Battery management device

Abstract

To efficiently grasp performance of a secondary battery and a fuel cell with a simple configuration, in regard to a battery management device.SOLUTION: There is disclosed a battery management device 10 for managing a secondary battery 3 and a fuel cell 5 installed in a vehicle 1. The battery management device 10 comprises: control means 11 that executes charge control for charging the secondary battery 3 with power generated by the fuel cell 5, during stopping of the vehicle 1; and determination means 12 for determining performance of each of the secondary battery 3 and the fuel cell 5, during execution of the charge control.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery management device that manages a secondary battery and a fuel cell mounted on a vehicle. [Background technology]

[0002] Conventionally, secondary batteries (e.g., lithium ion secondary batteries) that can be repeatedly charged and discharged, and fuel cells (e.g., solid polymer fuel cells) that generate power using an oxidation-reduction reaction of gaseous fuel are known as power supply sources for driving a driving motor mounted on a vehicle. Regarding performance evaluation of such secondary batteries, a technique is known in which the battery capacity is measured by performing constant current and constant voltage charging from a fully discharged state and then constant current discharging. Regarding performance evaluation of fuel cells, a technique is also known in which the performance (degree of catalyst poisoning) is evaluated based on the amount of decrease in cell voltage when the cathode humidity is decreased (see Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-040868 A [Patent Document 2] International Publication No. 2017 / 047353 [Patent Document 3] JP 2014-220094 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle equipped with the above-mentioned secondary battery and fuel cell, in order to improve the convenience and usability of the vehicle, it is preferable to appropriately determine the performance of each battery and to notify the vehicle user of a message encouraging maintenance or replacement as necessary. However, since the control for determining the performance of each battery takes time, there is a problem that it is difficult to increase the frequency of performance determination. For example, when measuring the battery capacity of a secondary battery, it takes several tens of hours to several days to change the charge state between a fully discharged state and a fully charged state, and the measurement itself is not easy. In addition, in performance evaluation of a fuel cell, the operation for reducing the cathode humidity takes time and costs.

[0005] One of the objectives of the present invention, which was invented in light of the above-mentioned problems, is to provide a battery management device that can efficiently grasp the performance of secondary batteries and fuel cells with a simple configuration. In addition to this objective, another objective of the present invention is to achieve effects derived from the respective configurations shown in the "Description of Embodiments" below, which cannot be obtained with conventional techniques. [Means for solving the problem]

[0006] The disclosed battery management device can be realized as the following disclosed aspects (application examples), which solve at least part of the above problems. Each of the aspects from aspect 2 onwards is an aspect that can be selected additionally as appropriate, and each of the aspects can be omitted. None of the aspects from aspect 2 onwards discloses an essential aspect or configuration for the present invention.

[0007] Aspect 1. The disclosed battery management device is a battery management device that manages a secondary battery and a fuel cell mounted on a vehicle. This battery management device includes a control means that performs charging control to charge the secondary battery with power generated by the fuel cell while the vehicle is stopped, and a determination means that determines the performance of both the secondary battery and the fuel cell while the charging control is being performed.

[0008] Aspect 2. In the above aspect 1, it is preferable that the determining means determines the performance of the fuel cell for a plurality of periods that are set according to the time that has elapsed since the start of the charging control. Aspect 3. In aspect 2 above, it is preferable that the judgment means, when judging the performance of the fuel cell, performs a first judgment to judge the magnitude relationship between the rate of change of the output voltage of the fuel cell and a predetermined rate threshold, and a second judgment to judge the magnitude relationship between the output voltage of the fuel cell and a predetermined voltage threshold.

[0009] Aspect 4. In any of the aspects including Aspect 1 above, it is preferable that the determining means determines the performance of the secondary battery based on a battery capacity calculated from an integrated value of an input current to the secondary battery. Aspect 5. In an aspect including aspect 1 above, when the vehicle's stopped time is expected to be longer than a predetermined time, it is preferable that the control means performs the charging control so that the secondary battery is charged at a current value equivalent to a low C rate corresponding to the value obtained by dividing the new capacity of the secondary battery by the predetermined time. Effect of the Invention

[0010] According to the disclosed battery management device, the performance of both the secondary battery and the fuel cell can be measured simultaneously during charging control, so that the deterioration of the secondary battery and the fuel cell and the necessity of maintenance can be efficiently determined. Therefore, the performance of the secondary battery and the fuel cell can be efficiently grasped with a simple configuration. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram of a vehicle to which a battery management device of the present invention is applied; [Diagram 2] 4 is a graph illustrating a voltage change of a fuel cell. [Diagram 3] 4 is a graph illustrating a voltage change of a secondary battery. [Figure 4] 4 is a flowchart relating to a determination of a start condition for charging control. [Diagram 5]4 is a flowchart relating to determination of the performance of a secondary battery and a fuel cell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The disclosed battery management device is applied to a vehicle shown in the following embodiment. This vehicle is equipped with at least a secondary battery and a fuel cell. The fuel cell has a function of charging at least the secondary battery. The secondary battery may function as a power supply source for driving a driving motor, for example, or may function as a power supply source for driving auxiliary equipment. The vehicle shown in the following embodiment is an electric vehicle, but the vehicle related to this case also includes engine vehicles, hybrid vehicles, etc.

[0013] The vehicle in question also includes a plug-in hybrid electric vehicle (PHEV). A plug-in hybrid vehicle is a hybrid vehicle that allows external charging of a secondary battery (driving battery) that serves as a power supply source for the driving motor, or allows external power supply from the driving battery to various electrical appliances. The plug-in hybrid vehicle referred to here is equipped with a charging port (inlet) for inserting a charging cable that supplies power from an external charging facility, and a socket (outlet) for external power supply. EXAMPLES

[0014] [1. Configuration] 1 is a block diagram showing the configuration of a vehicle 1 to which a battery management device 10 according to an embodiment is applied. The vehicle 1 is equipped with a motor 2, a secondary battery 3, and an inverter 4. The motor 2 is an electric motor that generates driving force for running the vehicle 1, and is, for example, a three-phase AC synchronous electric motor / generator. The motor 2 is connected to drive wheels via a speed change mechanism and a differential mechanism (not shown).

[0015] The secondary battery 3 is a power supply source for driving the motor 2, and is, for example, a lithium-ion secondary battery or a nickel-metal hydride battery. The secondary battery 3 has a built-in heating device (heater) for increasing the temperature of the secondary battery 3 and a built-in cooling device (fan) for decreasing the temperature. The state of the secondary battery 3 is managed by a battery management device 10. The inverter 4 is a power conversion device for converting AC power on the motor 2 side and DC power on the secondary battery 3 side, and is installed in the power supply path connecting the motor 2 and the secondary battery 3.

[0016] The vehicle 1 is equipped with a fuel cell 5, a fuel tank 6, a compressor 7, a DC-DC converter 8, and an operation panel 9. The fuel cell 5 is a power generation device that generates electric power by utilizing an oxidation-reduction reaction of gaseous fuel. The electric power generated by the fuel cell 5 can be supplied to the motor 2 and the secondary battery 3. Specific examples of the fuel cell 5 include a polymer electrolyte fuel cell (PEFC, Polymer Electrolyte Fuel Cell), a solid oxide fuel cell (SOFC, Solid Oxide Fuel Cell), and a molten carbonate fuel cell (MCFC, Molten Carbonate Fuel Cell). The fuel cell 5 is provided with auxiliary devices such as a heating device (heater) and a cooling device (radiator) for adjusting the temperature of the anode (negative electrode) and the cathode (positive electrode) (not shown), and a humidifier and a dehumidifier for adjusting the humidity. The state of the fuel cell 5 is managed by a battery management device 10.

[0017] A fuel tank 6 is connected to the anode side of the fuel cell 5 shown in FIG. 1, and a compressor 7 is connected to the cathode side. The fuel tank 6 is a container that stores pressurized fuel gas such as hydrogen or carbon monoxide. By opening a fuel valve (not shown), the fuel gas in the fuel tank 6 is supplied to the anode side of the fuel cell 5. The compressor 7 is a compressor that compresses outside air (air containing oxygen) and supplies it to the fuel cell 5. By operating the compressor 7, air containing oxygen is supplied to the cathode side of the fuel cell 5.

[0018] The DCDC converter 8 is a transformer device that transforms (boosts or reduces) the power generated by the fuel cell 5. The transformed power is supplied to a power supply path between the secondary battery 3 and the inverter 4. At this time, the secondary battery 3 is charged by making the voltage introduced into the power supply path higher than the voltage of the secondary battery 3. The battery management device 10 of this embodiment charges the secondary battery 3 at a low speed with the power generated by the fuel cell 5 while the vehicle 1 is stopped (for example, by utilizing the parking time), and performs control to determine the performance of both the secondary battery 3 and the fuel cell 5 during charging.

[0019] The operation panel 9 is an input / output device with a touch panel attached to the surface of a display. The operation panel 9 is provided, for example, on the dashboard or instrument panel of the vehicle 1, and is connected to a battery management unit 10. Information regarding the operating states of the secondary battery 3, the fuel cell 5, the fuel tank 6, the compressor 7, and the DCDC converter 8 is transmitted to the battery management unit 10, as well as information input via the operation panel 9.

[0020] [2. Control] The battery management device 10 is an electronic control device (computer) that manages the secondary battery 3 and the fuel cell 5. A processor (central processing unit), memory (main memory), storage device, interface device, etc. are built into the battery management device 10. The contents of the control (control program) performed by the battery management device 10 are stored in the memory or storage device, and are executed by appropriately loading the contents into the processor.

[0021] The main functions of the battery management device 10 are illustrated below. -Management of the charging state of the secondary battery 3 -Measurement of input / output voltage, input / output current, and temperature of secondary battery 3 -Management of power generation status of fuel cell 5 Measurement of the generated voltage, generated current, temperature, and humidity of the fuel cell 5 - Fuel tank 6 residual pressure measurement, fuel gas flow control Compressor 7 pressure measurement, compressed air flow control · Performance assessment of secondary batteries 3 and fuel cells 5

[0022] 1, the battery management device 10 is provided with a control means 11 and a determination means 12. These elements are conveniently classified according to their functions for determining the performance of both the secondary battery 3 and the fuel cell 5. These elements may be written as independent programs, or may be written as a composite program combining the functions of each element.

[0023] The control means 11 has a function of implementing charging control for charging the secondary battery 3 with power generated by the fuel cell 5 while the vehicle 1 is parked. The charging control is preferably implemented when the vehicle 1 is expected to be parked for a predetermined time or longer (for example, 5 to 6 hours or longer). As a specific example, when the user of the vehicle 1 parks the vehicle 1 for a long period of time and operates the operation panel 9 to start charging control, the control means 11 starts charging control. Alternatively, when the mileage or number of years of use of the vehicle 1 exceeds a specified mileage or number of years, information prompting the implementation of charging control while the vehicle is parked is displayed on the operation panel 9, and when the user subsequently permits the implementation of charging control, the control means 11 starts charging control.

[0024] The charge control is preferably a control for charging the secondary battery 3 at a lower C rate than during general external charging, and it is preferable to set a C rate (charging speed) of about 0.2 to 0.5 [C]. For example, when a secondary battery 3 with a charge / discharge capacity (battery capacity) of 60 [Ah] is charged at a C rate of 0.2 [C], a current of 12 [A] is continuously supplied to the secondary battery 3. In addition, it is preferable that the C rate during the charge control is constant, that is, it is preferable to perform constant current charging on the secondary battery 3. By performing constant current charging at a low C rate, the accuracy of measuring the capacity of the secondary battery 3 is improved.

[0025] The C rate during charging control may be set to a value corresponding to the expected parking time of the vehicle 1. That is, when the parking time of the vehicle 1 is expected to be equal to or longer than the predetermined time X, the C rate may be set to a value obtained by dividing the capacity of the secondary battery 3 when it is new by the predetermined time X. For example, assuming that the capacity of the secondary battery 3 when it is new (the charge / discharge capacity when it is new) is 60 [Ah], when the user parks the vehicle 1 for 12 hours, the secondary battery 3 may be charged at a constant current of 5 [A]. In this case, the actual charging time varies depending on the remaining capacity at the start of charging, but even if the remaining capacity at the start of charging is 0, the charging of the secondary battery 3 can be completed while the vehicle is parked. Therefore, the current value can be reduced within a range in which the charging of the secondary battery 3 can be completed while the vehicle is parked. The value of the predetermined time X may be input by the user using the operation panel 9, or a value expected based on the usage history of the vehicle 1 may be used.

[0026] The determination means 12 has a function of determining the performance of both the secondary battery 3 and the fuel cell 5 while the control means 11 is carrying out the charging control. The performance of the fuel cell 5 is preferably determined in a plurality of periods set according to the elapsed time since the start of the charging control. For example, from among the expected implementation period of the charging control, a first measurement period in the early stage of charging, a second measurement period in the middle stage of charging, and a third measurement period in the final stage of charging are set, and the performance of the fuel cell 5 is determined in each measurement period. As a specific example, assuming that the implementation time of the charging control is 5 hours, the first measurement period is set to a period of 30 to 60 minutes from the start of charging, the second measurement period is set to a period of 135 to 165 minutes, and the third measurement period is set to a period of 240 to 270 minutes. By performing the determination in a plurality of measurement periods, the performance degradation during the charging control of the fuel cell 5 can be accurately grasped.

[0027] The determining means 12 of this embodiment performs two types of performance determination during each measurement period. The first determination is to determine whether the rate of change of the output voltage of the fuel cell 5 is larger than a predetermined speed threshold A0. When the performance of the fuel cell 5 is good, the rate of change of the output voltage remains almost zero. On the other hand, when the performance of the fuel cell 5 deteriorates, the rate of change of the output voltage becomes negative, and the absolute value of the negative value increases as the performance deterioration becomes more severe. Therefore, by determining whether the rate of change of the output voltage is larger than the predetermined speed threshold A0, the deterioration of the performance of the fuel cell 5 can be accurately grasped. The predetermined speed threshold A0 may be a fixed value of 0 or close to 0, or may be a variable value set according to the cell temperature, number of years of use, etc. of the fuel cell 5.

[0028] The second determination is to determine whether the output voltage of the fuel cell 5 is larger than a predetermined voltage threshold. When the performance of the fuel cell 5 is good, the output voltage will be equal to or larger than a predetermined voltage threshold according to the cell voltage and the number of cell stacks. On the other hand, as the performance of the fuel cell 5 deteriorates, the output voltage decreases. Therefore, by determining whether the output voltage is larger than the predetermined voltage threshold, the deterioration of the performance of the fuel cell 5 can be accurately grasped.

[0029] FIG. 2 shows the output voltage V FC 1 is a graph illustrating an example of a change over time in the output voltage V. In the figure, times t1 to t2 correspond to a first measurement period, times t3 to t4 correspond to a second measurement period, and times t5 to t6 correspond to a third measurement period. OCV represents the open circuit voltage of the fuel cell 5 when it is new, and V0 represents a predetermined voltage threshold. In the first determination, the determination means 12 measures the output voltage V FC The change rates A1, A2, and A3 [mV / m] of the output voltage V are calculated, and the magnitude relationship between each of the change rates A1, A2, and A3 and a predetermined speed threshold A0 is determined. FC and a predetermined voltage threshold V0. The value of the voltage threshold V0 may be a fixed value set in advance, or may be a variable value set according to the cell temperature, number of years of use, etc. of the fuel cell 5.

[0030] The determination means 12 has a function of determining the performance of not only the fuel cell 5 but also the secondary battery 3. The performance of the secondary battery 3 is determined based on the charge / discharge capacity B calculated from the integrated value of the input current to the secondary battery 3, for example. In constant current charging, the input current to the secondary battery 3 is almost constant, so the charge / discharge capacity B at that time can be determined by multiplying the input current by the charging time. This charge / discharge capacity B decreases when the performance of the secondary battery 3 deteriorates. Therefore, by determining the magnitude relationship between this charge / discharge capacity B and a predetermined reference capacity B0, the deterioration of the performance of the secondary battery 3 can be accurately determined.

[0031] FIG. 3 shows the terminal voltage V of the secondary battery 3 during charging control. Li 1 is a graph showing an example of the change over time in the full charge voltage V MAX is the terminal voltage V at which charging of the secondary battery 3 is determined to be complete. Li represents the value of the terminal voltage V of the secondary battery 3 (i.e., the charge end voltage), B represents the charge / discharge capacity at the time of completion of charging, and B0 represents a predetermined reference capacity. Li is the full charge voltage V MAX The charge / discharge capacity B of the secondary battery 3 is calculated by integrating the input current until the charge / discharge capacity B reaches the reference capacity B0, and a comparison is made between the charge / discharge capacity B and the reference capacity B0. The value of the reference capacity B0 may be a preset fixed value, or may be a variable value that is set according to the cell temperature, number of years of use, etc. of the secondary battery 3.

[0032] [3. Flowchart] Fig. 4 is a flowchart related to the determination of the start condition of the charging control. The flow shown in Fig. 4 is repeatedly executed at a predetermined cycle by the battery management unit 10. Fig. 5 is a flowchart related to the determination of the performance of the secondary battery 3 and the fuel cell 5, and is executed after the charging control is started.

[0033] In step A1 in Fig. 4, it is determined whether or not a measurement start operation has been performed by the user of the vehicle 1. Here, it is determined, for example, whether or not the user has performed an operation to start charging control via the operation panel 9. Only when the conditions of step A1 are met, control proceeds to step A2. In step A2, various information related to the secondary battery 3 and fuel cell 5 is acquired by sensors (not shown), and input to the battery management unit 10, and the process proceeds to step A3.

[0034] In step A3, it is determined whether the residual pressure of the fuel gas stored in the fuel tank 6 is equal to or greater than a predetermined pressure. The predetermined pressure may be a preset fixed value, or may be a variable value that is set to a higher value as the charging rate of the secondary battery 3 is lower. If the residual pressure is below the predetermined pressure, it is determined that power generation by the fuel cell 5 is not possible, and the process proceeds to step A4. In step A4, the user is notified, for example via the operation panel 9, that performance measurement of the secondary battery 3 and the fuel cell 5 is not possible. On the other hand, if the residual pressure is equal to or greater than the predetermined pressure in step A3, it is determined that power generation by the fuel cell 5 is possible, and the process proceeds to step A5.

[0035] Steps A5 to A9 are steps related to temperature management of the secondary battery 3. In step A5, it is determined whether the cell temperature of the secondary battery 3 is lower than a first temperature (for example, lower than 25° C.). If this condition is met, the process proceeds to step A6, where flag F1 is set to 0. Flag F1 being 0 means that "the secondary battery 3 is in a cold state (it has not yet reached a state of a first temperature or higher suitable for charging)". In the following step A7, a temperature raising device is operated to raise the temperature of the secondary battery 3, and the process proceeds to step A10. On the other hand, if the condition of step A5 is not met, the process proceeds to step A8, where flag F1 is set to 1. Flag F1 being 1 means that "the secondary battery 3 is in a state of a first temperature or higher suitable for charging". In the following step A9, a temperature raising device or a cooling device is operated to keep the secondary battery 3 warm, and the process proceeds to step A10.

[0036] Steps A10 to A14 are steps related to temperature management of the fuel cell 5. In step A10, it is determined whether the cell temperature of the fuel cell 5 is less than a second temperature (for example, less than 60 to 80° C.). If this condition is met, the process proceeds to step A11, where flag F2 is set to 0. Flag F2 being 0 means that "the fuel cell 5 is in a cold state (it has not yet reached a state of the second temperature or higher suitable for power generation)". In the following step A12, a temperature raising device is operated to raise the temperature of the fuel cell 5, and the process proceeds to step A15. On the other hand, if the condition of step A10 is not met, the process proceeds to step A13, where flag F2 is set to 1. Flag F2 being 1 means that "the fuel cell 5 is in a state of the second temperature or higher suitable for power generation". In the following step A14, a temperature raising device is operated to keep the fuel cell 5 warm, and the process proceeds to step A15.

[0037] In step A15, it is determined whether flags F1 and F2 are both 1. If this condition is not met, control returns to step A5, and heating and warming are repeated until both flags F1 and F2 are 1. If the condition of step A15 is met, the process proceeds to step A16, where charging control is started and the elapsed time since the start of charging control is measured. Furthermore, in charging control, power generation by the fuel cell 5 is started, the secondary battery 3 is charged with the generated power, and the flow shown in FIG. 5 is started.

[0038] In step B1 of Fig. 5, various information related to the secondary battery 3 and fuel cell 5 is acquired by sensors (not shown) and input to the battery management unit 10, and the process proceeds to step B2. Steps B2 to B5 are steps related to judging the initial stage of charging. In step B2, it is judged whether the elapsed time of charging control is within a first measurement period (for example, between times t1 and t2 in Fig. 2). If this condition is met, the process proceeds to step B3, and if not, the process proceeds to step B6.

[0039] In step B3, the output voltage V FCThen, in step B4, it is determined whether the change rate A1 is equal to or greater than the rate threshold A0. If the change rate A1 is equal to or greater than the rate threshold A0, it is determined that there is no (or is slow) performance degradation of the fuel cell 5, and the process proceeds to step B6. On the other hand, if the change rate A1 is less than the rate threshold A0, it is determined that there is a performance degradation of the fuel cell 5 (is deteriorating rapidly), and the process proceeds to step B5.

[0040] In step B5, the output voltage V FC It is determined whether the output voltage V is equal to or greater than the voltage threshold V0. FC If the output voltage V is equal to or greater than the voltage threshold V0, it is determined that the performance of the fuel cell 5 is not significantly impaired, and the process proceeds to step B6. FC is less than the voltage threshold value V0, it is determined that the performance of the fuel cell 5 is significantly impaired, and the process proceeds to step B18. In step B18, the user is notified, for example via the operation panel 9, of information recommending replacement of parts of the fuel cell 5, and the charging control ends.

[0041] Steps B6 to B9 are steps related to determining whether the charging is in the middle of the charging period, and the same control as steps B2 to B5 is performed. In step B6, it is determined whether the elapsed time of the charging control is within the second measurement period (for example, the time t3 to t4 in FIG. 2). If this condition is met, the process proceeds to step B7, and if not, the process proceeds to step B10. In step B7, the output voltage V FC In step B9, the change rate A2 of the output voltage V of the fuel cell 5 is calculated, and in the next step B8, it is determined whether the change rate A2 is equal to or greater than the speed threshold value A0. If the condition in step B8 is met, the process proceeds to step B10, and if not, the process proceeds to step B9. FC It is determined whether or not the voltage threshold value V0 is equal to or greater than the voltage threshold value V0. If the condition in step B9 is met, the process proceeds to step B10, and if not, the process proceeds to step B18.

[0042] Steps B10 to B13 are steps related to determining the end of charging, and the same control as steps B2 to B5 is performed. In step B10, it is determined whether the elapsed time of the charging control is within the third measurement period (for example, the time t5 to t6 in FIG. 2). If this condition is met, the process proceeds to step B11, and if not, the process proceeds to step B14. In step B11, the output voltage V FC In step B12, it is determined whether the change rate A3 is equal to or greater than the speed threshold value A0. If the condition in step B12 is met, the process proceeds to step B14. If not, the process proceeds to step B13. In step B13, the output voltage V of the fuel cell 5 is calculated. FC It is determined whether or not the voltage threshold value V0 is equal to or greater than the voltage threshold value V0. If the condition in step B13 is met, the process proceeds to step B14, and if not, the process proceeds to step B18.

[0043] In step B14, it is determined whether the secondary battery 3 is in a fully charged state. Li is the full charge voltage V MAX If the charging time has not yet reached the full charge state, it is determined that the battery is not yet fully charged, and the control returns to step B1. As a result, if the elapsed time of the charging control is not within the first, second, or third measurement period, the power generation of the fuel cell 5 and the charging of the secondary battery 3 continue. On the other hand, the terminal voltage V of the secondary battery 3 Li is the full charge voltage V MAX If it has reached this value, it is determined that the secondary battery 3 is sufficiently charged, power generation by the fuel cell 5 and charging of the secondary battery 3 are stopped, and the process proceeds to step B15.

[0044] In step B15, the charge / discharge capacity B of the secondary battery 3 is calculated based on the integrated value of the input current supplied until the secondary battery 3 is fully charged. In the following step B16, it is determined whether the charge / discharge capacity B is equal to or greater than the reference capacity B0. If this condition is met, it is determined that the performance of the secondary battery 3 has not deteriorated, and the process proceeds to step B17. In step B17, information that there is no problem with the performance of the secondary battery 3 and the fuel cell 5 is notified to the user, for example, via the operation panel 9, and the charging control ends. On the other hand, if the condition in step B16 is not met, it is determined that the performance of the secondary battery 3 has deteriorated, and the process proceeds to step B19. In step B19, information that it is recommended to replace the secondary battery 3 is notified to the user, for example, via the operation panel 9, and the charging control ends.

[0045] [4. Effects] (1) The battery management device 10 according to the above embodiment manages the secondary battery 3 and fuel cell 5 mounted on the vehicle 1, and includes a control means 11 and a determination means 12. The control means 11 performs charging control to charge the secondary battery 3 with power generated by the fuel cell 5 while the vehicle 1 is stopped. The determination means 12 determines the performance of both the secondary battery 3 and the fuel cell 5 while the charging control is being performed.

[0046] This type of control makes it possible to efficiently determine whether the secondary battery 3 and fuel cell 5 have deteriorated or whether maintenance is required. In other words, the performance of the secondary battery 3 and fuel cell 5 can be measured simultaneously by utilizing the idle time when the vehicle 1 is stopped. Furthermore, performance measurement can be completed in a short time compared to when performance measurement of the secondary battery 3 and fuel cell 5 is performed separately. Therefore, the performance of the secondary battery 3 and fuel cell 5 can be efficiently grasped with a simple configuration.

[0047] Furthermore, the above-mentioned charging control is implemented, for example, when the user parks the vehicle 1 for an extended period of time, by operating the operation panel 9 to start charging control. This allows the secondary battery 3 to be charged at a lower C rate than during general external charging, and the secondary battery 3 can be charged slowly with a small current. This improves the accuracy of calculation of the battery capacity (charge / discharge capacity B) of the secondary battery 3, and allows the performance of the fuel cell 5 to be accurately understood. Furthermore, because the charging rate is low (the charging current is small), the amount of power generated by the fuel cell 5 can be relatively small, and waste of fuel gas can be reduced.

[0048] (2) The above-mentioned determination means 12 can determine the performance of the fuel cell 5 in a plurality of periods that are set according to the time that has elapsed since the start of charging control. In the example shown in Fig. 2, a first measurement period (times t1 to t2) in the early stage of charging, a second measurement period (times t3 to t4) in the middle stage of charging, and a third measurement period (times t5 to t6) in the final stage of charging are set, and the performance of the fuel cell 5 is determined in each measurement period.

[0049] This type of control makes it possible to accurately determine the deterioration of the performance of the fuel cell 5. For example, even if the fuel cell 5 suddenly deteriorates for some reason while the secondary battery 3 is being charged, the deterioration can be quickly discovered and the user can be prompted to replace the part. Furthermore, compared to control in which the performance evaluation of the fuel cell 5 is performed at the end of charging control, the number of performance evaluations can be increased, thereby improving the reliability of the evaluation.

[0050] (3) The above-mentioned determination means 12 can perform a first determination and a second determination when determining the performance of the fuel cell 5. The first determination is FC The second determination is to determine whether the change rates A1 to A3 of the output voltage V of the fuel cell 5 are larger than a predetermined speed threshold A0. FC is compared with a predetermined voltage threshold V0. By carrying out such a two-stage determination, the deterioration of the performance of the fuel cell 5 can be determined with high accuracy, and the reliability of the determination result can be further improved.

[0051] (4) The above-mentioned determination means 12 can determine the performance of the secondary battery 3 based on the battery capacity (charge / discharge capacity B) calculated from the integrated value of the input current to the secondary battery 3. In this way, by calculating the integrated value of the input current related to constant current charging, the battery capacity (charge / discharge capacity B) can be determined with high accuracy. Therefore, the deterioration of the secondary battery 3 can be determined with high accuracy, and the reliability of the determination result can be further improved.

[0052] (5) In general, the smaller the current value during constant current charging, the more accurate the calculation of the battery capacity (charge / discharge capacity B) is. In consideration of this characteristic, the above-mentioned control means 11 can perform charging control so that the secondary battery 3 is charged at a current value equivalent to a low C rate corresponding to a value obtained by dividing the capacity of the secondary battery 3 when it is new by the predetermined time X, when the vehicle 1 is expected to be parked for a period of time equal to or longer than the predetermined time X. By such control, the secondary battery 3 can be charged at a small current value within a range in which charging of the secondary battery 3 can be completed while the vehicle is parked, and deterioration of the secondary battery 3 can be determined with high accuracy without impairing the convenience of the vehicle 1.

[0053] [5.Other] The above embodiment is merely illustrative, and is not intended to exclude various modifications or application of techniques not specified in the embodiment. Each configuration of the embodiment can be modified in various ways without departing from the spirit of the embodiment. Furthermore, each configuration of the embodiment can be selected as necessary, or can be combined appropriately.

[0054] In the above embodiment, as shown in Fig. 2, the control for determining the performance of the fuel cell 5 in three periods during charging control has been described in detail, but the timing for determining the performance of the fuel cell 5 is not limited to these periods, and the number of times of determination is not limited to these. In addition, in the above embodiment, the control for determining the performance of the fuel cell 5 in two stages has been exemplified, but it is also possible to perform the determination in either one of the stages. By determining the performance of both the secondary battery 3 and the fuel cell 5 in at least one charging control, the performance of the secondary battery 3 and the fuel cell 5 can be efficiently grasped, and the same effect as in the above embodiment can be obtained. [Industrial Applicability]

[0055] The present invention is applicable to the manufacturing industry of battery management devices mounted on vehicles, and also to the manufacturing industry of vehicles mounted with battery management devices. [Explanation of symbols]

[0056] 1 vehicle 2 Motors 3 Secondary battery 4 Inverter 5 fuel cell 6. Fuel Tank 7. Compressor 8. DC-DC Converter 9 Operation Panel 10 Battery Management Device 11 Control Means 12 Judgment means A1, A2, A3 change rate A0 Speed ​​Threshold V FC Fuel cell output voltage V0 Voltage Threshold V Li Terminal voltage of secondary battery V MAX Full charge voltage B Charge / discharge capacity (battery capacity) B0 Reference Capacity X predetermined time

Claims

1. A battery management device for managing a secondary battery and a fuel cell mounted on a vehicle, comprising: a control means for performing charging control for charging the secondary battery with power generated by the fuel cell while the vehicle is stopped; and a determination means for determining the performance of both the secondary battery and the fuel cell during the execution of the charging control. A battery management device comprising:

2. The determining means determines the performance of the fuel cell for a plurality of periods that are set according to the elapsed time from the start of the charging control.

2. The battery management device according to claim 1, wherein the battery management device comprises:

3. When judging the performance of the fuel cell, the judging means performs a first judgment to judge whether the change rate of the output voltage of the fuel cell is larger than a predetermined rate threshold, and a second judgment to judge whether the output voltage of the fuel cell is larger than a predetermined voltage threshold.

3. The battery management device according to claim 2 .

4. The determining means determines the performance of the secondary battery based on a battery capacity calculated from an integrated value of an input current to the secondary battery.

2. The battery management device according to claim 1, wherein the battery management device comprises:

5. The control means performs the charging control so that the secondary battery is charged at a current value equivalent to a low C rate corresponding to a value obtained by dividing a new capacity of the secondary battery by the predetermined time when the vehicle is expected to be stopped for a predetermined time or more.

2. The battery management device according to claim 1, wherein the battery management device comprises:

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