of the fuel cell stack 1 becomes lower than the theoretical voltage by the amount of thermal energy released to the outside as a loss.

  As shown in FIG. 2, the fuel cell stack 1 has a characteristic (IV characteristic) that the output voltage decreases as the output current increases regardless of the temperature of the fuel cell stack 1.

  Therefore, as the output current of the fuel cell stack 1 increases, the thermal energy released to the outside increases, so that the warm-up speed of the fuel cell stack 1 increases as the output current of the fuel cell stack 1 increases.

  Therefore, when the fuel cell stack 1 is warmed up, it is desired to increase the output current as much as possible in order to increase the warm-up speed as much as possible. However, since the electrical parts that can be energized during warm-up without permission to travel are limited to auxiliary machines such as the cathode compressor 23 and the PTC heater 46, an output current higher than the current energized to the auxiliary machine is obtained from the fuel cell stack 1. I could not take it out. Further, in order to suppress deterioration of the electrolyte membrane of the fuel cell, it is necessary to prevent the output voltage of the fuel cell stack 1 from falling below a predetermined minimum voltage.

  Therefore, in the present embodiment, the drive motor 53 that has not been energized at the time of warm-up is energized so that the output voltage of the fuel cell stack 1 does not fall below the minimum voltage. Thereby, the output current of the fuel cell stack 1 can be increased and the warm-up speed can be increased. Hereinafter, the warm-up control according to this embodiment will be described.

  FIG. 3 is a flowchart illustrating the warm-up control according to the present embodiment. The controller 8 repeatedly executes this routine every predetermined time (for example, 10 ms).

  In step S1, the controller 8 determines whether or not the fuel cell stack 1 needs to be warmed up. Specifically, it is determined whether or not the stack cooling water temperature detected by the water temperature sensor 47 is lower than a predetermined warm-up completion temperature. This warm-up completion temperature is a temperature at which travel permission can be issued, and is set according to the characteristics of the fuel cell system 100 in a timely manner. If the stack cooling water temperature is lower than the warm-up completion temperature, the controller 8 performs the process of step S2. On the other hand, if the stack coolant temperature is equal to or higher than the warm-up completion temperature, the current process is terminated.

  In step S2, the controller 8 determines whether or not the position of the shift lever selected by the driver is within the parking range. If the position of the shift lever detected by the shift lever position detection sensor 72 is the parking range, the controller 8 performs step S3. On the other hand, if the position of the shift lever is a travel range other than the parking range (D range), a reverse travel range (R range), or a neutral range (N range), the process of step S7 is performed.

  In step S <b> 3, the controller 8 performs a calculation process of power to be supplied to the drive motor 53 during warm-up (hereinafter referred to as “drive motor supply power”). The drive motor supply power calculation process will be described later with reference to FIG.

  In step S <b> 4, the controller 8 supplies drive motor supply power to the drive motor 53. Specifically, the fuel cell stack 1 is driven by the DC / DC converter 56 so that the power generated by the fuel cell stack 1 is the sum of the power consumption of the auxiliary machines (the cathode compressor 23 and the PTC heater 46) and the drive motor supply power. 1 is controlled to supply drive motor supply power to the drive motor 53.

  At this time, the controller 8 simultaneously controls the operation of the inverter 54 so that the drive motor 53 does not rotate. Specifically, the position of the rotor of the drive motor 53 is detected by a sensor such as a resolver, and a current is passed through the stator coil so that the magnetic field does not alternate in the drive motor 53.

  In step S <b> 5, the controller 8 performs an estimated drive motor temperature calculation process for estimating the temperature of the drive motor 53. The estimated drive motor temperature calculation process will be described later with reference to FIG.

  In step S <b> 6, the controller 8 performs an estimated inverter temperature calculation process for estimating the temperature of the inverter 54. The estimated inverter temperature calculation process will be described later with reference to FIG.

  In step S <b> 7, the controller 8 prohibits power supply to the drive motor 53.

  FIG. 4 is a flowchart illustrating the drive motor supply power calculation process.

  In step S <b> 31, the controller 8 calculates the generated power of the fuel cell stack 1 by multiplying the output current detected by the current sensor 51 and the output voltage detected by the voltage sensor 52.

  In step S <b> 32, the controller 8 divides the output voltage detected by the voltage sensor 52 by the number of fuel cells in the fuel cell stack 1, thereby obtaining an average voltage value of each fuel cell (hereinafter referred to as “average cell voltage”). calculate.

  In step S33, the controller 8 refers to the map of FIG. 5 described later, and the amount of heat generated by the fuel cell stack 1 per unit time (calculation cycle) based on the generated power of the fuel cell stack 1 and the average cell voltage. Is calculated.

  In step S <b> 34, the controller 8 calculates the temperature increase rate of the fuel cell stack 1 by dividing the calculated heat generation amount of the fuel cell stack 1 by a predetermined heat capacity of the fuel cell stack 1.

  In step S35, the controller 8 calculates a temperature difference between a predetermined warm-up completion temperature and the stack cooling water temperature.

  In step S36, the controller 8 divides the temperature difference between the warm-up completion temperature and the stack cooling water temperature by the rate of temperature rise, so that the time required to complete the warm-up (hereinafter, “warm-up completion predicted time”), That is, the time required for the stick cooling water temperature to rise to the warm-up completion temperature is calculated.

  In step S37, the controller 8 refers to a map of FIG. 6 to be described later, and the temperature of the drive motor 53 falls within a predetermined allowable drive within the predicted warm-up completion time based on the predicted warm-up completion time and the estimated drive motor temperature. The maximum power that can be supplied to the drive motor 53 within a range that does not exceed the motor temperature (hereinafter referred to as “first maximum drive motor supply power”) is calculated. In other words, this first maximum drive motor supply power must be supplied to the drive motor 53 in order to raise the temperature of the drive motor 53 to a predetermined allowable drive motor temperature when the warm-up completion prediction time has elapsed. It is power that does not become.

  The allowable drive motor temperature is a temperature that is slightly lower than the temperature at which the stator coil of the drive motor 53 may be deteriorated, and is a temperature that is appropriately set according to the characteristics of the drive motor 53. The initial value of the estimated drive motor temperature is set to the outside air temperature detected by the outside air temperature sensor 71.

  In step S38, the controller 8 refers to a map of FIG. 7 described later, and the temperature of the inverter 54 reaches a predetermined allowable inverter temperature within the predicted warm-up completion time based on the predicted warm-up completion time and the estimated inverter temperature. The maximum power that can be supplied to the drive motor 53 within the range not exceeding (hereinafter referred to as “second maximum drive motor supply power”) is calculated. In other words, the second maximum drive motor supply power is the power that must be supplied to the drive motor 53 in order to raise the temperature of the inverter 54 to a predetermined allowable inverter temperature when the estimated warm-up completion time has elapsed. It is.

  The allowable inverter temperature is a temperature that is slightly lower than the temperature at which the semiconductor switch that is a component of the inverter 54 may be deteriorated, and is a temperature that is appropriately set according to the characteristics of the inverter 54. The initial value of the estimated inverter temperature is set to the outside air temperature detected by the outside air temperature sensor 71.

  In step S39, the controller 8 compares the first maximum drive motor supply power and the second maximum drive motor supply power, and supplies the smaller one to the drive motor 53 without deteriorating the drive motor 53 and the inverter 54. It is set as the maximum power (hereinafter referred to as “maximum drive motor supply power”) that can be performed.

  In step S40, the controller 8 determines whether or not the torque obtained when the drive motor 53 is rotationally driven with the maximum drive motor supply power (hereinafter referred to as “assumed drive torque”) is equal to or greater than a predetermined upper limit torque. To do. The predetermined upper limit torque is released when the torque is further applied to the output shaft 531 of the drive motor 53 while the output shaft 531 of the drive motor 53 is mechanically fixed by the parking lock device 7, or This torque is likely to deteriorate the parking lock device 7. If the assumed driving torque is equal to or greater than the upper limit torque, the controller 8 performs the process of step S41. On the other hand, if the assumed driving torque is smaller than the upper limit torque, the process of step S42 is performed.

  In step S41, the controller 8 sets, as basic drive motor supply power, a predetermined power limit that is determined in advance so that the torque obtained when the drive motor 53 is rotationally driven becomes the upper limit torque. This is because if the assumed drive torque is equal to or greater than the upper limit torque, if the maximum drive motor supply power is supplied to the drive motor 53, the vehicle will erroneously start when the drive motor 53 is rotationally driven due to a malfunction. Because there is a fear.

  In step S42, the controller 8 sets the maximum drive motor supply power as the basic drive motor supply power.

  In step S43, the controller 8 calls the current IV characteristic of the fuel cell stack 1 based on the stack cooling water temperature, and the output voltage of the fuel cell stack 1 does not fall below the minimum voltage based on the called IV characteristic. An upper limit of generated power (hereinafter referred to as “upper limit generated power”) is calculated.

  In step S44, the controller 8 calculates the sum of the basic drive motor supply power and the power consumption of the auxiliary machine, that is, the required value of the generated power of the fuel cell stack 1 (hereinafter referred to as “required generated power”).

  In step S45, the controller 8 determines whether or not the requested generated power is equal to or lower than the upper limit generated power. If the requested generated power is equal to or lower than the upper limit output, the controller 8 performs the process of step S42. On the other hand, if the required generated power is larger than the upper limit generated power, the process of step S43 is performed.

  In step S46, the controller 8 sets the drive motor supply power to the basic drive motor supply power. This is because the output voltage of the fuel cell stack 1 does not fall below the minimum voltage even if the basic drive motor supply power is supplied to the drive motor 53 if the required generated power is less than or equal to the upper limit output.

  In step S47, the controller 8 sets the drive motor supply power to a power obtained by subtracting the power consumption of the auxiliary machine from the upper limit generated power. This is because, if the required generated power is larger than the upper limit output, if the basic drive motor supply power is supplied to the drive motor 53, the output voltage of the fuel cell stack 1 may fall below the minimum voltage.

  FIG. 5 is a map for calculating the amount of heat generated by the fuel cell stack 1 per unit time (calculation cycle) based on the power generated by the fuel cell stack 1 and the average cell voltage.

  As shown in FIG. 5, the amount of heat generated by the fuel cell stack 1 increases as the power generated by the fuel cell stack increases and as the average cell voltage decreases.

  FIG. 6 is a map for sequentially calculating the first maximum drive motor supply power based on the estimated warm-up completion time and the estimated drive motor temperature.

  As shown in the map of FIG. 6, the first maximum drive motor supply power is set to increase as the warm-up completion prediction time becomes longer. In this way, the power generation power of the fuel cell stack 1 is increased and the warm-up speed is increased by sequentially correcting the first maximum drive motor supply power to increase as the predicted warm-up completion time becomes longer (warm-up speed). Completion prediction time is shortened).

  The first maximum drive motor supply power is set to increase as the estimated drive motor temperature decreases. Thus, when the temperature of the estimated drive motor 53 has a margin until it reaches the allowable drive motor temperature, that is, when the temperature of the estimated drive motor 53 is lower, the first maximum drive motor supply power is sequentially corrected. As a result, the power generated by the fuel cell stack 1 is increased to increase the warm-up speed.

  FIG. 7 is a map for sequentially calculating the second maximum drive motor supply power based on the estimated warm-up completion time and the estimated inverter temperature.

  As shown in the map of FIG. 7, the second maximum drive motor supply power is also increased as the warm-up completion prediction time is longer and the estimated inverter temperature is lower, similar to the first maximum drive motor supply power. Is set. The reason for this setting is also the same.

  FIG. 8 is a flowchart illustrating an estimated drive motor temperature calculation process.

  In step S <b> 51, the controller 8 reads the initial temperature of the drive motor 53. In the present embodiment, the outside air temperature when the fuel cell system 100 is started is read as the initial temperature of the drive motor 53.

  In step S <b> 52, the controller 8 calculates an integrated value of drive motor supply power (hereinafter referred to as “power integrated value”).

  In step S53, the controller 8 refers to the table of FIG. 9 and calculates the rising temperature of the drive motor 53 based on the integrated power value.

  In step S54, the controller 8 calculates the estimated drive motor temperature by adding the rising temperature of the drive motor 53 to the initial temperature of the drive motor 53.

  FIG. 10 is a flowchart illustrating an estimated inverter temperature calculation process.

  In step S61, the controller 8 reads the initial temperature of the inverter 54. In the present embodiment, the outside air temperature when the fuel cell system 100 is started is read as the initial temperature of the inverter 54.

  In step S62, the controller 8 calculates an integrated power value.

  In step S63, the controller 8 refers to the table in FIG. 11 and calculates the rising temperature of the inverter 54 based on the integrated power value.

  In step S64, the controller 8 calculates the estimated inverter temperature by adding the rising temperature of the inverter 54 to the initial temperature of the inverter 54.

  According to the present embodiment described above, the fuel is prevented so that the drive motor 53 does not rotate even for the drive motor 53 that has not supplied the generated power of the fuel cell stack 1 until the time when the fuel cell stack 1 is warmed up. The power generated by the battery stack 1 is supplied.

  As a result, the drive motor 53 is added in addition to the auxiliary machine as an electrical component that can be energized when the fuel cell stack 1 is warmed up. Therefore, the output current of the fuel cell stack 1 can be increased, The speed can be increased.

  Further, according to the present embodiment, the warm-up completion predicted time is sequentially calculated according to the generated power of the fuel cell stack 1, and the warm-up completion predicted time is calculated based on the warm-up completion predicted time and the estimated drive motor temperature. In addition, the maximum power (first maximum drive motor supply power) that can be supplied to the drive motor 53 within a range in which the temperature of the drive motor 53 does not exceed a predetermined allowable drive motor temperature is calculated. Further, based on the estimated warm-up completion time and the estimated inverter temperature, the maximum power (second electric power) that can be supplied to the drive motor 53 within a range in which the temperature of the inverter 54 does not exceed a predetermined allowable inverter temperature within the estimated warm-up completion time. The maximum drive motor power supply) was calculated.

  And comparing the magnitude of the first maximum drive motor supply power and the second drive motor supply power, and setting the smaller one as the maximum power (maximum drive motor supply power) supplied to the drive motor 53 during warm-up. did.

  Thereby, the electric power value supplied to the drive motor 53 at the time of warming-up can be set to the maximum electric power value that does not deteriorate the drive motor 53 and the inverter 54. Therefore, the warm-up of the fuel cell stack 1 can be terminated as soon as possible while suppressing deterioration of the drive motor 53 and the inverter 54.

  Further, according to the present embodiment, the torque (assumed drive torque) obtained when the drive motor 53 is rotationally driven with the maximum drive motor supply power is used to fix the output shaft 531 of the drive motor 53 by the parking lock device 7. When the torque is larger than a predetermined upper limit torque determined according to the force, the power supplied to the drive motor 53 is limited. Specifically, the maximum value of the electric power supplied to the drive motor 53 is set to a predetermined predetermined limit power at which the torque obtained when the drive motor 53 is rotationally driven becomes the upper limit torque.

  Thereby, even if the drive motor 53 is rotationally driven by mistake, the erroneous start of the vehicle can be prevented by the fixing force of the park lock device 7.

  Further, according to the present embodiment, the current IV characteristic is called from the stack cooling water temperature, and the upper limit generated power of the fuel cell stack 1 is calculated from the IV characteristic. Then, the required generated power, which is the sum of the basic drive motor supply power (maximum drive motor supply power or limited power) and the power consumption of the auxiliary devices (cathode compressor 23 and PTC heater 46) driven during warm-up, When it is larger than the upper limit generated power, the power supplied to the drive motor 53 is further restricted. Specifically, the maximum value of the power supplied to the drive motor 53 is limited to the power value obtained by subtracting the power consumption of the auxiliary machine from the upper limit generated power.

  Thereby, since it can suppress that the output voltage of the fuel cell stack 1 falls below the minimum voltage, deterioration of the electrolyte membrane can be suppressed.

  Further, according to the present embodiment, when the output shaft 531 of the drive motor 53 is not fixed by the parking lock device 7, that is, when the position of the shift lever is a range other than the parking range, The power supply was prohibited.

  Thereby, the erroneous start of the vehicle can be surely prevented.

  Note that the present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, in the above embodiment, a synchronous motor is used as the drive motor 53, but an induction motor may be used. In this case, in order to prevent the drive motor 53 from rotating, the inverter 54 may be controlled so that a current flows through the winding so that a magnetic field does not alternate in the motor.

  Moreover, in the said embodiment, although the temperature of the drive motor 53 and the inverter 54 was each estimated, you may detect with a sensor etc. actually.

  In the above embodiment, the upper limit torque is set according to the fixing force of the output shaft 531 by the park lock device 7, but may be set in consideration of the fixing force by another braking device such as a foot brake. .

1 Fuel cell stack (fuel cell)
7 Park lock device (fixing device)
53 Drive motor 54 Inverter (drive motor control device)
DESCRIPTION OF SYMBOLS 100 Fuel cell system S2 Fixing determination means S3 Warm-up drive motor supply power calculation means S4 Warm-up control means, drive motor control means S5 Temperature detection means S6 Temperature detection means S7 Warm-up power supply prohibition means S43 Upper limit generated power calculation means S45 determination means

Claims (9)

A fuel cell system that supplies anode gas and cathode gas to a fuel cell to generate power, and supplies generated power to a vehicle drive motor,
When the fuel cell is warmed up, it comprises warm-up control means for promoting the warm-up by supplying generated power to the drive motor ,
The warm-up control means supplies the generated power to the drive motor so as to increase the output current of the fuel cell. A drive motor control device for controlling the drive motor;
The warm-up control means includes
A warm-up drive motor supply power calculating means for calculating power supplied to the drive motor when the fuel cell is warmed up;
Drive motor control means for controlling the drive motor control device so that the drive motor does not rotate when power is supplied to the drive motor when the fuel cell is warmed up;
The fuel cell system according to claim 1, comprising: Temperature detecting means for detecting the temperature of the drive motor or the drive motor control device;
The warm-up drive motor supply power calculation means is
Calculate the predicted warm-up completion time of the fuel cell according to the generated power of the fuel cell,
Based on the predicted warm-up completion time of the fuel cell and the temperature of the drive motor or the drive motor control device, the temperature of the drive motor or the drive motor control device within the predicted warm-up completion time of the fuel cell Calculates the power to be supplied to the drive motor so that does not exceed a predetermined allowable temperature,
The fuel cell system according to claim 2. The temperature detecting means includes
Detecting the temperature of the drive motor or the drive motor control device by estimating the temperature of the drive motor or the drive motor control device based on an integrated value of the power supplied to the drive motor;
The fuel cell system according to claim 3. The warm-up drive motor supply power calculation means is
The longer the expected warm-up completion time of the fuel cell, the greater the power supplied to the drive motor.
The fuel cell system according to claim 3 or 4, characterized by the above. The warm-up drive motor supply power calculation means is
Increasing the power supplied to the drive motor as the temperature of the drive motor or the drive motor control device is lower,
The fuel cell system according to any one of claims 3 to 5, wherein The warm-up drive motor supply power calculation means is
Upper limit generated power calculating means for calculating the upper limit generated power of the fuel cell according to the temperature of the fuel cell;
Determining means for determining whether or not the generated power of the fuel cell exceeds the upper limit generated power when the calculated supply power is supplied to the drive motor;
With
When it is determined that the generated power of the fuel cell exceeds the upper limit generated power, the power supplied to the drive motor is limited so that the generated power of the fuel cell becomes the upper limit generated power.
The fuel cell system according to any one of claims 2 to 6, wherein A fixing device for fixing the output shaft of the drive motor;
The warm-up drive motor supply power calculation means is configured to supply the calculated supply power to the drive motor and rotate the drive motor so that the torque obtained when the drive motor rotates the output shaft of the drive motor. The electric power supplied to the drive motor is limited so that the torque obtained when the drive motor is driven to rotate is smaller than the upper limit torque when the torque is larger than a predetermined upper limit torque determined according to the fixing force of ,
The fuel cell system according to any one of claims 2 to 7, characterized in that: Fixing determination means for determining whether or not the output shaft of the drive motor is fixed;
When it is determined that the output shaft of the drive motor is not fixed at the time of warming up the fuel cell, warm-up power supply prohibiting means for prohibiting power supply to the drive motor;
The fuel cell system according to claim 8, comprising:

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