CN-122003796-A - Vehicle-mounted capacitor device

CN122003796ACN 122003796 ACN122003796 ACN 122003796ACN-122003796-A

Abstract

When the main power supply (7) is abnormal, the vehicle-mounted capacitor device (18) outputs the power of the capacitor (19) as a standby power supply for the main power supply (7). A capacitance calculation unit (26) calculates or acquires the current flowing through the capacitor (19) during the charging period and the voltage variation of the capacitor (19) generated during the sampling period of the current, and calculates the capacitance of the capacitor (19) based on the current and the voltage variation. A deterioration determination unit (28) determines deterioration of the capacitor (19) based on the capacitance calculated by the capacitance calculation unit (26). A deterioration determination unit (28) uses the result of the calculation by the capacitance calculation unit (26) that satisfies the condition that the voltage change amount is equal to or greater than a threshold value to perform deterioration determination.

Inventors

Kawamura breath
Koshi Yuya

Assignees

住友电装株式会社

Dates

Publication Date: 20260508
Application Date: 20241024
Priority Date: 20231025

Claims (8)

1. An in-vehicle capacitor device having a capacitor that is charged by a main power supply when a main power supply voltage supplied from the main power supply on a vehicle is equal to or greater than a predetermined value, and that outputs power of the capacitor as a backup power supply of the main power supply when the main power supply is abnormal, the in-vehicle capacitor device comprising: A capacitance calculation unit for calculating or acquiring a current flowing through the capacitor during a charging period and a voltage variation of the capacitor generated during a sampling period of the current, and calculating a capacitance of the capacitor based on the current and the voltage variation, and A deterioration determination unit configured to determine deterioration of the capacitor based on the capacitance calculated by the capacitance calculation unit, The degradation determination unit performs degradation determination using the calculation result of the capacitance calculation unit that satisfies the condition that the voltage change amount is equal to or greater than a threshold value.
2. The vehicle-mounted capacitor device according to claim 1, wherein, The degradation determination unit performs degradation determination using the calculation result of the capacitance calculation unit that satisfies the condition that the sampling time of the current is equal to or longer than a threshold value.
3. The vehicle-mounted capacitor device according to claim 1, wherein, The capacitance calculation unit discards the calculation result when the calculation does not satisfy the condition, The degradation determination unit performs degradation determination using a past operation result when the capacitance operation unit discards the operation result.
4. The vehicle-mounted capacitor device according to claim 1, wherein, The degradation determination unit obtains an average value of the plurality of capacitances calculated by the capacitance calculation unit at each charge, and performs degradation determination using the average value.
5. The vehicle-mounted capacitor device according to claim 1, wherein, The capacitance calculating unit obtains the current and the voltage change amount while avoiding a transition region at the start of charging.
6. The vehicle-mounted capacitor device according to claim 1, wherein, The capacitance calculating unit calculates or obtains a total amount of current flowing through the capacitor during the sampling period, and divides the total amount of current by the voltage variation amount, thereby calculating the capacitance.
7. The vehicle-mounted capacitor device according to claim 1, wherein, The capacitor supplies power to the standby object device, The standby object device includes at least one of a running gear system electric device related to running of a vehicle and a locking/unlocking gear system electric device related to locking/unlocking of a door of the vehicle.
8. The vehicle-mounted capacitor device according to claim 1, wherein, The vehicle on which the capacitor is mounted has an engine as a running drive source, The main power supply voltage fluctuates due to cranking at the time of engine start.

Description

Vehicle-mounted capacitor device Technical Field The present invention relates to a vehicle-mounted capacitor device. Background Conventionally, as disclosed in patent document 1, a vehicle-mounted power supply device capable of detecting degradation of a power storage unit of a backup power supply in a vehicle is known. In patent document 1, it is determined that the power storage unit is in a degraded state when the capacitance of the power storage unit determined based on the output voltage value detected by the voltage detection unit and the resistance value of the constant load unit is equal to or less than a certain value. Prior art literature Patent literature Patent document 1, japanese patent application laid-open No. 2018-164323. Disclosure of Invention Problems to be solved by the invention However, in such a vehicle-mounted power supply device, there is a demand for determining the degradation state of the power storage unit of the backup power supply with higher accuracy. The purpose of the present disclosure is to provide a vehicle-mounted capacitor device that can improve the accuracy of determining whether or not a capacitor has deteriorated. Means for solving the problems The vehicle-mounted capacitor device for solving the problem comprises a capacitor charged by a main power supply when the main power supply voltage supplied from the main power supply of a vehicle is equal to or higher than a predetermined value, and outputs the power of the capacitor as a standby power supply of the main power supply when the main power supply is abnormal, wherein the vehicle-mounted capacitor device comprises a capacitance calculation unit for calculating or acquiring a current flowing through the capacitor during charging and a voltage variation of the capacitor generated during sampling of the current, and calculating the capacitance of the capacitor based on the current and the voltage variation; and a degradation determination unit configured to determine degradation of the capacitor based on the capacitance calculated by the capacitance calculation unit, wherein the degradation determination unit performs degradation determination using a calculation result of the capacitance calculation unit that satisfies a condition that the voltage change amount is equal to or greater than a threshold value. Effects of the invention The present disclosure can improve the accuracy of determining whether or not a capacitor is degraded. Drawings Fig. 1 is a block diagram of a vehicle-mounted capacitor device according to an embodiment. Fig. 2 is a waveform diagram of the capacitor current and the capacitor voltage. Fig. 3 is a waveform diagram of the main power supply voltage. Fig. 4 is a waveform diagram of the main power supply voltage, the capacitor voltage, and the capacitor current. Fig. 5 is a waveform diagram of the main power supply voltage, the capacitor voltage, and the capacitor current. Fig. 6 is a table showing the relationship of the driving cycle and the capacitance. Detailed Description First, embodiments of the present disclosure are listed and described. [1] The vehicle-mounted capacitor device comprises a capacitor charged by a main power supply when the main power supply voltage supplied from the main power supply is equal to or higher than a predetermined value, and outputs the power of the capacitor as a standby power supply of the main power supply when the main power supply is abnormal, wherein the vehicle-mounted capacitor device comprises a capacitance calculation unit for calculating or acquiring a current flowing through the capacitor during charging and a voltage variation of the capacitor generated during sampling of the current, and calculating the capacitance of the capacitor based on the current and the voltage variation; and a degradation determination unit configured to determine degradation of the capacitor based on the capacitance calculated by the capacitance calculation unit, wherein the degradation determination unit performs degradation determination using a calculation result of the capacitance calculation unit that satisfies a condition that the voltage change amount is equal to or greater than a threshold value. According to this configuration, since the charging of the capacitor is performed on the condition that the main power supply voltage is equal to or higher than the predetermined value, the charging is forcibly stopped when the main power supply voltage drops below the predetermined value. In this case, since the charging is completed in the middle, a sufficient sampling number of the current of the capacitor cannot be ensured. Therefore, the capacitance of the capacitor cannot be calculated or obtained with high accuracy, and the accuracy of the degradation determination becomes low. Incidentally, in the case where the charging of the capacitor is forcibly ended, the amount of voltage change should be small because of insufficient charging time. In view of this,