On-board power storage system, vehicle, and recording medium storing a computer program

Abstract

Provided are an on-board power supply system and a vehicle, the on-board power supply system being able to perform stable battery output and including a relatively high-output secondary battery and a relatively high-capacity secondary battery which are connected in parallel. The on-board power storage system includes a high capacity-type battery assembly and a high output-type battery assembly that are connected in parallel. If the voltage value of the high capacity-type battery assembly decreases to a lower limit voltage value or approaches the lower limit voltage value, a battery control device disconnects the high capacity-type battery assembly from a circuit by means of a switching mechanism, while maintaining continuous output from the high output-type battery assembly.

Description

[Technical Field]

[0001] The present disclosure relates to an on-board power storage system in which a relatively high-output non-aqueous secondary battery and a relatively high-capacity non-aqueous secondary battery are connected in parallel and mounted on a vehicle, a vehicle equipped with this on-board power storage system, a control method for this on-board power storage system, etc. [Background technology]

[0002] Non-aqueous electrolyte secondary batteries (hereinafter simply referred to as "nonaqueous secondary batteries") are known as chargeable and dischargeable power storage devices mounted on vehicles. Lithium-ion secondary batteries, an example of such non-aqueous secondary batteries, are being developed for in-vehicle use because of their extremely high energy density. Batteries for in-vehicle use are required to have high levels of high output and high capacity in order to be able to handle a variety of driving conditions.

[0003] For example, Patent Document 1 proposes mounting a first assembled battery and a second assembled battery that are electrically connected in parallel and have different characteristics on a vehicle. Patent Document 2 also proposes that the energy storage system disclosed includes a connection means for arbitrarily connecting or disconnecting a high-power battery in parallel to a high-capacity battery, and that the high-power battery is connected in parallel to the high-capacity battery when an output current greater than the current that the high-capacity battery can supply is required. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-102226 [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-41620 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the prior art, including the above-mentioned patent documents, does not yet meet market needs, and the following problems remain. Specifically, the onboard energy storage system disclosed in Patent Document 1 employs a configuration in which a high-power battery pack is switched to a high-capacity battery pack when the battery pack is depleted. With this configuration, for example, when switching from a high-power battery pack to a high-capacity battery pack while driving, there is a risk that the battery output of the energy storage device may suddenly decrease, which may adversely affect vehicle control and ride comfort. On the other hand, the onboard energy storage system disclosed in Patent Document 2 basically connects the high-power battery pack in parallel with the high-capacity battery only when a high output current is required. When the batteries are not connected in parallel, the vehicle weight simply increases, which is far from being efficient.

[0006] The present disclosure has been made in consideration of the above-mentioned problem as an example, and aims to provide an in-vehicle power storage system in which a relatively high-output secondary battery and a relatively high-capacity secondary battery are connected in parallel to provide stable battery output, a vehicle equipped with this in-vehicle power storage system, a control method for this in-vehicle power storage system, a computer program, and a recording medium on which the computer program is recorded. [Means for solving the problem]

[0007] In order to solve the above problems, according to one aspect of the present disclosure, there is provided a battery control device including a high-capacity battery set having a higher capacity than one of the battery sets, a high-power battery set connected in parallel to the high-capacity battery set and having a higher power output than the high-capacity battery set, a switch mechanism that separates the high-capacity battery set from a circuit including the high-power battery set, and a battery control device that controls the switch mechanism, ofA different number of cells are connected in series so that the voltages between their terminals are equal to each other, and the lower limit voltage of the high-power battery group is set lower than the lower limit voltage of the high-capacity battery group, and the battery control device (a) when the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage, disconnects the high-capacity battery group from the circuit via the switch mechanism and continues output from the high-power battery group, and (b) before the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage, does not supply power only from the high-capacity battery group but supplies power in parallel from the high-capacity battery group and the high-power battery group based on the parallel connection.

[0008] In order to solve the above-described problems, according to yet another aspect of the present disclosure, there is provided a vehicle equipped with an on-board power storage system according to the present disclosure. In order to solve the above-described problems, according to still another aspect of the present disclosure, a high-capacity battery set and a high-power battery set mounted on a vehicle are connected in parallel, and the high-capacity battery set and the high-power battery set connected in parallel are connected in parallel. of Provided is a recording medium having recorded thereon a computer program applicable to an in-vehicle power storage system having a power storage device in which different numbers of cells are connected in series so that the inter-terminal voltages of the respective cells are equal to each other, the recording medium having recorded thereon a computer program that causes one or more processors to execute processes including: acquiring voltage value information of the power storage device; when the voltage value of the high-capacity battery group reaches or approaches a lower limit voltage, controlling the high-capacity battery group to be disconnected from the circuit via a switch mechanism and to continue output from the high-power battery group; and controlling the high-capacity battery group and the high-power battery group to be supplied in parallel, assuming the parallel connection, rather than supplying power only from the high-capacity battery group, before the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage. [Effects of the Invention]

[0009] According to the present disclosure, a relatively high-output non-aqueous secondary battery and a relatively high-capacity non-aqueous secondary battery are connected in parallel, making it possible to achieve stable battery output. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a configuration example of a vehicle equipped with an in-vehicle power storage system according to the present disclosure. [Figure 2] 3 is a schematic diagram showing a first connection pattern (parallel connection state) of an electricity storage device to a load according to an embodiment of the present disclosure. FIG. [Figure 3] 10 is a schematic diagram showing a second connection pattern (a state in which the parallel connection is released) of the power storage device to the load according to the embodiment of the present disclosure. FIG. [Figure 4] 1 is a schematic diagram comparing the capacities and outputtable voltages of a high-capacity battery group and a high-power battery group that constitute an electricity storage device. [Figure 5] 1 is a functional block diagram of a vehicle including a control device according to an embodiment of the present disclosure. [Figure 6] 4 is a flowchart illustrating a control method for an in-vehicle power storage system executed by a control device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description will be omitted. Furthermore, for configurations other than those described in detail below, publicly known technologies, including those described in the patent documents listed above, and vehicle configurations may be appropriately applied.

[0012] <1-1. In-vehicle energy storage system> 1 to 5, a configuration example of an in-vehicle power storage system 100 and a vehicle 200 according to an embodiment of the present disclosure will be described. FIG. 1 is a schematic diagram showing a vehicle 200 equipped with an in-vehicle power storage system 100. Note that, hereinafter, an electric vehicle (BEV) equipped with an electric motor will be illustrated as an example of a "vehicle," but the vehicle of this embodiment may be a hybrid electric vehicle (HEV) that also uses a known engine (internal combustion engine) in combination, or may be an electric vehicle equipped with another known power generation device such as a gas turbine.

[0013] As shown in Fig. 1, a vehicle 200 of this embodiment is equipped with a load 60 that supplies driving force to wheels 1, which are drive wheels, via a known power transmission mechanism 2 including a differential gear. In the following, a front-wheel drive (FWD) vehicle in which driving force is supplied from the load 60 to the front wheels of the wheels 1 is illustrated as an example, but this embodiment is not limited to this form and may also be a rear-wheel drive (RWD) vehicle in which the driving force is supplied to the rear wheels, or an all-wheel drive (AWD) vehicle in which driving force is supplied to all wheels. Furthermore, the vehicle 200 of the present disclosure may also be, in addition to the above, an in-wheel motor type electric vehicle in which an electric motor is mounted individually for each wheel 1, for example.

[0014] The load 60 includes a known inverter 61 that receives a supply of electric power from the electricity storage device 30 described below, and a known electric motor 62 such as an electric motor that is connected to the inverter 61 and supplies driving force to the wheels 1. As shown in the figure, the load 60 of this embodiment is electrically connected to the electricity storage device 30 as an on-board power source via a switch mechanism 40 that can switch connection patterns.

[0015] The power storage device 30 is configured to include a high-capacity battery set 10 that has a higher capacity than one of the battery sets, and a high-power battery set 20 that is connected in parallel to the high-capacity battery set 10 and has a higher power output than the high-capacity battery set 10. Note that, in the following, two sets of non-aqueous secondary batteries (lithium ion secondary batteries) with different characteristics are exemplified as the battery sets of this embodiment, but other well-known secondary batteries other than non-aqueous secondary batteries may also be included, such as one set of lithium ion secondary batteries and the other set of nickel-metal hydride batteries.

[0016] For example, the high-capacity battery set 10 may be composed of one or more lithium-ion secondary batteries LiB-1 connected in series. Examples of lithium-ion secondary batteries LiB-1 suitable for such high-capacity battery set 10 include known lithium-ion secondary batteries using a carbon-based material for the negative electrode and known high-capacity lithium-ion secondary batteries using lithium iron phosphate for the positive electrode. As a non-limiting example, the lithium ion secondary battery LiB-1 of this embodiment uses lithium iron phosphate or a ternary positive electrode (nickel-cobalt-lithium manganese oxide) as the positive electrode material, and uses a known carbon-based material as the negative electrode material.

[0017] On the other hand, the high-power battery set 20 may be composed of one or a plurality of lithium-ion secondary batteries LiB-2 connected in series, each having characteristics different from those of the high-capacity battery set 10. An example of a lithium-ion secondary battery LiB-2 suitable for such a high-power battery set 20 is a known high-power lithium-ion secondary battery that uses lithium titanate for the negative electrode. Similarly, as a non-limiting example, in the lithium ion secondary battery LiB-2 of this embodiment, lithium manganese oxide is used as the positive electrode material, and lithium titanate is used as the negative electrode material.

[0018] 2 and 3, in the power storage device 30 of this embodiment, the above-described high-capacity battery group 10 and high-power battery group 20 are connected to an electric circuit that is connected to a load 60 via a switch mechanism 40. That is, as shown in FIG. 2, the switch mechanism 40 of this embodiment is configured to have a first function of connecting the high-capacity battery group 10 and the high-power battery group 20 in parallel to the load 60. Such a configuration in which the high-capacity battery group 10 and the high-power battery group 20 are connected in parallel to the load 60 is also referred to as a "first connection pattern."

[0019] 3, the switch mechanism 40 of this embodiment is configured to have a second function of disconnecting the high-capacity battery group 10 from the load 60 and connecting the high-power battery group 20 to the load 60. This form in which the high-power battery group 20 is connected to the load 60 while the high-capacity battery group 10 is disconnected is also referred to as a "second connection pattern." In this way, the switch mechanism 40 of this embodiment is configured to be able to switch the connection state of the power storage device 30 to the load 60 between the first connection pattern and the second connection pattern described above.

[0020] In other words, the switch mechanism 40 of this embodiment has the function of disconnecting, at a predetermined timing, the high-capacity battery group 10 from the circuit including the high-power battery group 20. There are no particular limitations on the specific example of the switch mechanism 40, and any known switch such as a semiconductor switch or a mechanical switch may be used as long as it performs the above-mentioned function.

[0021] <1-2. Detailed configuration of the energy storage device> Next, the detailed configuration of the electricity storage device 30 of this embodiment will be described with reference to FIGS. 4, in the power storage device 30 of this embodiment, the lower limit voltage VL2 of the high-power battery group is set lower than the lower limit voltage VL1 of the high-capacity battery group 10. As an example, in this embodiment, the lower limit voltage VL1 of the high-capacity battery group 10 may be set to 190V, and the lower limit voltage VL2 of the high-power battery group 20 may be set to 170V.

[0022] 4, the capacity of the high-power battery group 20 from 170V (lower limit voltage VL2) to 190V is the power supplied to the load 60 in the second connection pattern described above. As will be described later, in this embodiment, the first connection pattern is the standard when supplying power from the power storage device 30 to the load 60, and therefore the capacity of the high-power battery group 20 from 170V (lower limit voltage VL2) to 190V is also referred to as the "emergency capacity" in this embodiment.

[0023] On the other hand, the upper limit voltage of the high-power battery group 20 is set to be approximately equal to the upper limit voltage of the high-capacity battery group 10. Therefore, the upper limit voltage VH of the power storage device 30 corresponds to the upper limit voltage of the high-capacity battery group 10 and the upper limit voltage of the high-power battery group 20. As an example, in this embodiment, the upper limit voltage VH of the power storage device 30 may be set to 300V.

[0024] In this embodiment, the weight energy density ratio of the high-capacity lithium-ion secondary battery LiB-1 and the high-power lithium-ion secondary battery LiB-2 used respectively is set to 3:1, so when the electricity storage device 30 with the above-mentioned upper limit voltage and lower limit voltage is configured, the capacity ratio is as shown in Fig. 4. Note that in this embodiment, the weight energy density ratio of the lithium-ion secondary battery LiB-1 and the lithium-ion secondary battery LiB-2 is set to 3:1, but is not limited to this ratio and may be set to another ratio according to the vehicle application, etc.

[0025] As described above, this embodiment is premised on the parallel connection of the high-capacity battery group 10 and the high-power battery group 20. Therefore, in the power storage device 30 of this embodiment, different numbers of cells (single cells) are connected in series so that the terminal voltages of the parallel-connected high-capacity battery group 10 and the high-power battery group 20 are equal.

[0026] As an example, if the upper limit voltage of the high-capacity lithium-ion secondary battery LiB-1 used in this embodiment is 4.2 V in its specifications, then connecting a total of 71 cells in series will set the voltage to 300 V (4.2 V × 71 = 298.2 V) as described above. On the other hand, if the upper limit voltage of the high-power lithium-ion secondary battery LiB-2 used in this embodiment is 2.7 V in its specifications, then connecting a total of 111 cells in series (2.7 V × 111 = 299.7 V) will make it possible to roughly match the upper limit voltage of the high-capacity battery set 10.

[0027] <1-3. Detailed configuration of the battery control device> 1, the in-vehicle power storage system 100 in this embodiment is configured to include a battery control device 50 that controls the above-mentioned switch mechanism 40. The battery control device 50 may also be configured to have a function of monitoring the state of charge (SOC) of the above-mentioned power storage device 30, a function of controlling charging and discharging of the above-mentioned power storage device 30, and the like.

[0028] Such a battery control device 50 is also called a BMU (Battery Management Unit) and is configured with one or more processors, such as a CPU (Central Processing Unit), and one or more memories, such as a RAM (Random Access Memory) or a ROM (Read Only Memory), connected to the processor so as to be able to communicate with the processor.

[0029] In this way, the battery control device 50 functions as a device that controls the charging and discharging of the high-capacity battery set 10 and the high-power battery set 20 via the switch mechanism 40 by having one or more processors execute a computer program. The computer program is a computer program that causes the processor to execute the operations to be performed by the battery control device 50, which will be described later. The computer program executed by the processor may be recorded on a recording medium that functions as a storage unit (memory) provided in the battery control device 50, or may be recorded on a recording medium built into the battery control device 50 or any recording medium that can be externally attached to the battery control device 50.

[0030] The recording medium for recording a computer program may be a magnetic medium such as a hard disk, a floppy disk, or a magnetic tape; an optical recording medium such as a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disk), or a Blu-ray (registered trademark); a magneto-optical medium such as a floptical disk; a memory element such as a RAM or a ROM; a flash memory such as a USB (Universal Serial Bus) memory; an SSD (Solid State Drive); or any other medium capable of storing a program.

[0031] More specifically, the battery control device 50 in this embodiment includes a processing unit 50A and a storage unit 50B. The processing unit 50A is configured by one or more processors such as the CPUs described above, and includes a battery state value acquiring unit 51, an SOC monitoring unit 52, a switch control unit 53, and a display control unit 54. Each unit included in the processing unit 50A is a function realized by the execution of a program by the processor described above. However, some of the battery state value acquiring unit 51, the SOC monitoring unit 52, the switch control unit 53, and the display control unit 54 may be configured by known analog circuits.

[0032] The processing unit 50A may be configured to be able to communicate with a vehicle drive control device 70 configured with another known ECU mounted on the vehicle. The vehicle drive control device 70 may have a function to control the drive of the battery control device 50 of this embodiment based on detection values ​​of known vehicle state sensors including, for example, a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, a steering angle sensor, an accelerator pedal sensor, and a brake pedal sensor. The processing unit 50A may be configured to be able to communicate information with a known external network NET such as the Internet via a known in-vehicle communication device 71.

[0033] The storage unit 50B may be configured to include a known memory MR such as RAM that temporarily stores information, and a known recording device RD such as a hard disk HDD or SSD that can store programs, etc. The storage unit 50B of this embodiment may store programs executed by the processing unit 50A, various parameters used in executing the programs, acquired data, data of calculation results, etc.

[0034] The battery state value acquiring unit 51, the SOC monitoring unit 52, the switch control unit 53, and the display control unit 54 in the processing unit 50A will be described below.

[0035] (Battery status value acquisition unit) The battery state value acquisition unit 51 executes a process of acquiring state values ​​(specifically, information related to current values ​​and voltage values) of the power storage device 30 mounted on the vehicle 200. Specifically, the battery state value acquisition unit 51 has a function of detecting state values ​​(voltage values ​​and current values) of the power storage device 30 in the vehicle 200 while the vehicle is running or stopped, via a known current sensor 72a and a known voltage sensor 72b provided in the power storage device 30.

[0036] (SOC monitoring department) The SOC monitoring unit 52 executes a process of detecting and monitoring the SOC (charging rate) of each of the power storage devices 30 (the high-capacity battery group 10 and the high-power battery group 20) mounted on the vehicle 200 via an on-board current sensor 72a and voltage sensor 72b. The specific method of detecting the SOC by the SOC monitoring unit 52 is not particularly limited as long as it does not deviate from the spirit of this embodiment, and various known SOC estimation techniques such as those disclosed in JP 2021-68637 A and WO 2019 / 193471 A may be applied.

[0037] (Switch control section) The switch control unit 53 executes a process of switching the above-described connection state of the power storage device 30 with respect to the above-described load 60. For example, the switch control unit 53 may execute a process of switching between the first connection pattern exemplified in Fig. 2 and the second connection pattern exemplified in Fig. 3 via the above-described switch mechanism 40.

[0038] (Display control unit) The display control unit 54 executes a process of displaying various information such as the connection state of the power storage device 30 to the load 60 on the display device 73. Here, the display device 73 of the present embodiment may be, for example, a known in-vehicle display. The display control unit 54 may display the above-mentioned various information by voice on an in-vehicle speaker, or may display the information on an external terminal such as a smartphone carried by the occupant.

[0039] The computer program that realizes each function of the processing unit 50A is, for example, a computer program applied to an onboard power supply system of a vehicle that includes a high-capacity battery group composed of one or more nonaqueous secondary batteries (lithium ion secondary batteries) and a high-power battery group connected in parallel with a lower limit voltage set lower than the lower limit voltage of the high-capacity battery group, and causes one or more processors to acquire voltage value information of the power storage device 30, and when the voltage value of the high-capacity battery group becomes the lower limit voltage or approaches the lower limit, executes control to disconnect the high-capacity battery group 10 from the circuit via the switch mechanism 40 and continue output from the high-power battery group 20. Furthermore, such a computer program may be stored in, for example, a known recording medium as described above, or may be downloaded to the vehicle 200 from a known server such as a cloud server.

[0040] <1-4. Other in-vehicle equipment> The vehicle 200 of this embodiment may further include a vehicle drive control device 70 that cooperates with the battery control device 50 described above to control the load 60, the generator described above, and the like. Such a vehicle drive control device 70 is configured to have a function of controlling the drive of the vehicle 200 based on, for example, state information of the vehicle 200 detected by sensors 72 mounted on the vehicle 200. The vehicle drive control device 70 is configured to include, for example, one or more processors such as a CPU (Central Processing Unit) and one or more memories such as a RAM (Random Access Memory) or a ROM (Read Only Memory) connected to the processor so as to be able to communicate with the processor.

[0041] Such a vehicle state sensor is a device that measures information indicating the behavior and operating state of the vehicle 200. As an example, the vehicle state sensor belongs to the sensors 72 of this embodiment and may include at least one of a known vehicle speed sensor, an acceleration sensor, and an angular velocity sensor. The vehicle state sensor may also include a known steering angle sensor, an accelerator pedal sensor, and a brake pedal sensor.

[0042] The vehicle drive control device 70 may also be configured to have a function of controlling the drive of the vehicle 200 based on position information detected by a vehicle position information sensor 72c mounted on the vehicle 200. Such vehicle position information sensor 72c may be, for example, a well-known GPS (Global Positioning System) sensor. Note that, although a GPS sensor is used as the vehicle position information sensor 72c in this embodiment, the present invention is not limited to this example, and the vehicle position information sensor 72c may also be equipment that receives satellite signals from other satellite systems that identify the position of the vehicle 200.

[0043] <2-1. Control method for in-vehicle energy storage system> Next, a control method for the in-vehicle power storage system 100 including the power storage device 30 of this embodiment will be specifically described with reference to Fig. 6. The control method may be used as an algorithm of the above-mentioned program. A program having such an algorithm may be distributed, for example, in a downloadable manner via a known network, or in a form stored on a recording medium. The following description will be given assuming that, for example, a user gets into vehicle 200, turns on the system power supply, and starts driving.

[0044] First, in step 1, the battery control device 50 detects whether the lower limit voltage of the power storage device 30 is below the set lower limit of the high-capacity battery group 10 (190 V as described above in this example). More specifically, the battery control device 50 monitors the voltage value of the high-capacity battery group 10 in the vehicle 200 while it is running or stopped via the voltage sensor 72b. Note that in this example, the battery control device 50 monitors the voltage value of the high-capacity battery group 10, but this is not a limitation and the battery control device 50 may also monitor the voltage value of the high-power battery group 20 or the entire power storage device 30, for example.

[0045] If the lower limit voltage of the power storage device 30 is not lower than the set lower limit of the high-capacity battery group 10 in step 1 (No in step 1), the process proceeds to step 2A. In step 2A, the battery control device 50 executes control to supply power to the load 60 in the first connection pattern described above via the switch mechanism 40. As a result, power is supplied in parallel from the high-capacity battery group 10 and the high-power battery group 20 before the voltage value of the high-capacity battery group 10 reaches or approaches the lower limit voltage.

[0046] On the other hand, if the lower limit voltage of the power storage device 30 is lower than the set lower limit of the high-capacity battery group 10 in step 1 (Yes in step 1), the process proceeds to step 2B. In step 2B, the battery control device 50 executes control to supply power to the load 60 via the switch mechanism 40 in the second connection pattern described above.

[0047] In other words, when the voltage value of the high-capacity battery group 10 reaches or approaches the lower limit voltage, the battery control device 50 executes control to disconnect the high-capacity battery group 10 from the circuit and continue output from the high-power battery group 20. The timing for disconnecting the high-capacity battery group 10 from the circuit via the switch mechanism 40 does not necessarily have to be the moment when the voltage value reaches the lower limit voltage, but the high-capacity battery group 10 may be disconnected from the circuit slightly before that. This makes it possible to further suppress deterioration of the lithium-ion secondary batteries LiB-1 of the high-capacity battery group 10.

[0048] In this embodiment, the lower limit voltage of the high-power battery group 20 connected in parallel is set lower than the lower limit voltage of the high-capacity battery group 10. Therefore, the SOC of the high-capacity battery group 10 is basically depleted first, causing a switch to the high-power battery group 20. This makes it possible to suppress a decrease in output relative to conventional examples, stabilize vehicle control, and improve ride comfort.

[0049] As described above, the vehicle 200 equipped with the in-vehicle power storage system 100 according to an embodiment of the present disclosure uses a combination of two types of power storage devices (the high-capacity battery group 10 and the high-power battery group 20) that have different lower limit voltages. The high-capacity battery group 10 and the high-power battery group 20 form an electric circuit that is connected in parallel to the vehicle load 60 via the switch mechanism 40. In this case, the battery control device 50 executes control to disconnect the high-capacity power storage device (i.e., the high-capacity battery group 10) that has the higher lower limit voltage of the two types of power storage devices from the circuit when the SOC is depleted. As a result, in-vehicle power storage system 100 and vehicle 200 of this embodiment, a relatively high-output non-aqueous secondary battery and a relatively high-capacity non-aqueous secondary battery are connected in parallel, making it possible to achieve stable battery output.

[0050] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technology of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the technology to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0051] For example, in the above embodiment, the battery control device 50 executes control to disconnect the high-capacity battery group (high-capacity battery group 10) from the circuit in step 2B. However, the present disclosure is not limited to the above embodiment, and by appropriately controlling the switch mechanism 40 during subsequent regeneration, charging of the high-capacity battery group 10 may be performed preferentially when charging the electricity storage device 30.

[0052] In addition, in the above-described embodiment, one high-capacity battery set 10 and one high-power battery set 20 are configured as the power storage device 30, but for example, a configuration may be adopted in which at least one of these is configured as multiple sets and the battery sets are further arranged in parallel.

[0053] Furthermore, when the voltage value of the high-capacity battery group 10 falls below a set lower limit, the switch mechanism 40 may be controlled in a manner that takes into account the state when the electricity storage device 30 is being charged, as described below. In other words, when the voltage value of the high-capacity battery group 10 falls below the set lower limit value and the first connection pattern described above is maintained by the switch mechanism 40, the battery control device 50 may perform the charging process until the high-capacity battery group 10 is fully charged, although the charging time will be relatively long due to the rate determined by the charging current value (input rate) of the high-capacity battery group 10.

[0054] On the other hand, when the voltage value of the high-capacity battery group 10 falls below the set lower limit and the switch mechanism 40 maintains the second connection pattern, the battery control device 50 can charge only the high-power battery group 20, and may therefore execute a rapid charge process on the high-power battery group 20. This enables efficient charging of the power storage device 30 when, for example, a long driving range is not necessary but it is desired to charge the power storage device 30 as quickly as possible. [Explanation of symbols]

[0055] 1: Wheel, 2: Power transmission mechanism, 10: High-capacity battery set, 20: High-output battery set, 30: Power storage device, 40: Switch mechanism, 50: Battery control device, 60: Load, 70: Vehicle control device, 71: Communication device, 72: Sensors, 73: Display device, 100: In-vehicle power storage system, 200: Vehicle

Claims

1. A high-capacity battery set that has a higher capacity than one battery set, a high-power battery set connected in parallel to the high-capacity battery set and having a higher power output than the high-capacity battery set; a switch mechanism for isolating the high-capacity battery set from a circuit including the high-power battery set; a battery control device that controls the switch mechanism, a different number of cells are connected in series so that the terminal voltages of the high-capacity battery group and the high-power battery group connected in parallel are equal to each other; a lower limit voltage of the high-power battery group is set lower than a lower limit voltage of the high-capacity battery group; The battery control device (a) disconnects the high-capacity battery group from the circuit via the switch mechanism and continues output from the high-power battery group when the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage, and (b) before the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage, does not supply power only from the high-capacity battery group but supplies power in parallel from the high-capacity battery group and the high-power battery group on the premise of the parallel connection. In-vehicle energy storage system.

2. A vehicle comprising the on-board power storage system according to claim 1.

3. A recording medium having recorded thereon a computer program applicable to an in-vehicle power storage system in which a high-capacity battery group and a high-power battery group are connected in parallel to each other and which has a power storage device in which different numbers of cells are connected in series so that the inter-terminal voltages of the high-capacity battery group and the high-power battery group connected in parallel are equal to each other, one or more processors, acquiring voltage value information of the power storage device; When the voltage value of the high-capacity battery group reaches or approaches a lower limit voltage, the high-capacity battery group is disconnected from the circuit via a switch mechanism, and output from the high-power battery group is controlled to continue; and Before the voltage value of the high-capacity battery group reaches or approaches the lower limit voltage, power is not supplied only from the high-capacity battery group, but power is supplied in parallel from the high-capacity battery group and the high-power battery group on the premise of the parallel connection. A recording medium on which a computer program for executing a process including the steps of:

Images