Battery System

Abstract

To normally start up a battery system while reducing inrush power.SOLUTION: A battery system 1 includes a plurality of battery modules 10 arranged in parallel. The battery module 10 includes a battery unit 12, a positive electrode side contactor 20 and a negative electrode side contactor 30 that are connected in series to the battery unit 12, and a pre-charge circuit 40 provided in parallel to the positive electrode side contactor 20. The control device 60 executes pre-charge processing on predetermined one battery module 10 out of the plurality of battery modules 10. When a malfunction occurs in the pre-charge processing, the control device 60 excludes the battery module 10 in which the malfunction occurs, from the battery modules 10 to be connected during the pre-charge processing, and executes the pre-charge processing on predetermined one battery module 10 out of the battery modules 10 other than the excluded battery module 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery system. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open Publication No. 2012-182882 discloses a power supply device in which multiple secondary battery devices are connected in parallel. Each secondary battery device includes a secondary battery module having multiple battery packs connected in series, a contactor connected in series to the secondary battery module, and a pre-charge current limiter connected in parallel to the contactor.

[0003] When starting up the power supply device, the voltages of the secondary battery modules of each secondary battery device may differ, which may cause a large inrush current. Therefore, when starting up the power supply device, the inrush current can be suppressed by passing a current through the pre-charge current limiter of each secondary battery device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-182882 Summary of the Invention [Problem to be solved by the invention]

[0005] In the power supply device disclosed in JP 2012-182882 A, a malfunction such as a failure may occur in the precharge current limiter of the secondary battery device. If a malfunction occurs in the precharge current limiter, it may be impossible to properly flow current to the precharge current limiter when starting up the power supply device, and as a result, it may be impossible to properly start up the power supply device while suppressing inrush current. [Means for solving the problem]

[0006] The battery system disclosed herein includes a pair of output terminals connected to a load, a plurality of battery modules connected to the pair of output terminals and arranged in parallel, and a control device. The plurality of battery modules each include a battery unit having a plurality of series-connected single cells, a positive contactor provided at a positive end of the battery unit, a negative contactor provided at a negative end of the battery unit, and a precharge circuit provided in parallel with one of the positive and negative contactors. The precharge circuit includes a precharge resistor and a precharge contactor connected in series to the precharge resistor. The control device includes a precharge process execution unit, a connection control unit, and an exclusion control unit. When the plurality of battery modules are connected to the load via the pair of output terminals, the precharge process execution unit executes a precharge process on a predetermined battery module among the plurality of battery modules. After the precharge process, the connection control unit connects the other battery modules among the plurality of battery modules to the load. The precharge process is a process of turning on the precharge contactor and the other of the positive and negative contactors that is not connected in parallel to the precharge circuit for the one predetermined battery module, and turning on the one contactor and turning off the precharge contactor after the voltage of the one predetermined battery module acts on the load. If a malfunction occurs during the precharge process, the exclusion control unit excludes the battery module in which the malfunction occurred from the battery modules connected in the precharge process among the multiple battery modules. The precharge process execution unit executes the precharge process on one predetermined battery module among the battery modules other than the battery module excluded by the exclusion control unit.

[0007] According to the battery system, even if a malfunction occurs when a pre-charge process is performed on a predetermined battery module among the plurality of battery modules, the battery module in which the malfunction occurred can be excluded from the battery modules on which the pre-charge process is performed. Therefore, the pre-charge process can be performed on the predetermined battery modules among the battery modules other than the excluded battery module. Therefore, the pre-charge process can be performed on the battery modules that are not malfunctioning, thereby suppressing inrush current and enabling the battery system to start up normally. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a battery system according to an embodiment. [Figure 2A] 10 is a flowchart showing a procedure for connecting a battery system to a load and starting it up. [Figure 2B] 10 is a flowchart showing a procedure for connecting a battery system to a load and starting it up. [Figure 2C] 10 is a flowchart showing a procedure for connecting a battery system to a load and starting it up. [Figure 3] FIG. 10 is a schematic diagram showing a battery system according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of the technology disclosed herein will be described with reference to the drawings. It should be noted that the embodiment described here is not intended to limit the present invention in any way. Each drawing is a schematic diagram and does not necessarily faithfully reflect an actual product. Furthermore, the same reference numerals are appropriately used for components and parts that perform the same function, and redundant explanations will be omitted where appropriate.

[0010] FIG. 1 is a schematic diagram showing a battery system 1 according to this embodiment. As shown in FIG. 1, the battery system 1 is connected to a load 100. The load 100 is not particularly limited, but may be, for example, a drive device such as an electric motor of a vehicle, or an inverter. A smoothing capacitor for reducing sudden changes in current may be connected to the load 100. Here, the battery system 1 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle, and is used as a power source that supplies power to an electric motor that drives the vehicle. However, the battery system 1 is not limited to use in a vehicle.

[0011] The battery system 1 includes a pair of output terminals 5, a plurality of battery modules 10, and a control device 60. The pair of output terminals 5 are connected to a load 100. Here, one of the pair of output terminals 5 is a positive terminal, and the other output terminal 5 is a negative terminal.

[0012] The battery modules 10 are connected to a pair of output terminals 5. In this embodiment, the battery modules 10 are connected to a main bus 8, which is connected to a pair of output terminals 5. Therefore, the battery modules 10 are indirectly connected to the pair of output terminals 5 via the main bus 8. The battery modules 10 are also connected to a load 100 via the pair of output terminals 5. The load 100 can convert the power of the battery modules 10 into motive power or supply regenerated power to the battery modules 10. The battery modules 10 are arranged (in other words, connected) in parallel. In this embodiment, the number of battery modules 10 is two. However, the number of battery modules 10 is not particularly limited and may be more than one. The number of battery modules 10 may be three or more. Here, the two battery modules 10 will be referred to as a first battery module 10A and a second battery module 10B as appropriate. The battery module 10 includes a first battery module 10A and a second battery module 10B. In the following description, when the first battery module 10A and the second battery module 10B are commonly described, the term battery module 10 will be used.

[0013] The multiple battery modules 10, here the first battery module 10A and the second battery module 10B, have the same configuration. As shown in FIG. 1 , each battery module 10 includes multiple cells 11, a positive electrode contactor 20, a negative electrode contactor 30, and a precharge circuit 40. The cells 11 are rechargeable. The cells 11 may be, for example, a secondary battery that can be repeatedly charged and discharged by the movement of charge carriers between a pair of electrodes (e.g., a positive electrode and a negative electrode) via an electrolyte. The cells 11 may be, for example, a lithium-ion secondary battery or a nickel-metal hydride battery. The multiple cells 11 are connected in series. Here, the multiple cells 11 are connected in series via a bus bar (not shown). The number of cells 11 in one battery module 10 is not particularly limited and is a predetermined number. In this embodiment, the number of cells 11 in the first battery module 10A is the same as the number of cells 11 in the second battery module 10B, but they may be different. Here, the plurality of cells 11 connected in series is referred to as a battery unit 12. The battery module 10 includes a battery unit 12, and the battery unit 12 has a plurality of cells 11 connected in series.

[0014] The positive electrode contactor 20 is connected in series to the plurality of cells 11 (in other words, the battery unit 12). Here, the positive electrode contactor 20 is provided at the positive electrode end of the battery unit 12. The positive electrode contactor 20 switches the connection between the positive electrode end of the battery unit 12 and the load 100 between ON and OFF. Here, the contactor is, in other words, a relay.

[0015] In this embodiment, turning the contactor ON refers to a connected state (e.g., a closed state), and turning the contactor OFF refers to a disconnected state (e.g., an open state).

[0016] The negative electrode side contactor 30 is connected in series to the plurality of cells 11 (in other words, the battery unit 12). Here, the negative electrode side contactor 30 is provided at the negative electrode side end of the battery unit 12, in other words, at the end opposite to the positive electrode side. The negative electrode side contactor 30 switches ON and OFF the connection between the negative electrode side end of the battery unit 12 and the load 100. In this embodiment, a fuse 31 is connected in series to the negative electrode side contactor 30. The fuse 31 is provided between the battery unit 12 and the negative electrode side contactor 30. The fuse 31 is connected in series to the battery unit 12.

[0017] The precharge circuit 40 is provided in parallel with one of the positive contactor 20 and the negative contactor 30. In this embodiment, the precharge circuit 40 is connected in parallel with the positive contactor 20. The precharge circuit 40 is provided at the positive end of the battery unit 12. The precharge circuit 40 is a circuit that suppresses inrush current from flowing to the load 100 when power is supplied from the battery system 1 to the load 100. The configuration of the precharge circuit 40 is not particularly limited. In this embodiment, the precharge circuit 40 includes a precharge resistor 41 and a precharge contactor 42 connected in series to the precharge resistor 41. The precharge contactor 42 can be switched between ON and OFF states.

[0018] The control device 60 is configured, for example, by a microcomputer. The control device 60 includes a communication interface, a central processing unit (CPU) that executes instructions from a control program, a read-only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores the program and various data. The control device 60 may be configured as a single device (for example, a single CPU), or may be configured to be controlled by multiple devices working together. For example, the control device 60 may include battery control devices that control each battery module 10 (for example, a first battery control device that controls the first battery module 10A and a second battery control device that controls the second battery module 10B) and a main control device that is communicatively connected to the battery control devices.

[0019] The control device 60 is electrically connected to the positive electrode contactors 20 and negative electrode contactors 30 of the multiple battery modules 10 (here, the first battery module 10A and the second battery module 10B) and the precharge contactor 42 of the precharge circuit 40. The control device 60 independently controls the ON / OFF switching of the positive electrode contactor 20, the negative electrode contactor 30, and the precharge contactor 42 for each battery module 10. Although not shown, the control device 60 is configured to be able to detect the voltage of each cell 11 of the multiple battery modules 10, the voltage of the battery units 12 of the multiple battery modules 10, and the voltage between a pair of output terminals 5 (hereinafter also referred to as the main voltage). The control device 60 is also configured to be able to detect the current flowing through the main bus 8.

[0020] In this embodiment, the control device 60 includes a storage unit 61, a fault diagnosis unit 63, a precharge process execution unit 65, a connection control unit 67, and an exclusion control unit 69. The storage unit 61, the fault diagnosis unit 63, the precharge process execution unit 65, the connection control unit 67, and the exclusion control unit 69 may be realized by one or more processors or by circuits. The storage unit 61 is realized by, for example, a nonvolatile memory.

[0021] When the plurality of battery modules 10 are connected to the load 100 through a pair of output terminals 5, the precharge process execution unit 65 executes the precharge process on a predetermined one of the plurality of battery modules 10. Here, the precharge process execution unit 65 executes the precharge process on either the first battery module 10A or the second battery module 10B.

[0022] In the precharge process, first, for one predetermined battery module 10, the precharge contactor 42 and the other of the positive and negative contactors 20 and 30 to which the precharge circuit 40 is not connected in parallel (here, the negative contactor 30) are turned ON. In the precharge process, the precharge contactor 42 and the negative contactor 30 are turned ON, and the voltage of the predetermined battery module 10 acts on the load 100. After that, one of the contactors connected in parallel to the precharge circuit 40 (here, the positive contactor 20) is turned ON, and the precharge contactor 42 is turned OFF. Here, the voltage of the battery module 10 acts on the load 100 when, for example, the main voltage between the pair of output terminals 5 reaches a predetermined threshold V after a predetermined determination time has elapsed after the precharge contactor 42 and the negative contactor 30 are turned ON. th2 (See Figure 2B) and threshold V th3 (See FIG. 2C) is equal to or greater than a predetermined threshold value. th2 , threshold V th3 is stored in advance in the storage unit 61 (see FIG. 1). th2, threshold V th3 is an example of a threshold value disclosed herein. th2 , threshold V th3 The specific values ​​of the threshold V may be the same or different. th2 , threshold V th3 The specific value of is determined appropriately depending on the determination time.

[0023] In this embodiment, a malfunction may occur in the target battery module 10 while the precharge process is being performed, and the precharge process may not be performed properly. The malfunction here refers to, for example, a situation where current does not flow properly in the precharge circuit 40, causing the main voltage between the pair of output terminals 5 to exceed the threshold V th2 and threshold V th3 1 excludes the battery module 10 in which the malfunction has occurred from the battery modules 10 connected in the precharge process among the plurality of battery modules 10. For example, the exclusion control unit 69 excludes the battery module 10 in which the malfunction has occurred from the battery modules 10 connected in the precharge process if the main voltage between the pair of output terminals 5 is maintained below the predetermined threshold V th2 and threshold V th3 If the difference is less than a predetermined threshold, it is determined that a malfunction has occurred in the precharge process. In this case, the precharge process execution unit 65 executes the precharge process on one predetermined battery module 10 from among the battery modules 10 other than the battery module 10 excluded by the exclusion control unit 69.

[0024] In this embodiment, the precharge process execution unit 65 may be configured to change one battery module 10 on which the precharge process is first executed. For example, if the precharge process was executed first on the first battery module 10A in the previous precharge process, the precharge process execution unit 65 may first execute the precharge process on a battery module 10 (e.g., the second battery module 10B) excluding the first battery module 10A in the next precharge process. In other words, the order of the battery modules 10 on which the precharge process is executed by the precharge process execution unit 65 may be random or may be changed each time.

[0025] In this embodiment, before the precharge process is started, a preliminary fault diagnosis process may be performed on the plurality of battery modules 10 to determine whether or not a malfunction has occurred. For example, the fault diagnosis unit 63 in FIG. 1 performs the fault diagnosis process before the precharge process is performed by the precharge process execution unit 65. Here, the fault diagnosis unit 63 turns off the positive electrode contactor 20 and the negative electrode contactor 30 of each of the plurality of battery modules 10 and turns on the precharge contactor 42, and then, after a predetermined time has elapsed, checks whether or not the main voltage between the pair of output terminals 5 reaches the fault threshold V th1 If the time is greater than the failure threshold V (see FIG. 2A), a failure diagnosis process is executed in which a diagnosis is made that a failure has occurred in one battery module 10. This predetermined time may be the same as or different from the above-mentioned determination time used when determining a failure during the precharge process. th1 is the threshold V used to determine if there is a problem during precharge processing. th2 , threshold V th3 The failure threshold V may be the same as or different from th1 The specific value of is determined appropriately depending on the predetermined time. In this embodiment, the precharge process execution unit 65 executes the precharge process when the failure diagnosis unit 63 diagnoses that no malfunction has occurred in the plurality of battery modules 10.

[0026] In this embodiment, after the precharge process execution unit 65 executes the precharge process without any malfunction, the connection control unit 67 in FIG. 1 connects other battery modules 10 (here, battery modules 10 other than the battery module 10 for which the precharge process was executed without any malfunction) among the plurality of battery modules 10 to the load 100. Here, the connection control unit 67 turns on the positive electrode side contactor 20 and the negative electrode side contactor 30 for the plurality of battery modules 10 and turns off the precharge contactor 42, thereby connecting the plurality of battery modules 10 to the load 100.

[0027] Next, the procedure for connecting the battery system 1 to the load 100 and starting it up will be described with reference to the flowcharts in Figures 2A, 2B, and 2C. Here, the procedure for first performing the precharge process on the first battery module 10A, and then performing the precharge process on the second battery module 10B when a malfunction occurs in the first battery module 10A will be described. However, in this embodiment, the precharge process may be first performed on the second battery module 10B, and then performing the precharge process on the first battery module 10A when a malfunction occurs in the second battery module 10B.

[0028] Before step S101 in FIG. 2A is executed, the positive electrode side contactor 20, the negative electrode side contactor 30, and the pre-charge contactor 42 in the first battery module 10A and the second battery module 10B are in the OFF state (open state, unconnected state).

[0029] Here, steps S101 to S109 in Fig. 2A are first executed as appropriate to perform a preliminary fault diagnosis process by the fault diagnosis unit 63 in Fig. 1. In this preliminary fault diagnosis process, it is diagnosed whether or not a malfunction has occurred in the negative electrode contactor 30 for each of the multiple battery modules 10. In this embodiment, the fault diagnosis unit 63 performs the preliminary fault diagnosis process for the first battery module 10A and the second battery module 10B.

[0030] First, in step S101 of Fig. 2A, while the positive contactor 20, the negative contactor 30, and the pre-charge contactor 42 of the battery modules 10A and 10B are in the OFF state, the fault diagnosis unit 63 of Fig. 1 turns on the pre-charge contactor 42 of the first battery module 10. Next, in step S103, the fault diagnosis unit 63 calculates the main voltage V m This main voltage V m is the voltage between the pair of main buses 8 and is also the overall voltage of the plurality of battery modules 10. Here, the main voltage V m 1, the voltage between point P1 on the positive side main bus 8 and point P2 on the negative side main bus 8 is acquired. For example, the control device 60 is provided with connection terminals that can be connected to points P1 and P2, and the fault diagnosis unit 63 converts the voltage between points P1 and P2 through the connection terminals into the main voltage V m Obtain as.

[0031] Next, in step S105 of FIG. 2A, the fault diagnosis unit 63 detects the main voltage V m is the failure threshold V th1 If there is no malfunction in the negative contactor 30, the negative contactor 30 is normally in the OFF state (i.e., open state), so the battery unit 12 is not connected to the load 100, and the main voltage V m is the failure threshold V th1 The following state occurs. In this case, the process proceeds to step S107 in Fig. 2A. In step S107, the fault diagnosis unit 63 determines that the negative electrode side contactor 30 of the first battery module 10A is not faulty, i.e., that no malfunction has occurred in the negative electrode side contactor 30, and turns off the pre-charge contactor 42 of the first battery module 10A.

[0032] On the other hand, in step S105 of FIG. 2A, if a malfunction occurs in the negative electrode contactor 30 of the first battery module 10A, for example, if the negative electrode contactor 30 is welded, the negative electrode contactor 30 may be turned ON, even though it should be turned OFF. In this case, the main voltage V m is the failure threshold V th1 In this case, the process proceeds to step S109 in FIG. 2A. In step S109, the fault diagnosis unit 63 determines that a malfunction has occurred in the negative electrode contactor 30 of the first battery module 10A, that the negative electrode contactor 30 is welded in this case, and the flowcharts in FIGS. 2A to 2C end without performing the precharge process. In this way, when a malfunction has occurred in the battery module 10, the control device 60 executes a predetermined error process. This error process is not particularly limited, but for example, the error process may be to notify the user of the malfunction. The notification of the malfunction may be, for example, a notification that a malfunction has occurred in the battery module 10 displayed on a display screen (not shown). At this time, the specific details of the malfunction may be displayed on the display screen.

[0033] In this way, if the preliminary fault diagnosis process is performed on the first battery module 10A and no malfunction has occurred in the negative electrode contactor 30, the fault diagnosis unit 63 in Fig. 1 appropriately performs steps S101 to S109 on the second battery module 10B to perform the preliminary fault diagnosis process. Then, if it is determined that no malfunction has occurred in the negative electrode contactor 30 in any of the multiple battery modules 10, the process proceeds to step S111 in Fig. 2B.

[0034] 1 turns on the negative electrode contactors 30 of the plurality of battery modules 10. In this embodiment, the precharge process execution unit 65 turns on the negative electrode contactor 30 of the first battery module 10A and the negative electrode contactor 30 of the second battery module 10B.

[0035] Next, the precharge process execution unit 65 executes the precharge process for the first battery module 10A. First, in step S113 of FIG. 2B, the precharge process execution unit 65 turns on the precharge contactor 42 of the first battery module 10A. This turns on the negative electrode contactor 30 and the precharge contactor 42 in the first battery module 10A. When the precharge process is executed normally, the battery unit 12 of the first battery module 10A is connected to the pair of output terminals 5 and is connected to the load 100, and the main voltage V m will rise.

[0036] Therefore, in order to determine whether or not a malfunction has occurred during the pre-charge process, next, in step S115 of FIG. 2B, the exclusion control unit 69 of FIG. 1 determines whether or not the main voltage V m This main voltage V m 2A, for example, the exclusion control unit 69 acquires the voltage between points P1 and P2 on the main bus 8 as shown in FIG. 1, thereby obtaining the main voltage V m Get.

[0037] Next, in step S117 of FIG. 2B, the exclusion control unit 69 determines whether the main voltage V m is the threshold V th2 Here, if the precharge process is being performed normally, the main voltage V m rises, the main voltage V m is the threshold V th2 Therefore, in step S117, the main voltage V m is the threshold V th2In the above cases, the process proceeds to step S119 in FIG. 2B. After step S119, the connection control unit 67 in FIG. 1 performs a process of connecting the multiple battery modules 10 to the load 100 because the pre-charge process for the first battery module 10A has ended normally. First, in step S119, the connection control unit 67 turns on the positive electrode contactors 20 of the first battery module 10A and the second battery module 10B. Next, in step S121 in FIG. 2B, the connection control unit 67 turns off the pre-charge contactor 42 of the first battery module 10A. As a result, the positive electrode contactors 20 and negative electrode contactors 30 of the multiple battery modules 10 are turned on and the pre-charge contactor 42 is turned off, so the multiple battery modules 10 are connected to the load 100 and the battery system 1 starts up normally.

[0038] On the other hand, in step S117 of FIG. 2B, if a malfunction occurs in the precharge process, for example, if a malfunction occurs in the precharge resistor 41 or the precharge contactor 42 of the first battery module 10A, the main voltage V m does not rise, and the threshold V th2 Therefore, the main voltage V m is the threshold V th2 If it is less than this, the process proceeds to step S123 in FIG. 2C. In step S123 and thereafter, since a malfunction has occurred in the precharge process of the first battery module 10A, the target of the precharge process is changed. Here, the exclusion control unit 69 excludes the first battery module 10A in which the malfunction has occurred from the battery modules 10 to be connected in the precharge process. Here, in step S123, the precharge process execution unit 65 in FIG. 1 turns off the precharge contactor 42 of the first battery module 10A.

[0039] From step S125 onward in FIG. 2C, the battery module 10 to be subjected to the precharge process is switched, and the precharge process execution unit 65 executes the precharge process on the battery module 10 (here, the second battery module 10B) other than the first battery module 10A excluded by the exclusion control unit 69. Here, first, in step S125 in FIG. 2C, the precharge process execution unit 65 turns on the precharge contactor 42 of the second battery module 10B. As a result, the negative electrode side contactor 30 and the precharge contactor 42 in the second battery module 10B are turned on. When the precharge process is executed normally, the battery unit 12 of the second battery module 10B is connected to the pair of output terminals 5 and is thus connected to the load 100, and the main voltage V m will rise.

[0040] Therefore, in order to determine whether or not a malfunction has occurred during the precharge process of the second battery module 10B, next, in step S127 of FIG. 2C, the exclusion control unit 69 of FIG. 1 determines whether or not the main voltage V m The predetermined determination time for the second battery module 10B and the predetermined determination time for the first battery module 10A may be the same or different. m 2A, the main voltage V is obtained by obtaining the voltage between points P1 and P2 on the main bus 8, as shown in FIG. m Get.

[0041] Next, in step S129 of FIG. 2C, the exclusion control unit 69 determines whether the main voltage V m is the threshold V th3 Here, if the precharge process is being performed normally, the main voltage V m rises, the main voltage V m is the threshold V th3 Therefore, in step S129, the main voltage Vm is the threshold V th3 In the above cases, the process proceeds to step S131 in FIG. 2C. After step S131, the pre-charge process for the second battery module 10B has been completed successfully, so the connection control unit 67 in FIG. 1 performs a process to connect the multiple battery modules 10 to the load 100. First, in step S131, the connection control unit 67 turns on the positive electrode contactors 20 in the first battery module 10A and the second battery module 10B. Next, in step S133 in FIG. 2C, the connection control unit 67 turns off the pre-charge contactor 42 in the second battery module 10B. As a result, the positive electrode contactors 20 and negative electrode contactors 30 in the multiple battery modules 10 are turned on and the pre-charge contactor 42 is turned off, so the multiple battery modules 10 are connected to the load 100, and the battery system 1 starts up normally.

[0042] On the other hand, in step S129 of FIG. 2C, if a malfunction occurs in the precharge process for the second battery module 10B, for example, if a malfunction occurs in the precharge resistor 41 or the precharge contactor 42 of the second battery module 10B, the main voltage V m does not rise, and the threshold V th3 Therefore, in step S129, the main voltage V m is the threshold V th3 If the battery system 1 is less than the predetermined value, the process proceeds to step S135 in FIG. 2C. In step S135, a malfunction has occurred in the precharge process of both the first battery module 10A and the second battery module 10B, and the battery system 1 is not started up. In this case, for example, in step S135, the control device 60 performs a predetermined error process. This error process is not particularly limited. For example, as the error process, a malfunction is notified to the user, as in step S109 in FIG. 2A. The malfunction notification may be, for example, a notification displayed on a display screen (not shown) indicating that the battery system 1 did not start up normally due to a malfunction in the precharge process. At this time, the specific details of the malfunction may be displayed on the display screen.

[0043] Although the present embodiment illustrates two battery modules 10, similar processing is performed even when there are three or more battery modules 10. For example, if the battery module 10 includes a first battery module 10A, a second battery module 10B, and a third battery module, a precharge process is first performed on the first battery module 10A. If a malfunction occurs during the precharge process on the first battery module 10A, the first battery module 10A is excluded from the battery modules 10 to be connected during the precharge process. In this case, a precharge process is then performed on either the second battery module 10B or the third battery module. Here, for example, a precharge process is performed on the second battery module 10B. If a malfunction occurs during the precharge process on the second battery module 10B, the second battery module 10B is excluded from the battery modules 10 to be connected during the precharge process. In this case, a precharge process is then performed on the third battery module. If no malfunction occurs during the precharge process on the third battery module, a process is performed to connect all of the battery modules 10 to the load 100, and the battery system 1 is started up. On the other hand, if a problem occurs during the precharge process for the third battery module, error processing is performed and the battery system 1 is not started up.

[0044] As described above, in this embodiment, as shown in FIG. 1 , the battery system 1 includes a pair of output terminals 5 connected to a load 100, a plurality of battery modules 10 connected to the pair of output terminals 5 and arranged in parallel, and a control device 60. Each of the plurality of battery modules 10 includes a battery unit 12 having a plurality of serially connected cells 11, a positive contactor 20 provided at a positive end of the battery unit 12, a negative contactor 30 provided at a negative end of the battery unit 12, and a precharge circuit 40 provided in parallel with one of the positive contactor 20 and the negative contactor 30 (here, the positive contactor 20). The precharge circuit 40 includes a precharge resistor 41 and a precharge contactor 42 connected in series with the precharge resistor 41. The control device 60 includes a precharge process execution unit 65, a connection control unit 67, and an exclusion control unit 69. When the plurality of battery modules 10 are connected to the load 100 via a pair of output terminals 5, the precharge process execution unit 65 executes a precharge process on a predetermined one of the plurality of battery modules 10. The precharge process is a process in which, for the predetermined one battery module 10, the precharge contactor 42 and the other contactor (here, the negative contactor 30) of the positive contactor 20 and the negative contactor 30 to which the precharge circuit 40 is not connected in parallel are turned ON, and after the voltage of the predetermined one battery module 10 acts on the load 100, one of the contactors (here, the positive contactor 20) is turned ON and the precharge contactor 42 is turned OFF. After the precharge process, the connection control unit 67 connects the other battery module 10 of the plurality of battery modules 10 to the load 100. When a malfunction occurs in the precharge process, the exclusion control unit 69 excludes the battery module 10 in which the malfunction occurred from the battery modules 10 to be connected in the precharge process among the plurality of battery modules 10. The precharge process execution unit 65 executes the precharge process on one predetermined battery module 10 among the battery modules 10 other than the battery module 10 excluded by the exclusion control unit 69.

[0045] As a result, even if a malfunction occurs when a pre-charge process is performed on a predetermined battery module 10 among the plurality of battery modules 10, the battery module 10 where the malfunction occurred can be excluded from the targets for which the pre-charge process is performed. Therefore, the pre-charge process can be performed on the predetermined battery modules 10 among the battery modules 10 other than the excluded battery module 10. Therefore, the pre-charge process can be performed on the battery modules 10 where no malfunction occurs, and the battery system 1 can be started up normally while suppressing inrush current.

[0046] In this embodiment, the exclusion control unit 69 in FIG. 1 detects the main voltage V between the pair of output terminals 5 during the precharge process for the first battery module 10A in step S117 in FIG. 2B, for example. m is a predetermined threshold V th2 If the precharge process is performed normally, it is determined that a malfunction has occurred in the precharge process. m becomes higher, and the threshold V th2 In this way, for example, in step S117, the main voltage V m is the threshold V th2 By comparing the above, it is easy to determine whether or not a malfunction has occurred during the precharge process (for example, during the precharge process for the first battery module 10A).

[0047] 1 is configured to change the battery module 10 that is to be first subjected to the precharge process among the plurality of battery modules 10. This changes the battery module 10 that is to be first subjected to the precharge process, thereby preventing the precharge process from being performed on only one arbitrary battery module 10 and smoothing the number of times the precharge process is performed on each battery module 10. This prevents the deterioration of only one arbitrary battery module 10 among the plurality of battery modules 10 due to the precharge process being performed too many times.

[0048] 1, the control device 60 includes a fault diagnosis unit 63. Before the precharge process is executed by the precharge process execution unit 65, the fault diagnosis unit 63 determines the main voltage V between the pair of output terminals 5 in each of the plurality of battery modules 10 with the positive electrode contactor 20 and the negative electrode contactor 30 turned OFF and the precharge contactor 42 turned ON. m is a predetermined failure threshold V th1 If the difference is greater than the predetermined value, the precharge process execution unit 65 executes a fault diagnosis process in which it is diagnosed that a fault has occurred in one battery module 10. If the fault diagnosis unit 63 diagnoses that no fault has occurred in the plurality of battery modules 10, the precharge process execution unit 65 executes the precharge process. This makes it possible to determine that a fault has occurred in a battery module 10 before executing the precharge process. Therefore, by determining in advance that a fault has occurred in a battery module 10, it is possible to prevent a fault from occurring during the precharge process.

[0049] As described above, in the above embodiment, the fault diagnosis unit 63 executes the fault diagnosis process before the precharge process execution unit 65 executes the precharge process. That is, steps S101 to S109 of the fault diagnosis process in FIG. 2A are executed before step S111 of FIG. 2B, at which the precharge process starts. However, the fault diagnosis unit 63 may execute the fault diagnosis process after the precharge process execution unit 65 executes the precharge process. For example, steps S101 to S109 of the fault diagnosis process in FIG. 2A may be executed after step S133 of FIG. 2C, at which the precharge process ends. As described above, when the fault diagnosis process is executed after the precharge process and the fault diagnosis unit 63 diagnoses that no malfunction has occurred in the plurality of battery modules 10, the series of processes in the flowcharts shown in FIGS. 2A to 2C end. For example, when the fault diagnosis process is executed after the precharge process, other processes (e.g., normal charging / discharging processes) may be executed between the precharge process and the fault diagnosis process. For example, after the precharge process is completed (i.e., after step S133 is executed), the battery system 1 is started up and a normal charge / discharge process is executed. Then, when the battery system 1 is shut down, the battery system 1 may be stopped after a fault diagnosis process is executed.

[0050] When the fault diagnosis process is executed after the precharge process, the result of the fault diagnosis process (i.e., whether or not a malfunction has occurred in the battery module 10 (specifically, whether or not a malfunction has occurred in the negative electrode contactor 30)) may be stored in the storage unit 61 (see FIG. 1). Then, when the battery system 1 is started up and before the precharge process is started, the result of the fault diagnosis process stored in the storage unit 61 may be referred to, and if no malfunction has occurred in the battery module 10, the precharge process may be started. On the other hand, if the result of the fault diagnosis process indicates that a malfunction has occurred in the battery module 10, the precharge process may not be started, and an error process such as step S109 in FIG. 2A may be executed to stop the battery system 1. If the result of the fault diagnosis process indicates that a malfunction has occurred in the battery module 10, and the malfunction is resolved by replacing the negative electrode contactor 30, the result of the fault diagnosis process stored in the storage unit 61 may be rewritten to indicate that no malfunction has occurred in the battery module 10.

[0051] In this way, since the fault diagnosis process is executed after the precharge process, the time until the precharge process starts can be shortened, and as a result, the time required for the battery system 1 to start up can be shortened.

[0052] In the above embodiment, as shown in FIG. 1 , the precharge circuit 40 is provided at the positive end of the battery unit 12 and is provided in parallel to the positive contactor 20. However, the precharge circuit 40 may be provided in parallel to one of the positive contactor 20 and the negative contactor 30. Therefore, as in the battery system 1A shown in FIG. 3 , the precharge circuit 40 may be provided in parallel to the negative contactor 30. In FIG. 3 , the precharge circuit 40 is provided at the negative end of the battery unit 12. Note that in FIG. 3 , a fuse 21 is provided at the positive end of the battery unit 12. The fuse 21 is connected in series to the positive contactor 20. Here, the fuse 21 is provided on the opposite side of the battery unit 12 from the positive contactor 20. Even in this case, the same effects as those of the above embodiment can be obtained. When the flowcharts of FIGS. 2A to 2C are executed in order based on the battery system 1A shown in FIG. 3, the control may be such that the positive electrode side contactor 20 and the negative electrode side contactor 30 are interchanged in the flowcharts of FIGS. 2A to 2C.

[0053] In the above embodiment, in step S103 of FIG. 2A, the main voltage V m In step S105, the main voltage V m is the failure threshold V th1 However, in step S103, the main current (for example, the current flowing through point P2 (or point P1) of the main bus 8 in FIG. 1) may be acquired, and in step S105, it may be determined whether the main current is equal to or less than a predetermined fault current threshold. Here, if the main current is equal to or less than the fault current threshold, the process may proceed to step S107, and if the main current is greater than the fault current threshold, the process may proceed to step S109.

[0054] Similarly, the main current may be acquired in step S115 of Fig. 2B and step S127 of Fig. 2C, and it may be determined whether the main current is less than a current threshold in step S117 of Fig. 2B and step S129 of Fig. 2C. Here, if the main current is less than the current threshold in step S117, the process may proceed to step S119, and if the main current is equal to or greater than the current threshold, the process may proceed to step S123 of Fig. 2C. If the main current is less than the current threshold in step S129, the process may proceed to step S131, and if the main current is equal to or greater than the current threshold, the process may proceed to step S135.

[0055] Also, in step S105 of FIG. 2A, the main voltage V m For example, in step S105, the main voltage V m is the failure threshold V th1 and whether the main current is equal to or less than a fault current threshold. m is the failure threshold V th1 If the main current is equal to or less than the fault current threshold, then proceed to step S107, and the main voltage V m is the failure threshold V th1 If the main current is greater than the fault current threshold, then proceed to step S109. m is the failure threshold V th1 If the main current is equal to or less than the fault current threshold, then proceed to step S107, and m is the failure threshold V th1 If it is greater and the main current is greater than the fault current threshold, then you may proceed to step S109.

[0056] Similarly, in step S117 of FIG. 2B and step S129 of FIG. 2C, the main voltage V m For example, in step S117, the main voltage V m is the threshold V th2If the main current is equal to or greater than the current threshold, the process proceeds to step S119, where the main voltage V m is the threshold V th2 If the main current is equal to or greater than the current threshold, the process may proceed to step S123. Alternatively, in step S117, the main voltage V m is the threshold V th2 If the main current is equal to or greater than the current threshold, or if the main current is less than the current threshold, then proceed to step S119, and m is the threshold V th2 If the main voltage V is less than the threshold current and the main current is equal to or greater than the threshold current, the process may proceed to step S123. m is the threshold V th3 If the main current is equal to or greater than the current threshold, the process proceeds to step S131, where the main voltage V m is the threshold V th3 If the main current is equal to or greater than the current threshold, the process may proceed to step S135. Alternatively, in step S129, the main voltage V m is the threshold V th3 If the main current is equal to or greater than the current threshold, or if the main current is less than the current threshold, then proceed to step S131, and m is the threshold V th3 If it is less than the threshold current and the main current is equal to or greater than the threshold current, the process may proceed to step S135.

[0057] The invention disclosed herein has been described in various ways. Unless otherwise specified, the embodiments described herein do not limit the present invention. Furthermore, the embodiments of the invention disclosed herein can be modified in various ways, and each component and each process described herein can be omitted or combined as appropriate, unless a particular problem arises.

[0058] As described above, this specification includes the disclosures set forth in the following sections. Section 1: a pair of output terminals connected to a load; a plurality of battery modules connected to the pair of output terminals and arranged in parallel; a control device; Equipped with The plurality of battery modules include: a battery unit having a plurality of cells connected in series; a positive electrode contactor provided at a positive electrode end of the battery unit; a negative electrode contactor provided at the negative electrode end of the battery unit; a precharge circuit provided in parallel with one of the positive contactor and the negative contactor; Each of them has The precharge circuit A precharge resistor; a precharge contactor connected in series with the precharge resistor; Equipped with The control device a precharge process execution unit that executes a precharge process on a predetermined one of the battery modules when the battery modules are connected to the load through the pair of output terminals; a connection control unit that connects another battery module among the plurality of battery modules to the load after the precharge process; Equipped with the precharge process is a process of turning on the precharge contactor and the other of the positive electrode side contactor and the negative electrode side contactor to which the precharge circuit is not connected in parallel for the one predetermined battery module, and turning on the one contactor and turning off the precharge contactor after the voltage of the one predetermined battery module acts on the load; the control device includes an exclusion control unit that, when a malfunction occurs in the precharge process, excludes the malfunctioning battery module from among the plurality of battery modules to be connected in the precharge process; The precharge process execution unit executes the precharge process on one predetermined battery module among battery modules other than the battery module excluded by the exclusion control unit.

[0059] Section 2: Item 1. The battery system according to item 1, wherein the exclusion control unit determines that a malfunction has occurred in the precharge process when the main voltage between the pair of output terminals is less than a predetermined threshold during the precharge process.

[0060] Section 3: 3. The battery system according to claim 1, wherein the precharge process execution unit is configured to change the battery module that is to first execute the precharge process among the plurality of battery modules.

[0061] Section 4: The battery system according to any one of items 1 to 3, wherein the control device is provided with a fault diagnosis unit that executes a fault diagnosis process of diagnosing that a malfunction has occurred in one battery module among the plurality of battery modules when the main voltage between the pair of output terminals is greater than a predetermined fault threshold value with the positive electrode side contactor and the negative electrode side contactor turned OFF and the pre-charge contactor turned ON for each battery module among the plurality of battery modules.

[0062] Section 5: the fault diagnosis unit executes the fault diagnosis process before the precharge process execution unit executes the precharge process, 5. The battery system according to item 4, wherein the precharge process execution unit executes the precharge process when the failure diagnosis unit diagnoses that no malfunction has occurred in the plurality of battery modules.

[0063] Item 6: 5. The battery system according to item 4, wherein the failure diagnosis unit executes the failure diagnosis process after the precharge process execution unit executes the precharge process. [Explanation of symbols]

[0064] 1 Battery System 5 pairs of output terminals 8 Main Bus 10 Battery Module 11 D battery 12 Battery unit 20 Positive contactor 30 Negative contactor 31 Fuse 40 Precharge circuit 41 Precharge resistor 42 Precharge Contactor 60 Control device 61 Storage section 63 Fault diagnosis section 65 Precharge processing execution unit 67 Connection control section 69 Exclusion Control Section 100 load

Claims

1. a pair of output terminals connected to a load; a plurality of battery modules connected to the pair of output terminals and arranged in parallel; a control device; Equipped with The plurality of battery modules include: a battery unit having a plurality of cells connected in series; a positive electrode contactor provided at a positive electrode end of the battery unit; a negative electrode contactor provided at the negative electrode end of the battery unit; a precharge circuit provided in parallel with one of the positive contactor and the negative contactor; Each of them has The precharge circuit A precharge resistor; a precharge contactor connected in series with the precharge resistor; Equipped with The control device a precharge process execution unit that executes a precharge process on a predetermined one of the plurality of battery modules when the plurality of battery modules are connected to the load through the pair of output terminals; a connection control unit that connects another battery module among the plurality of battery modules to the load after the precharge process; Equipped with the precharge process is a process of turning on the precharge contactor and the other of the positive electrode side contactor and the negative electrode side contactor to which the precharge circuit is not connected in parallel for the one predetermined battery module, and turning on the one contactor and turning off the precharge contactor after the voltage of the one predetermined battery module acts on the load; the control device includes an exclusion control unit that, when a malfunction occurs in the precharge process, excludes the malfunctioning battery module from among the plurality of battery modules to be connected in the precharge process; the precharge process execution unit executes the precharge process on a predetermined one of the battery modules other than the battery module excluded by the exclusion control unit; the control device includes a fault diagnosis unit that executes a fault diagnosis process of diagnosing that a malfunction has occurred in one battery module among the plurality of battery modules when the main voltage between the pair of output terminals is greater than a predetermined fault threshold value with the positive electrode side contactor and the negative electrode side contactor turned OFF and the pre-charge contactor turned ON, for the one battery module; the fault diagnosis unit executes the fault diagnosis process before the precharge process execution unit executes the precharge process, the precharge process execution unit executes the precharge process when the failure diagnosis unit diagnoses that no malfunction has occurred in the plurality of battery modules; The precharge process execution unit does not execute the precharge process when the failure diagnosis unit diagnoses that a malfunction has occurred in any of the plurality of battery modules.

2. 2. The battery system according to claim 1, wherein the exclusion control unit determines that a malfunction has occurred in the precharge process when the main voltage between the pair of output terminals is less than a predetermined threshold during the precharge process.

3. The battery system according to claim 1 , wherein the precharge process execution unit is configured to change the battery module that is to first execute the precharge process among the plurality of battery modules.

4. The battery system according to claim 1 , wherein the failure diagnosis unit executes the failure diagnosis process after the precharge process execution unit executes the precharge process.

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