JP4910345B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system including a fuel cell that generates electricity by supplying hydrogen and air.

  The fuel cell system supplies hydrogen as fuel to the anode of the fuel cell and air as oxidant to the cathode, and generates electric power by generating an electrode reaction with an electrolyte membrane sandwiched between the anode and cathode. System. Since such a fuel cell system can realize clean exhaust and high energy efficiency, there is a great expectation for applications such as a vehicle drive source.

By the way, in a fuel cell system mounted on a vehicle, for example, the air is usually sucked and pressurized by a compressor or the like and supplied to the cathode of the fuel cell. When the vehicle travels, the air density sucked by the compressor is reduced, and therefore it is necessary to increase the torque and the rotational speed of the compressor motor as compared with the normal time. At this time, if the compressor motor is requested to have a rotational speed or torque exceeding the capacity of the compressor motor and a large current is taken out from the fuel cell, the compressor motor may fail or the durability of the fuel cell may be reduced. It will be. Therefore, a technique has been proposed in which the atmospheric pressure is detected and the extraction current from the fuel cell is limited in accordance with the detected atmospheric pressure to protect the compressor and the fuel cell (see, for example, Patent Document 1). ).
JP 2002-352833 A

  However, the performance of a compressor used as an air supply device in a fuel cell system is not always constant, and there are some variations in performance. For this reason, in consideration of variations in compressor performance, it is strictly necessary to limit the extraction current from the fuel cell in order to reliably avoid demands for rotational speed and torque that exceed the capacity of the compressor motor. It was necessary to set it to be applied, and there were many cases where it became an excessive restriction and a factor of a decrease in power performance.

  The present invention was devised in view of the conventional situation as described above, and optimally controls the torque of the motor according to the performance of the air supply device, and supplies air without excessive output limitation. It aims at providing the fuel cell system which can aim at protection of an apparatus and a fuel cell reliably.

  The fuel cell system according to the present invention limits not only the target limit torque set according to the number of revolutions of the motor but also the current motor torque value as a parameter, thereby limiting the extraction power or extraction current from the fuel cell. This solves the problem. That is, the fuel cell system of the present invention includes target limit torque setting means, motor torque detection means, and output limit means, and the output limit means sets the target torque set by the target limit torque setting means and the motor torque. Depending on the current motor torque value detected or estimated by the detection means, the extraction power or extraction current from the fuel cell is limited.

  Further, another fuel cell system according to the present invention uses not only the target limit torque set according to the number of revolutions of the motor but also the current motor torque value as a parameter, and supplies the air supplied to the cathode of the fuel cell. The above-mentioned problem is solved by limiting the pressure. That is, the fuel cell system of the present invention includes target limit torque setting means, motor torque detection means, and air pressure limit means, wherein the air pressure limit means is set to the target torque set by the target limit torque setting means, The pressure of the air supplied to the cathode of the fuel cell is limited in accordance with the current motor torque value detected or estimated by the motor torque detecting means.

  According to the fuel cell system of the present invention, since optimal motor torque control is performed according to the performance of the air supply device, while effectively avoiding problems such as power performance degradation due to excessive output limitation, The air supply device and the fuel cell can be reliably protected.

  Hereinafter, specific embodiments of a fuel cell system to which the present invention is applied will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows the main configuration of the fuel cell system according to the first embodiment. The fuel cell system of the present embodiment is mounted on a vehicle and used as a power source of the vehicle, for example, and includes a fuel cell 1 that generates electric power.

  The fuel cell 1 includes an anode (fuel electrode) to which hydrogen is supplied and a cathode (oxidant electrode) to which air is supplied to overlap each other with an electrolyte interposed therebetween, and a plurality of power generation cells are provided in multiple stages. It has a stacked structure, and converts chemical energy into electrical energy by an electrode reaction in an electrolyte. In each power generation cell of the fuel cell 1, a reaction occurs in which hydrogen supplied to the anode is separated into hydrogen ions and electrons, the hydrogen ions pass through the electrolyte, the electrons pass through an external circuit to generate electric power, and the cathode Move to each side. At the cathode, oxygen in the supplied air reacts with hydrogen ions and electrons that have moved through the electrolyte to produce water, which is discharged to the outside. That is, in the fuel cell 1, the electrode reaction shown below proceeds and electric power is generated.

Anode (fuel electrode): H ₂ → 2H ⁺ + 2e ⁻ (1)
Cathode (oxidant electrode): 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (2)
As the electrolyte of the fuel cell 1, for example, a solid polymer electrolyte membrane is used in consideration of high energy density, low cost, light weight, and the like. The solid polymer electrolyte membrane is made of an ion (proton) conductive polymer membrane such as a fluororesin ion exchange membrane, and functions as an ion conductive electrolyte when saturated with water.

  As described above, in order to generate power in the fuel cell 1, it is necessary to supply air as an oxidant gas to the cathode of the fuel cell 1 and hydrogen as a fuel gas to the anode, respectively. System and hydrogen supply system.

  Here, the air supply system includes a compressor (air supply device) 2 for sucking outside air and pumping air to the cathode of the fuel cell 1, an air supply pipe 3, an air exhaust pipe 4 for discharging cathode exhaust gas, and The air pressure regulating valve 5 is provided. The air is pressurized by the compressor 2 and sent to the air supply pipe 3 and supplied to the cathode of the fuel cell 1. Oxygen that has not been consumed in the fuel cell 1 and other components in the air are discharged from the air exhaust pipe 4 into the atmosphere. The cathode air pressure is detected by the pressure sensor 6 and is controlled by driving the air pressure regulating valve 5.

  The hydrogen supply system is configured, for example, to adjust the pressure of high-pressure hydrogen taken out from a hydrogen tank that is a hydrogen supply source via a pressure reducing valve and a hydrogen pressure regulating valve, and supply the high pressure hydrogen to the anode of the fuel cell 1 from the hydrogen supply pipe. . Since the hydrogen supply system is not a part directly related to the present invention, illustration and detailed description thereof are omitted.

  In the fuel cell system of the present embodiment, power (current) generated in the fuel cell 1 is taken out by the power manager 7 and supplied to, for example, a drive motor of the vehicle. The fuel cell system of the present embodiment has a motor torque detection means 8, a compressor rotation speed detection means 9, a target as a control system for controlling the extraction of electric power (current) from the fuel cell 1 by the power manager 7. A limiting torque setting unit 10, an atmospheric pressure sensor 11, and an output limiting unit 12 are provided.

  The motor torque detection means 8 detects or estimates the current torque value of the compressor motor that is the drive source of the compressor 2. Specifically, the motor torque detection means 8 estimates the current torque value of the compressor motor from, for example, the motor drive current, or detects the current torque value of the compressor motor using a torque sensor or the like. .

  The compressor rotation speed detection means 9 detects the rotation speed of the compressor motor (that is, the rotation speed of the compressor 2). Specifically, the compressor rotation speed detection means 9 detects the rotation speed of the compressor motor using a sensor such as a resolver or an encoder.

  The target limit torque setting means 10 sets a target limit torque for limiting the torque of the compressor motor so as not to exceed the capacity of the compressor motor. Specifically, the target limit torque setting means 10 uses, for example, a map representing the relationship between the rotation speed of the compressor motor and the upper limit torque as shown in FIG. 2, and the compressor motor detected by the compressor rotation speed detection means 9. The upper limit torque that can be output by the compressor motor at the rotation speed is set as the target limit torque.

  At this time, the target limit torque setting means 10 does not use the rotation speed of the compressor motor detected by the compressor rotation speed detection means 9 as it is as an input value of the map, but as shown in FIG. It is desirable to set the target limit torque using the output obtained by correcting the rotational speed of the compressor motor detected by the compressor rotational speed detection means 9 as the input value of the map.

  That is, in the fuel cell system of the present embodiment, as will be described later, the target torque limit set by the target torque limit setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detection means 8. Accordingly, the output current from the fuel cell 1 is limited by the output limiting means 12, but when the current extracted from the fuel cell 1 is limited, the air flow rate is reduced, so that the rotation speed of the compressor motor is reduced. Accordingly, the target limit torque increases, so that the restriction on the extraction current from the fuel cell 1 is relaxed. When the restriction on the extraction current from the fuel cell 1 is relaxed, the number of revolutions of the compressor motor increases, the target limiting torque decreases accordingly, and the restriction on the extraction current from the fuel cell 1 becomes tight. Such a phenomenon will be repeated. For this reason, there is a concern that the calculation of the target limit torque and the calculation of the extraction current limit from the fuel cell 1 interfere with each other, which may cause hunting in the extraction current limit. If the target limit torque is set according to the output obtained by correcting the rotation speed of the compressor motor detected by the compressor rotation speed detection means 9 using a first-order lag filter, the fluctuation of the rotation speed of the compressor motor is reduced. Furthermore, interference between the calculation of the target limit torque and the calculation of the extraction current limit value from the fuel cell 1 can be avoided, and problems such as hunting in the extraction current limit can be effectively suppressed.

  The atmospheric pressure sensor 11 is a pressure sensor that detects atmospheric pressure. The atmospheric pressure sensor 11 is connected to the output restriction unit 12, and information on the atmospheric pressure detected by the atmospheric pressure sensor 11 is input to the output restriction unit 12.

  The output limiting means 12 takes out from the fuel cell 1 in accordance with the target limiting torque set by the target limiting torque setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detecting means 8. The current is limited, and includes an input limit torque correction unit 12a, an output limit value calculation unit 12b, and a limit unit 12c. Here, the output limiting means 12 will be described as limiting the extraction current from the fuel cell 1, but both the current and voltage, that is, the extraction power from the fuel cell 1 may be limited. Good. When limiting the electric power extracted from the fuel cell 1, the content of the control is the same as when limiting the electric current extracted from the fuel cell 1.

  The input limit torque correction unit 12a calculates the output limit value according to the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8. The target limit torque used for the calculation in the unit 12b is corrected and calculated as the second target limit torque.

  The output limit value calculation unit 12b limits the extraction current from the fuel cell 1 according to the second target limit torque calculated by the input limit torque correction unit 12a and the atmospheric pressure detected by the atmospheric pressure sensor 11. Current limit value is calculated.

  The limiter 12c limits the target extraction current from the fuel cell 1 to the current limit value calculated by the output limit value calculator 12b. That is, if the target extraction current required for the fuel cell 1 in accordance with, for example, the operating state of the drive motor is smaller than the current limit value calculated by the output limit value calculation unit 12b, the limiting unit 12c The current is output to the power manager 7 as an extraction current command value. If the target extraction current is larger than the current limit value, the current limit value is output to the power manager 7 as an extraction current command value. Thereby, the extraction current from the fuel cell 1 is limited to the current limit value.

  A specific example of control in the output limiting means 12 is shown in FIG. In the example shown in FIG. 3, the input limit torque correction unit 12 a calculates the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8. A corresponding input torque correction value is obtained, and the second target limit torque is calculated by correcting the target limit torque set by the target limit torque setting means 10 using this input torque correction value. Then, the second target limit torque is input to the output limit value calculation unit 12b.

  The output limit value calculation unit 12b displays, for example, the relationship between the extraction current value from the fuel cell 1 and the necessary torque required for the compressor motor so that the current value can be extracted from the fuel cell 1 for each atmospheric pressure. Based on the second target limit torque input from the input limit torque correction unit 12a and the atmospheric pressure detected by the atmospheric pressure sensor 11, the motor torque of the compressor motor is calculated at the current atmospheric pressure. A current value that can be taken out from the fuel cell 1 when the target limit torque is limited to 2 is calculated as a current limit value.

  The limiting unit 12c selects the target extraction current of the fuel cell 1 and the current limit value calculated by the output limit value calculation unit 12b, and outputs the selected value to the power manager 7 as an extraction current command value. Limit the current drawn from.

  Here, the map used for the calculation in the output limit value calculation unit 12b is created by a method as shown in FIG. 4, for example. That is, the air flow rate and pressure (cathode operating pressure) supplied to the cathode of the fuel cell 1 are determined according to the extraction current from the fuel cell 1. Since the air system pressure loss from the compressor 2 to the fuel cell 1 is determined by the supply air flow rate, the discharge air pressure in the compressor 2 is determined from the air system pressure loss and the cathode operating pressure. And the pressure ratio of the compressor input / output is determined from the atmospheric pressure and the discharge air pressure of the compressor 2, and the required torque of the compressor motor is obtained. If the required torque is plotted on the horizontal axis of the graph (map input value), the current drawn from the fuel cell 1 is plotted on the vertical axis of the graph (map output value), and this is created for each atmospheric pressure, the output limit map is completed.

  As described above, the map used for the calculation by the output limit value calculation unit 12b is designed based on the extraction current from the fuel cell 1 and the necessary torque of the compressor motor, and is detected or estimated by the motor torque detecting means 8. When the current motor torque value of the compressor motor deviates from the target limit torque set by the target limit torque setting means 10, the motor deviation of the compressor motor is corrected by returning the corrected torque deviation to the map input. The torque value can be brought close to the target limit torque.

  FIG. 5 shows the relationship between the limitation on the extraction current from the fuel cell 1 and the response of the motor torque of the compressor motor due to the limitation. FIG. 5A shows an example in which a current limit value is obtained as a map input value without correcting the target limit torque set by the target limit torque setting means 10, and FIG. In this example, the target limit torque set by the limit torque setting means 10 is corrected according to the deviation from the current motor torque value of the compressor motor, and the current limit value is obtained as a map input value.

  In the example shown in FIG. 5A, the motor torque value of the compressor motor may exceed the target limit torque depending on the performance variation of the compressor 2 and the compressor motor, and further deterioration with time. Therefore, in the example shown in FIG. 5A, in order to prevent the motor torque value of the compressor motor from exceeding the target limit torque, the output limit is set so that the current limit is tightly applied according to the target limit torque. You must set up a map.

  On the other hand, in the example shown in FIG. 5 (b), the map input used for calculating the deviation between the set target limit torque and the current motor torque value of the compressor motor in the output limit value calculation unit 12b. By increasing the torque, the extraction current from the fuel cell 1 is further limited, and the overshoot of the motor torque value can be reduced. Therefore, in the example shown in FIG. 5B, in consideration of performance variations of the compressor and the compressor motor, the current limit need not be set in advance.

  As described above in detail with specific examples, in the fuel cell system of the present embodiment, the motor torque detection means 8 detects or estimates the current motor torque value of the compressor motor, and only the target limit torque is used. Since the current motor torque value is also used to limit the extraction current from the fuel cell 1, the motor torque value of the compressor motor can be accurately controlled below the allowable torque. Therefore, in this fuel cell system, it is not necessary to excessively limit the extraction current from the fuel cell 1 in consideration of performance variations of the compressor 2 and the compressor motor, and the upper limit output of the compressor motor is used up. As a result, the flow rate of air supplied to the cathode can be increased to improve the power performance, and the compressor 2, the compressor motor, the fuel cell 1 and the like can be reliably protected.

  In order not to excessively limit the extraction current from the fuel cell 1, it is conceivable to use a high-output motor as the compressor motor. However, if a high-output motor is used, the size of the compressor is increased, and consequently the system. This will lead to an increase in the overall size and increase the cost. On the other hand, in the fuel cell system of the present embodiment, it is not necessary to overdesign parts such as adopting a high output motor, and an inexpensive and compact system can be realized.

  In the fuel cell system of the present embodiment, the deviation between the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 is calculated. Accordingly, the target limit torque used for the calculation of the current limit value in the output limit means 12 is corrected, that is, the current limit value is calculated while feeding back the deviation between the target limit torque and the current motor torque value. Therefore, the control for suppressing the motor torque value of the compressor motor below the allowable torque can be performed with extremely high accuracy.

  In the fuel cell system of the present embodiment, the current limit value is calculated by the output limiting unit 12 in consideration of the atmospheric pressure, so that the current limit is tight when the atmospheric pressure is low, such as at high altitudes. Since the limit value is calculated, the control for suppressing the motor torque value of the compressor motor to be equal to or lower than the allowable torque can be performed with extremely high accuracy while adapting to changes in the use environment.

  Further, in the fuel cell system of the present embodiment, the target limit torque setting means 10 causes the compressor motor torque not to exceed its capacity according to the compressor motor speed detected by the compressor speed detection means 9. Since the target limit torque is set to limit the torque to the normal value, the general compressor motor torque control in which the upper limit torque value is determined according to the motor rotation speed can be performed with extremely high accuracy. In addition, by setting the upper limit torque value low in the region where the compressor motor speed is high, the compressor motor torque is greatly restricted in the region where the compressor speed is high. It is also possible to limit the number so that it does not become a number.

(Second Embodiment)
Next, a fuel cell system according to a second embodiment to which the present invention is applied will be described.

  The principal part structure of the fuel cell system of 2nd Embodiment is shown in FIG. As shown in FIG. 6, the fuel cell system of this embodiment includes an air pressure limiting means 21 and an air pressure control means 22 instead of the output limiting means 12 and the power manager 7 in the first embodiment described above. It is a thing. That is, in the fuel cell system according to the first embodiment described above, the target limit torque set by the target limit torque setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detection means 8 are used. Accordingly, the extraction current from the fuel cell 1 is limited, but in the fuel cell system of this embodiment, the target limit torque set by the target limit torque setting means 10 and the motor torque detection means 8 are set. The pressure of the air supplied to the cathode of the fuel cell 1 (cathode operating pressure of the fuel cell 1) is limited according to the current torque value of the compressor motor detected or estimated in step (b). That is, in the fuel cell system according to the present embodiment, the air pressure supplied to the cathode of the fuel cell 1 (cathode operating pressure) is limited, thereby reducing the air compression ratio between the suction side and the discharge side of the compressor 2. The motor torque value of the motor can be suppressed below the allowable torque.

  In addition, since the other configuration and the basic part of the control in the fuel cell system of this embodiment are the same as those in the first embodiment described above, the common parts with the first embodiment are the same in the drawings. The description will be omitted with overlapping reference numerals, and the air pressure limiting means 21 and the air pressure control means 22 that are characteristic of the present embodiment and their control contents will be mainly described.

  The air pressure limiting means 21 is a cathode of the fuel cell 1 according to the target limiting torque set by the target limiting torque setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detecting means 8. The pressure of the air supplied to the air is limited, and includes an input limit torque correction unit 21a, an air pressure limit value calculation unit 21b, and a limit unit 21c.

  The input limit torque correction unit 21a determines the air pressure limit value according to the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8. The target limit torque used for the calculation in the calculation unit 21b is corrected and calculated as the second target limit torque.

  The air pressure limit value calculation unit 21 b supplies air to the cathode of the fuel cell 1 according to the second target limit torque calculated by the input limit torque correction unit 21 a and the atmospheric pressure detected by the atmospheric pressure sensor 11. The air pressure limit value for limiting the pressure is calculated.

  The limiting unit 21c limits the pressure of the air supplied to the cathode of the fuel cell 1 to the air pressure limit value calculated by the air pressure limit value calculation unit 21b. That is, if the target air pressure corresponding to the power generation amount required for the fuel cell 1 is smaller than the air pressure limit value calculated by the air pressure limit value calculator 21b, the limiter 21c sets the target air pressure to the air pressure. If the target air pressure is larger than the air pressure limit value, the air pressure limit value is output to the air pressure control means 22 as the air pressure control command value.

  The air pressure control means 22 adjusts the opening of the pressure regulating valve 5 according to the air pressure control command value output from the restriction unit 21 c of the air pressure restriction means 21 and the current air pressure detected by the pressure sensor 6. By adjusting, the pressure of the air supplied to the cathode of the fuel cell 1 is controlled. Thereby, in the fuel cell system of the present embodiment, the pressure of the air supplied to the cathode of the fuel cell 1 is limited to the air pressure limit value calculated by the air pressure limit value calculation unit 21b of the air pressure limiter 21. Will be.

  A specific example of control in the air pressure limiting means 21 is shown in FIG. In the example shown in FIG. 7, the input limit torque correction unit 21 a calculates the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8. A corresponding input torque correction value is obtained, and the second target limit torque is calculated by correcting the target limit torque set by the target limit torque setting means 10 using this input torque correction value. Then, the second target limit torque is input to the air pressure limit value calculation unit 21b.

  For example, the air pressure limit value calculation unit 21b calculates the pressure of air supplied to the cathode of the fuel cell 1 (cathode operating pressure of the fuel cell 1) and the necessary torque required for the compressor motor to realize the air pressure. Based on the second target limit torque input from the input limit torque correction unit 21a and the atmospheric pressure detected by the atmospheric pressure sensor 11, using a map representing the relationship for each atmospheric pressure, the current atmospheric pressure An upper limit pressure that can be realized when the motor torque of the compressor motor is limited to the second target limit torque is calculated as an air pressure limit value.

  The limiting unit 21c selects the target air pressure corresponding to the power generation amount required for the fuel cell 1 and the air pressure limit value calculated by the air pressure limit value calculating unit 21b, and sets the air pressure control command value as air pressure. By outputting to the pressure control means 22, the pressure of the air supplied to the cathode of the fuel cell 1 (cathode operating pressure) is limited.

  Here, the map used for the calculation in the air pressure limit value calculation unit 21b is designed based on the cathode operating pressure of the fuel cell 1 and the required torque of the compressor motor, and is detected or estimated by the motor torque detecting means 8. When the current motor torque value of the compressor motor deviates from the target limit torque set by the target limit torque setting means 10, the shifted torque deviation is returned to the map input and corrected, thereby correcting the compressor motor. The motor torque value can be brought close to the target limit torque.

  As described above in detail with specific examples, in the fuel cell system of the present embodiment, the motor torque detection means 8 detects or estimates the current motor torque value of the compressor motor, and only the target limit torque is used. Since the current motor torque value is also used and the pressure of the air supplied to the cathode of the fuel cell 1 is limited, the motor torque value of the compressor motor can be accurately controlled below the allowable torque. Therefore, in this fuel cell system, as in the fuel cell system of the first embodiment described above, it is necessary to excessively limit the extraction current from the fuel cell 1 in consideration of performance variations of the compressor 2 and the compressor motor. The upper limit output of the compressor motor can be used up and the air flow supplied to the cathode of the fuel cell 1 can be increased to improve the power performance, and the compressor 2, the compressor motor, the fuel cell 1 and the like can be reliably protected. You can plan.

  Further, in the fuel cell system of the present embodiment, as with the fuel cell system of the first embodiment described above, there is no need to overdesign parts such as employing a high output motor, and an inexpensive and compact system can be achieved. realizable.

  Further, in the fuel cell system of this embodiment, instead of limiting the extraction current (electric power) from the fuel cell 1, the air pressure supplied to the cathode of the fuel cell 1 is limited so that the suction side of the compressor 2 Since the air compression ratio on the discharge side is lowered so that the motor torque value of the compressor motor can be suppressed to an allowable torque or less, the power performance deterioration caused by limiting the extraction current (electric power) from the fuel cell 1 is further reduced. While avoiding effectively, protection of the compressor 2, the compressor motor, the fuel cell 1, etc. can be achieved reliably.

  In the fuel cell system of the present embodiment, the deviation between the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 is calculated. Accordingly, the target limit torque used for the calculation of the air pressure limit value in the air pressure limit means 21 is corrected, that is, the air pressure limit value is calculated while feeding back the deviation between the target limit torque and the current motor torque value. As a result, the control for suppressing the motor torque value of the compressor motor below the allowable torque can be performed with extremely high accuracy.

(Third embodiment)
Next, a fuel cell system according to a third embodiment to which the present invention is applied will be described.

  The principal part structure of the fuel cell system of 3rd Embodiment is shown in FIG. As shown in FIG. 8, the fuel cell system of this embodiment includes an output limiting means 31 instead of the output limiting means 12 in the first embodiment described above. That is, in the fuel cell system of the first embodiment described above, the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 The target limit torque used for the calculation of the current limit value in the output limiting means 12 is corrected according to the deviation of the above. However, in the fuel cell system of this embodiment, the target limit torque setting means 9 sets the target limit torque. The current limiting value calculated based on the target limiting torque by the output limiting means 31 according to the deviation between the target limiting torque and the current motor torque value of the compressor motor detected or estimated by the motor torque detecting means 8. I am trying to correct it.

  In addition, since the other configuration and the basic part of the control in the fuel cell system of this embodiment are the same as those in the first embodiment described above, the common parts with the first embodiment are the same in the drawings. The description will be omitted with the reference numerals added, and the description will focus on the configuration of the output limiting means 31 and the control contents that are characteristic of the present embodiment.

  The output limiting means 31 takes out from the fuel cell 1 in accordance with the target limiting torque set by the target limiting torque setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detecting means 8. The current is limited, and includes an output limit value calculation unit 31a, an output limit value correction unit 31b, and a limit unit 31c. Here, the output limiting means 31 will be described as limiting the extraction current from the fuel cell 1, but both the current and voltage, that is, the extraction power from the fuel cell 1 may be limited. Good. When limiting the electric power extracted from the fuel cell 1, the content of the control is the same as when limiting the electric current extracted from the fuel cell 1.

  The output limit value calculation unit 31 a is a current for limiting the extraction current from the fuel cell 1 according to the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure detected by the atmospheric pressure sensor 11. The limit value is calculated.

  The output limit value correction unit 31b calculates the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and the integrated value of the deviation. Accordingly, the current limit value calculated by the output limit value calculation unit 31a is corrected.

  The limiting unit 31c limits the target extraction current from the fuel cell 1 to the current limit value calculated by the output limit value calculating unit 31a and corrected by the output limit value correcting unit 31b. In other words, the limiting unit 31c is a current obtained by calculating the target extraction current required for the fuel cell 1 according to, for example, the operating state of the drive motor by the output limit value calculating unit 31a and correcting it by the output limit value correcting unit 31b If the target extraction current is larger than the limit value, the target extraction current is output to the power manager 7 as the extraction current command value. If the target extraction current is larger than the current limitation value, the current limitation value is output to the power manager 7 as the extraction current command value. To do. Thereby, the extraction current from the fuel cell 1 is limited to the current limit value.

  A specific example of control in the output limiting means 31 is shown in FIG. In the example shown in FIG. 9, for example, the output limit value calculation unit 31 a includes a current value taken out from the fuel cell 1 and a required torque required for the compressor motor so that the current value can be taken out from the fuel cell 1. Compressor motor at the current atmospheric pressure based on the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure detected by the atmospheric pressure sensor 11 using a map representing the relationship of The current value that can be taken out from the fuel cell 1 when the motor torque is limited to the target limit torque is calculated as the current limit value.

  The output limit value correction unit 31b responds to the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and the integrated value of the deviation. The current limit correction value is obtained, and the current limit value calculated by the output limit value calculation unit 31a is corrected using the current limit correction value.

  The limiting unit 31c selects the target extraction current of the fuel cell 1 and the current limit value calculated by the output limit value calculating unit 31a and corrected by the output limit value correcting unit 31b, and uses the power manager as the extraction current command value. The output current from the fuel cell 1 is limited.

  As described above, in the output limiting unit 31 in the fuel cell system of the present embodiment, the current motor torque value of the compressor motor detected or estimated by the motor torque detecting unit 8 is set by the target limiting torque setting unit 10. When the torque limit deviates from the target limit torque, the deviated torque deviation is fed back and the current limit value is adjusted, so that the motor torque value of the compressor motor can be accurately controlled to be equal to or less than the allowable torque.

  FIG. 10 shows the relationship between the limitation of the extraction current from the fuel cell 1 in the fuel cell system of this embodiment and the response of the motor torque of the compressor motor due to the limitation. As shown in FIG. 10, in the fuel cell system of this embodiment, the motor torque of the compressor motor is adjusted by adjusting the current limit value by feeding back the deviation between the target limit torque and the current motor torque value of the compressor motor. The value can be brought close to the target limit torque, and the deviation between the target limit torque and the current motor torque value of the compressor motor is integrated and fed back, so that the deviation can be made close to zero in a steady state. .

  As described above in detail with specific examples, in the fuel cell system of the present embodiment, the motor torque detection means 8 detects or estimates the current motor torque value of the compressor motor, and only the target limit torque is used. Since the current motor torque value is also used to limit the extraction current from the fuel cell 1, the motor torque value of the compressor motor can be accurately controlled below the allowable torque. Therefore, in this fuel cell system, as in the fuel cell system of the first embodiment described above, it is necessary to excessively limit the extraction current from the fuel cell 1 in consideration of performance variations of the compressor 2 and the compressor motor. The upper limit output of the compressor motor can be used up and the air flow supplied to the cathode of the fuel cell 1 can be increased to improve the power performance, and the compressor 2, the compressor motor, the fuel cell 1 and the like can be reliably protected. Can be planned.

  Further, in the fuel cell system of the present embodiment, as with the fuel cell system of the first embodiment described above, there is no need to overdesign parts such as employing a high output motor, and an inexpensive and compact system can be achieved. realizable.

  In the fuel cell system of the present embodiment, the deviation between the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 is calculated. Accordingly, the current limiting value calculated based on the target limiting torque is corrected by the output limiting means 31, that is, the current limiting value is calculated while feeding back the deviation between the target limiting torque and the current motor torque value. Therefore, the control for suppressing the motor torque value of the compressor motor below the allowable torque can be performed with extremely high accuracy.

(Fourth embodiment)
Next, a fuel cell system according to a fourth embodiment to which the present invention is applied will be described.

  FIG. 11 shows the main configuration of the fuel cell system according to the fourth embodiment. As shown in FIG. 11, the fuel cell system of this embodiment includes an air pressure limiting means 41 instead of the air pressure limiting means 21 in the second embodiment described above. That is, in the fuel cell system of the second embodiment described above, the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 The target limit torque used for the calculation of the air pressure limit value in the air pressure limiter 21 is corrected according to the deviation of the air pressure limiter 21. In the fuel cell system of this embodiment, the target limit torque setting unit 9 Air calculated based on the target limit torque by the air pressure limiting means 41 in accordance with the deviation between the set target limit torque and the current motor torque value of the compressor motor detected or estimated by the motor torque detecting means 8 The pressure limit value is corrected.

  In addition, since the other structure and the basic part of control in the fuel cell system of this embodiment are the same as those in the second embodiment described above, the common parts with the second embodiment are the same in the drawings. The description will be omitted with overlapping reference numerals, and the configuration and control contents of the air pressure limiting means 41 characteristic of this embodiment will be mainly described.

  The air pressure limiting means 41 is a cathode of the fuel cell 1 in accordance with the target limiting torque set by the target limiting torque setting means 10 and the current torque value of the compressor motor detected or estimated by the motor torque detecting means 8. The pressure of the air supplied to the fuel cell (the cathode operating pressure of the fuel cell 1) is limited, and includes an air pressure limit value calculation unit 41a, an air pressure limit value correction unit 41b, and a limit unit 41c.

  The air pressure limit value calculation unit 41 a calculates the pressure of the air supplied to the cathode of the fuel cell 1 according to the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure detected by the atmospheric pressure sensor 11. An air pressure limit value for limiting is calculated.

  The air pressure limit value correction unit 41b is a deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and the integral value of the deviation. Accordingly, the air pressure limit value calculated by the air pressure limit value calculation unit 41a is corrected.

  The limiter 41c limits the pressure of the air supplied to the cathode of the fuel cell 1 to the air pressure limit value calculated by the air pressure limit value calculator 41a and corrected by the air pressure limit value correction unit 41b. . In other words, the limiting unit 41c is configured such that the target air pressure corresponding to the power generation amount required for the fuel cell 1 is calculated by the air pressure limit value calculating unit 41a and corrected by the air pressure limit value correcting unit 41b. If the target air pressure is larger than the air pressure limit value, the target air pressure is output to the air pressure control command value as the air pressure control command value. Output to the pressure control means 22.

  The air pressure control means 22 adjusts the opening of the pressure regulating valve 5 according to the air pressure control command value output from the restriction unit 41 c of the air pressure restriction means 41 and the current air pressure detected by the pressure sensor 6. By adjusting, the pressure of the air supplied to the cathode of the fuel cell 1 is controlled. Thereby, in the fuel cell system of the present embodiment, the pressure of the air supplied to the cathode of the fuel cell 1 is calculated by the air pressure limit value calculation unit 41a of the air pressure limiting means 41, and the air pressure limit value correcting unit. It is limited to the air pressure limit value corrected in 41b.

  A specific example of control in the air pressure limiting means 41 is shown in FIG. In the example shown in FIG. 12, the air pressure limit value calculation unit 41a is, for example, a compressor motor for realizing the pressure of the air supplied to the cathode of the fuel cell 1 (the cathode operating pressure of the fuel cell 1) and the air pressure. Based on the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure detected by the atmospheric pressure sensor 11, using a map representing the relationship with the required torque required for each atmospheric pressure, The upper limit pressure that can be realized when the motor torque of the compressor motor is limited to the target limit torque at the current atmospheric pressure is calculated as the air pressure limit value.

  The air pressure limit value correction unit 41b calculates the deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and the integrated value of the deviation. A corresponding air pressure limit correction value is obtained, and the air pressure limit value calculated by the air pressure limit value calculation unit 41a is corrected using the air pressure limit correction value.

  The restriction unit 41c selects the target air pressure corresponding to the power generation amount required for the fuel cell 1 and the air pressure limit value calculated by the air pressure limit value calculation unit 41a and corrected by the air pressure limit value correction unit 41b. The pressure of the air supplied to the cathode of the fuel cell 1 (cathode operating pressure) is limited by outputting to the air pressure control means 22 as an air pressure control command value.

  As described above, in the air pressure limiting means 41 in the fuel cell system of the present embodiment, the current motor torque value of the compressor motor detected or estimated by the motor torque detecting means 8 is set by the target limiting torque setting means 10. When the target limit torque is deviated, the deviated torque deviation is fed back and the air pressure limit value is adjusted, so that the motor torque value of the compressor motor can be accurately controlled below the allowable torque.

  As described above in detail with specific examples, in the fuel cell system of the present embodiment, the motor torque detection means 8 detects or estimates the current motor torque value of the compressor motor, and only the target limit torque is used. Since the current motor torque value is also used and the pressure of the air supplied to the cathode of the fuel cell 1 is limited, the motor torque value of the compressor motor can be accurately controlled below the allowable torque. Therefore, in this fuel cell system, similarly to the fuel cell system of the second embodiment described above, it is necessary to excessively limit the extraction current from the fuel cell 1 in consideration of performance variations of the compressor 2 and the compressor motor. The upper limit output of the compressor motor can be used up and the air flow supplied to the cathode of the fuel cell 1 can be increased to improve the power performance, and the compressor 2, the compressor motor, the fuel cell 1 and the like can be reliably protected. Can be planned.

  Further, in the fuel cell system of the present embodiment, similarly to the fuel cell system of the second embodiment described above, there is no need to overdesign parts such as adopting a high output motor, and an inexpensive and compact system can be achieved. realizable.

  Further, in the fuel cell system of this embodiment, instead of limiting the extraction current (electric power) from the fuel cell 1, the air pressure supplied to the cathode of the fuel cell 1 is limited so that the suction side of the compressor 2 Since the air compression ratio on the discharge side is lowered so that the motor torque value of the compressor motor can be suppressed to an allowable torque or less, the power performance deterioration caused by limiting the extraction current (electric power) from the fuel cell 1 is further reduced. While avoiding effectively, protection of the compressor 2, the compressor motor, the fuel cell 1, etc. can be achieved reliably.

  In the fuel cell system of the present embodiment, the deviation between the target limit torque set by the target limit torque setting means 9 and the current motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 is calculated. Accordingly, the air pressure limiter 41 corrects the air pressure limit value calculated based on the target limit torque, that is, calculates the air pressure limit value while feeding back the deviation between the target limit torque and the current motor torque value. Therefore, the control for suppressing the motor torque value of the compressor motor below the allowable torque can be performed with extremely high accuracy.

(Fifth embodiment)
Next, a fuel cell system according to a fifth embodiment to which the present invention is applied will be described.

  The fuel cell system of the fifth embodiment is based on the configuration of the fuel cell system of the third embodiment described above (see FIG. 8), and the output limit value correcting unit 31b of the output limiting means 31 corrects the current limit value. It has a feature in the calculation method at the time. That is, in the fuel cell system of the present embodiment, when the output limit value correction unit 31b of the output limit means 31 corrects the current limit value, the target limit torque and the motor torque detection means set by the target limit torque setting means 10 A current limit correction value is obtained in accordance with the deviation from the current motor torque value detected or estimated in 8 and the integral value of the deviation and the lower limit limiter set, and this current limit correction The current limit value calculated by the output limit value calculation unit 31a is corrected using the value.

  In the fuel cell system of the present embodiment, the current motor torque value detected or estimated by the motor torque detecting means 8 is a value lower than the target limit torque set by the target limit torque setting means 10 by a predetermined value α. When the value becomes equal to or greater than the first threshold set in step S3, a correction calculation is performed by the output limit value correction unit 31b of the output limitation unit 31, and after the correction calculation is performed, the target limit torque setting unit 10 sets the correction calculation. The correction calculation is terminated when it becomes less than a second threshold value (second threshold value <first threshold value) set to a value lower than the target limit torque by a predetermined value β (β> α). ing. Furthermore, in the fuel cell system of the present embodiment, after the correction calculation by the output limit value correction unit 31b of the output limiting unit 31 is completed, the next correction calculation is started until the next correction calculation is started. An integral value (an integral value of the deviation between the target limit torque and the motor torque value) is held.

  A specific example of control by the output limiting means 31 in the fuel cell system of this embodiment is shown in FIG. In the example shown in FIG. 13, the processing contents in the output limit value calculation unit 31a and the limit unit 31c are the same as those in the fuel cell system of the third embodiment described above (see FIG. 9). The output limit value correction unit 31b is a deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and an integrated value of the deviation. Then, a current limit correction value is obtained by PI control according to the integral value for which the lower limit value limiter is set, and the current limit value calculated by the output limit value calculation unit 31a is corrected using this current limit correction value. To do.

  Here, the calculation method of the integral term and the proportional term in the output limit value correction unit 31b in the example shown in FIG. 13 will be described.

  (1) Set zero or the final calculated value at the previous stop as the initial value of the integral term at startup.

  (2) The current motor torque value detected or estimated by the motor torque detection means 8 is less than the second threshold value, which is a value lower than the target limit torque set by the target limit torque setting means 10 by a predetermined value β. If the integral gain is switched from the I gain to the zero gain, the integral calculation value is held. At this time, the proportional gain is also switched from the P gain to the zero gain.

  As a result, the calculation of integration can be stopped in a state where the motor torque value is far from the target limit torque (a state where the output is not limited), and the integral term can be prevented from diverging. Further, since the integral value is calculated to an optimum value that brings the deviation between the target limit torque and the current motor torque value close to zero when the output is limited, the integral value is limited to the extraction current from the fuel cell 1. By holding the integral calculation value in such a situation that does not take place, the integral value calculation will start from the optimum value the next time the current limit is applied, further preventing overshoot of the motor torque value. Thus, the control for suppressing the motor torque value below the allowable torque can be performed with higher accuracy.

  For switching from zero gain to I gain of the integral gain and switching from zero gain to P gain of the proportional gain, the current motor torque value detected or estimated by the motor torque detection means 8 is the target limit torque setting means 10. Hysteresis when returning to and canceling the correction calculation when the value exceeds a first threshold value (first threshold value> second threshold value) that is lower than the set target limit torque by a predetermined value α (α <β). Set.

  (3) For the calculation of the integral value, a limiter that sets the lower limit value to zero is set.

  If the motor torque value is kept between the target limit torque and the first threshold value (threshold for starting the integral calculation) for a long time when the extraction current from the fuel cell 1 is not limited, the target limit torque and the current There is a possibility that the integrated value diverges as the deviation from the motor torque value continues to be accumulated. Therefore, a lower limit value limiter is set for the calculation of the integral value. Thereby, the divergence of the integral value can be prevented, and the extraction current from the fuel cell 1 can be normally restricted.

  FIG. 14 shows the relationship between the limitation of the extraction current from the fuel cell 1 in the fuel cell system of this embodiment and the response of the motor torque of the compressor motor due to the limitation. As shown in FIG. 14, in the fuel cell system of this embodiment, when the extraction current is first limited, the motor torque value of the compressor motor may slightly overshoot the target limiting torque. When the current limit is applied once, overshoot of the motor torque value can be prevented for the reason (2) described above.

  As described above in detail with a specific example, in the fuel cell system of the present embodiment, the output limit value correcting unit 31b of the output limiting unit 31 corrects the current limit value by the above-described method. In addition to the effects of the fuel cell system of the third embodiment, the following effects can be obtained.

  That is, in the fuel cell system of the present embodiment, the output limit value correction unit 31b of the output limit unit 31 is detected or estimated by the target limit torque set by the target limit torque setting unit 10 and the motor torque detection unit 8. Since the current limit value calculated by the output limit value calculation unit 31a is corrected according to the deviation from the motor torque value and the integral value of the deviation, the influence of the steady deviation is eliminated, Control for suppressing the motor torque value of the compressor motor below the allowable torque can be performed with higher accuracy. In addition, by setting a lower limit value limiter in the calculation of the integral value, the integral value can be prevented from divergence and the extraction current from the fuel cell 1 can be normally restricted.

  Further, in the fuel cell system of the present embodiment, when the motor torque value of the compressor motor becomes equal to or higher than the first threshold value set to a value lower than the target limit torque by a predetermined value α, the output of the output limiting means 31 Since the correction calculation by the limit value correction unit 31b is performed, the current limit value can be prevented from being diverged and the extraction current from the fuel cell 1 can be normally limited. That is, in a state where the motor torque value of the compressor motor is far from the target limit torque and is low (a state in which the output limit is not applied), a correction calculation (torque deviation feedback correction calculation) by the output limit value correction unit 31b of the output limit means 31 However, the torque deviation is accumulated in the integral term and the current limit value diverges, and the current limit may not be properly applied. Since the deviation feedback correction calculation is not performed, the divergence of the current limit value can be prevented.

  Further, in the fuel cell system of the present embodiment, after performing the correction calculation by the output limit value correction unit 31b of the output limiting means 31, the motor torque value of the compressor motor is a predetermined value β (β> α) than the target limit torque. The correction calculation by the output limit value correcting unit 31b of the output limiting unit 31 is terminated when the value is less than the second threshold value (second threshold value <first threshold value) set to a low value. Therefore, hysteresis is provided in the execution and termination of the torque deviation feedback correction calculation, and chattering of the execution / end of the feedback correction calculation can be prevented.

  Further, in the fuel cell system of the present embodiment, after the feedback correction calculation of the torque deviation is completed, the integration value at the time of the previous correction calculation is held until the next correction calculation is started. Therefore, even when the next current limit is applied, the calculation of the integral value can be started from the optimum value, and the control for preventing the motor torque value from overshooting and suppressing the motor torque value below the allowable torque, Furthermore, it becomes possible to carry out with high precision.

  In the above description, the correction calculation in the output limit value correction unit 31b characteristic of the present embodiment has been described on the premise of the configuration of the fuel cell system of the third embodiment. The present invention can be effectively applied to any of the configurations of the fuel cell system of the first embodiment, the fuel cell system of the second embodiment, and the fuel cell system of the fourth embodiment. Of course, when the correction calculation characteristic of the present embodiment is applied on the premise of the configuration of the fuel cell system of the second embodiment or the fuel cell system of the fourth embodiment, the correction calculation calculates the air pressure limit. The value will be corrected.

(Sixth embodiment)
Next, a fuel cell system according to a sixth embodiment to which the present invention is applied will be described.

  The fuel cell system according to the sixth embodiment is a modification of the fuel cell system according to the fifth embodiment described above. That is, in the fuel cell system of the present embodiment, the current limiting value calculated by the output limiting value calculation unit 31a of the output limiting means 31 is basically used to limit the extraction current from the fuel cell 1, but the output limiting When the design of the value calculation unit 31a deviates from the actual design and the motor torque value of the compressor motor exceeds the target limit torque, the correction calculation by the output limit value correction unit 31b is performed. Specifically, in the fuel cell system of the present embodiment, the current motor torque value detected or estimated by the motor torque detector 8 is greater than the target limit torque set by the target limit torque setting unit 10 by a predetermined value γ. When the value becomes equal to or higher than the third threshold value set to a higher value, a correction calculation is performed by the output limit value correction unit 31b of the output limit means 31, and after the correction calculation is performed, the target limit torque setting means 10 When the value becomes less than the fourth threshold value (fourth threshold value <third threshold value) set to a value that is higher by a predetermined value δ (δ <γ) than the target limit torque set in step (b), the correction calculation ends. Like to do.

  A specific example of control by the output limiting means 31 in the fuel cell system of this embodiment is shown in FIG. In the example shown in FIG. 15, the processing contents in the output limit value calculation unit 31a and the limit unit 31c are the same as those in the fuel cell system of the third embodiment described above (see FIG. 9). The correction calculation in the output limit value correction unit 31b is the same as that in the fifth embodiment described above, and is detected or estimated by the target limit torque set by the target limit torque setting means 10 and the motor torque detection means 8. The current limit correction value is obtained by PI control according to the deviation from the current motor torque value and the integral value of the deviation and the lower limit value limiter is set. The current limit value calculated by the output limit value calculation unit 31a is corrected.

  However, in the fuel cell system of the present embodiment, the correction calculation in the output limit value correction unit 31b of the output limiting unit 31 is different from the actual design of the output limit value calculation unit 31a, and the motor torque value of the compressor motor is the target. This is done when the torque limit is exceeded. That is, in the fuel cell system of the present embodiment, the output limit value correction unit 31 b of the output limit unit 31 sets the current motor torque value detected or estimated by the motor torque detection unit 8 using the target limit torque setting unit 10. When the value is less than the fourth threshold value, which is higher than the target limit torque by a predetermined value δ, the integral gain is switched from I gain to zero gain. At this time, the proportional gain is also switched from the P gain to the zero gain.

  For switching from zero gain to I gain of the integral gain and switching from zero gain to P gain of the proportional gain, the current motor torque value detected or estimated by the motor torque detection means 8 is the target limit torque setting means 10. Hysteresis when returning to and canceling the correction calculation when the value exceeds a third threshold value (third threshold value> fourth threshold value) that is higher than the set target limit torque by a predetermined value γ (γ> δ). Set.

  As described above, in the fuel cell system of the present embodiment, when the motor torque value of the compressor motor becomes equal to or higher than the third threshold value set to a value higher than the target limit torque by the predetermined value γ, the output limit means 31 is performed by the output limit value correction unit 31b. When the output limit value calculation unit 31a deviates from the actual design, the deviation of the compressor motor is detected by the torque deviation feedback correction calculation. The motor torque value can be suppressed below the allowable torque.

  Further, in the fuel cell system of the present embodiment, after performing the correction calculation by the output limit value correction unit 31b of the output limiting means 31, the motor torque value of the compressor motor is greater than the target limit torque by a predetermined value δ (δ <γ). The correction calculation by the output limit value correcting unit 31b of the output limiting unit 31 is terminated when the value becomes less than the fourth threshold (fourth threshold <third threshold) set to a higher value. Therefore, hysteresis is provided in the execution and termination of the torque deviation feedback correction calculation, and chattering of the execution / end of the feedback correction calculation can be prevented.

  In the above, the correction calculation in the output limit value correction unit 31b characteristic of the present embodiment has been described on the premise of the configuration of the fuel cell system of the third embodiment. Similarly to the correction calculation described in the embodiment, any of the configurations of the fuel cell system of the first embodiment, the fuel cell system of the second embodiment, and the fuel cell system of the fourth embodiment described above is assumed. It can be effectively applied to cases. Of course, when the correction calculation characteristic of the present embodiment is applied on the premise of the configuration of the fuel cell system of the second embodiment or the fuel cell system of the fourth embodiment, the correction calculation calculates the air pressure limit. The value will be corrected.

(Seventh embodiment)
Next, a fuel cell system according to a seventh embodiment to which the present invention is applied will be described.

  The principal part structure of the fuel cell system of 7th Embodiment is shown in FIG. As shown in FIG. 16, the fuel cell system of this embodiment includes an output limiting means 71 instead of the output limiting means 31 in the third embodiment described above. That is, in the fuel cell system of the third embodiment described above, the current limit value calculated by the output limit value calculation unit 31a of the output limit means 31 and corrected by the output limit value correction unit 31b is Although the extraction current is limited, in the fuel cell system of this embodiment, the current limit value calculated by the output limit value calculation unit 71a of the output limiting means 71 is supplied to the cathode of the fuel cell 1. Further correction is made in accordance with the pressure, flow rate, and temperature of the air to be taken, and the current extracted from the fuel cell 1 is limited by the finally obtained current limit value.

  In addition, since the other structure and the basic part of control in the fuel cell system of this embodiment are the same as those in the third embodiment described above, the parts common to the third embodiment are the same in the drawings. The description will be omitted with the reference numerals added, and the description will focus on the configuration of the output restriction means 71 and the control contents thereof characteristic of the present embodiment.

  In the fuel cell system of the present embodiment, the output restriction means 71 includes an output restriction value calculation unit 71a, an output restriction value correction unit 71b, an air pressure correspondence correction unit 71c, an air flow correspondence correction unit 71d, an air temperature correspondence correction unit 71e, It has a limiting part 71f. Here, the output limiting means 71 will be described as limiting the extraction current from the fuel cell 1, but both the current and voltage, that is, the extraction power from the fuel cell 1 may be limited. Good. When limiting the electric power extracted from the fuel cell 1, the content of the control is the same as when limiting the electric current extracted from the fuel cell 1.

  The output limit value calculation unit 71 a is detected by the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure sensor 11, similarly to the output limit value calculation unit 31 a in the fuel cell system of the third embodiment. The current limit value for limiting the extraction current from the fuel cell 1 is calculated according to the atmospheric pressure.

  The output limit value correction unit 71b is detected by the target limit torque set by the target limit torque setting unit 10 and the motor torque detection unit 8 or the same as the output limit value correction unit 31b in the fuel cell system of the third embodiment. The current limit value calculated by the output limit value calculation unit 71a is corrected in accordance with the deviation from the estimated current motor torque value and the integral value of the deviation.

  The air pressure correction unit 71c corrects the current limit value calculated by the output limit value calculation unit 71a according to the fuel cell inlet target air pressure determined corresponding to the power generation amount required for the fuel cell 1. Is. Note that the air pressure correspondence correction unit 71c corresponds to the cathode operating pressure of the fuel cell 1 detected by the pressure sensor 6 (pressure of air supplied to the cathode of the fuel cell 1), and an output limit value calculation unit 71a. The current limit value calculated in (1) may be corrected.

  The air flow rate correction unit 71d corrects the current limit value calculated by the output limit value calculation unit 71a according to the fuel cell supply target air flow rate determined in accordance with the power generation amount required for the fuel cell 1. Is. The air flow rate correction unit 71d uses the current limit value calculated by the output limit value calculation unit 71a according to the air flow rate detected by a flow rate sensor (not shown) provided on the cathode inlet side of the fuel cell 1. You may make it correct | amend.

  The air temperature correspondence correction unit 71e corrects the current limit value calculated by the output limit value calculation unit 71a according to the air temperature detected by the temperature sensor 72 provided on the cathode inlet side of the fuel cell 1. is there.

  The limiter 71f calculates the target extraction current from the fuel cell 1 by the output limit value calculator 71a and outputs an output limit value correction unit 71b, an air pressure correction unit 71c, an air flow rate correction unit 71d, and an air temperature correction. This is limited to the current limit value corrected by the unit 71e. In other words, the limiting unit 71f calculates the target extraction current required for the fuel cell 1 in accordance with, for example, the operating state of the drive motor, etc., by calculating the output limiting value calculating unit 71a, and the output limiting value correcting unit 71b. If it is smaller than the current limit value corrected by the unit 71c, the air flow rate correction unit 71d, and the air temperature correction unit 71e, the target extraction current is output to the power manager 7 as the extraction current command value. If it is larger than the limit value, the current limit value is extracted and output to the power manager 7 as a current command value. Thereby, the extraction current from the fuel cell 1 is limited to the current limit value.

  A specific example of control in the output limiting means 71 is shown in FIG. In the example shown in FIG. 17, for example, the output limit value calculation unit 71 a includes a current value taken out from the fuel cell 1 and a necessary torque required for the compressor motor so that the current value can be taken out from the fuel cell 1. Compressor motor at the current atmospheric pressure based on the target limit torque set by the target limit torque setting means 10 and the atmospheric pressure detected by the atmospheric pressure sensor 11 using a map representing the relationship of The current value that can be taken out from the fuel cell 1 when the motor torque is limited to the target limit torque is calculated as the current limit value.

  The output limit value correction unit 71b is a deviation between the target limit torque set by the target limit torque setting means 10 and the current motor torque value detected or estimated by the motor torque detection means 8, and an integrated value of the deviation. Then, a current limit correction value is obtained by PI control according to the integral value for which the lower limit value limiter is set, and the current limit value calculated by the output limit value calculation unit 31a is corrected using this current limit correction value. To do. The correction calculation by the output limit value correction unit 71b in the example shown in FIG. 17 is the same as that in the sixth embodiment described above.

  The air pressure correspondence correction unit 71c calculates a correction coefficient for the current limit value in accordance with the deviation between the fuel cell inlet target air pressure and the reference air pressure. Here, the reference air pressure is a target air pressure of the fuel cell 1 assumed when the map of the output limit value calculation unit 71a is created. Since the fuel cell inlet target air pressure may vary depending on the operating temperature of the fuel cell 1 and the like, if a difference occurs between the fuel cell inlet target air pressure and the reference air pressure, the target air pressure is output using the map. By correcting the current limit value calculated by the limit value calculation unit 71a, the motor torque value of the compressor motor can be accurately suppressed below the allowable torque.

  The air flow rate correction unit 71d calculates a correction coefficient for the current limit value according to the deviation between the fuel cell supply target air flow rate and the reference air flow rate. Here, the reference air flow rate is the supply air flow rate to the fuel cell 1 assumed when the map of the output limit value calculation unit 71a is created. The fuel cell supply target air flow rate also varies depending on the operating temperature of the fuel cell 1 as well as the fuel cell inlet target air pressure described above, so there is a difference between the fuel cell supply target air flow rate and the reference air flow rate. When this occurs, the motor torque value of the compressor motor can be accurately suppressed below the allowable torque by correcting the current limit value calculated by the output limit value calculating unit 71a using the map. .

  The air temperature correction unit 71e calculates a correction coefficient for the current limit value according to the deviation between the temperature of the air supplied to the cathode of the fuel cell 1 (detected value of the temperature sensor 72) and the reference air temperature. Here, the reference air temperature is the temperature of the supply air to the fuel cell 1 assumed when the map of the output limit value calculation unit 71a is created. The relationship between the mass air flow rate required by the fuel cell 1 and the volume air flow rate supplied by the compressor 2 varies depending on the air temperature. When the volumetric air flow rate changes, the pressure loss of the air system changes, and the compression ratio of the compressor 2 and the motor torque value also change. Therefore, when the temperature of the air supplied to the cathode of the fuel cell 1 deviates from the reference air temperature, the compressor motor is corrected by correcting the current limit value calculated by the output limit value calculation unit 71a using the map. The motor torque value can be accurately controlled below the allowable torque.

  The limiting unit 71f is calculated by the target extraction current of the fuel cell 1 and the output limit value calculating unit 71a and output limit value correcting unit 71b, air pressure corresponding correcting unit 71c, air flow rate correcting unit 71d, air temperature corresponding correcting unit. The current limit value corrected at 71e is selected low and output to the power manager 7 as an extraction current command value, thereby limiting the extraction current from the fuel cell 1.

  As described above in detail with a specific example, in the fuel cell system of the present embodiment, the current limit value calculated by the output limit value calculation unit 71a of the output limit means 71 is used as the output limit value correction unit. In addition to the correction calculation at 71b, correction is performed using correction coefficients calculated by the air pressure correction unit 71c, air flow correction unit 71d, and air temperature correction unit 71e, respectively, and finally obtained current limit values Therefore, since the current drawn from the fuel cell 1 is limited, the control for suppressing the motor torque value of the compressor motor to be equal to or lower than the allowable torque can be performed with higher accuracy.

  In the above, an example in which the configuration of the fuel cell system according to the third embodiment is slightly changed and the current limit value is corrected according to the pressure, flow rate, and temperature of the air supplied to the cathode of the fuel cell 1 will be described. However, such a correction method can be effectively applied to any of the fuel cell system of the first embodiment, the fuel cell system of the second embodiment, and the fuel cell system of the fourth embodiment described above. It is. Of course, when applied to the fuel cell system of the second embodiment or the fuel cell system of the fourth embodiment, the air is supplied to the cathode of the fuel cell 1 depending on the pressure, flow rate, and temperature of the air. The pressure limit value is corrected.

(Eighth embodiment)
Next, a fuel cell system according to an eighth embodiment to which the present invention is applied will be described.

  FIG. 18 shows a main configuration of the fuel cell system according to the eighth embodiment. As shown in FIG. 18, the fuel cell system of the present embodiment includes target limit torque setting means 81 instead of the target limit torque setting means 10 in the third embodiment described above. That is, in the fuel cell system of the third embodiment described above, the target limit torque setting means 10 sets one type of target limit torque according to the rotation speed of the compressor motor. In the system, the target limit torque setting means 81 sets two types of target limit torques, a time rated limit torque and a continuous rated limit torque, as the target limit torque. The target limit torque setting means 81 normally outputs the time rated limit torque as the target limit torque to the output limit means 31, but the state where the motor torque value of the compressor motor exceeds the continuous rated limit torque is a predetermined time. When the operation is continued, the target limit torque is switched from the time rated limit torque to the continuous rated limit torque, and the continuous rated limit torque is output to the output limiting means 31 as the target torque.

  In addition, since the other structure and the basic part of control in the fuel cell system of this embodiment are the same as those in the third embodiment described above, the parts common to the third embodiment are the same in the drawings. The description will be omitted with the reference numerals attached, and the description will focus on the configuration of the target limit torque setting means 81 and the control content thereof characteristic of the present embodiment.

  In the fuel cell system of this embodiment, the target limit torque setting means 81 sets the target limit torque using two types of maps, a first map and a second map, as shown in FIG. 19, for example. The first map is a map for obtaining the time rated limit torque, and is the same map as the map (see FIG. 2) used in the target limit torque setting means 10 in the fuel cell system of the third embodiment described above. That is, the first map represents the relationship between the rotation speed of the compressor motor and the upper limit torque that can be output by the compressor motor at the rotation speed. On the other hand, the second map is a map for obtaining the continuous rated limit torque, and is the same as the first map in that it represents the relationship between the rotation speed of the compressor motor and the upper limit torque. However, the second map defines an upper limit torque when it is assumed that the compressor motor is continuously in a high load state for a predetermined time. Even if the rotation speed of the compressor is the same, the second map A low torque value is set as the upper limit torque.

  The target limit torque setting means 81 uses the first map and the second map as described above, and the upper limit torque obtained from the first map in accordance with the compressor motor speed detected by the compressor speed detector 9. Is set as the time rated limit torque, and the upper limit torque obtained from the second map is set as the continuous rated limit torque. The target limit torque setting means 81 monitors the motor torque value of the compressor motor detected or estimated by the motor torque detection means 8 and compares the motor torque value of the compressor motor with the continuous rated limit torque. If the motor torque value of the motor is less than or equal to the continuous rated limit torque, or if the motor torque value of the compressor motor exceeds the continuous rated limit torque, but the time that does not exceed the predetermined time, the time rated limit torque Is selected as the target limiting torque and output to the output limiting means 31. On the other hand, when the state where the motor torque value of the compressor motor exceeds the continuous rated limit torque continues for a predetermined time, the target limit torque setting means 81 switches the target limit torque from the time rated limit torque to the continuous rated limit torque, The continuous rated limit torque is selected as the target limit torque and output to the output limiting means 31.

  As described above, in the fuel cell system of the present embodiment, the target limit torque setting means 81 sets two types of target limit torques, that is, the time rated limit torque and the continuous rated limit torque, as the target limit torque. Outputs the time rated limit torque as the target limit torque to the output limiting means 31. When the motor torque value of the compressor motor exceeds the continuous rated limit torque for a predetermined time, the target limit torque is calculated from the time rated limit torque. Since the continuous rated limit torque is switched to the continuous rated limit torque and the continuous rated limit torque is output to the output limiting means 31 as the target torque, the performance degradation when the compressor motor is in a high load state for a long time is also caused. In consideration, the motor torque value of the compressor motor can be controlled so as not to exceed the allowable torque. It is possible to achieve protection of the compressor motor more reliably.

  In the above, the method of setting the target limit torque by the target limit torque setting means 81 characteristic of the present embodiment has been described on the premise of the configuration of the fuel cell system of the third embodiment. The setting method is effectively applied to any of the configurations of the fuel cell system of the first embodiment, the fuel cell system of the second embodiment, and the fuel cell system of the fourth embodiment described above. It can be done.

(Ninth embodiment)
Next, a fuel cell system according to a ninth embodiment to which the present invention is applied will be described.

  The principal part structure of the fuel cell system of 9th Embodiment is shown in FIG. As shown in FIG. 20, the fuel cell system according to the present embodiment includes a compressor target rotational speed calculation means 91 in place of the compressor rotational speed detection means 9 in the first embodiment described above, and includes the first embodiment described above. The target limit torque setting means 92 is provided instead of the target limit torque setting means 9 in FIG. That is, in the fuel cell system according to the first embodiment described above, the compressor speed detecting means 9 detects the speed of the compressor motor, and the target limit torque setting means 10 detects the compressor speed detected by the compressor speed detecting means 9. The target limit torque of the compressor motor is set according to the motor speed. In the fuel cell system of this embodiment, the target speed of the compressor motor is calculated by the compressor target speed calculating means 91. The target limit torque setting means 92 sets the target limit torque of the compressor motor in accordance with the target speed of the compressor motor calculated by the compressor target speed calculation means 91.

  In addition, since the other configuration and the basic part of the control in the fuel cell system of this embodiment are the same as those in the first embodiment described above, the common parts with the first embodiment are the same in the drawings. A description will be omitted with overlapping reference numerals, and only the characteristic features of this embodiment will be described.

  In the fuel cell system of the present embodiment, the compressor target rotational speed calculation means 91 uses this target extraction current based on the target extraction current required for the fuel cell 1 in accordance with the operating status of the drive motor, for example. The required air flow rate required for taking out from 1 is obtained, and the target rotational speed required for the compressor motor (that is, the target rotational speed of the compressor 2) to calculate the required air flow rate is calculated.

  Further, as shown in FIG. 21, for example, the target limit torque setting means 92 uses a map representing the relationship between the rotation speed of the compressor motor and the upper limit torque, so that the compressor motor rotation speed calculation means 91 calculates the compressor motor rotation speed. A target limit torque for limiting the torque of the compressor motor so as not to exceed the capacity of the compressor motor is set according to the target rotational speed. At this time, similarly to the target limit torque setting unit 10 in the first embodiment described above, the target limit torque setting unit 92 uses the target rotation number of the compressor motor calculated by the compressor target rotation number calculation unit 91 as it is. Instead of using it as an input value of the map, as shown in FIG. 21, an output obtained by correcting the target rotational speed of the compressor motor calculated by the compressor target rotational speed calculating means 91 using a first-order lag filter is input to the map. It is desirable to set the target limit torque as a value. As described above, if the target limiting torque is set according to the output obtained by correcting the target rotational speed of the compressor motor calculated by the compressor target rotational speed calculating means 91 using the first-order lag filter, the above-described first torque is set. As in the first embodiment, fluctuations in the rotation speed of the compressor motor can be smoothed to avoid interference between the calculation of the target limit torque and the calculation of the extraction current limit value from the fuel cell 1, thereby limiting the extraction current. The problem of causing hunting can be effectively suppressed.

  As described above, in the fuel cell system of the present embodiment, the target rotational speed of the compressor motor is calculated by the compressor target rotational speed calculation means 91, and the target limit torque setting means 92 is calculated by the compressor target rotational speed calculation means 91. Since the target limit torque of the compressor motor is set according to the target rotational speed of the compressor motor, the following effects can be obtained in addition to the effects of the fuel cell system of the first embodiment described above. That is, when the rotation speed of the compressor motor is detected and the target limit torque of the compressor motor is set according to the detected value, the actual rotation speed may vary from the target value depending on the rotation speed control accuracy of the compressor motor. There is a possibility that the set value of the target limit torque fluctuates due to this, and the extraction current limit value from the fuel cell 1 may become oscillating. However, in the fuel cell system of this embodiment, the target rotation with little fluctuation Since the target limit torque of the compressor motor is set according to the number, the set value of the target limit torque can be stabilized and the vibration of the extraction current limit value from the fuel cell 1 can be effectively suppressed. .

(Tenth embodiment)
Next, a fuel cell system according to a tenth embodiment to which the present invention is applied will be described.

  The principal part structure of the fuel cell system of 10th Embodiment is shown in FIG. The fuel cell system according to the present embodiment includes a compressor target rotational speed calculation unit 101 instead of the compressor rotational speed detection unit 9 according to the second embodiment described above, and the target limit torque setting unit 9 according to the second embodiment described above. Instead of this, a target limit torque setting means 102 is provided. That is, the fuel cell system according to the present embodiment is similar to the fuel cell system according to the second embodiment described above, and the air supplied to the cathode of the fuel cell 1 according to the target limit torque and the current torque value of the compressor motor. In the configuration in which the pressure (the cathode operating pressure of the fuel cell 1) is limited, the target limiting torque of the compressor motor is set according to the target rotational speed of the compressor motor as in the fuel cell system of the ninth embodiment described above. Like to do.

  In addition, since the other configuration and the basic part of the control in the fuel cell system of the present embodiment are the same as those of the second embodiment described above, the common parts with the first embodiment are the same in the drawings. A description will be omitted with overlapping reference numerals, and only the characteristic features of this embodiment will be described.

  In the fuel cell system of the present embodiment, the compressor target rotational speed calculation means 101 is, for example, a fuel cell according to the operating status of the drive motor, etc., as with the compressor target rotational speed calculation means 91 in the ninth embodiment described above. 1, a required air flow rate required to extract the target extraction current from the fuel cell 1 is obtained based on the target extraction current required for the compressor 1, and the compressor motor is requested to realize the required air flow rate. A target rotational speed (that is, a target rotational speed of the compressor 2) is calculated.

  Further, the target limit torque setting means 102 is a map representing the relationship between the rotational speed of the compressor motor and the upper limit torque as shown in FIG. 21, for example, as with the target limit torque setting means 92 in the ninth embodiment described above. Is used to set a target limiting torque for limiting the compressor motor torque so as not to exceed the capacity of the compressor motor in accordance with the target rotational speed of the compressor motor calculated by the compressor target rotational speed calculation means 101. . At this time, the target limit torque setting means 102 uses the target rotation speed of the compressor motor calculated by the compressor target rotation speed calculation means 101 as it is, similarly to the target limit torque setting means 92 in the ninth embodiment described above. Rather than using it as an input value for the map, as shown in FIG. 22, an output obtained by correcting the target rotational speed of the compressor motor calculated by the compressor target rotational speed calculating means 101 using a first-order lag filter is displayed on the map. It is desirable to set a target limit torque as an input value. As described above, if the target limit torque is set according to the output obtained by correcting the target rotation speed of the compressor motor calculated by the compressor target rotation speed calculation means 101 using the first-order lag filter, the above-mentioned first torque is set. Similarly to the ninth embodiment, the fluctuation of the rotation speed of the compressor motor can be smoothed to avoid the interference between the calculation of the target limit torque and the calculation of the extraction current limit value from the fuel cell 1, thereby limiting the extraction current. The problem of causing hunting can be effectively suppressed.

  As described above, in the fuel cell system of the present embodiment, the target rotational speed of the compressor motor is calculated by the compressor target rotational speed calculating means 101, and the target limit torque setting means 102 is calculated by the compressor target rotational speed calculating means 101. Since the target limit torque of the compressor motor is set according to the target rotation speed of the compressor motor, the set value of the target limit torque is stabilized in addition to the effect of the fuel cell system of the second embodiment described above. As a result, it is possible to effectively suppress the vibration of the extraction current limit value from the fuel cell 1.

  The fuel cell system according to the first to tenth embodiments to which the present invention is applied has been described in detail above. However, each of the above embodiments exemplifies an application example of the present invention, and the technology of the present invention. The scope of the present invention is not limited to the contents disclosed in the description of the above embodiments, and various alternative techniques that can be easily derived from these disclosures are also included.

It is a figure which shows the principal part structure of the fuel cell system of 1st Embodiment. It is a figure explaining the method of setting a target limiting torque with a target limiting torque setting means. It is a control block diagram explaining the specific example of the output limiting means in the fuel cell system of 1st Embodiment. It is a figure explaining the production method of the output limitation map used when calculating an electric current limitation value in an output limitation value calculating part. It is a characteristic view which shows the relationship between the restriction | limiting of the extraction current from the fuel cell in the fuel cell system of 1st Embodiment, and the response of the motor torque of the compressor motor by the restriction | limiting, (a) is set by the target limitation torque setting means 7 is an example of obtaining a current limit value as a map input value without correcting the set target limit torque, and (b) shows the current motor torque value of the compressor motor by using the target limit torque set by the target limit torque setting means. In this example, the current limit value is obtained as the map input value after correction according to the deviation. It is a figure which shows the principal part structure of the fuel cell system of 2nd Embodiment. It is a control block diagram explaining the specific example of the air pressure limiting means in the fuel cell system of 2nd Embodiment. It is a figure which shows the principal part structure of the fuel cell system of 3rd Embodiment. It is a control block diagram explaining the specific example of the output limiting means in the fuel cell system of 3rd Embodiment. It is a characteristic view which shows the relationship between the restriction | limiting of the extraction current from the fuel cell in the fuel cell system of 3rd Embodiment, and the response of the motor torque of the compressor motor by the restriction | limiting. It is a figure which shows the principal part structure of the fuel cell system of 4th Embodiment. It is a control block diagram explaining the specific example of the air pressure limiting means in the fuel cell system of 4th Embodiment. It is a control block diagram explaining the specific example of the output limiting means in the fuel cell system of 5th Embodiment. It is a characteristic view which shows the relationship between the restriction | limiting of the extraction current from the fuel cell in the fuel cell system of 5th Embodiment, and the response of the motor torque of the compressor motor by the restriction | limiting. It is a control block diagram explaining the specific example of the output limiting means in the fuel cell system of 6th Embodiment. It is a figure which shows the principal part structure of the fuel cell system of 7th Embodiment. It is a control block diagram explaining the specific example of the output limiting means in the fuel cell system of 7th Embodiment. It is a figure which shows the principal part structure of the fuel cell system of 8th Embodiment. It is a figure explaining the method of setting a target limiting torque with the target limiting torque setting means in the fuel cell system of 8th Embodiment. It is a figure which shows the principal part structure of the fuel cell system of 9th Embodiment. It is a figure explaining the method of setting a target limiting torque with a target limiting torque setting means. It is a figure which shows the principal part structure of the fuel cell system of 9th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Compressor 7 Power manager 8 Motor torque detection means 9 Compressor rotation speed detection means 10 Target restriction torque setting means 11 Atmospheric pressure sensor 12 Output restriction means 12a Input restriction torque correction part 12b Output restriction value calculation part 12c Restriction part 21 Air Pressure limit means 21a Input limit torque correction section 21b Air pressure limit value calculation section 21c Limit section 22 Air pressure control means 31 Output limit means 31a Output limit value calculation section 31b Output limit value correction section 31c Limit section 41 Air pressure limit means 41a Air Pressure limit value calculating unit 41b Air pressure limit value correcting unit 41c Limiting unit 71 Output limiting means 71a Output limit value calculating unit 71b Output limit value correcting unit 71c Air pressure corresponding correcting unit 71d Air flow rate corresponding correcting unit 71e Air temperature corresponding correcting unit 71f Limit part 81 Target system Torque setting means 91 compressor target speed calculation unit 92 target limiting torque setting means 101 compressor target speed calculation means 102 target limiting torque setting means

Claims (31)

A fuel cell comprising: a fuel cell that generates electricity by an electrode reaction in an electrolyte membrane sandwiched between an anode and a cathode; and an air system that supplies air from an air supply device using a motor as a drive source to the cathode of the fuel cell. In the system,
Target limit torque setting means for setting a target limit torque for limiting the torque of the motor of the air supply device so as not to exceed the capacity of the motor;
Motor torque detection means for detecting or estimating a current torque value of the motor of the air supply device;
Output for limiting the extraction power or extraction current from the fuel cell in accordance with the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means Limiting means ,
The output limiting means is
According to a deviation between the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means, the target limit torque is corrected and the second limit torque is corrected. An input limit torque correction unit for calculating a target limit torque;
An output limit value calculation unit that calculates a power limit value or a current limit value according to the second target limit torque;
A limiting unit that limits the extraction power or extraction current from the fuel cell based on the power limit value or the current limit value calculated by the output limit value calculation unit;
The fuel cell system characterized by having a. A fuel cell comprising: a fuel cell that generates electricity by an electrode reaction in an electrolyte membrane sandwiched between an anode and a cathode; and an air system that supplies air from an air supply device using a motor as a drive source to the cathode of the fuel cell. In the system,
Target limit torque setting means for setting a target limit torque for limiting the torque of the motor of the air supply device so as not to exceed the capacity of the motor;
Motor torque detection means for detecting or estimating a current torque value of the motor of the air supply device;
Output for limiting the extraction power or extraction current from the fuel cell in accordance with the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means Limiting means,
The output limiting means is
An output limit value calculation unit that calculates a power limit value or a current limit value according to the target limit torque set by the target limit torque setting means;
The electric power calculated by the output limit value calculation unit according to the deviation between the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means An output limit value correction unit for correcting the limit value or current limit value;
A limiting unit that limits the extraction power or extraction current from the fuel cell based on the power limit value or the current limit value corrected by the output limit value correction unit;
A fuel cell system comprising: Motor rotation number detecting means for detecting the rotation number of the motor of the air supply device,
3. The fuel cell according to claim 1, wherein the target limit torque setting means sets the target limit torque in accordance with a motor speed detected by the motor speed detection means. system. A motor target rotation number calculating means for calculating a target rotation number of the motor of the air supply device;
3. The target limit torque setting unit sets the target limit torque according to a target rotation number of the motor calculated by the motor target rotation number calculation unit. 4. Fuel cell system. The target limit torque setting means corrects an output obtained by correcting the rotational speed of the motor detected by the motor rotational speed detection means or a target rotational speed of the motor calculated by the motor target rotational speed calculation means. 5. The fuel cell system according to claim 3, wherein the target limit torque is set according to the output . It further comprises an atmospheric pressure detection means for detecting atmospheric pressure,
The output limit value calculation unit of the output limit unit includes a target limit torque set by the target limit torque setting unit or a second target limit torque calculated by the input limit torque correction unit and the atmospheric pressure detection unit. 3. The fuel cell system according to claim 1, wherein the power limit value or the current limit value is calculated according to the detected atmospheric pressure . 4. The output limit value correction unit or the input limit torque correction unit of the output limit unit calculates a target limit torque set by the target limit torque setting unit and a current motor torque value detected or estimated by the motor torque detection unit. 7. The correction amount for the correction is calculated according to a deviation and an integral value that is an integral value of the deviation and a lower limit value is set. The fuel cell system described in 1 . The output limit value correction unit or the input limit torque correction unit of the output limit unit has a current motor torque value detected or estimated by the motor torque detection unit based on a target limit torque set by the target limit torque setting unit. 8. The fuel cell according to claim 1, wherein the calculation for the correction is performed when the value becomes equal to or greater than a first threshold set to a value lower by a predetermined value. system. The output limit value correcting unit or the input limit torque correcting unit of the output limiting unit performs the calculation for the correction, and then the current motor torque value detected or estimated by the motor torque detecting unit is the first motor torque value. The fuel cell system according to claim 8, wherein the calculation for the correction is terminated when the value becomes less than a second threshold value set to a value lower than the threshold value . The output limit value correction unit or the input limit torque correction unit of the output limit unit has a current motor torque value detected or estimated by the motor torque detection unit based on a target limit torque set by the target limit torque setting unit. 8. The fuel cell according to claim 1, wherein the calculation for the correction is performed when the value becomes equal to or greater than a third threshold set to a value higher by a predetermined value. system. The output limit value correction unit or the input limit torque correction unit of the output limiting unit performs the calculation for the correction, and then the current motor torque value detected or estimated by the motor torque detection unit is the third motor torque value. 11. The fuel cell system according to claim 10, wherein the calculation for the correction is terminated when the value becomes less than a fourth threshold value set to a value lower than the threshold value . The output limit value correction unit or the input limit torque correction unit of the output limiting unit holds the previous integration value until the next calculation is performed after the calculation for the correction is completed. The fuel cell system according to claim 9 or 11 . Air pressure detecting means for determining or detecting the pressure of air supplied to the cathode of the fuel cell;
The output limit means outputs the power limit value or current limit value corrected by the output limit value correction unit, or the power limit value or current limit value calculated by the output limit value calculation unit by the air pressure detection unit. The fuel cell system according to any one of claims 1 to 12, further comprising an air pressure correction unit that corrects the air pressure according to the determined or detected air pressure . An air flow rate detecting means for determining or detecting a flow rate of air supplied to the cathode of the fuel cell;
The output limiting means outputs the power limit value or current limit value corrected by the output limit value correcting unit, or the power limit value or current limit value calculated by the output limit value calculating unit by the air flow rate detecting unit. The fuel cell system according to any one of claims 1 to 13, further comprising an air flow rate correction unit that corrects the air flow rate according to the determined or detected air flow rate . Air temperature detecting means for detecting the temperature of the air supplied to the cathode of the fuel cell,
The output limiting means outputs the power limit value or current limit value corrected by the output limit value correction unit, or the power limit value or current limit value calculated by the output limit value calculation unit, by the air temperature detection unit. 15. The fuel cell system according to claim 1, further comprising an air temperature correction unit that corrects the detected air temperature according to the detected air temperature . The target limit torque setting means sets two types of target limit torques, a time rated limit torque and a continuous rated limit torque, as the target limit torque, and a current motor torque value detected or estimated by the motor torque detection means 16. The target limit torque is switched from the time rated limit torque to the continuous rated limit torque when a state where the torque exceeds the continuous rated limit torque continues for a predetermined time. 2. The fuel cell system according to item 1 . A fuel cell comprising: a fuel cell that generates electricity by an electrode reaction in an electrolyte membrane sandwiched between an anode and a cathode; and an air system that supplies air from an air supply device using a motor as a drive source to the cathode of the fuel cell. In the system,
Target limit torque setting means for setting a target limit torque for limiting the torque of the motor of the air supply device so as not to exceed the capacity of the motor;
Motor torque detection means for detecting or estimating a current torque value of the motor of the air supply device;
The pressure of the air supplied to the cathode of the fuel cell is limited according to the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means. Applying air pressure limiting means,
The air pressure limiting means is
According to a deviation between the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means, the target limit torque is corrected and the second limit torque is corrected. An input limit torque correction unit for calculating a target limit torque;
An air pressure limit value calculating unit for calculating an air pressure limit value according to the second target limit torque;
A limiting unit that limits the pressure of the air supplied to the cathode of the fuel cell based on the air pressure limit value calculated by the air pressure limit value calculation unit;
A fuel cell system comprising: A fuel cell comprising: a fuel cell that generates electricity by an electrode reaction in an electrolyte membrane sandwiched between an anode and a cathode; and an air system that supplies air from an air supply device using a motor as a drive source to the cathode of the fuel cell. In the system,
Target limit torque setting means for setting a target limit torque for limiting the torque of the motor of the air supply device so as not to exceed the capacity of the motor;
Motor torque detecting means for detecting or estimating a current torque value of the motor of the air supply device;
The pressure of the air supplied to the cathode of the fuel cell is limited according to the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means. Applying air pressure limiting means,
The air pressure limiting means is
An air pressure limit value calculating unit for calculating an air pressure limit value according to the target limit torque set by the target limit torque setting means;
Calculated by the air pressure limit value calculation unit according to the deviation between the target limit torque set by the target limit torque setting means and the current motor torque value detected or estimated by the motor torque detection means. An air pressure limit value correction unit for correcting the air pressure limit value;
A limiting unit that limits the pressure of the air supplied to the cathode of the fuel cell based on the air pressure limiting value corrected by the air pressure limiting value correcting unit;
A fuel cell system comprising: Motor rotation number detecting means for detecting the rotation number of the motor of the air supply device,
19. The fuel cell according to claim 17, wherein the target limit torque setting means sets the target limit torque according to the motor speed detected by the motor speed detection means. system. A motor target rotation number calculating means for calculating a target rotation number of the motor of the air supply device;
The target limiting torque setting means according to claim 17 or 18 and sets the target limiting torque in accordance with the target rotational speed of the motor calculated by the motor target speed calculation means Fuel cell system. The target limit torque setting means corrects an output obtained by correcting the rotational speed of the motor detected by the motor rotational speed detection means or a target rotational speed of the motor calculated by the motor target rotational speed calculation means. the fuel cell system according to claim 19 or 20 and sets the target limit torque according to the output was. It further comprises an atmospheric pressure detection means for detecting atmospheric pressure,
The air pressure limit value calculating unit of the air pressure limiting unit includes a target limit torque set by the target limit torque setting unit or a second target limit torque calculated by the input limit torque correcting unit, and the atmospheric pressure detection. The fuel cell system according to any one of claims 17 to 21, wherein the air pressure limit value is calculated according to an atmospheric pressure detected by the means . The air pressure limit value correction unit or the input limit torque correction unit of the air pressure limiter includes a target limit torque set by the target limit torque setting unit and a current motor torque value detected or estimated by the motor torque detection unit. 23. The correction amount at the time of the correction is obtained in accordance with a deviation between the correction value and an integration value that is an integral value of the deviation and a lower limit value is set. 2. The fuel cell system according to item 1 . The air pressure limit value correcting unit or the input limit torque correcting unit of the air pressure limiting unit is configured such that the current motor torque value detected or estimated by the motor torque detecting unit is a target limit set by the target limit torque setting unit. The calculation for the correction is performed when a value equal to or more than a first threshold value set to a value lower than a torque by a predetermined value is performed. Fuel cell system. The air pressure limit value correcting unit or the input limit torque correcting unit of the air pressure limiting unit performs the calculation for the correction, and the current motor torque value detected or estimated by the motor torque detecting unit is 25. The fuel cell system according to claim 24, wherein the calculation for the correction is terminated when the value becomes less than a second threshold set to a value lower than the first threshold . The air pressure limit value correcting unit or the input limit torque correcting unit of the air pressure limiting unit is configured such that the current motor torque value detected or estimated by the motor torque detecting unit is a target limit set by the target limit torque setting unit. The calculation for the correction is performed when a value equal to or more than a third threshold set to a value higher than the torque by a predetermined value is performed. Fuel cell system. The air pressure limit value correcting unit or the input limit torque correcting unit of the air pressure limiting unit performs the calculation for the correction, and the current motor torque value detected or estimated by the motor torque detecting unit is 27. The fuel cell system according to claim 26, wherein the calculation for the correction is ended when the value becomes less than a fourth threshold set to a value lower than the third threshold . The air pressure limit value correction unit or the input limit torque correction unit of the air pressure limiting unit holds the previous integrated value until the next calculation is performed after the calculation for the correction is completed. The fuel cell system according to any one of claims 25 and 27 . An air flow rate detecting means for determining or detecting a flow rate of air supplied to the cathode of the fuel cell;
The air pressure limiter determines or detects the air pressure limit value corrected by the air pressure limit value correction unit or the air pressure limit value calculated by the air pressure limit value calculation unit by the air flow rate detection unit. The fuel cell system according to any one of claims 17 to 28, further comprising an air flow rate correction unit that corrects the air flow rate according to the air flow rate . Air temperature detecting means for detecting the temperature of the air supplied to the cathode of the fuel cell,
The air pressure limiter detects the air pressure limit value corrected by the air pressure limit value correction unit or the air pressure limit value calculated by the air pressure limit value calculation unit by the air temperature detection unit. 30. The fuel cell system according to claim 17, further comprising an air temperature correction unit that corrects the air temperature according to the air temperature . The target limit torque setting means sets two types of target limit torques, a time rated limit torque and a continuous rated limit torque, as the target limit torque, and a current motor torque value detected or estimated by the motor torque detection means 31. The target limit torque is switched from the time rated limit torque to the continuous rated limit torque when the state where the value exceeds the continuous rated limit torque continues for a predetermined time. 2. The fuel cell system according to item 1 .

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