US-12623546-B2 - Storage battery control apparatus

US12623546B2US 12623546 B2US12623546 B2US 12623546B2US-12623546-B2

Abstract

A power supply system includes a storage battery and first and second current sensors for detecting electric current flowing to the storage battery. The second current sensor has a wider current detection range than the first current sensor. A storage battery control apparatus includes: an abnormality determination unit that determines whether an abnormality has occurred in the first current sensor; a first charging control unit that performs, when no abnormality has occurred in the first current sensor, a charging completion determination based on the electric current detected by the first current sensor; and a second charging control unit that performs, when an abnormality has occurred in the first current sensor, the charging completion determination based on the electric current detected by the second current sensor. The first charging control unit and the second charging control unit have different determination criteria for determining completion of the charging of the storage battery.

Inventors

Ryuta Yamaguchi
Yamato Utsunomiya

Assignees

DENSO CORPORATION

Dates

Publication Date: 20260512
Application Date: 20230109
Priority Date: 20200710

Claims (9)

1 . A storage battery control apparatus to be applied to a power supply system, the power supply system comprising a storage battery and first and second current sensors that detect electric current inputted/outputted to/from the storage battery, the first current sensor having a first current detection range, the second current sensor having a second current detection range that is wider than the first current detection range, the storage battery control apparatus being configured to perform a charging completion determination when the storage battery is charged by a charging apparatus, the storage battery control apparatus comprising: an abnormality determination unit that determines whether an abnormality has occurred in the first current sensor; a first charging control unit that performs, when it is determined by the abnormality determination unit that no abnormality has occurred in the first current sensor, the charging completion determination based on the electric current detected by the first current sensor; and a second charging control unit that performs, when it is determined by the abnormality determination unit that an abnormality has occurred in the first current sensor, the charging completion determination based on the electric current detected by the second current sensor, wherein a determination criterion with which the first charging control unit performs the charging completion determination is different from a determination criterion with which the second charging control unit performs the charging completion determination.
2 . The storage battery control apparatus as set forth in claim 1 , wherein: the first charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the first current sensor having become lower than or equal to a first threshold value; and the second charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the second current sensor having become lower than or equal to a second threshold value larger than the first threshold value.
3 . The storage battery control apparatus as set forth in claim 2 , wherein: the storage battery control apparatus controls the charging of the storage battery by the charging apparatus so that constant-current charging is first performed and then constant-voltage charging is performed; in the constant-current charging, the storage battery is charged with the charging current of the charging apparatus kept at a constant value; in the constant-voltage charging, the storage battery is charged with the charging voltage of the charging apparatus kept at a constant value; and a target voltage in the constant-voltage charging is set to be lower when the charging completion determination is performed by the second charging control unit than when the charging completion determination is performed by the first charging control unit.
4 . The storage battery control apparatus as set forth in claim 1 , wherein: the storage battery control apparatus controls the charging of the storage battery by the charging apparatus so that constant-current charging is first performed and then constant-voltage charging is performed; in the constant-current charging, the storage battery is charged with the charging current of the charging apparatus kept at a constant value; in the constant-voltage charging, the storage battery is charged with the charging voltage of the charging apparatus kept at a constant value; the first charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the first current sensor having become lower than or equal to a first threshold value; and the second charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the second current sensor having become lower than or equal to a second threshold value larger than the first threshold value or to a predetermined time having elapsed from the start of the constant-voltage charging, whichever comes first.
5 . The storage battery control apparatus as set forth in claim 1 , wherein: the storage battery control apparatus controls the charging of the storage battery by the charging apparatus so that constant-current charging is first performed and then constant-voltage charging is performed; in the constant-current charging, the storage battery is charged with the charging current of the charging apparatus kept at a constant value; in the constant-voltage charging, the storage battery is charged with the charging voltage of the charging apparatus kept at a constant value; the charging mode of the storage battery is selectable between a normal charging mode and a rapid charging mode; the first charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the first current sensor having become lower than or equal to a first threshold value; when the charging mode is the normal charging mode, the second charging control unit determines that the charging of the storage battery has been completed in response to the electric current detected by the second current sensor having become lower than or equal to a second threshold value larger than the first threshold value; and when the charging mode is the rapid charging mode, the second charging control unit determines that the charging of the storage battery has been completed in response to the constant-current charging having been completed.
6 . The storage battery control apparatus as set forth in claim 2 , further comprising a correction unit that acquires, when the charging completion determination has been performed by the second charging control unit using the second threshold value, a terminal voltage of the storage battery after the completion of the charging of the storage battery and corrects the second threshold value based on the acquired terminal voltage of the storage battery.
7 . The storage battery control apparatus as set forth in claim 3 , further comprising a correction unit that acquires, when the charging completion determination has been performed by the second charging control unit using the second threshold value, a terminal voltage of the storage battery after the completion of the charging of the storage battery and corrects the second threshold value based on the acquired terminal voltage of the storage battery.
8 . The storage battery control apparatus as set forth in claim 4 , further comprising a correction unit that acquires, when the charging completion determination has been performed by the second charging control unit using the second threshold value, a terminal voltage of the storage battery after the completion of the charging of the storage battery and corrects the second threshold value based on the acquired terminal voltage of the storage battery.
9 . The storage battery control apparatus as set forth in claim 5 , further comprising a correction unit that acquires, when the charging completion determination has been performed by the second charging control unit using the second threshold value, a terminal voltage of the storage battery after the completion of the charging of the storage battery and corrects the second threshold value based on the acquired terminal voltage of the storage battery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation application of International Application No. PCT/JP2021/023666 filed on Jun. 22, 2021, which is based on and claims priority from Japanese Patent Application No. 2020-119244 filed on Jul. 10, 2020. The entire contents of these applications are incorporated by reference into the present application. BACKGROUND 1. Technical Field The present disclosure relates to storage battery control apparatuses. 2. Description of Related Art There is known a charging control apparatus for a storage battery that is included in a power supply system of a vehicle and can be charged by a charging apparatus provided outside the vehicle. The charging control apparatus includes a current detection unit having at least one current sensor for detecting electric current inputted to the storage battery and configured to output first and second detected values of the electric current. The first detected value has a first resolution, whereas the second detected value has a second resolution higher than the first resolution. When charging power calculated using the first detected value exceeds a predetermined limit value, the charging control apparatus controls a charger so as to reduce the charging power. Otherwise, the charging control apparatus controls, based on charging power calculated using the second detected value, the charger so as to bring the storage battery into a predetermined fully-charged state. SUMMARY According to the present disclosure, there is provided a storage battery control apparatus to be applied to a power supply system. The power supply system includes a storage battery and first and second current sensors that detect electric current inputted/outputted to/from the storage battery. The first current sensor has a first current detection range, whereas the second current sensor has a second current detection range that is wider than the first current detection range. The storage battery control apparatus is configured to perform a charging completion determination when the storage battery is charged by a charging apparatus. The storage battery control apparatus includes: an abnormality determination unit that determines whether an abnormality has occurred in the first current sensor; a first charging control unit that performs, when it is determined by the abnormality determination unit that no abnormality has occurred in the first current sensor, the charging completion determination based on the electric current detected by the first current sensor; and a second charging control unit that performs, when it is determined by the abnormality determination unit that an abnormality has occurred in the first current sensor, the charging completion determination based on the electric current detected by the second current sensor. Moreover, a determination criterion with which the first charging control unit performs the charging completion determination is different from a determination criterion with which the second charging control unit performs the charging completion determination. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a power supply system of a vehicle, which includes a storage battery control apparatus according to a first embodiment. FIG. 2 is a timing chart illustrating CC charging and CV charging. FIG. 3 is a flowchart illustrating steps of a charging control process according to the first embodiment. FIG. 4 is a flowchart illustrating steps of a charging control process according to a second embodiment. FIG. 5 is a flowchart illustrating steps of a charging control process according to a third embodiment. FIG. 6 is a flowchart illustrating steps of a charging control process according to a fourth embodiment. FIG. 7 is a flowchart illustrating steps of a correction process for correcting a second threshold value according to a fifth embodiment. FIG. 8 is a flowchart illustrating steps of a setting process for setting a second threshold value according to a modification. FIG. 9 is a graph illustrating the relationship between the storage battery deterioration degree and the second threshold value in the modification. DESCRIPTION OF EMBODIMENTS The inventors of the present application have found that the charging control apparatus known in the art (see, for example, Japanese Patent Application Publication No. JP2011050175A) may involve the following problem. That is, if an abnormality occurs in the at least one current sensor, it may become impossible to detect the electric current inputted to the storage battery; thus, it may become difficult to suitably charge the storage battery. The present disclosure has been accomplished in view of the above problem. In the above-described storage battery control apparatus according to the present disclosure, when an abnormality has occurred in the first current sensor, the storage battery control apparatus uses the second current sensor instead of the fi