VEHICLE INTERNAL POWER SUPPLY SYSTEM, CHARGING / DISCHARGING CONTROL UNIT, VEHICLE, COMPUTER PROGRAM AND RECORDING MEDIUM ON WHICH THE COMPUTER PROGRAM IS RECORDED

Abstract

An in-vehicle power supply system can maintain a state of charge suitable for both acceleration and deceleration states of the vehicle. The vehicle's internal power supply system comprises the following: an energy storage device in which a lithium-ion secondary battery, a first capacitor bank, and a second capacitor bank are connected in parallel to control the charging / discharging of the energy storage device. The first and second capacitor banks are composed of lithium-ion capacitors. If the first capacitor bank discharges electrical energy preferentially over the second capacitor bank, the vehicle's internal power supply system implements a control mechanism to preferentially charge the second capacitor bank over the first.

Description

Technical area

[0001] The invention relates to an in-vehicle power supply system for installation in a vehicle, in which a lithium-ion secondary battery and a lithium-ion capacitor are connected in parallel, a charge / discharge control device of the in-vehicle power supply system, and a vehicle. The invention also relates to a computer program and a recording medium on which the computer program is recorded. Conventional technology

[0002] A lithium-ion secondary battery and a lithium-ion capacitor are known as chargeable / dischargeable energy storage devices mounted on a vehicle. Since the lithium-ion secondary battery and the lithium-ion capacitor have different advantages and disadvantages, it is expected that the lithium-ion secondary battery and the lithium-ion capacitor will be used efficiently in combination in a parallel state.

[0003] For example, PTL 1 discloses that when an energy storage unit including a lithium-ion secondary battery and an additional energy storage unit including a lithium-ion capacitor are connected in parallel, a state of charge balance between the energy storage units is controlled. Literature listPatent literature

[0004] PTL 1: International Publication WO 2014 / 156564 A1 Brief description of the inventionTechnical problem

[0005] However, conventional energy storage devices disclosed in PTL 1 or the like perform charge / discharge control of the energy storage device without sufficiently considering a state of charge (hereinafter also referred to as "SOC") suitable for an acceleration state and a deceleration state of the vehicle. That is, for example, in a situation where the SOC of the lithium-ion capacitor is low, the amount of current to the lithium-ion secondary battery is increased at the time of acceleration, accumulating battery deterioration. Consequently, the service life of the lithium-ion secondary battery is shortened.

[0006] Furthermore, in a situation where the SOC of the lithium-ion capacitor is high, since the charge capacity in the lithium-ion capacitor is low at the time of regeneration, the supply to the lithium-ion secondary battery becomes high. Consequently, battery deterioration progresses, or there is no choice but to decelerate through normal braking, and energy efficiency decreases.

[0007] The invention was conceived with the above-mentioned problem in mind. The invention provides an in-vehicle power supply system, a charge / discharge control device for a vehicle, a vehicle, a computer program, and a recording medium on which the computer program is recorded. The in-vehicle power supply system, the charge / discharge control device for a vehicle, the vehicle, the computer program, and the recording medium make it possible to maintain a charge state in an energy storage device that is suitable for the acceleration and deceleration states of the vehicle. In the energy storage device, a lithium-ion secondary battery and a lithium-ion capacitor are connected in parallel. Solution to the problem

[0008] To solve the above-mentioned problem, one aspect of the invention provides an in-vehicle power supply system comprising: a first power storage device for mounting in a vehicle, which is formed of one or more lithium-ion secondary batteries; a second power storage device for mounting in the vehicle, which is connected in parallel to the first power storage device; and a charge / discharge control device configured to control the charge / discharge of the first power storage device and the second power storage device to supply electric power to a power source of the vehicle and recover regenerative energy of the vehicle.

[0009] The second energy storage device is constructed from a plurality of lithium-ion capacitor groups, which are formed from a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel. The charge / discharge control device is configured to perform a control such that, when the first capacitor group connected in parallel discharges electrical energy preferentially to the second capacitor group, the second capacitor group is charged preferentially to the first capacitor group connected in parallel.

[0010] To solve the above-mentioned problem, one aspect of the invention provides a charge / discharge control device for mounting in a vehicle for controlling the charge / discharge of a first energy storage device and a second energy storage device arranged in the vehicle. The first energy storage device is formed of one or more lithium-ion secondary batteries. The second energy storage device is connected in parallel to the first energy storage device and is composed of a plurality of lithium-ion capacitor groups formed of a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel to each other.

[0011] The charge / discharge control device comprises: one or more processors; and one or more memories communicatively connected to the one or more processors, wherein the one or more processors are configured to acquire acceleration information of the vehicle, acquire state of charge information of the first energy storage device and state of charge information of the second energy storage device, and, when the parallel-connected first capacitor group discharges electrical energy preferentially than the second capacitor group, perform a control based on the acceleration information of the vehicle such that the second capacitor group is charged preferentially than the parallel-connected first capacitor group.

[0012] To solve the above-mentioned problem, one aspect of the invention provides a vehicle comprising: a first energy storage device formed of one or more lithium-ion secondary batteries; a second energy storage device connected in parallel to the first energy storage device and composed of a plurality of lithium-ion capacitor groups formed of a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel to each other; acceleration information detecting means configured to detect acceleration information of the vehicle; charge state information detecting means configured to detect charge state information of the first energy storage device and charge state information of the second energy storage device;and a switching controller configured to, when the parallel-connected first capacitor group discharges electrical energy preferentially to the second capacitor group, perform control based on the acceleration information of the vehicle such that the second capacitor group is charged preferentially to the parallel-connected first capacitor group;

[0013] To solve the above-mentioned problem, one aspect of the invention provides a computer program and a recording medium on which the computer program is recorded. The program can be used in an in-vehicle power supply system for mounting in a vehicle to control the charging / discharging of a first power storage device and a second power storage device arranged in the vehicle. The first power storage device is formed of one or more lithium-ion secondary batteries. The second power storage device is connected in parallel with the first power storage device and is composed of a plurality of lithium-ion capacitor groups formed of a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel with each other.

[0014] The computer program causes one or more processors to execute a process comprising acquiring acceleration information of the vehicle, acquiring state of charge information of the first energy storage device and state of charge information of the second energy storage device, and, when the parallel-connected first capacitor group discharges electrical energy preferentially over the second capacitor group, to carry out a control based on the acceleration information of the vehicle such that the second capacitor group is charged preferentially over the parallel-connected first capacitor group. Advantageous effects of the invention

[0015] As described above, according to the invention, it is possible to perform charge / discharge control of an in-vehicle power supply in consideration of the charge state suitable for the acceleration state and the deceleration state of the vehicle. Short description of the drawings

[0016] The drawings show in: Fig. 1 is a schematic diagram showing a configuration example of a vehicle equipped with an in-vehicle power supply system according to the invention. Fig. 2 is a schematic diagram showing a first connection pattern of an energy storage device according to an embodiment of the invention with respect to a load. Fig. 3 is a schematic diagram showing a second connection pattern of the energy storage device according to the embodiment of the invention with respect to the load. Fig. 4 is a schematic diagram showing a third connection pattern of the energy storage device according to the embodiment of the invention with respect to the load. Fig. 5 is a block diagram of a charge / discharge control device in a vehicle according to the embodiment of the invention. Fig. 6 is a flowchart illustrating a charge / discharge control method for an in-vehicle power supply by a charge / discharge control device according to the embodiment of the invention. Fig. 7 is a flowchart at the time of regenerative charging in the charge / discharge control method by the charge / discharge control device according to the embodiment of the invention. Fig. 8 is a schematic diagram showing an example of a driving pattern of a vehicle. Description of embodiments

[0017] A preferred embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the description and drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant descriptions are omitted. 1-1. In-vehicle power supply system

[0018] A configuration example of an in-vehicle power supply system 100 according to an embodiment of the invention will be described with reference to Fig. 1 to 4 described. Fig. 1 is a schematic diagram of a vehicle 200 equipped with the in-vehicle power supply system 100. Note that, hereinafter, an electric vehicle equipped with an electric motor is illustrated as an example of a "vehicle." However, the vehicle according to the present embodiment may also be a hybrid electric vehicle that uses a known engine (internal combustion engine) in combination, or an electric vehicle equipped with another known power generation device, such as a gas turbine.

[0019] As in Fig. 1, the vehicle 200 according to the present embodiment is equipped with a load 50 that transmits driving power to the wheels 1 serving as drive wheels via a known power transmission mechanism 2 including a differential gear. Hereinafter, a front-wheel drive (FWD) vehicle will be illustrated in which the driving power from the load 50 is transmitted to the front wheels from the wheels 1. However, the present embodiment is not limited to the above-mentioned case and may also be a rear-wheel drive (RWD) vehicle in which the above-described driving power is transmitted to the rear wheels, or an all-wheel drive (AWD) vehicle in which the driving power is transmitted to all wheels.

[0020] The load 50 includes a known inverter 51 to which electrical energy is supplied from an energy storage device 30 described later, and a known electric motor 52, such as an electric motor, which is connected to the inverter 51 and supplies the above-described driving force to the wheels 1.

[0021] As in Fig. 1, the energy storage device 30 as an in-vehicle power supply according to the present embodiment is connected to the load 50 having the inverter 51 via a power supply line EL having an input terminal IT and an output terminal OT.

[0022] The energy storage device 30 comprises a first energy storage device 10 and a second energy storage device 20. The first energy storage device 10 is formed from one or more lithium-ion secondary batteries LiB. The second energy storage device 20 is formed from a plurality of lithium-ion capacitors LiC. Of these, as shown in Fig. 2 and other figures, the first energy storage device 10 is mounted in the vehicle 200, and a plurality of known lithium-ion secondary batteries are connected in series in the first energy storage device 10.

[0023] The second energy storage device 20 is connected in parallel to the above-described first energy storage device 10 via a known switching circuit ST (a first switching circuit ST1 and a second switching circuit ST2, which will be described later) and is mounted in the vehicle 200. Such a second energy storage device 20 includes a first capacitor group 20A and a second capacitor group 20B such that a plurality of known lithium-ion capacitors are connected in parallel. The first capacitor group 20A is formed of one or more lithium-ion capacitors, and the second capacitor group 20B is formed of one or more lithium-ion capacitors. Note that in the second energy storage device 20 according to the present embodiment, the two capacitor groups described above are connected in parallel.However, a configuration can also be used in which any number of three or more capacitor groups are connected in parallel.

[0024] As in Fig. As shown in Figure 1, the vehicle 200 is equipped with a plurality of control devices that control the travel of the vehicle. The control device according to the present embodiment includes a charge / discharge control device 40 and a vehicle drive control device 60. The charge / discharge control device 40 serves as a battery management unit (BMU) that controls the charging / discharging of the first energy storage device 10 and the second energy storage device 20 to supply electric power to a drive source (the load 50 or the like) of the vehicle 200 and recover regenerative energy of the vehicle 200. The vehicle drive control device 60 includes one or more known control devices (ECUs) that are electrically connected to the charge / discharge control device 40 and control the drive of the load 50.

[0025] In the present embodiment, the “in-vehicle power supply system” includes the above-described energy storage device 30 and the charge / discharge control device 40 that controls the energy storage device 30.

[0026] The vehicle drive control device 60 has the function of controlling the driving of the vehicle 200 based on state information of the vehicle 200 detected by known vehicle state sensors 62c mounted in the vehicle 200. Such vehicle state sensors 62c are devices that measure information indicative of a behavior and operating state of the vehicle 200. For example, the vehicle state sensors 62c include one or more of a known vehicle speed sensor, a known acceleration sensor, and a known angular velocity sensor. Furthermore, the vehicle state sensors may include a known steering angle sensor, a known accelerator pedal sensor, and a known brake pedal sensor.

[0027] The vehicle drive control device 60 may have the function of controlling the driving of the vehicle 200 based on position information detected by a known vehicle position information sensor (not shown) mounted in the vehicle 200. An example of such a vehicle position detection sensor is a sensor used in a GNSS (Global Navigation Satellite System) represented by a known GPS (Global Positioning System). The vehicle position detection sensor receives satellite signals transmitted from satellites and transmits the position information of the vehicle 200 contained in the satellite signals to the vehicle drive control device 60. The vehicle position detection sensor may also include an antenna that receives satellite signals from another satellite system that identifies the position of the vehicle 200 in addition to the GPS.

[0028] The charge / discharge controller 40 and vehicle drive controller 60 described above include one or more processors and one or more memories. Examples of the one or more processors include a CPU (central processing unit), and examples of the one or more memories include a RAM (random access memory) and a ROM (read-only memory) connected to the one or more processors. One or both of the charge / discharge controller 40 and the vehicle drive controller 60 may be formed from an updatable device such as firmware, or may be a program module or the like executed by an instruction from a processor.

[0029] The charge / discharge control device 40 serves as a device that controls the charge / discharge of the first energy storage device 10 and the second energy storage device 20 by the one or more processors executing a computer program.

[0030] The computer program is a computer program that causes a processor to execute operations to be performed by the charge / discharge controller 40, which are described below. The computer program executed by the processor may be recorded on a recording medium serving as a storage device (memory) in the charge / discharge controller 40. The computer program executed by the processor may also be recorded on a recording medium mounted in the charge / discharge controller 40 or on any recording medium that can be externally connected to the charge / discharge controller 40.

[0031] The recording medium on which the computer program is recorded may be a magnetic medium, an optical recording medium, a magnetic-optical medium, a storage element, a flash memory, an SSD (solid state drive), or any other medium that can store a program. Examples of a magnetic medium include a hard disk, a floppy disk, a magnetic tape, and the like. Examples of an optical recording medium include a CD-ROM (Compact Disk Read Only Memory), DVD (Digital Versatile Disk), Blu-ray (registered trademark), and the like. Examples of a magnetic-optical medium include flexible optical disks and the like. Examples of the storage element include a RAM, a ROM, and the like. Examples of a flash memory include a USB (Universal Serial Bus) memory, and the like.

[0032] The charge / discharge control device 40 controls the power supply state of the first energy storage device 10 and the second energy storage device 20, which are connected in parallel to each other via the switching circuit ST described above, on the basis of the Fig. Connection patterns shown in 2 to 4.

[0033] For example, the charge / discharge control device 40 in the Fig. 2, the first energy storage device 10 is connected to the power supply line EL via the first switching circuit ST1. The charge / discharge control device 40 also connects the input terminal IT and the output terminal OT of the power supply line EL to the first capacitor group 20A of the second energy storage device 20 via the second switching circuit ST2. Consequently, only the first capacitor group 20A of the energy storage device 30 is connected to the load 50, so that electrical energy can be transmitted and received.

[0034] Second in Fig. 3, the charge / discharge control device 40 connects the first energy storage device 10 to the input terminal IT and the output terminal OT of the power supply line EL via the first switching circuit ST1. The charge / discharge control device 40 also connects the input terminal IT and the output terminal OT of the power supply line EL to the first capacitor group 20A of the second energy storage device 20 via the second switching circuit ST2. Consequently, the first energy storage device 10 and the first capacitor group 20A of the energy storage device 30 are connected in parallel with the load 50, so that electrical power can be supplied and received. At this time, in addition to the load 50, electrical power can also be supplied from the first energy storage device 10 to the first capacitor group 20A in the energy storage device 30.

[0035] The Fig. In the third connection pattern shown in Figure 4, the charge / discharge control device 40 disconnects the first energy storage device 10 from the power supply line EL via the first switching circuit ST1. The charge / discharge control device 40 also connects the input terminal IT and the output terminal OT of the power supply line EL to the second capacitor group 20B of the second energy storage device 20 via the second switching circuit ST2. Consequently, only the second capacitor group 20B of the energy storage device 30 is connected to the load 50, so that electrical energy can be supplied and received.

[0036] As described above, the charge / discharge control device 40 according to the present embodiment can switch at least between the states of the above-described first connection pattern and the third connection pattern via the switching circuit ST. Thus, the charge / discharge control device 40 can establish a state in which electrical energy can be supplied and received between the load 50 and the energy storage device 30. 1-2. Configuration of the charge / discharge control device

[0037] Next, the configuration of the charge / discharge control device 40 according to the present embodiment will be described with reference to Fig. 5 described.

[0038] As from Fig. 5, the charge / discharge control device 40 according to the present embodiment includes a processor 40A and a memory device 40B.

[0039] The processor 40A is formed of one or more processors, such as CPUs, and includes an acceleration information acquisition unit 41, an SOC monitor 42, a shift controller 43, and a display controller 44. Each of the units included in the processor 40A has a function realized by the above-described one or more processors executing a program. However, part of the acceleration information acquisition unit 41, the SOC monitor 42, the shift controller 43, and the display controller 44 may also be formed by a known analog circuit.

[0040] As described above, the processor 40A may be configured to communicate with the vehicle drive controller 60, which is comprised of another known in-vehicle ECU. The vehicle drive controller 60 may have the function of controlling the driving of the charge / discharge controller 40 based on detection values ​​of the known vehicle state sensors 62c. Examples of the known vehicle state sensors 62c include a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, a steering angle sensor, an accelerator pedal sensor, and a brake pedal sensor.

[0041] Furthermore, the processor 40A may be configured to communicate with a known external network NET, such as the Internet, via a known in-vehicle communication device 61.

[0042] The storage device 40B may include a known memory MR that temporarily stores information, such as a RAM, and a known hard disk HDD or SSD that can store a program and the like. The storage device 40B according to the present embodiment may also store acquired data, operation result data, and the like, in addition to a program executed by the processor 40A and various parameters used for program execution.

[0043] Hereinafter, the functions of the acceleration information detecting means 41, the SOC monitoring means 42, the shift controller 43, and the display controller 44 of the processor 40A will be briefly described, and then the processing operations performed by the respective units will be described in detail. Acceleration information acquisition device

[0044] The acceleration information acquisition device 41 performs a process for acquiring acceleration information in the vehicle 200 during travel. For example, the acceleration information acquisition device 41 detects the accelerations of the vehicle 200 during travel using an accelerometer (vehicle state sensor 62c) mounted in the vehicle 200. Note that the acceleration information acquisition device 41 may also calculate the acceleration of the vehicle 200 during travel based on the speed information from the vehicle speed sensor (another vehicle state sensor 62c) of the vehicle 200. SOC monitoring device

[0045] The SOC monitor 42 performs a process of detecting and monitoring the SOC (state of charge) of each of the first energy storage device 10 and the second energy storage device 20 mounted in the vehicle 200 via an in-vehicle current sensor 62a and an in-vehicle voltage sensor 62b. Note that a specific method for detecting the SOC by the SOC monitor 42 is not limited to a particular method as long as it does not deviate from the gist of the present embodiment. Various known SOC estimation techniques, such as those disclosed in Japanese Unexamined Patent Application Publication JP 2021-68637 A and International Publication WO 2019 / 193471 A1, can be applied. Switch control

[0046] The switching controller 43 performs a process for switching the connection state of the first energy storage device 10 and the second energy storage device 20 with respect to the above-described load 50. For example, the switching controller 43 may control the above-described switching circuit ST (the first switching circuit ST1 and the second switching circuit ST2). Thus, the connection state between the energy storage device 30 and the load 50 via the switching circuit ST may become one of the first and third connection patterns. Display control

[0047] The display controller 44 performs a process of displaying various types of information, such as the connection state of the energy storage device 30 with respect to the load 50, on a display device 63. As an example of the display device 63 according to the present embodiment, a known in-vehicle display device may be provided. Note that the display controller 44 may output the above-described various types of information by voice via an in-vehicle speaker or display the information on an external terminal such as a smartphone carried by a passenger. 1-3. Charge / discharge processing procedure of the on-vehicle power supply system having the charge / discharge control device

[0048] Next, with reference to Fig. 6 to 8, an example of a charge / discharge processing operation performed by the in-vehicle power supply system 100 having the charge / discharge control device 40 according to the present embodiment will be described.

[0049] In this example, the first energy storage device 10 is in a fully charged state (SOC 100%) as an example of an initial state of the energy storage device 30. Furthermore, the first capacitor group 20A of the second energy storage device 20 is in a fully charged state (SOC 100%). Furthermore, the second capacitor group 20B of the second energy storage device 20 is in an empty state (SOC 0%). The above-described SOC states are examples, and the SOCs in the energy storage device 30 can be specified as any initial states.

[0050] Various capacitances can be specified for the first capacitor group 20A and the second capacitor group 20B described above, as long as they do not deviate from the essence of the present embodiment. For example, the capacitances of the first capacitor group 20A and the second capacitor group 20B can be specified as a capacitance sufficient for an acceleration of 100 km / h from the start of the vehicle 200.

[0051] In this example, the second energy storage device 20 is specified as the output capacitor LiC-1 in the above-described fully charged state (SOC 100%). Furthermore, the second energy storage device 20 is specified as the input capacitor LiC-2 in the empty state (SOC 0%). Although the SOC of the output capacitor LiC-1 is specified as 100% in the present embodiment, the output capacitor does not necessarily have to have an SOC of 100%.

[0052] For example, a capacitor group with a relatively higher SOC than the other capacitor group can be specified as the output capacitor. Similarly, even if the SOC of the input capacitor LiC-2 is specified as 0% in the present embodiment, the input capacitor does not necessarily have to have a 0% SOC. For example, a capacitor group with a relatively lower SOC than the other capacitor group can be specified as the input capacitor.

[0053] Note that, in the present embodiment, the "output capacitor" among the first capacitor group 20A and the second capacitor group 20B refers to the capacitor group that preferentially supplies electrical power to the load 50. Furthermore, in the present embodiment, the "input capacitor" among the first capacitor group 20A and the second capacitor group 20B refers to the capacitor group that preferentially receives regenerative charge from the load 50. Since the "output capacitor" and the "input capacitor" are functions determined by the size of the SOC relative to the other capacitor group, the functions described above can be interchanged accordingly during operation of the vehicle 200 or the like.

[0054] In the following description, a driving pattern A and driving pattern B are used, as in Fig. 8, as examples of driving patterns of the vehicle 200.

[0055] As in Fig. 8, the driving pattern A represents the following example. The vehicle 200 starts at time t0 and accelerates until time t1, then travels at a constant speed (0 acceleration) from time t1 to time t2 and then accelerates again from time t2 to time t3.

[0056] Driving pattern B, on the other hand, represents the following example. The vehicle 200 starts at time t0 and accelerates until time t1, then drives at a constant speed (0 acceleration) from time t1 to time t2, then decelerates from time t2 (negative acceleration) and finally stops at time t3.

[0057] Also with reference to Fig. 6, the connection state between the energy storage device 30 and the load 50 in a case where the vehicle 200 travels according to the travel pattern A out of the travel patterns described above will first be described. (α) Acceleration period from time t0 to time t1

[0058] In step 1, the charging / discharging controller 40 determines whether the vehicle 200 is accelerating or decelerating. For example, the charging / discharging controller 40 may determine whether the vehicle 200 is accelerating or decelerating from time t0 to time t1 using the vehicle state sensors 62c described above. If the vehicle 200 is accelerating or decelerating in step 1, the process proceeds to step 2A.

[0059] If it is determined in step 2A that the vehicle is not accelerating but decelerating, the process continues with a Fig. 7 shown regeneration process. As in Fig. As shown in Figure 8, in this example, since the vehicle 200 is in an acceleration period from time t0 to time t1, the charge / discharge controller 40 determines whether the SOC of the output capacitor LiC-1 is sufficient in the subsequent step 3. The determination standard in step 3 may be, for example, whether there is sufficient capacity for an acceleration of 100 km / h from the start of the vehicle 200. However, the determination standard in step 3 may also be, for example, whether the SOC has a predetermined state of charge (80% or more).

[0060] As described above, in this example, since the SOC of the output capacitor LiC-1 is in the fully charged state, the charge / discharge controller 40 performs a process of connecting the output capacitor LiC-1 to the load 50 to supply electric power in step 4A. For example, in step 4A, the charge / discharge controller 40 controls the switching of the switching circuit ST to Fig. 2 to produce the first connection pattern shown.

[0061] In this way, during the acceleration period from time t0 to time t1, the above-described process is repeated, and electric power is supplied to the load 50 from the output capacitor LiC-1. In other words, the charge / discharge controller 40 disconnects the first energy storage device 10 from the load 50 of the vehicle 200 when the vehicle 200 is accelerating. Further, the charge / discharge controller 40 connects the load 50 and the first capacitor group (in this example, the output capacitor LiC-1) to each other so that the first capacitor group can discharge electric power. Thus, when the vehicle 200 is accelerating, electric power can be supplied to the load 50 from the second energy storage device 20 instead of the first energy storage device 10, and deterioration of the first energy storage device 10 is suppressed. (b) Period of constant speed from time t1 to time t2

[0062] Similar to the above, the charge / discharge controller 40 determines whether the vehicle 200 is accelerating or decelerating in step 1. In this case, since the vehicle 200 is traveling at a constant speed without accelerating or decelerating, the charge / discharge controller 40 performs control in step 2B to connect the first energy storage device 10 (lithium-ion secondary battery LiB) to the load 50 and supply electric power from the first energy storage device 10 to the load 50.

[0063] After connecting the first energy storage device 10 to the load 50 in step 2B, the charge / discharge controller 40 determines whether the SOC of the output capacitor LiC-1 is sufficient in the subsequent step 3. In this example, as described above, electric power is supplied from the output capacitor LiC-1 to the load 50 from time t0 to time t1, and the SOC of the output capacitor LiC-1 is insufficient. Thus, the process proceeds to step 4B. In step 4B, the charge / discharge controller 40 determines whether the SOC of the input capacitor LiC-2 is sufficient. Note that the determination standard in step 4B may be the same as that described above in step 3, for example.

[0064] In this example, since the SOC of the input capacitor LiC-2 is in the empty state, the charge / discharge controller 40 proceeds to step 5B, maintains the state in step 2B, and continues supplying electrical energy from the first energy storage device 10 to the load 50. After step 5B, in the subsequent step 6, the charge / discharge controller 40 performs a process for connecting the output capacitor LiC-1 to the first energy storage device 10 to charge the output capacitor LiC-1. For example, the charge / discharge controller 40 performs a process for switching the switching circuit ST to Fig. 3 to produce the second connection pattern shown.

[0065] Thus, during a low-load period in which the vehicle 200 is traveling at a constant speed, electrical energy can be supplied to the load 50 from the first energy storage device 10 and the output capacitor LiC-1. Thus, the SOC of the output capacitor LiC-1 can be restored to prepare for the next acceleration. As described above, in the present embodiment, the input capacitor LiC-2 is controlled to be in a low-charge state (in this example, the empty state) when the output capacitor LiC-1 constituting the second energy storage device 20 is in a high-charge state (in this example, the SOC is 100%).

[0066] In other words, when the vehicle 200 is neither accelerating nor decelerating, the charge / discharge controller 40 connects one of the first capacitor group and the second capacitor group to the first energy storage device 10 to charge it from the first energy storage device 10. In this way, the charge states of the first capacitor group and the second capacitor group can be in opposite states. (c) Re-acceleration period from time t2 to time t3

[0067] Similarly to the above, the charge / discharge controller 40 determines in step 1 whether the vehicle 200 is accelerating or decelerating. In this case, since the vehicle 200 begins to accelerate again, the charge / discharge controller 40 determines in step 2A that the vehicle 200 is accelerating. Further, in the subsequent step 3, the charge / discharge controller 40 determines whether the SOC of the output capacitor LiC-1 is sufficient. In this example, as described above, electrical energy is supplied from the load 50 to the output capacitor LiC-1 from time t1 to time t2, and the SOC of the output capacitor LiC-1 is sufficient. Thus, the process proceeds to step 4A, and control is performed to switch the switching circuit ST again to achieve the Fig. 2 to produce the first connection pattern shown.

[0068] In this way, during the re-acceleration period, the above-described process is repeated from time t2 to time t3, and electrical energy is again supplied to the load 50 from the output capacitor LiC-1.

[0069] As described above, the charge / discharge controller 40 according to the present embodiment controls the switching circuit ST. Thus, the first capacitor group and the second capacitor group of the second energy storage device 20 connected in parallel with the first energy storage device 10 are in different charge states (the fully charged state and the empty state). In other words, the charge / discharge controller 40 performs control such that the second capacitor group (input capacitor) is charged preferentially over the first capacitor group (output capacitor). This control is performed when the parallel-connected first capacitor group (output capacitor) discharges electrical energy preferentially over the second capacitor group (input capacitor).

[0070] Thus, even when the vehicle is traveling on an uphill road or the like where acceleration and constant speed are repeated as in the traveling pattern A, it is possible to suppress the application of the load to the first energy storage device 10 and prevent deterioration of the first energy storage device 10. The deterioration of the first energy storage device 10 can be prevented compared to the case where the second energy storage device 20 connected in parallel with the first energy storage device 10 is a single capacitor bank.

[0071] It should be noted that the following process can be performed. When the SOC of the second capacitor group enters the fully charged state by the regenerative charging of the second capacitor group described later, as shown in Fig. As shown in Figure 6, when the SOC of the output capacitor LiC-1 is insufficient, electrical energy can be supplied to the load 50 from the input capacitor LiC-2. In this way, the charge / discharge controller 40 can control the charge / discharge so that the state of charge (SOC) in the second capacitor group becomes lower than that in the first capacitor group. This control is performed when the state of charge (SOC) in the second capacitor group is higher than that in the first capacitor group.

[0072] Next, with reference to Fig. 6 and Fig. 7, the connection state between the energy storage device 30 and the load 50 in a case where the vehicle 200 travels according to the travel pattern B out of the above-described travel patterns will be described. Note that the period from time t0 to time t2 in the travel pattern B is the same as that in the above-described travel pattern A, so a repeated description thereof will be omitted. (d) Deceleration period from time t2 to time t3

[0073] Similarly to the above, the charge / discharge controller 40 determines in step 1 whether the vehicle 200 is accelerating or decelerating. In this case, the vehicle 200 begins to decelerate. Thus, in step 2A, the charge / discharge controller 40 determines that the vehicle 200 is not accelerating (ie, decelerating) and continues with the regeneration process as in step 10 according to Fig. 7 shown.

[0074] As in Fig. As shown in Figure 7, the charge / discharge controller 40 determines whether the SOC of the output capacitor LiC-1 is sufficient in step 11. Note that, for example, the determination standard described above in step 3 can also be used as the determination standard in step 11. If the SOC of the output capacitor LiC-1 is insufficient in step 11, the charge / discharge controller 40 connects the output capacitor LiC-1 to the load 50 via the switching circuit ST in step 12A. Thus, the charge / discharge controller 40 performs regenerative charging of the output capacitor LiC-1.

[0075] On the other hand, if the SOC of the output capacitor LiC-1 is sufficient in step 11, the charge / discharge controller 40 determines whether regenerative charging is possible in the input capacitor LiC-2 in the subsequent step 12B. Note that the determination standard in step 12B may be, for example, whether the input capacitor LiC-2 can be charged with a capacity sufficient for acceleration of 100 km / h from the start of the vehicle 200. The determination standard in step 12B may also be, for example, whether the SOC has a predetermined state of charge (10% or less).

[0076] If regenerative charging of the input capacitor LiC-2 is not possible in step 12B, the charge / discharge controller 40 performs a process of connecting the first energy storage device 10 to the load 50 via the switching circuit ST in the subsequent step 13B. In this case, regenerative charging from the load 50 to the first energy storage device 10 is performed during the above-described deceleration of the vehicle 200.

[0077] On the other hand, if regenerative charging of the input capacitor LiC-2 is possible in step 12B, the charge / discharge control device 40 executes a process for connecting the input capacitor LiC-2 to the load 50 via the switching circuit ST in the subsequent step 13A. In this way, the Fig. 4 is established. In other words, when the vehicle 200 decelerates, the charge / discharge control device 40 disconnects the first energy storage device 10 from the load 50 of the vehicle 200. Furthermore, the charge / discharge control device 40 connects the load 50 to the second capacitor group for regenerative charging. In this case, during the above-described deceleration of the vehicle 200, regenerative charging is performed from the load 50 to the second capacitor group 20B of the second energy storage device 20.

[0078] As in Fig.As shown in Figure 7, in step 14 following step 13A, the charge / discharge controller 40 determines whether the SOC of the input capacitor LiC-2 is sufficient. If the SOC of the input capacitor LiC-2 is determined to be sufficient in step 14, the charge / discharge controller 40 returns to step 1 and repeats the above-described process (step 15). In this way, the above-described process is repeated during the deceleration period from time t2 to time t3 of the load 50, and regenerative charging of either the first energy storage device 10 or the second energy storage device 20 is performed accordingly.

[0079] As described above, the in-vehicle power supply system 100 including the charge / discharge control device 40 according to the embodiment of the invention has the following features. When the parallel-connected first group of lithium-ion capacitors (in this example, the output capacitors) discharges electrical energy preferentially to the second group (input capacitors), the second group of lithium-ion capacitors is charged preferentially to the first group. Thus, the acceleration / deceleration of the vehicle 200 can be performed using the second energy storage device 20 formed of lithium-ion capacitors, while suppressing deterioration of the first energy storage device 10 formed of lithium-ion secondary batteries due to charging / discharging.

[0080] Although a preferred embodiment of the invention has been described in detail above with reference to the accompanying drawings, the technology of the invention is not limited to these examples. It is clear that a person skilled in the art can devise various modifications or corrections within the scope of the technical idea described in the claims. It is clear that these are naturally included within the technical scope of the invention. List of reference symbols 1 wheel 2 Power transmission mechanism 10 first energy storage device (lithium-ion secondary battery) 20 second energy storage device (lithium-ion capacitor) 30 Energy storage device 40 Charging / discharging control device 50 load 60 Vehicle drive control device 61 Communication device 62a vehicle-internal current sensor 62b vehicle-internal voltage sensor 62c Vehicle condition sensor 63 Display device 100 in-vehicle energy supply system 200 vehicles QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2014 / 156564 A1

[0004] JP 2021-68 637 A

[0045] WO 2019 / 193471 A1

[0045]

Claims

[1] On-vehicle energy supply system comprising: - a first energy storage device for installation in a vehicle, which is formed from one or more lithium-ion secondary batteries; - a second energy storage device for installation in the vehicle, which is connected in parallel to the first energy storage device, wherein the second energy storage device is constructed from a plurality of lithium-ion capacitor groups formed from a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel to one another; and - a charge / discharge control device configured to control the charge / discharge of the first energy storage device and the second energy storage device to supply electrical energy to a power source of the vehicle and to recover regenerative energy of the vehicle, - wherein the charge / discharge control device is designed to carry out such a control that the second capacitor group is charged preferentially compared to the first capacitor group connected in parallel. [2] The in-vehicle power supply system according to claim 1, wherein the charge / discharge control means is configured to, when a state of charge (SOC) in the first capacitor group is higher than a state of charge (SOC) in the second capacitor group, control the charge / discharge so that the state of charge (SOC) in the second capacitor group becomes lower than the state of charge (SOC) in the first capacitor group. [3] An in-vehicle power supply system according to claim 1 or 2, wherein the charge / discharge control device is designed to: - when the vehicle decelerates, disconnecting the first energy storage device from a load of the vehicle and connecting the load to the second capacitor group for regenerative charging, and - when the vehicle accelerates, disconnecting the first energy storage device from the vehicle load and connecting the load to the first capacitor group to discharge electrical energy from the first capacitor group. [4] A charge / discharge control device for mounting in a vehicle for controlling the charge / discharge of a first energy storage device and a second energy storage device arranged in the vehicle, wherein the first energy storage device is formed of one or more lithium-ion secondary batteries, the second energy storage device is connected in parallel to the first energy storage device and is constructed of a plurality of lithium-ion capacitor groups formed of a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel to each other, the charge / discharge control device comprising: - one or more processors, and - one or more memories communicatively connected to the one or more processors, the one or more processors being designed to: - Collecting vehicle acceleration information, - detecting state of charge information of the first energy storage device and state of charge information of the second energy storage device, and - when the parallel-connected first capacitor group discharges electrical energy preferentially to the second capacitor group, based on the acceleration information of the vehicle, performing such a control that the second capacitor group is charged preferentially to the parallel-connected first capacitor group. [5] Vehicle having: - a first energy storage device formed from one or more lithium-ion secondary batteries; - a second energy storage device connected in parallel to the first energy storage device and constructed from a plurality of lithium-ion capacitor groups formed from a first capacitor group and a second capacitor group such that one or more lithium-ion capacitors are connected in parallel to one another; - an acceleration information detecting device configured to detect acceleration information of the vehicle; - a charge state information acquisition device configured to acquire charge state information of the first energy storage device and charge state information of the second energy storage device; and - a switching controller configured to, when the parallel-connected first capacitor group discharges electrical energy preferentially to the second capacitor group, perform a control based on the acceleration information of the vehicle such that the second capacitor group is charged preferentially to the parallel-connected first capacitor group.

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