US-12618908-B2 - Vehicle power supply system

US12618908B2US 12618908 B2US12618908 B2US 12618908B2US-12618908-B2

Abstract

A vehicle power supply system including a battery that supplies electric power to an in-vehicle load, comprising: an acquisition unit that acquires information on discharging of a battery; a derivation unit that derives a current life discharge amount of the battery based on information on discharging of the battery acquired by the acquisition unit and a correlation between a discharge depth of the battery and a life discharge amount; and an calculation unit that calculates data related to determination of a softening deterioration state of the battery based on the current life discharge amount of the battery derived by the derivation unit and information on discharging of the battery acquired by the acquisition unit.

Inventors

Masaaki Kyo

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20230908
Priority Date: 20221116

Claims (3)

1 . A vehicle power supply system comprising: a battery that supplies electric power to an in-board load of a vehicle; and a processor configured to perform a process related to a softening deterioration state of the battery in response to an ignition switch of the vehicle being turned on, wherein the process includes acquiring information on discharging of the battery that includes information on a plurality of actual depths of discharge performed by the battery, deriving a current lifetime discharge amount of the battery by specifying an actual depth of discharge that satisfies a predetermined condition from among the plurality of actual depths of discharge, and applying the specified actual depth of discharge to a correlation between a depth of discharge and a lifetime discharge amount of the battery that is created in advance, and calculating data related to determination of the softening deterioration state of the battery, based on the derived current lifetime discharge amount of the battery and the acquired information on the discharging of the battery, wherein the information on the discharging of the battery includes an accumulated discharge amount of the battery, and the number of occurrences of each of the plurality of the actual depths of discharge, the data related to determination of the softening deterioration state of the battery is a softening deterioration rate of the battery the softening deterioration rate of the battery is calculated based on the accumulated discharge amount of the battery and the current lifetime discharge amount of the battery, and the predetermined condition is that a depth of discharge is maximum among actual depths at which the battery has been discharged at least a predetermined number of times.
2 . The vehicle power supply system according to claim 1 , wherein the softening deterioration rate of the battery is a ratio of the accumulated discharge amount of the battery to the current lifetime discharge amount of the battery.
3 . The vehicle power supply system according to claim 1 , wherein the correlation is created based on at least one of the depth of discharge of the battery, a capacity and characteristics of the battery, or performance required for a vehicle on which the battery is mounted.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2022-183300 filed on Nov. 16, 2022, incorporated herein by reference in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a power supply system mounted on a vehicle. 2. Description of Related Art Japanese Unexamined Patent Application Publication No. 2019-078572 (JP 2019-078572 A) discloses a power supply system capable of accurately determining softening deterioration of a lead battery used for supplying electric power to an electric load of a vehicle. In the power supply system, the charge amount, the discharge amount, and the depth of discharge of the lead battery are each acquired, and the softening deterioration of the lead battery is determined based on the charge amount, the discharge amount, and the depth of discharge of the lead battery that are acquired. SUMMARY A lifetime discharge amount of a battery that serves as a reference for determining softening deterioration of the battery is estimated by, for example, a single-piece test of the battery. However, the discharge pattern used in the single-piece test of the battery is generally a pattern in which the depth of discharge is constant. Therefore, there is an issue that the lifetime discharge amount estimated by the single-piece test of the battery deviates from a lifetime discharge amount based on the depth of discharge of various patterns actually occurred in the vehicle used in the market. Therefore, there is room for further study on a method for accurately determining the softening deterioration of the battery. The present disclosure has been made in view of the above issue, and an object of the present disclosure is to provide a vehicle power supply system capable of improving accuracy of data related to determination of a softening deterioration state of a battery. In order to solve the above issue, an aspect of the present disclosure includes a vehicle power supply system including a battery that supplies electric power to an in-board load. The vehicle power supply system includes: an acquisition unit that acquires information on discharging of the battery; a derivation unit that derives a current lifetime discharge amount of the battery based on the information on the discharging of the battery acquired by the acquisition unit and a correlation between a depth of discharge and a lifetime discharge amount of the battery; and a calculation unit that calculates data related to determination of a softening deterioration state of the battery, based on the current lifetime discharge amount of the battery derived by the derivation unit and the information on the discharging of the battery acquired by the acquisition unit. In the vehicle power supply system according to the present disclosure, the data related to the determination of the softening deterioration state of the battery is calculated based on the correlation between the information on the discharging of the battery, and the depth of discharge and the lifetime discharge amount of the battery. As a result, it is possible to improve the accuracy of the data related to the determination of the softening deterioration state of the battery. BRIEF DESCRIPTION OF THE DRAWINGS Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: FIG. 1 is a schematic configuration diagram of a vehicle power supply system according to an embodiment of the present disclosure; FIG. 2 is a table diagram showing the correspondence between the actual discharge depth and the number of occurrences of the battery; FIG. 3 is a graph showing the correlation between the discharge depth of the battery and the lifetime discharge amount; and FIG. 4 is a processing flowchart of a softening degradation rate calculation of a battery executed by the vehicle power supply system. DETAILED DESCRIPTION OF EMBODIMENTS The vehicle power supply system of the present disclosure derives a life discharge amount of a battery at present based on a history of a discharge depth generated in a current battery and a correlation between a discharge depth of the battery and a life discharge amount obtained in advance by simulation or the like. Then, the softening degradation rate of the battery is calculated from the derived current life discharge amount of the battery and the previous accumulated discharge amount of the battery. Accordingly, it is possible to improve the accuracy of determining the softening deterioration state of the battery. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. Embodiment Configuration FIG. 1 is a schematic diagram for explaining a configuration example of a vehicle power supply system 100 according to an embodiment of the present disclosure.