JP2005243329A - Fuel cell system and its controlling method as well as automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make consideration of an abnormality which can be recovered in a short time when one is generated at a voltage sensor detecting voltage between terminals of a fuel cell. <P>SOLUTION: When an abnormality of a voltage sensor is detected, a detected voltage V<SB>pre</SB>detected by the voltage sensor is set (S160, S240) before the abnormality is determined as a detected voltage V<SB>p</SB>, a voltage insutruction V* is set (S170) using the set detected voltage V<SB>p</SB>, and then, a DC/DC converter is driven and controlled (S180) to make a voltage between terminals of the fuel cell be a target voltage V<SB>req</SB>. Then, a normal operation is resumed (S210) when the abnormality is overcome within a given period of time, the DC/DC converter is stopped when the abnormality can not be overcome (S250). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell system, a control method thereof, and an automobile.

Conventionally, this type of fuel cell system has been proposed that includes a fuel cell, a battery, and a DC / DC converter that connects a power line from the fuel cell to a load and an output terminal of the battery (for example, , See Patent Document 1). In this fuel cell system, the voltage between the terminals of the fuel cell and the voltage between the terminals of the battery are adjusted by a DC / DC converter, and when there is a delay in the output response of the fuel cell, insufficient power is supplied from the battery to the load. Power is supplied quickly.
JP 2002-118979 A

  In the above-described system, the voltage between the terminals of the fuel cell is appropriately controlled by detecting the voltage between the terminals of the fuel cell with the voltage sensor and performing feedback control of the DC / DC converter based on the detected value. When an abnormality such as disconnection occurs in the voltage sensor by such control, the operation of the system is generally stopped because the control of the DC / DC converter cannot be performed. However, abnormalities in voltage sensors include abnormalities that recover in a short time, such as an instantaneous disconnection, and it may be desirable to continue system operation when such abnormalities occur. Therefore, when an abnormality occurs in the voltage sensor, it is necessary to take account of the abnormality that recovers in a short time.

  An object of the fuel cell system, the control method thereof, and the automobile of the present invention is to deal with an abnormality that recovers in a short time when an abnormality occurs in the inter-terminal voltage detection means that detects the inter-terminal voltage of the fuel cell. And

  The fuel cell system, the control method thereof, and the automobile of the present invention employ the following means in order to achieve the above-described object.

The fuel cell system of the present invention comprises:
A fuel cell system capable of supplying to a load generated power from a fuel cell that generates power upon receiving fuel supply,
Charge / discharge power storage means;
A voltage adjustment connecting means for connecting a power line from the fuel cell to the load and an output terminal of the power storage means and adjusting a voltage between terminals of the fuel cell and a voltage between terminals of the power storage means;
Target voltage setting means for setting a target voltage of the terminal voltage of the fuel cell based on the required power required for the fuel cell;
An inter-terminal voltage detecting means for detecting an inter-terminal voltage of the fuel cell;
An abnormality determining means for determining an abnormality of the inter-terminal voltage detecting means based on the inter-terminal voltage detected by the inter-terminal voltage detecting means;
When the abnormality determination means does not determine the abnormality of the inter-terminal voltage detection means, the voltage so that the terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the inter-terminal voltage detection means. The adjustment connection means is controlled, and when the abnormality determination means determines that the abnormality of the inter-terminal voltage detection means, a specific voltage is used as the voltage detected by the inter-terminal voltage detection means, and the terminal voltage of the fuel cell is determined. Voltage control means for controlling the voltage adjustment connecting means so that becomes the set target voltage,
It is a summary to provide.

  In the fuel cell system of the present invention, when the abnormality determination means does not determine the abnormality of the terminal voltage detection means, the terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the terminal voltage detection means. The voltage adjustment connecting means is controlled so that when the abnormality determining means determines that the abnormality of the inter-terminal voltage detecting means, the specific voltage is used as the voltage detected by the inter-terminal voltage detecting means to set the terminal voltage of the fuel cell. The voltage adjustment connecting means is controlled so as to achieve the set target voltage. When the abnormality of the inter-terminal voltage detection means is determined, the voltage adjustment connecting means is set so that the inter-terminal voltage of the fuel cell becomes the set target voltage using a specific voltage as the voltage detected by the inter-terminal voltage detection means. Since the control is performed, it is possible to appropriately deal with without stopping the adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the power storage means by the voltage adjustment connecting means. In addition, when the abnormality of the inter-terminal voltage detection means is not determined, the voltage adjustment connecting means is controlled so that the inter-terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the inter-terminal voltage detection means. Even when no abnormality occurs, it can be appropriately dealt with.

  In such a fuel cell system of the present invention, the specific voltage is a voltage detected by the inter-terminal voltage detection means before the abnormality determination means determines that the abnormality of the inter-terminal voltage detection means. You can also. In this way, when an abnormality is determined, the voltage adjusting means can be controlled using the voltage detected by the terminal voltage detecting means before the abnormality of the terminal voltage detecting means is determined.

  In the fuel cell system according to the present invention, the abnormality determination means may detect the abnormality of the inter-terminal voltage detection means when the change rate of the inter-terminal voltage detected by the inter-terminal voltage detection means is equal to or higher than a predetermined change rate. The abnormality determination means is a means for determining an abnormality of the inter-terminal voltage detection means when the inter-terminal voltage detected by the inter-terminal voltage detection means is equal to or lower than a predetermined voltage. The fuel cell is a battery having a fuel cell stack in which a plurality of unit cells are stacked, and includes a unit cell voltage detection unit that detects a voltage of each unit cell, and the abnormality determination unit includes The inter-terminal voltage detection means when the difference between the sum of the voltages of the individual cells detected by the single-cell voltage detection means and the inter-terminal voltage detected by the inter-terminal voltage detection means is greater than or equal to a predetermined value. It may be assumed to be means for determining abnormality.

  Further, in the fuel cell system of the present invention, it is determined whether or not the inter-terminal voltage detection unit has been determined to be abnormal by the abnormality determination unit based on the inter-terminal voltage detected by the inter-terminal voltage detection unit. The voltage control means is configured to detect the abnormality of the voltage between the terminals when the return determination means determines the return of the inter-terminal voltage detection means within a predetermined time after the abnormality is determined by the abnormality determination means. Based on the voltage detected by the detecting means, the voltage adjustment connecting means is controlled so that the terminal voltage of the fuel cell becomes the set target voltage, and within a predetermined time after the abnormality is judged by the abnormality judging means. When the return determination means does not determine the return of the inter-terminal voltage detection means, the voltage between the terminals of the fuel cell by the voltage adjustment connection means The adjustment of the voltage between the terminals of the spare the accumulator unit may be assumed to be a means for stopping. When the return is determined within a predetermined time after the abnormality of the inter-terminal voltage detecting means is determined, the inter-terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the inter-terminal voltage detecting means. Therefore, when the abnormality is an abnormality that recovers within a predetermined time, it is possible to appropriately deal with the voltage adjustment connection means without stopping. Further, when the return is not determined within a predetermined time after the abnormality is determined by the abnormality determination means, the adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the power storage means by the voltage adjustment connecting means is stopped. Even when it does not return in time, it is possible to cope appropriately.

  In the fuel cell system of the present invention having such a return determination means, the return determination means is detected by the inter-terminal voltage detection means before the abnormality determination means determines an abnormality of the inter-terminal voltage detection means. The return from the abnormality is determined when the difference between the terminal voltage detected by the abnormality determination unit and the voltage between the terminals detected by the terminal voltage detection unit is within a predetermined voltage difference after the abnormality is determined by the abnormality determination unit. Or a means for determining return from the abnormality when the inter-terminal voltage detected by the inter-terminal voltage detection means is greater than a predetermined voltage, or the fuel cell is a single cell Is a battery having a fuel cell stack formed by stacking a plurality of battery cells, and includes a unit cell voltage detection unit that detects a voltage of each unit cell, and the return determination unit includes: Means for determining return from the abnormality when the difference between the sum of the voltages of the individual cells detected by the battery voltage detecting means and the voltage between the terminals detected by the inter-terminal voltage detecting means is smaller than a predetermined value; It can also be.

  The automobile of the present invention is the fuel cell system of the present invention according to any one of the above-described aspects, that is, the fuel cell system that can basically supply the generated power from the fuel cell that generates power by receiving the supply of fuel to the load. A chargeable / dischargeable power storage means, a power line from the fuel cell to the load and an output terminal of the power storage means, and a terminal voltage of the fuel cell and a terminal voltage of the power storage means. Voltage adjusting connection means for adjusting, target voltage setting means for setting a target voltage of the terminal voltage of the fuel cell based on required power required for the fuel cell, and a terminal for detecting the terminal voltage of the fuel cell An inter-voltage detection means, an abnormality determination means for determining an abnormality of the inter-terminal voltage detection means based on the inter-terminal voltage detected by the inter-terminal voltage detection means, and an abnormality determination means When the abnormality of the inter-terminal voltage detection means is not determined, the voltage adjustment connecting means is controlled based on the voltage detected by the inter-terminal voltage detection means so that the inter-terminal voltage of the fuel cell becomes the set target voltage. When the abnormality is determined by the abnormality determination unit, the terminal voltage of the fuel cell is set to the target set by using a specific voltage as the voltage detected by the terminal voltage detection unit. And a voltage control means for controlling the voltage adjustment connecting means so as to be a voltage. The gist of the invention is that the load is a traveling generator motor.

  Since the automobile of the present invention is equipped with the fuel cell system of the present invention according to any one of the aspects described above, the effects exhibited by the fuel cell system of the present invention, for example, when abnormality occurs in the inter-terminal voltage detection means The same effects as the effect that can be appropriately dealt with without stopping the adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the power storage means by the voltage adjustment connecting means can be obtained.

The control method of the fuel cell system of the present invention includes:
A fuel cell capable of generating power by receiving supply of fuel and supplying generated power to a load; chargeable / dischargeable power storage means; a power line from the fuel cell to the load; and an output terminal of the power storage means A control method for a fuel cell system, comprising: a voltage adjustment connecting unit that adjusts a voltage between terminals of the fuel cell and a voltage between terminals of the power storage unit; and a voltage detecting unit between terminals that detects a voltage between terminals of the fuel cell. There,
(A) setting a target voltage of the terminal voltage of the fuel cell based on the required power required for the fuel cell;
(B) determining an abnormality of the inter-terminal voltage detection means;
(C) The voltage adjustment connection so that the terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the terminal voltage detection means when the abnormality of the terminal voltage detection means is not determined. And the terminal voltage of the fuel cell is set to the set target voltage using a specific voltage as the voltage detected by the terminal voltage detection means when an abnormality of the terminal voltage detection means is determined. The gist is to control the voltage regulation connecting means.

  In the fuel cell system of the present invention, when the abnormality of the inter-terminal voltage detection means is not determined, the voltage adjustment connection is made so that the inter-terminal voltage of the fuel cell becomes a set target voltage based on the voltage detected by the inter-terminal voltage detection means. The voltage is controlled so that the inter-terminal voltage of the fuel cell becomes the set target voltage by using the specific voltage as the voltage detected by the inter-terminal voltage detecting means when an abnormality of the inter-terminal voltage detecting means is determined. Control adjustment connection means. When the abnormality of the inter-terminal voltage detection means is determined, the voltage adjustment connecting means is set so that the inter-terminal voltage of the fuel cell becomes the set target voltage using a specific voltage as the voltage detected by the inter-terminal voltage detection means. Since the control is performed, it is possible to appropriately deal with without stopping the adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the power storage means by the voltage adjustment connecting means. In addition, when the abnormality of the inter-terminal voltage detection means is not determined, the voltage adjustment connecting means is controlled so that the inter-terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the inter-terminal voltage detection means. Even when no abnormality occurs, it can be appropriately dealt with.

  In such a control method of the fuel cell system of the present invention, (d) the inter-terminal voltage detection means in which the abnormality of the inter-terminal voltage detection means is determined based on the inter-terminal voltage detected by the inter-terminal voltage detection means. (E) based on the voltage detected by the inter-terminal voltage detection means when the return of the inter-terminal voltage detection means is determined within a predetermined time after the abnormality is determined. The voltage adjustment connecting means is controlled so that the terminal voltage of the fuel cell becomes the set target voltage, and when the return of the terminal voltage detecting means is not determined within a predetermined time after the abnormality is determined, The adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the power storage means by the voltage adjustment connecting means may be stopped. When a return is determined within a predetermined time after the abnormality of the inter-terminal voltage detecting means is determined, the inter-terminal voltage of the fuel cell becomes a set target voltage based on the voltage detected by the inter-terminal voltage detecting means. Since the voltage adjustment connecting means is controlled, when the abnormality is an abnormality that recovers within a predetermined time, the voltage adjustment connecting means can be appropriately dealt with without stopping. In addition, when the return is not determined within a predetermined time after the abnormality is determined, the adjustment of the voltage between the terminals of the fuel cell and the voltage between the terminals of the storage means by the voltage adjustment connecting means is stopped, so that the abnormality does not return within the predetermined time. Sometimes it can be dealt with appropriately.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 10 equipped with a fuel cell system as an embodiment of the present invention. As shown in the figure, the electric vehicle 10 of the embodiment is supplied from a hydrogen high-pressure tank 22 and supplied as hydrogen gas as a fuel gas circulated by a circulation pump 26 and from an air compressor 28 and an accumulator 24 via a switching valve 50. A fuel cell 30 that generates power using oxygen in the air, an inverter 34 that converts DC power from the fuel cell 30 into three-phase AC power, and a three-phase AC power converted by the inverter 34 that is driven through a differential gear 14. DC / DC that converts the DC power from the fuel cell 30 to low voltage and supplies it to the traveling motor 36 that outputs power to the drive wheels 12 and the secondary battery 60 for auxiliary equipment and the auxiliary equipment 62 mounted on the vehicle. A DC converter 54 and an electronic control unit 70 for controlling the entire vehicle are provided.

  The fuel cell 30 is a fuel obtained by laminating a plurality of unit cells 32 including an electrolyte membrane formed of, for example, a solid polymer membrane and an anode electrode and a cathode electrode sandwiching the electrolyte membrane together with a separator that forms a partition between cells. The battery stack is configured to generate power by an electrochemical reaction between hydrogen gas supplied to the anode electrode and air supplied to the cathode electrode through a gas flow path formed in the separator. Although not shown, the fuel cell 30 is provided with a circulation path through which a cooling medium (for example, cooling water) can be circulated. The circulation of the cooling medium in the circulation path causes the temperature in the fuel cell 30 to be an appropriate temperature (for example, , 65 ° C. to 85 ° C.).

  The traveling motor 36 is configured as, for example, a well-known synchronous generator motor that functions as an electric motor and also as a generator, and serves as an electric motor according to the depression amount of the accelerator pedal 83 and the brake pedal 85 of the driver and the vehicle speed V. Or it drives as a generator.

  A diode 58 is attached to the power line from the fuel cell 30 in such a direction that the secondary battery 60 can be charged from the fuel cell 30 via the DC / DC converter 54, and the secondary battery 60 is discharged. The reverse current does not flow to the fuel cell 30 even if the traveling motor 36 generates power.

  The electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs and the like, a RAM 76 that temporarily stores data, an input / output port (not shown), and the like. Is provided. The electronic control unit 70 includes a cell monitor 56 that detects a detection voltage Vp from a voltage sensor 52 attached to a power line from the fuel cell 30 to the inverter 34 and a voltage between terminals of each single cell 32 of the fuel cell 30. The voltage Vcell between terminals of each single cell, the rotational position from the rotational position detection sensor 36a that detects the position of the rotor of the traveling motor 36, the shift position from the shift position sensor 82 that detects the position of the shift lever 81, and the accelerator pedal From the accelerator pedal position AP from the accelerator pedal position sensor 84 for detecting the depression amount of 83, the brake position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, and the vehicle speed sensor 88 for detecting the traveling speed of the vehicle. Vehicle speed V etc. via the input port It has been input. Further, from the electronic control unit 70, a drive signal to the circulation pump 26, a drive signal to the air compressor 28, a switching signal to the inverter 34, a DC power conversion signal to the DC / DC converter 54, and switching to the switching valve 50. A signal, a switching signal to the inverter 34, and the like are output via the output port.

  Next, the operation of the electric vehicle 10 of the embodiment configured as described above, particularly the operation of controlling the DC / DC converter 54 when an abnormality has occurred in the voltage sensor 52 will be described. FIG. 2 is a flowchart illustrating an example of a DC / DC converter control routine executed by the electronic control unit 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every 8 msec).

  When the control routine is executed, the CPU 72 of the electronic control unit 70 first starts the accelerator pedal opening AP from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm of the traveling motor 36, and the voltage sensor 52. Data necessary for processing, such as the detection voltage Vp, the abnormality determination flag F, the counter value Ct, and the detection voltage Vpre detected by the voltage sensor 52 when this control routine is executed before the abnormality is determined. Processing is executed (step S100). Here, as for the rotational speed Nm of the traveling motor 36, in the embodiment, a value calculated based on the rotational position of the rotor detected by the rotational position detection sensor 36 a is input. It is good also as what converts, and it is good also as what inputs the sensor which attaches the sensor which detects directly the rotation speed of the motor 36 for driving | running | working, and is detected by this sensor. The abnormality determination flag F is set to a value of 0 as an initial value, and is set to a value of 1 when an abnormality occurs in the voltage sensor 52 by this routine. Further, the counter value Ct is set to 0 as an initial value. When an abnormality of the voltage sensor 52 is determined, the value 1 is added every time this control routine is executed, and is set to 0 when returning from the abnormality. . Therefore, the product of the counter value Ct and the time required for this control routine to execute once (for example, 8 msec) is the elapsed time after the occurrence of the abnormality in the voltage sensor 52. In the embodiment, the detected voltage Vpre before the abnormality determination is, in the embodiment, when the value 0 is set in the abnormality determination flag F, the detection voltage detected by the voltage sensor 52 when the control routine was executed last time is read to determine the abnormality. When the value 1 is set in the flag F, the detection voltage detected by the previous voltage sensor 52 read when the value 1 is first set in the abnormality determination flag F is read.

  Subsequently, the motor torque Tm * to be output from the traveling motor 36 based on the accelerator opening AP and the vehicle speed V that have been read in, and a value obtained by multiplying the set motor torque Tm * by the rotational speed Nm of the traveling motor 36. The required power P * required by the vehicle is set by adding the required power Pa * required by the machine 62, the charge / discharge required power Pb * required by the secondary battery 60, and the loss Loss (step S110). Here, in the embodiment, the motor torque Tm * is set in advance in a relationship between the accelerator opening AP, the vehicle speed V, and the required torque T * and stored in the ROM 74 as a motor torque setting map. By giving the vehicle speed V, the corresponding motor torque Tm * is derived and set from the motor torque setting map. An example of the motor torque setting map is shown in FIG.

  Next, the target voltage Vreq to be output from the fuel cell 30 is set based on the set required power P * (step S120). Here, in the embodiment, the target voltage Vreq is set in advance by storing the relationship between the required power P * and the output current Ifc of the fuel cell 30 in the ROM 74 as an output current setting map, and the output current Ifc and the target voltage Vreq. Is previously stored in the ROM 74 as a target voltage setting map, and the output current Ifc corresponding to the required power P * is derived from the output current setting map and the output current Ifc derived from the target voltage setting map is derived. The corresponding target voltage Vreq is derived and set. An example of the output current setting map is shown in FIG. 4, and an example of the target voltage setting map is shown in FIG.

  Subsequently, it is determined whether or not the abnormality determination flag F is 0 (step S130). When the abnormality determination flag F is 0, since the abnormality of the voltage sensor 52 has not been determined when the previous control routine was executed, it is next determined whether an abnormality has occurred in the voltage sensor 52 (step) S140). Here, the determination of the abnormality of the voltage sensor 52 is performed by inputting the voltage detected by the voltage sensor 52 when the previous control routine is executed, that is, the detected voltage Vpre detected before the abnormality determination is performed in step S100. The time change rate of the inter-terminal voltage of the fuel cell 30 is derived from the detected voltage Vp, and this is performed when the time change rate is larger than the change rate assumed when no abnormality occurs. This is based on the fact that when an abnormality such as a disconnection occurs in the voltage sensor 52, the detection voltage Vp detected by the voltage sensor 52 rapidly decreases from the detection voltage Vpre before the abnormality determination is made, for example, becomes 0. .

  When the abnormality of the voltage sensor 52 is not determined in the process of step S140, the voltage command V * of the voltage across the terminals of the fuel cell 30 is obtained from the equation (1) based on the detection voltage Vp and the target voltage Vreq input in step S100. Calculate (step S170). Here, Expression (1) is a relational expression in feedback control for setting the inter-terminal voltage of the fuel cell 30 to the target voltage Vreq. In Expression (1), “k1” in the second term on the right side is a proportional term. “K2” in the third term on the right side is the gain of the integral term, and “k3” in the fourth term on the right side is the gain of the differential term.

  V * = previous V * + k1 (Vreq−Vp) + k2∫ (Vreq−Vp) dt + k3 · d (Vreq−Vp) / dt + (1)

  When the voltage command V * is thus set, the DC / DC converter is controlled so that the voltage across the terminals of the fuel cell 30 becomes the voltage command V * (step S180), and this routine is terminated. Thus, when the abnormality of the voltage sensor 52 is not determined, the DC / DC converter 54 is controlled based on the detected voltage Vp detected by the voltage sensor 52 so that the terminal voltage of the fuel cell 30 becomes the target voltage Vreq. Appropriate measures can be taken when no abnormality occurs.

  On the other hand, if it is determined in step S140 that there is an abnormality in the voltage sensor 52, the abnormality determination flag F is set to 1 and the value 1 is added to the counter value Ct (step S150) and the detected voltage Vp. As a result, the detection voltage Vpre before the abnormality is determined is set (step S160), the processing after step S170 is executed, and this control routine is terminated. The detection voltage Vpre before the abnormality is determined as the detection voltage Vp in the process of step S160 is set when the abnormality such as a disconnection occurs in the voltage sensor 52. The detection voltage Vp is set based on the actual voltage across the terminals of the fuel cell 30. Since the voltage command V * is set by using the detection voltage Vp input in step S100 in the process of step S170, the second term and the third term on the right side in the equation (1) are increased and DC / DC. This is based on the fact that control by the converter 54 becomes impossible. Therefore, by setting the voltage command V * using the detection voltage Vpre before the abnormality is determined as the detection voltage Vp, the voltage between the terminals of the actual fuel cell 30 is close when the abnormality of the voltage sensor 52 occurs. The voltage command V * can be set using the value as the detection voltage Vp. As a result, even if an abnormality occurs in the voltage sensor 52, the DC / DC converter 54 can be controlled so that the terminal voltage of the fuel cell 30 becomes the target voltage Vreq without stopping the control of the DC / DC converter 54.

  On the other hand, when it is determined in step S130 that the abnormality determination flag F is not 0, that is, when the abnormality of the voltage sensor 52 is determined when the previous control routine is executed, the voltage sensor 52 is subsequently detected from the abnormality. It is determined whether or not it has returned (step S200). Here, the return determination is performed by calculating a difference between the detection voltage Vpre before the abnormality is determined and the detection voltage Vp input in step S100, and when the difference is within a predetermined value, the voltage sensor 52 is detected from the abnormality. It is assumed that it has returned. This is because when the voltage sensor 52 recovers from an abnormality, the detection voltage Vp, which has become significantly smaller when an abnormality occurs, is within a predetermined value from the voltage used for normal control, that is, the detection voltage Vpre before the abnormality is determined. This is based on returning to a voltage controllable by the DC / DC converter 54.

  If it is determined in step S200 that the voltage sensor 52 has recovered from the abnormality, both the abnormality determination flag F and the counter value Ct are set to 0 (step S210), and the detection detected by the voltage sensor 52 is detected. The subsequent processing of step S170 is executed using the voltage Vp, and this control routine ends. As described above, when the voltage sensor 52 is recovered from the abnormality, the terminal-to-terminal voltage command V * is set using the detection voltage Vp detected by the voltage sensor 52, so that the DC / DC converter 54 is appropriately controlled. be able to.

  On the other hand, if it is determined in step S200 that the voltage sensor 52 has not recovered from the abnormality, this is a counter value for determining that the abnormality is an instantaneous interruption of about 0.1 seconds or 0.3 seconds, for example. It is determined whether or not the counter value Ct is smaller than the threshold value Ct_0 (step S220). If the counter value Ct is smaller than the threshold value Ct_0, there is a possibility of returning from an abnormality, and the control is continued without stopping the DC / DC converter 54. Therefore, the value 1 is added to the counter value Ct (step S230), the detection voltage Vpre before the abnormality is determined is set to the detection voltage Vp (step S240), and the processing after step S170 is executed. This control routine is then terminated. Thus, when it is determined that there is a possibility that the voltage sensor 52 is recovered from the abnormality even when the voltage sensor 52 has not recovered from the abnormality, the detection voltage Vpre before the abnormality is determined is set as the detection voltage Vp to set the voltage command V Since * is set, the control of the DC / DC converter 54 can be continued.

  If it is determined in step S220 that the counter value Ct is greater than the threshold value Ct_0, it is determined that the abnormality is not an instantaneous interruption and cannot be recovered, and the DC / DC converter 54 is controlled to stop (step S250). ), This control routine is terminated. Thus, when there is no possibility of returning from an abnormality, the control of the DC / DC converter 54 can be stopped.

  According to the electric vehicle 10 of the embodiment described above, when the abnormality of the voltage sensor 52 is determined, DC is detected using the detection voltage Vpre detected by the voltage sensor 52 before the abnormality is determined as the detection voltage Vp. Since the voltage command V * to the DC / DC converter 54 is set, the DC / DC converter 54 is controlled so that the terminal voltage of the fuel cell 30 becomes the target voltage Vreq without stopping the control of the DC / DC converter 54. Can do. Further, when the abnormality of the voltage sensor 52 is not determined, the voltage command V * to the DC / DC converter 54 is set using the detected voltage Vp, so that the DC / DC converter 54 can be appropriately controlled. On the other hand, when the voltage sensor 52 recovers from the abnormality, the voltage command V * to the DC / DC converter 54 is set using the detected voltage Vp, so that the abnormality is recovered when a predetermined time elapses such as an instantaneous interruption of the voltage sensor 52. Even so, the control of the DC / DC converter 54 can be appropriately performed without stopping. When the voltage sensor 52 does not recover from the abnormality, the control of the DC / DC converter 54 can be stopped.

  In the electric vehicle 10 of the embodiment, when the abnormality of the voltage sensor 52 is determined, the voltage command V * is set using the detected voltage Vpre detected by the voltage sensor 52 before the abnormality is determined. Since it is sufficient to use a value different from the detection voltage Vp input in step S100, other preset voltage values such as a lower limit voltage value of the voltage across the terminals of the fuel cell 30 assumed when the fuel cell 30 is operated are set. It may be used.

  In the electric vehicle 10 according to the embodiment, the time change rate of the inter-terminal voltage of the fuel cell 30 calculated from the detection voltage Vpre detected before the abnormality determination is performed and the detection voltage Vp input in step S100 is abnormal. The abnormality of the voltage sensor 52 is determined when the rate of change is larger than the expected rate of change when no occurrence of the voltage is detected, but any method may be used as long as the abnormality of the voltage sensor 52 can be determined. When the detected voltage Vp is smaller than the lower limit value of the voltage across the terminals of the fuel cell 30 assumed when the fuel cell 30 is operated, an abnormality is determined, or the fuel cell 30 detected by the detected voltage Vp and the cell monitor 56 It is good also as what determines with abnormality, when the difference with the sum total of the voltage Vcell between terminals of each single cell 32 of this exceeds the predetermined value.

  In the electric vehicle 10 according to the embodiment, when the difference between the detection voltage Vpre before the abnormality is determined and the detection voltage Vp input in step S100 is within a predetermined value, it is determined that the voltage sensor 52 has recovered from the abnormality. However, any method may be used as long as the return from the abnormality of the voltage sensor 52 can be determined. For example, the terminal of the fuel cell 30 assumed when the detection voltage Vp operates the fuel cell 30 The difference between the detected voltage Vp and the sum of the inter-terminal voltages Vcell of each unit cell 32 of the fuel cell 30 detected by the cell monitor 56 is within a predetermined value based on whether the return is greater than the lower limit of the inter-voltage. Sometimes it is possible to determine return.

  In the electric vehicle 10 of the embodiment, a solid polymer type fuel cell that generates power using hydrogen supplied from the hydrogen high-pressure tank 22 is mounted as the fuel cell 30, but the hydrocarbon-based fuel is a hydrogen-rich fuel gas. A solid polymer fuel cell of a type provided with a reformer that is reformed and supplied to the fuel cell 30 may be mounted, or a fuel cell of a type different from the solid polymer fuel cell is mounted. It doesn't matter as a thing.

  Although the electric vehicle 10 of the embodiment is configured to use one traveling motor 36, it may be configured to use two wheel-in motors built in the drive wheels 12, and different axles, that is, the axles of the front wheels. Of course, different motors may be attached to the axles of the rear wheels.

   Furthermore, in the above-described embodiments, the fuel cell system is mounted on the electric vehicle 10, but this fuel cell system may be applied to transportation equipment such as trains and airplanes, homes, factories, etc. May be incorporated into a cogeneration system installed in In either case, the same effect as the above-described embodiment can be obtained.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

1 is a configuration diagram showing an outline of a configuration of an electric vehicle 10 equipped with a fuel cell system according to an embodiment of the present invention. It is a flowchart which shows an example of the DC / DC converter control routine performed by the electronic control unit 70 of an Example. It is explanatory drawing which shows an example of a motor torque setting map. It is explanatory drawing which shows an example of an output current setting map. It is explanatory drawing which shows an example of a target voltage setting map.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Electric vehicle, 12 Drive wheel, 14 Differential gear, 22 Hydrogen high pressure tank, 24 Accumulator, 26 Circulation pump, 28 Air compressor, 30 Fuel cell, 32 Single cell, 34 Inverter, 36 Driving motor, 36a Rotation position sensor, 52 Voltage sensor, 54 DC / DC converter, 56 cell monitor, 58 diode, 60 secondary battery, 62 auxiliary machine, 70 electronic control unit, 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift position sensor, 83 accelerator pedal 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor.

Claims (12)

A fuel cell system capable of supplying to a load generated power from a fuel cell that generates power upon receiving fuel supply,
Charge / discharge power storage means;
A voltage adjustment connecting means for connecting a power line from the fuel cell to the load and an output terminal of the power storage means and adjusting a voltage between terminals of the fuel cell and a voltage between terminals of the power storage means;
Target voltage setting means for setting a target voltage of the terminal voltage of the fuel cell based on the required power required for the fuel cell;
An inter-terminal voltage detecting means for detecting an inter-terminal voltage of the fuel cell;
An abnormality determining means for determining an abnormality of the inter-terminal voltage detecting means based on the inter-terminal voltage detected by the inter-terminal voltage detecting means;
When the abnormality determination means does not determine the abnormality of the inter-terminal voltage detection means, the voltage so that the terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the inter-terminal voltage detection means. The adjustment connection means is controlled, and when the abnormality determination means determines that the abnormality of the inter-terminal voltage detection means, a specific voltage is used as the voltage detected by the inter-terminal voltage detection means, and the terminal voltage of the fuel cell is determined. Voltage control means for controlling the voltage adjustment connecting means so that becomes the set target voltage,
A fuel cell system comprising:   2. The fuel cell system according to claim 1, wherein the specific voltage is a voltage detected by the inter-terminal voltage detection unit before the abnormality determination unit determines an abnormality of the inter-terminal voltage detection unit.   3. The abnormality determination unit is a unit that determines an abnormality of the inter-terminal voltage detection unit when a change rate of the inter-terminal voltage detected by the inter-terminal voltage detection unit is equal to or higher than a predetermined change rate. The fuel cell system described.   3. The fuel cell according to claim 1, wherein the abnormality determination unit is a unit that determines abnormality of the inter-terminal voltage detection unit when the inter-terminal voltage detected by the inter-terminal voltage detection unit is equal to or lower than a predetermined voltage. system. The fuel cell system according to claim 1 or 2, wherein
The fuel cell is a battery having a fuel cell stack in which a plurality of single cells are stacked,
A cell voltage detecting means for detecting the voltage of each cell;
The abnormality determination unit is configured to detect the difference between the terminals when the difference between the sum of the voltages of the individual cells detected by the unit cell voltage detection unit and the voltage between the terminals detected by the inter-terminal voltage detection unit is a predetermined value or more. A fuel cell system which is means for determining an abnormality of the voltage detection means. The fuel cell system according to any one of claims 1 to 5, wherein
A return determination means for determining a return from the abnormality of the inter-terminal voltage detection means determined to be abnormal by the abnormality determination means based on the voltage between the terminals detected by the inter-terminal voltage detection means;
The voltage control means detects the voltage detected by the inter-terminal voltage detection means when the return determination means determines the return of the inter-terminal voltage detection means within a predetermined time after the abnormality is determined by the abnormality determination means. The voltage adjustment connecting means is controlled so that the terminal voltage of the fuel cell becomes the set target voltage, and the return determination means within the predetermined time after the abnormality is determined by the abnormality determination means. A fuel cell system, which is a means for stopping adjustment of the inter-terminal voltage of the fuel cell and the inter-terminal voltage of the power storage means by the voltage adjustment connecting means when the return of the inter-terminal voltage detecting means is not determined.   The return determination means determines the abnormality by the terminal voltage detected by the terminal voltage detection means and the abnormality determination means before the abnormality determination means determines the abnormality of the terminal voltage detection means. 7. The fuel cell system according to claim 6, wherein the fuel cell system is a means for determining a return from the abnormality when a difference from the inter-terminal voltage detected by the inter-terminal voltage detecting means is within a predetermined voltage difference.   The fuel cell system according to claim 6, wherein the return determination means is means for determining return from the abnormality when the inter-terminal voltage detected by the inter-terminal voltage detection means is greater than a predetermined voltage. The fuel cell system according to claim 6, wherein
The fuel cell is a battery having a fuel cell stack in which a plurality of single cells are stacked,
A cell voltage detecting means for detecting the voltage of each cell;
When the difference between the sum of the voltages of the individual cells detected by the unit cell voltage detection unit and the voltage between the terminals detected by the terminal voltage detection unit is smaller than a predetermined value, the return determination unit A fuel cell system that is a means for determining the return of the fuel.   An automobile equipped with the fuel cell system according to any one of claims 1 to 9, wherein the load is a generator motor for traveling. A fuel cell capable of generating power by receiving supply of fuel and supplying generated power to a load; chargeable / dischargeable power storage means; a power line from the fuel cell to the load; and an output terminal of the power storage means A control method for a fuel cell system, comprising: a voltage adjustment connecting unit that adjusts a voltage between terminals of the fuel cell and a voltage between terminals of the power storage unit; and a voltage detecting unit between terminals that detects a voltage between terminals of the fuel cell. There,
(A) setting a target voltage of the terminal voltage of the fuel cell based on the required power required for the fuel cell;
(B) determining an abnormality of the inter-terminal voltage detection means;
(C) The voltage adjustment connection so that the terminal voltage of the fuel cell becomes the set target voltage based on the voltage detected by the terminal voltage detection means when the abnormality of the terminal voltage detection means is not determined. And the terminal voltage of the fuel cell is set to the set target voltage using a specific voltage as the voltage detected by the terminal voltage detection means when an abnormality of the terminal voltage detection means is determined. A control method for a fuel cell system, wherein the voltage regulation connecting means is controlled to become. A control method for a fuel cell system according to claim 11, comprising:
(D) determining a return from the abnormality of the inter-terminal voltage detection means in which an abnormality of the inter-terminal voltage detection means is determined based on the inter-terminal voltage detected by the inter-terminal voltage detection means;
(E) When the return of the inter-terminal voltage detection means is determined within a predetermined time after the abnormality is determined, the inter-terminal voltage of the fuel cell is determined based on the voltage detected by the inter-terminal voltage detection means. The voltage adjustment connecting means is controlled so as to reach a set target voltage, and when the return of the inter-terminal voltage detecting means is not determined within a predetermined time after the abnormality is determined, the fuel cell is controlled by the voltage adjustment connecting means. A control method for a fuel cell system, wherein adjustment of the inter-terminal voltage and the inter-terminal voltage of the power storage means is stopped.

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