Search

EP-4357798-B1 - SHORT CIRCUIT DETECTION DEVICE AND SHORT CIRCUIT DETECTION METHOD

EP4357798B1EP 4357798 B1EP4357798 B1EP 4357798B1EP-4357798-B1

Inventors

  • Nishimura, Kota
  • IIJIMA, JUNJI

Dates

Publication Date
20260513
Application Date
20220614

Claims (7)

  1. A short circuit detection device (100) for detecting a short circuit occurring in a detection target (1), the short circuit detection device comprising: a capacitance measurement means (22) configured to measure an electrostatic capacitance value (C) of the detection target (1); a current determination means (200) configured to determine a current value (I1) of a current (I) to be supplied to the detection target (1), on the basis of the electrostatic capacitance value (C) measured by the capacitance measurement means (22); a current supply means (11) configured to supply the current (I) having the current value (I1) determined by the current determination means (200) to the detection target (1); and a detection means (140) configured to detect a short circuit in the detection target (1) while the current (I) is being supplied to the detection target (1) by the current supply means (11).
  2. The short circuit detection device (100) according to claim 1, comprising: a storage means (230) configured to store in advance a detection time (T) for detecting a short circuit in the detection target (1) by the detection means (140), wherein the current determination means (200) determines the current value (I1) of the current (I) to be supplied to the detection target (1), on the basis of the detection time (T) stored in the storage means (230) and the electrostatic capacitance value (C) measured by the capacitance measurement means (22).
  3. The short circuit detection device (100) according to claim 1 or 2, comprising: a storage means (230) configured to store a set current value (Is) set in advance, wherein the current determination means (200) determines the current value (I1) of the current (I) to be supplied to the detection target (1), on the basis of the set current value (Is) stored in the storage means (230) and the electrostatic capacitance value (C) measured by the capacitance measurement means (22), and when the set current value (Is) is equal to or less than the determined current value (I1), detects a short circuit in the detection target (1) while a current having the set current value (Is) is being supplied to the detection target (1).
  4. The short circuit detection device (100) according to any one of claims 1 to 3, wherein the current determination means (200) increases the current value (I1) of the current (I) supplied to the detection target (1) as the electrostatic capacitance value (C) increases, and decreases the current value (I1) of the current (I) supplied to the detection target (1) as the electrostatic capacitance value (C) decreases.
  5. The short circuit detection device (100) according to any one of claims 1 to 3, wherein the current determination means (200) controls the current supply means (11) such that a value obtained by dividing the electrostatic capacitance value (C) by the current value (I1) of the current (I) supplied to the detection target (1) is constant.
  6. The short circuit detection device (100) according to any one of claims 1 to 5, comprising: a storage means (230) configured to store in advance an upper limit current value (Iu) indicating an upper limit of the current (I) to be supplied to the detection target (1), wherein the current determination means (200) determines the current value (I1) of the current (I) to be supplied to the detection target (1), on the basis of the upper limit current value (Iu) stored in the storage means (230) and the electrostatic capacitance value (C) measured by the capacitance measurement means (22), and when the determined current value (I1) exceeds the upper limit current value (Iu), detects a short circuit in the detection target (1) while a current having the upper limit current value (Iu) is being supplied to the detection target (1).
  7. A short circuit detection method of detecting a short circuit occurring in a detection target (1), the short circuit detection method comprising: a capacitance measurement step of measuring an electrostatic capacitance value (C) of the detection target (1); a current determination step of determining a current value (I1) of a current (I) to be supplied to the detection target (1), on the basis of the electrostatic capacitance value (C) measured in the capacitance measurement step; a current supply step of supplying the current (I) having the current value (I1) determined in the current determination step to the detection target (1); and a detection step of detecting a short circuit in the detection target (1) while the current (I) is being supplied to the detection target (1) in the current supply step.

Description

Technical Field The present invention relates to a short circuit detection device and a short circuit detection method. Background Art JP 2020-71054 A discloses a micro-short circuit detection device that detects a micro-short circuit by measuring a voltage between two ends of a detection target while a constant current is being supplied to a lithium secondary battery. US2019/146040 discloses an arrangement for measuring the isolation resistance of a car battery, wherein the long time constants due to parasitic capacitance are taken into account by doing two measurements with switches in different positions. Summary of Invention An inspection device such as described above supplies a current to a detection target such as a lithium secondary battery. However, a current value of the current to be supplied to the detection target needs to be set for each detection target, on the basis of a rated current value of the detection target or the like. The present invention has been contrived in view of the problems mentioned above, and an object thereof is to provide a short circuit detection device and a short circuit detection method capable of detecting a short circuit occurring in a detection target, without setting, for each detection target, a current value of a current to be supplied to the detection target. According to an aspect of the present invention, a short circuit detection device for detecting a short circuit occurring in a detection target includes a capacitance measurement means configured to measure an electrostatic capacitance value of the detection target, and a current determination means configured to determine a current value of a current to be supplied to the detection target, on the basis of the electrostatic capacitance value measured by the capacitance measurement means. The short circuit detection device further includes a current supply means configured to supply the current having the current value determined by the current determination means to the detection target, and a detection means configured to detect a short circuit in the detection target while the current is being supplied to the detection target by the current supply means. According to this aspect, by measuring the electrostatic capacitance value of the detection target before supplying the current to the detection target, the current value of the current to be supplied to the detection target can be determined, on the basis of the electrostatic capacitance value. Therefore, it is possible to detect a short circuit without setting, for each detection target, the current value of the current to be supplied to the detection target. Brief Description of Drawings FIG. 1 is a block diagram illustrating a functional configuration of a short circuit detection device according to a first embodiment of the present invention.FIG. 2 is a flowchart illustrating a processing procedure of a short circuit detection method according to the first embodiment.FIG. 3 is a block diagram illustrating a modification of the short circuit detection device according to the first embodiment. Description of Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings. First Embodiment FIG. 1 is a block diagram illustrating a functional configuration of a short circuit detection device 100 according to a first embodiment. The short circuit detection device 100 detects a short circuit occurring in a detection target 1. Here, the term "short circuit" includes not only a steady short circuit but also a short-time short circuit such as short-time insulation failure and insulation deterioration caused by an abnormal situation occurring in the detection target 1. Examples of factors causing a short-time short circuit include anomalies such as a foreign metal substance being present in an electrode constituting a battery, occurrence of contamination, burr between an electrode of a battery and an exterior casing of the battery, cracks in a laminated ceramic capacitor, and micro-short circuits between substrate patterns. As described above, the short circuit detection device 100 detects a short circuit caused by the above-mentioned anomaly occurring in the detection target 1. For example, the short circuit detection device 100 is used to measure or examine the detection target 1 in which a DC electric signal is supplied (applied) to the detection target 1. The short circuit detection device 100 according to the first embodiment supplies a DC voltage to the detection target 1 to measure an insulation resistance value R of the detection target 1, on the basis of the magnitude of a leakage current output from a negative electrode (-) of the detection target 1. The detection target 1 is an object having at least capacitance of an electrostatic capacitance value C and, in a state in which a DC electric signal is supplied to the object, a voltage signal generated in the object or a current signal flowing throu