Battery system

Abstract

To provide a battery system capable of accurately determining deterioration in a battery.SOLUTION: A battery system acquires a current during charging and discharging of a battery 11, a temperature of the battery 11, and an altitude corresponding to position information indicating a position at which a vehicle 10 is located; estimates an SOC of the battery 11 based on the current and the temperature of the battery 11; calculates an internal pressure of the battery 11 based on a history of the SOC of the battery 11 and a history of the temperature of the battery 11; corrects the internal pressure of the battery 11 using an atmospheric pressure corresponding to the altitude; and accumulates an integrated damage amount of the battery using the corrected internal pressure of the battery 11 and a time during which the battery 11 maintains the corrected internal pressure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a technology in which the internal pressure of a battery and the amount of time required for battery components to reach a defective state are obtained multiple times, and for each of the multiple obtained times, the amount of internal pressure damage is calculated from creep characteristics that show the relationship between the internal pressure of the battery and the amount of time, and the deterioration of the battery components is determined based on the accumulated damage amount. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-141790 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, when a vehicle equipped with a battery is used in a high-altitude area, the internal pressure of the battery changes depending on the air pressure, so the accumulated damage to the battery is undercalculated, making it difficult to accurately determine battery deterioration, and there is room for improvement.

[0005] The present disclosure has been made in view of the above, and aims to provide a battery system that can more accurately determine battery degradation. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, the battery system of the present disclosure is a battery system that determines the deterioration of a battery installed in a vehicle, and is equipped with a processor. The processor acquires the current when the battery is charged and discharged, the temperature of the battery, and the altitude corresponding to the location information of the vehicle, estimates the SOC of the battery based on the current and the temperature, calculates the internal pressure of the battery based on the SOC history and the temperature history of the battery, corrects the internal pressure using the atmospheric pressure corresponding to the altitude, and calculates the cumulative amount of damage to the battery using the corrected internal pressure and the time the battery maintained the internal pressure. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to more accurately determine the deterioration of a battery. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a functional configuration of a vehicle according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a flowchart illustrating an outline of processing executed by a control unit according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram showing the relationship between the internal pressure and atmospheric pressure of a battery according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] A vehicle equipped with a battery system according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical. Furthermore, the drawings referred to in the following description merely show a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present disclosure can be understood. In other words, the present disclosure is not limited to the shape, size, and positional relationship exemplified in each drawing.

[0010] [Vehicle functional configuration] Fig. 1 is a block diagram showing the functional configuration of a vehicle according to one embodiment. Vehicle 10 shown in Fig. 1 is assumed to be a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV). Vehicle 10 includes battery 11, current sensor 12, temperature sensor 13, a global positioning system (GPS) sensor 14, recording unit 15, display unit 16, and control unit 17.

[0011] Battery 11 is configured using, for example, a rechargeable storage battery such as a nickel-metal hydride battery or a lithium-ion battery, or a storage element such as an electric double layer capacitor. Battery 11 supplies power to a driving source such as a motor (not shown) under the control of control unit 17.

[0012] The current sensor 12 is provided on a power line connecting the battery 11 and a driving source (not shown), detects the current of the power supplied by the battery 11, and outputs the detection result to the control unit 17. The current sensor 12 is realized using, for example, an ammeter.

[0013] Temperature sensor 13 is provided near or adjacent to battery 11, detects the temperature of battery 11, and outputs the detection result to control unit 17. Temperature sensor 13 is realized using, for example, a thermistor.

[0014] The GPS sensor 14 receives signals from multiple GPS satellites or transmitting antennas, calculates position information regarding the position (longitude and latitude) of the vehicle 10 based on the received signals, and outputs the calculation result to the control unit 17. The GPS sensor 14 is realized by using a navigation system that uses a GPS (Global Positioning System) sensor.

[0015] The recording unit 15 is configured using a recording medium such as a hard disk drive (HDD) or a solid state drive (SSD), etc. The recording unit 15 has a map information recording unit 151 that records various map data, an altitude map information recording unit 152 that records altitude map information that associates altitude with location information, and a creep characteristic information recording unit 153 that records creep characteristics that indicate the internal pressure of the battery 11 and deterioration over time.

[0016] The display unit 16 is configured using a liquid crystal display, an organic electroluminescent display (EL display), or the like, and displays various information under the control of the control unit 17.

[0017] Control unit 17 is configured using a memory and a processor having hardware such as a CPU (Central Processing Unit). Control unit 17 controls the operation of each unit constituting vehicle 10. Control unit 17 includes an acquisition unit 171, an estimation unit 172, an identification unit 173, an altitude acquisition unit 174, a calculation unit 175, a correction unit 176, an integration unit 177, a determination unit 178, and an output control unit 179. In one embodiment, control unit 17 functions as a battery system.

[0018] The acquisition unit 171 sequentially acquires the current detected by the current sensor 12 during charging and discharging of the battery 11. The acquisition unit 171 also sequentially acquires the temperature of the battery 11 detected by the temperature sensor 13.

[0019] The estimation unit 172 estimates the SOC (State of Charge) of the battery 11 based on the temperature of the battery 11 and an integrated value of the current during charging and discharging of the battery 11 sequentially acquired by the acquisition unit 171.

[0020] The identification unit 173 identifies the current position of the vehicle 10 based on the position information of the vehicle 10 detected by the GPS sensor 14 and the ground information recorded by the map information recording unit 151.

[0021] The altitude acquisition unit 174 refers to the altitude map information recorded by the altitude map information recording unit 152 and acquires the altitude corresponding to the current position of the vehicle 10 identified by the identification unit 173. The calculation unit 175 calculates the internal pressure of the battery 11 based on the SOC of the battery 11 estimated by the estimation unit 172, the temperature of the battery 11 acquired by the acquisition unit 171, and the creep characteristic information recorded by the creep characteristic information recording unit 153.

[0022] The correction unit 176 corrects the internal pressure of the battery 11 using the internal pressure of the battery 11 calculated by the calculation unit 175, the atmospheric pressure for the altitude corresponding to the current position of the vehicle 10 acquired by the altitude acquisition unit 174, and correction information indicating the relationship between the internal pressure of the battery 11 and the atmospheric pressure.

[0023] The accumulating unit 177 calculates the accumulated damage value of the battery 11 using the internal pressure of the battery 11 corrected by the correcting unit 176 and the time during which this internal pressure is maintained (hereinafter simply referred to as "existence time"), and accumulates the accumulated damage amount of the battery 11.

[0024] The determining unit 178 determines whether or not the accumulated damage amount accumulated by the accumulating unit 177 is equal to or less than a threshold value.

[0025] The output control unit 179 notifies the driver of the vehicle 10 of the deterioration of the battery 11 by displaying the deterioration on the display unit 16.

[0026] [Processing of the control section] Next, a description will be given of the processing executed by the control unit 17. Fig. 2 is a flowchart showing an outline of the processing executed by the control unit 17.

[0027] As shown in FIG. 2, first, the acquisition unit 171 sequentially acquires the current detected by the current sensor 12 during charging and discharging of the battery 11 (step S101), and sequentially acquires the temperature of the battery 11 detected by the temperature sensor 13 (step S102).

[0028] Next, the estimation unit 172 estimates the SOC of the battery 11 based on the integrated value of the current during charging and discharging of the battery 11 sequentially acquired by the acquisition unit 171 and the temperature of the battery 11 (step S103).

[0029] Thereafter, the identification unit 173 identifies the current position of the vehicle 10 based on the position information of the vehicle 10 detected by the GPS sensor 14 and the ground information recorded by the map information recording unit 151 (step S104).

[0030] Next, the altitude acquisition unit 174 refers to the altitude map information recorded by the altitude map information recording unit 152, and acquires the altitude corresponding to the current position of the vehicle 10 identified by the identification unit 173 (step S105).

[0031] Then, the calculation unit 175 calculates the internal pressure of the battery 11 based on the SOC of the battery 11 estimated by the estimation unit 172, the temperature of the battery 11 acquired by the acquisition unit 171, and the creep characteristic information recorded by the creep characteristic information recording unit 153 (step S106).

[0032] Next, the correction unit 176 corrects the internal pressure of the battery 11 based on the internal pressure of the battery 11 calculated by the calculation unit 175, the atmospheric pressure for the altitude corresponding to the current location of the vehicle 10 acquired by the altitude acquisition unit 174, and correction information indicating the relationship between the internal pressure of the battery 11 and the atmospheric pressure (step S107). FIG. 3 is a diagram showing the relationship between the internal pressure of the battery 11 and the atmospheric pressure. In FIG. 3, the vertical axis represents pressure, bar graph B1 represents the battery internal pressure, and bar graph B2 represents the atmospheric pressure. As shown in FIG. 3, the correction unit 176 corrects the internal pressure of the battery 11 by adding a value obtained by subtracting the atmospheric pressure from 1 atmosphere (+1 atmosphere - atmospheric pressure) to the internal pressure of the battery 11 based on the internal pressure of the battery 11 calculated by the calculation unit 175, the atmospheric pressure for the altitude corresponding to the current location of the vehicle 10 acquired by the altitude acquisition unit 174, and correction information indicating the relationship between the internal pressure of the battery 11 and the atmospheric pressure.

[0033] Thereafter, the accumulating unit 177 calculates an accumulated damage value for the battery 11 using the internal pressure of the battery 11 corrected by the correcting unit 176 and the time during which this internal pressure is maintained (hereinafter simply referred to as "existence time"), and accumulates the accumulated damage amount for the battery 11 (step S108). Specifically, the accumulating unit 177 calculates and accumulates the accumulated damage amount using the internal pressure of the battery 11 corrected by the correcting unit 176 and the existence time during which this internal pressure of the battery 11 is maintained, for example, if the internal pressure is maintained for 5 hours, a value obtained by dividing this internal pressure by the existence time.

[0034] The determination unit 178 determines whether the amount of accumulated damage accumulated by the accumulating unit 177 is equal to or less than a threshold value (step S109). If the determination unit 178 determines that the amount of accumulated damage accumulated by the accumulating unit 177 is equal to or less than the threshold value (step S109: Yes), the control unit 17 proceeds to step S110, which will be described later. On the other hand, if the determination unit 178 determines that the amount of accumulated damage accumulated by the accumulating unit 177 is not equal to or less than the threshold value (step S109: No), the control unit 17 proceeds to step S111, which will be described later.

[0035] In step S110, the determination unit 178 determines whether or not the determination of deterioration of the battery 11 is to be ended due to the vehicle 10 being stopped (step S110). If the determination unit 178 determines that the determination of deterioration of the battery 11 is to be ended (step S110: Yes), the control unit 17 ends this process. On the other hand, if the determination unit 178 determines that the determination of deterioration of the battery 11 is not to be ended (step S110: No), the control unit 17 returns to step S101.

[0036] In step S111, the output control unit 179 notifies the driver of the vehicle 10 of the deterioration of the battery 11 by displaying the deterioration on the display unit 16 (step S111). After step S111, the control unit 17 ends this process.

[0037] According to the embodiment described above, the correction unit 176 corrects the internal pressure of the battery 11 based on the internal pressure of the battery 11, the atmospheric pressure for the altitude corresponding to the current position of the vehicle 10 acquired by the altitude acquisition unit 174, and correction information indicating the relationship between the internal pressure of the battery 11 and the atmospheric pressure, and the accumulator 177 calculates the accumulated damage value of the battery 11 using the internal pressure of the battery 11 corrected by the correction unit 176 and the duration over which this internal pressure is maintained, and accumulates the accumulated damage amount of the battery 11, thereby making it possible to more accurately determine battery deterioration.

[0038] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0039] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0040] 10 vehicles 11 Batteries 12 Current Sensor 13 Temperature Sensor 14 GPS sensor 15 Recording section 16 Display 17 Control Unit 151 Map information recording section 152 Elevation map information recording section 153 Creep characteristic information recording section 171 Acquisition Department 172 Estimation Department 173 Specific section 174 Elevation acquisition section 175 Calculation Unit 176 Correction Unit 177 Integration Department 178 Judgment Department 179 Output control section

Claims

[Claim 1] A battery system for determining deterioration of a battery mounted in a vehicle, a processor; The processor: acquiring a current during charging and discharging of the battery, a temperature of the battery, and an altitude corresponding to location information of the vehicle; estimating a SOC of the battery based on the current and the temperature; Calculating an internal pressure of the battery based on the history of the SOC and the history of the temperature of the battery; correcting the internal pressure using the atmospheric pressure corresponding to the altitude; accumulating the amount of damage to the battery using the corrected internal pressure and the time during which the battery maintained the internal pressure; Battery system.

Images