Short circuit detection device, short circuit detection method, and program

Abstract

A short-circuit detection device for detecting a short circuit occurring in a secondary battery as a detection object according to the present invention supplies a voltage of a predetermined voltage value until a predetermined charging completion condition is satisfied after charging the detection object. And measures a signal generated in the object to be detected due to the supply of the current or the voltage. The short circuit detection device stops the supply of the voltage of the predetermined voltage value when a short circuit is detected on the basis of the measured signal at least during the supply of the voltage of the predetermined voltage value.

Description

Technical Field

[0001] The present invention relates to a short-circuit detection device, a short-circuit detection method, and a program for detecting a short circuit occurring in a secondary battery as a detection object. Background Art

[0002] JP2020-071054A discloses an inspection device for charging a secondary battery as an inspection object to a target voltage. The inspection device determines that a micro short circuit has occurred in the inspection object when the voltage of the inspection object reaches a predetermined voltage change during the charging period, and stops charging when the number of micro short circuits determined to have occurred exceeds a predetermined number. Summary of the invention

[0003] The inspection device detects a short circuit occurring in the inspection object while performing constant current and constant voltage charging in which the charging method is switched from constant current to constant voltage during the charging period of the inspection object.

[0004] Regarding such short circuit of the detection object, the inventor of the present application has found that short circuit may sometimes occur by continuing to supply voltage to the detection object even after the charging period of constant current and constant voltage charging. However, if short circuit detection can be performed after the charging period in addition to the charging period, the influence of the short circuit on the characteristics or performance may be accumulated in the detection object, which may cause the yield of the detection object to deteriorate.

[0005] The present invention is completed with an eye on such a problem, and its purpose is to detect a short circuit occurring in a detection object even after a charging period, and to suppress a reduction in the yield rate of the detection object. Here, the charging period refers to a period during which the detection object is charged by a charging method such as constant current charging, constant voltage charging, constant current constant voltage charging, etc. until a prescribed charging end condition is met.

[0006] According to a certain embodiment of the present invention, a short circuit detection device for detecting a short circuit occurring in a secondary battery as a detection object includes: a charging unit that supplies a current or voltage to the detection object for charging until a specified charging termination condition is satisfied; a supply unit that supplies a voltage of a specified voltage value after the charging; and a measuring unit that measures a signal generated by the supply unit in the detection object. Furthermore, the short circuit detection device includes a stop processing unit that stops supplying the voltage when the short circuit is detected based on the signal measured by the measuring unit, at least during the period when the supply unit supplies the voltage of the specified voltage value.

[0007] According to this scheme, the short-circuit detection device supplies voltage to the detection object even after the charging period of the secondary battery as the detection object. Moreover, when the short-circuit detection device detects a short circuit in the detection object at least after the charging period, it stops supplying voltage to the detection object, thereby suppressing the influence on the characteristics or performance of the detection object.

[0008] Therefore, the short-circuit detection device can detect a short circuit occurring in the detection object even after the charging period, and can suppress a decrease in the yield of the detection object.

[0009] Furthermore, compared with a configuration in which the voltage is continuously supplied to the detection object until a predetermined time has elapsed even after the charging period, the time required for detecting a short circuit can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a block diagram showing the functional configuration of the short-circuit detection device according to the first embodiment of the present invention.

[0011] Figure 2 This is a circuit diagram showing a configuration example of a current measuring unit and a fluctuation detection circuit in a short-circuit detection device.

[0012] Figure 3A It is a diagram showing an example of changes in a measurement signal input to a change detection circuit.

[0013] Figure 3B It is used for Figure 3A FIG. 2 is a diagram for explaining the relationship between the variation of the measurement signal and the output of the variation detection circuit.

[0014] Figure 4 This is a diagram for explaining a method of detecting a change in a measurement signal indicating the magnitude of a voltage between two electrodes of a detection object.

[0015] Figure 5 This is a diagram for explaining a method of detecting a change in a measurement signal indicating the magnitude of a leakage current of a detection target object.

[0016] Figure 6 1 is a flowchart showing the short circuit detection method according to the first embodiment.

[0017] Figure 7 This is a flowchart showing an example of a processing procedure of a supply stop process included in the short-circuit detection method.

[0018] Fig. 8A This is a diagram for explaining a method of stopping voltage supply to a detection target object when a short circuit is detected during charging.

[0019] Figure 8BThis is a diagram for explaining a method of stopping voltage supply to a detection target object when a short circuit is detected during a steady-state period.

[0020] Fig. 9 It is a block diagram showing the functional configuration of a processing unit constituting the short-circuit detection device according to the second embodiment.

[0021] Fig. 10A This is a diagram for explaining the operation of the digital detection unit of the processing unit according to the third embodiment.

[0022] Fig. 10B It is a diagram for explaining the operation of the fluctuation detection circuit according to the third embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In this specification, the same elements are denoted by the same reference numerals throughout.

[0024] (First Embodiment)

[0025] Figure 1 1 is a block diagram showing the functional configuration of the short-circuit detection device 100 according to the first embodiment.

[0026] The short circuit detection device 100 is a device for detecting a short circuit occurring in the detection object 1. The short circuit mentioned here includes not only a steady-state short circuit but also a short-term short circuit such as an instantaneous insulation failure or insulation degradation caused by an abnormality occurring in the detection object 1.

[0027] The main causes of short-term short circuits include, for example, the mixing of metallic foreign matter in the electrodes constituting the battery, the generation of contamination, burrs between the battery electrodes and the battery casing, cracks in the stacked ceramic capacitors, and micro short circuits between substrate patterns.

[0028] Thus, the short-circuit detection device 100 detects a short circuit caused by the above-mentioned abnormality occurring in the inspection object 1. For example, the short-circuit detection device 100 is used for inspection, measurement, or testing such as supplying (applying) an electrical signal such as a DC voltage or current to the inspection object 1.

[0029] The short circuit detection device 100 of the first embodiment configures an insulation resistance device that supplies a DC voltage to the detection target 1 and measures the insulation resistance R of the detection target 1 based on the magnitude of a leakage current output from a negative electrode (−) of the detection target 1 .

[0030] The detection object 1 is an object having at least a capacitance C. When an abnormality occurs in the object while a DC electric signal is supplied to the object, a voltage signal generated in the object or a current signal flowing through the object temporarily changes.

[0031] Hereinafter, the above-mentioned electric signal rising from the standard level and then falling is referred to as "temporary rise", and the electric signal falling from the standard level and then rising is referred to as "temporary fall". In addition, these temporary changes are also simply referred to as "changes".

[0032] As the detection object 1, for example, a secondary battery can be cited. A secondary battery is a storage battery configured to be chargeable and dischargeable, and is a storage device including a capacitor-type storage element such as an electric double layer capacitor. A secondary battery can be an assembled battery formed by connecting a plurality of unit batteries in parallel, in series, or in series and parallel, or can be a single battery.

[0033] Examples of secondary batteries include lead acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, metal lithium batteries, lithium ion batteries, lithium ion polymer batteries, lithium ion all-solid batteries, sodium ion batteries, etc. In addition, aqueous solution-based electric double layer capacitors or aqueous solution-based electric double layer capacitors can also be used as secondary batteries.

[0034] The detection target 1 of the first embodiment is a lithium ion battery before liquid injection. The lithium ion battery has an insulation resistance R and a capacitance C, and the lithium ion battery is represented by an equivalent circuit in which these are connected in parallel.

[0035] In the first embodiment, the positive electrode (+) of the detection target 1 is connected to the connection terminal 101 of the short-circuit detection device 100 , and the negative electrode (−) of the detection target 1 is connected to the connection terminal 102 of the short-circuit detection device 100 .

[0036] The short circuit detection device 100 includes a power supply unit 110 , a voltage measurement unit 120 , a fluctuation detection circuit 130 , a current measurement unit 140 , a fluctuation detection circuit 150 , an AD converter 160 , a processing unit 200 , a display unit 300 , and an operation reception unit 400 .

[0037] The power supply unit 110 is composed of a charging unit that supplies a current or a voltage to the detection object 1 to charge the detection object 1 until a predetermined charging end condition is satisfied (for example, the voltage of the detection object 1 reaches a predetermined voltage value); and a supply unit that supplies a voltage of the predetermined voltage value after the detection object 1 is charged by the charging unit. The predetermined voltage value mentioned here is hereinafter referred to as voltage value V1.

[0038] It should be noted that, as the prescribed charging end condition, a condition such as the voltage or current of the detection object 1 reaching a prescribed value, or the voltage or current of the detection object 1 increasing or decreasing by a prescribed value or more, or a prescribed operation being performed in the operation receiving unit 400 may be adopted. In addition, the prescribed voltage value set in the charging unit and the prescribed voltage value set in the supply unit may be different values.

[0039] In the first embodiment, the power supply unit 110 is a supply circuit that supplies voltage to the detection target 1 until the voltage of the detection target 1 reaches the voltage value V1 and maintains the voltage of the detection target 1 at the voltage value V1. The power supply unit 110 includes a current limiter 111 and a constant voltage source 112.

[0040] The current limiter 111 is connected to the output terminal of the constant voltage source 112. The current limiter 111 limits the current output from the constant voltage source 112 according to the instruction of the processing unit 200 so that the current value of the current flowing into the detection target 1 does not exceed a predetermined upper limit value.

[0041] The constant voltage source 112 supplies a voltage V controlled to maintain the voltage of the detection object 1 at a voltage value V1 to the detection object 1. In order to detect the leakage current of the detection object 1, the constant voltage source 112 supplies a constant DC voltage between the positive electrode (+) and the negative electrode (-) in the detection object 1 through the connection terminal 101.

[0042] The voltage measuring unit 120 is a measuring unit that measures the magnitude of a signal generated in the detection object 1. In particular, the voltage measuring unit 120 is a voltage measuring unit that measures the magnitude of a voltage generated in the detection object 1. For example, the voltage measuring unit 120 is composed of a voltage sensor, a voltage measuring circuit, or a current measuring device.

[0043] In the first embodiment, the voltage measuring unit 120 measures the magnitude of the voltage generated between the two electrodes of the detection object 1 as a signal indicating the magnitude of the voltage generated in the detection object 1. Then, the voltage measuring unit 120 generates a measurement signal Vmv indicating the magnitude of the voltage generated between the two electrodes of the detection object 1, and outputs the generated measurement signal Vmv to the fluctuation detection circuit 130. The voltage measuring unit 120 includes, for example, a buffer circuit.

[0044] Furthermore, the voltage measuring unit 120 outputs the voltage detection signal Vv obtained by performing a predetermined filter process on the measurement signal Vmv for removing noise to the AD converter 160 as a short-circuit detection signal for digital processing.

[0045] The change detection circuit 130 constitutes a detection unit that detects a change in the signal measured by the voltage measuring unit 120 caused by a short circuit in the detection object 1. In particular, the change detection circuit 130 constitutes an analog processing unit that detects a change in the signal measured by the voltage measuring unit 120 by processing the measurement signal Vmv as an analog signal.

[0046] In the first embodiment, the change detection circuit 130 detects the change of the measurement signal Vmv caused by the short circuit generated in the detection object 1. Specifically, the change detection circuit 130 detects the temporary change of the measurement signal Vmv caused by the short circuit associated with the mixing of foreign matter in the detection object 1. The configuration of the change detection circuit 130 is the same as that of the change detection circuit 150.

[0047] The fluctuation detection circuit 130 generates a first hold signal Vh1 for holding the peak value of the measurement signal Vmv and a second hold signal Vh2 for holding the peak value of the difference between the measurement signal Vmv and the first hold signal Vh1 as fluctuation detection signals indicating the detected temporary fluctuation. The fluctuation detection circuit 130 outputs the generated fluctuation detection signals (Vh1, Vh2) to the AD converter 160.

[0048] The current measuring unit 140 is a measuring unit that measures the magnitude of a signal generated in the detection object 1. In particular, the current measuring unit 140 is a current measuring unit that measures the magnitude of a current flowing through the detection object 1 as a signal generated in the detection object 1. For example, the current measuring unit 140 is composed of a current sensor, a current measuring circuit, or a current measuring device.

[0049] In the first embodiment, the current measuring unit 140 measures the magnitude of the leakage current output from the negative electrode (-) of the detection object 1 as a signal indicating the magnitude of the current flowing through the detection object 1. Then, the current measuring unit 140 generates a measurement signal Vmi indicating the magnitude of the leakage current output from the negative electrode (-) of the detection object 1, and outputs the generated measurement signal Vmi to the fluctuation detection circuit 150.

[0050] When the power supply unit 110 is charging the detection object 1, the leakage current is about milliamperes (mA). On the other hand, when the power supply unit 110 is controlling the voltage of the detection object 1 to maintain the voltage value V1, the leakage current is about nanoamperes (nA) or microamperes (μA).

[0051] Furthermore, the current measuring unit 140 outputs a current detection signal Vi obtained by subjecting a measurement signal Vmi indicating the magnitude of the measured current to a predetermined filtering process to the AD converter 160. The current measuring unit 140 includes, for example, an IV conversion circuit that converts an input current into a voltage.

[0052] The fluctuation detection circuit 150 is constituted of the above-mentioned detection unit and analog processing unit in the same manner as the fluctuation detection circuit 130 .

[0053] In the first embodiment, the fluctuation detection circuit 150 detects fluctuations in the measurement signal Vmi caused by a short circuit occurring in the detection object 1. Specifically, the fluctuation detection circuit 150 detects temporary fluctuations in the measurement signal Vmi caused by a short circuit associated with the mixing of foreign matter in the detection object 1.

[0054] The fluctuation detection circuit 150 generates a first hold signal Vh3 for holding the peak value of the measurement signal Vmi and a second hold signal Vh4 for holding the peak value of the difference between the measurement signal Vmi and the first hold signal Vh3 as fluctuation detection signals indicating the detected fluctuation. The fluctuation detection circuit 150 outputs the generated fluctuation detection signals (Vh3, Vh4) to the AD converter 160. Figure 2 , an example of the configuration of the change detection circuit 150 will be described later.

[0055] AD converter 160 samples voltage detection signal Vv at a predetermined cycle and outputs voltage detection data generated by the sampling to processing unit 200. AD converter 160 also samples current detection signal Vi at a predetermined cycle and outputs current detection data generated by the sampling to processing unit 200.

[0056] Then, the AD converter 160 samples the first hold signal Vh1 and the second hold signal Vh2 from the fluctuation detection circuit 130 at a predetermined cycle, and outputs fluctuation detection data generated by the sampling to the processing unit 200 .

[0057] Similarly, the AD converter 160 samples the first hold signal Vh3 and the second hold signal Vh4 from the fluctuation detection circuit 150 at a predetermined cycle, and outputs fluctuation detection data generated by the sampling to the processing unit 200 .

[0058] The processing unit 200 constitutes a stop processing unit that stops the supply of current or voltage by the power supply unit 110 when a short circuit is detected in the detection object 1 based on a signal measured by at least one of the voltage measuring unit 120 and the current measuring unit 140. In the first embodiment, the stop processing unit is constituted by the change detection circuit 130, the change detection circuit 150, the AD converter 160, and the processing unit 200.

[0059] The processing unit 200 includes a computer-readable recording medium recording a program for detecting a short circuit occurring in the detection target object 1 of the first embodiment. The processing unit 200 executes the program read from the recording medium to control each unit of the short circuit detection device 100 .

[0060] For example, the processing unit 200 is a computer composed of a processor, a ROM (Read Only Memory), a RAM (Random Access Memory), a large-capacity storage device, an input / output interface, and a bus connecting them. Examples of the processor include a CPU (Central Processing Unit) or an MPU (Micro Processor Unit). Examples of the large-capacity storage device include an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0061] In the first embodiment, the processing unit 200 controls the operation of the current limiter 111 and the constant voltage source 112 constituting the power supply unit 110 and the display unit 300 .

[0062] The processing unit 200 acquires the voltage detection data and the current detection data from the AD converter 160. Then, the processing unit 200 controls the driving of the constant voltage source 112 based on the acquired voltage detection data so that the voltage generated between the two electrodes of the detection target 1 is maintained at the voltage value V1.

[0063] In addition, the processing unit 200 executes a short circuit detection process for detecting a short circuit occurring in the detection target object 1. For example, when receiving a request signal for executing the short circuit detection process from the operation receiving unit 400, the processing unit 200 executes a predetermined short circuit detection process.

[0064] In the short circuit detection process, the processing unit 200 outputs a supply command signal for supplying a voltage of the voltage value V1 to the detection target 1 to the constant voltage source 112. Thus, the constant voltage source 112 supplies the voltage of the voltage value V1 indicated by the supply command signal to the detection target 1.

[0065] The processing unit 200 acquires the variation detection data from the AD converter 160 while the voltage is supplied from the constant voltage source 112 to the detection target 1. The processing unit 200 detects a short circuit caused by an abnormality that may have occurred in the detection target 1 based on the acquired variation detection data.

[0066] Specifically, the fluctuation detection data shows the fluctuation amount (fluctuation component) of each of the measurement signal Vmi and the measurement signal Vmv, and the processing unit 200 determines whether the fluctuation amount of the measurement signal Vmv included in the fluctuation detection data exceeds the voltage threshold.

[0067] Then, when the processing unit 200 determines that the variation of the measurement signal Vmv exceeds the voltage threshold, it determines that a short circuit has occurred in the detection object 1. That is, the processing unit 200 detects a short circuit in the detection object 1 when the variation detection data indicating the variation of the measurement signal Vmv exceeds the threshold.

[0068] On the other hand, when the processing unit 200 determines that the variation of the measurement signal Vmi does not exceed the current threshold, it determines that a short circuit does not occur in the detection target 1. That is, when the variation detection data does not exceed the threshold, the processing unit 200 does not detect a short circuit in the detection target 1.

[0069] Similarly, the processing unit 200 may determine whether the variation of the measurement signal Vmi included in the variation detection data exceeds the current threshold, and determine that a short circuit has occurred when the variation of the measurement signal Vmi exceeds the current threshold. Alternatively, the processing unit 200 may determine that a short circuit has occurred when at least one of the variation of the measurement signal Vmv and the measurement signal Vmi exceeds the threshold.

[0070] Next, when the processing unit 200 detects a short circuit in the detection object 1, it stops the voltage supplied from the power supply unit 110 to the detection object 1. In particular, when the processing unit 200 detects a short circuit in the detection object 1, it stops the supply of the voltage of the voltage value V1 at least during the period when the power supply unit 110 supplies the voltage of the voltage value V1 to the detection object 1.

[0071] In the first embodiment, the processing unit 200 immediately stops the supply of voltage when a short circuit is detected. Specifically, the processing unit 200 stops the constant voltage control of the constant voltage source 112 when determining that a short circuit has occurred.

[0072] On the other hand, when the processing unit 200 does not detect a short circuit in the detection target 1, the power supply unit 110 continues to supply voltage to the detection target 1. Specifically, when the processing unit 200 determines that a short circuit has not occurred, the constant voltage control of the constant voltage source 112 is maintained.

[0073] In this way, the processing unit 200 configures a stop control means for stopping the supply of voltage by the power supply unit 110 when the fluctuation detection data exceeds the threshold value.

[0074] Furthermore, the processing unit 200 calculates the physical quantity of the detection object 1 based on the voltage detection data and the current detection data acquired from the AD converter 160. Examples of the physical quantity of the detection object 1 include the leakage current of the detection object 1 and the insulation resistance R of the detection object 1.

[0075] The processing unit 200 outputs the determination result indicating the presence or absence of a short circuit or the calculation results of the leakage current and the insulation resistance R to the display unit 300 .

[0076] The display unit 300 generates and displays image data representing the determination result or the calculation result output from the processing unit 200. For example, the display unit 300 is composed of an LED (Light Emitting Diode) display, a liquid crystal panel, a touch panel, or the like.

[0077] The operation accepting unit 400 accepts an input operation from the user and outputs an operation signal indicating the accepted input operation to the processing unit 200. The operation accepting unit 400 is composed of, for example, buttons provided near the screen of the display unit 300, a touch sensor built into a touch panel, a keyboard, and a mouse.

[0078] The operation accepting unit 400 receives, for example, an operation of pressing a button for executing the short-circuit detection process, and outputs the short-circuit detection request to the processing unit 200. As a result, the short-circuit detection process is executed in the short-circuit detection device 100.

[0079] Next, refer to Figure 2 , the structure of the change detection circuit 150 is described.

[0080] Figure 2 1 is a circuit diagram showing an example of the circuit configuration of the current measuring unit 140 and the fluctuation detection circuit 150 according to the first embodiment.

[0081] The current measuring unit 140 includes an IV conversion circuit 141 and a filter circuit 142 .

[0082] The IV conversion circuit 141 converts the current signal of the detection target object 1 input from the connection terminal 102 of the short-circuit detection device 100 into a voltage signal. The converted voltage signal changes in proportion to the magnitude of the current signal, for example.

[0083] The IV conversion circuit 141 outputs the converted voltage signal to the fluctuation detection circuit 150 as a measurement signal Vmi indicating the magnitude of the current flowing through the detection object 1. In addition, the IV conversion circuit 141 outputs the converted voltage signal to the filter circuit 142.

[0084] The filter circuit 142 removes noise components from the voltage signal output from the IV conversion circuit 141. The filter circuit 142 is formed of, for example, a low-pass filter (LPF). The filter circuit 142 outputs the voltage signal from which high-frequency components have been removed to the AD converter 160 as the current detection signal Vi.

[0085] The fluctuation detection circuit 150 includes an HPF circuit 150A, a maximum value holding circuit 150B, and a fluctuation holding circuit 150C.

[0086] The HPF circuit 150A constitutes a filter processing unit that extracts a predetermined high-frequency component caused by a short circuit in the measurement signal Vmi output from the IV conversion circuit 141. The predetermined high-frequency component here refers to a frequency component of several [kHz] or more, for example.

[0087] The HPF circuit 150A is constituted by a high-pass filter circuit and outputs an extraction signal obtained by extracting a predetermined high-frequency component to the maximum value holding circuit 150B as a new measurement signal Vmi.

[0088] The maximum value holding circuit 150B is a first holding circuit that holds a peak value indicating the maximum value of the measurement signal Vmi output from the HPF circuit 150A. The maximum value holding circuit 150B outputs a first hold signal Vh3 indicating the peak value of the held measurement signal Vmi to the AD converter 160 and the variation holding circuit 150C. The maximum value holding circuit 150B is composed of a peak holding circuit 151.

[0089] The variation holding circuit 150C holds the variation of the measurement signal Vmi output from the HPF circuit 150A. The variation holding circuit 150C is a second holding circuit that holds the peak value of the differential signal representing the difference between the measurement signal Vmi and the first held signal Vh3. The variation holding circuit 150C outputs a second held signal Vh4 representing the peak value of the held differential signal.

[0090] The variation hold circuit 150C of the first embodiment includes a subtraction circuit 152 and a peak hold circuit 153 .

[0091] The subtraction circuit 152 generates a differential signal obtained by subtracting the measurement signal Vmi from the first hold signal Vh3 , and outputs the generated differential signal to the peak hold circuit 153 .

[0092] The peak hold circuit 153 holds the peak value of the differential signal output from the subtraction circuit 152. The peak hold circuit 153 outputs a second hold signal Vh4 indicating the peak value of the differential signal as the fluctuation detection signal to the AD converter 160. The second hold signal Vh4 is a voltage signal indicating the fluctuation component of the extraction signal output from the HPF circuit 150A.

[0093] exist Figure 2 , the circuit configuration of the fluctuation detection circuit 150 is described, but the fluctuation detection circuit 130 also has the same circuit configuration as the fluctuation detection circuit 150, and includes the HPF circuit 150A, the maximum value holding circuit 150B, and the fluctuation holding circuit 150C.

[0094] Next, refer to Figure 3A , Figure 3B as well as Figure 4 , the operation of the variation detection circuit 150 according to the first embodiment will be described.

[0095] Figure 3A 2 is a diagram showing an example of changes in the measurement signal Vmi input to the change detection circuit 150 . Figure 3B It is used for Figure 3A 1 is a diagram for explaining the relationship between the change in the measurement signal Vmi and the change detection data (Dh3, Dh4) output from the AD converter 160.

[0096] Figure 3A An example of sampling processing of the measurement signal Vmi input to the fluctuation detection circuit 150 is shown in FIG. Figure 3A In order to facilitate understanding, it is assumed that the measurement signal Vmi temporarily rises or falls by 1 [V] with respect to 1 [V], and the temporary change period of the measurement signal Vmi is shorter than the sampling period Tp. In this example, the voltage of the measurement signal Vmi at the sampling time points Sp1 to Sp5 is 1 [V].

[0097] Figure 3B 2 shows the voltage values ​​of the measurement data Dmi, the first held data Dh3, and the second held data Dh4 at the sampling time points Sp1 to Sp5.

[0098] The measurement data Dmi and the change detection data (Dh3, Dh4) are data obtained by converting the measurement signal Vmi, the first hold signal Vh3, and the second hold signal Vh4 into digital signals by the AD converter 160, respectively. Figure 3B In the example shown, the peak hold circuits 151 , 153 are reset immediately after the sampling time points Sp1 to Sp5 .

[0099] like Figure 3BAs shown, when the measurement signal Vmi remains at 1 [V] without changing, the second held data Dh4 is 0 [V] at the sampling time points Sp1 and Sp3.

[0100] On the other hand, when the measurement signal Vmi temporarily rises or falls from 1 [V] within the sampling period Tp, the second held data Dh4 is 1 [V] at the sampling time points Sp4 and Sp5. In addition, when the measurement signal Vmi temporarily rises and temporarily falls relative to 1 [V] within the sampling period Tp, the second held data Dh4 is 2 [V] at the sampling time point Sp2.

[0101] Thus, when the measurement signal Vmi temporarily changes, the second hold data Dh4 indicates a value greater than 0 [V]. In other words, the second hold data Dh4 is data indicating the magnitude of the change in the measurement signal Vmi, that is, the change component. Of course, the second hold signal Vh4 is also the same.

[0102] In this example, the current threshold value associated with the second held data Dh4 is set to a predetermined value within a range from 0 to 1, and at the sampling time points Sp2, Sp4, and Sp5 where the second held data Dh4 exceeds the current threshold value, it is determined that there is a change due to a short circuit of the detection target 1. On the other hand, at the sampling time points Sp1 and Sp3 where the second held data Dh4 is below the current threshold value, it is determined that there is no change due to a short circuit.

[0103] therefore, Figure 1 The processing unit 200 shown can determine the presence or absence of a short circuit caused by an abnormality occurring in the detection target 1 based on the second held data Dh4 indicating the presence or absence of a change in the measurement signal Vmi and the current threshold value.

[0104] Specifically, when the second held data Dh4 exceeds the current threshold, the processing unit 200 determines that a short circuit has occurred in the detection target 1. On the other hand, when the second held data Dh4 is less than the current threshold, the processing unit 200 determines that a short circuit has not occurred in the detection target 1.

[0105] That is, the processing unit 200 determines that a short circuit has occurred in the detection object 1 when the second held data Dh4 exceeds the predetermined threshold, and determines that a short circuit has not occurred in the detection object 1 when the second held data Dh2 does not exceed the predetermined threshold.

[0106] In addition, if Figure 3B As shown, when the first held data Dh3 indicates 2 [V], it means that the measurement signal Vmi temporarily rises. Therefore, by using the first held data Dh3 in addition to the second held data Dh4, it is possible to determine whether the change in the measurement signal Vmi is a temporary rise.

[0107] Specifically, when the processing unit 200 determines that a short circuit has occurred in the detection target 1 based on the second held data Dh4 , the measurement signal Vmi is determined to have temporarily increased when the first held data Dh1 indicates a value greater than the voltage value V1 indicating 1 [V].

[0108] On the other hand, when it is determined based on the second held data Dh4 that a short circuit has occurred in the detection target 1 , if the first held data Dh3 indicates the same value as the measurement data Dmi, the processing unit 200 determines that the measurement signal Vmi has temporarily dropped.

[0109] In this way, when the processing unit 200 determines that a short circuit has occurred in the detection target object 1 based on the second held data Dh4 , it can determine whether the measurement signal Vmi temporarily rises or temporarily falls by using the first held data Dh3 .

[0110] Figure 4 1 is a timing chart for explaining a method for detecting a change in a measurement signal Vmi during a charging period Tc of the detection object 1. Figure 4 In the example shown, for easy understanding, even when a short circuit occurring in the detection target 1 is detected, the voltage is continuously supplied to the detection target 1 .

[0111] exist Figure 4 In (a), the solid line indicates the temporal change of the voltage generated between the two electrodes of the detection object 1, and the dotted line indicates the temporal change of the leakage current output from the negative electrode (-) of the detection object 1. Figure 4 (b) shows the time variation of the first hold signal Vh3, Figure 4 (c) shows the time variation of the second hold signal Vh4. Figure 4 The horizontal axes of (a) to (c) are a common time axis and represent the elapsed time from the time when charging of the detection target object 1 is started.

[0112] like Figure 4 As shown in (a), the voltage of the detection object 1 rises with time due to the voltage V supplied from the power supply unit 110 during the charging period Tc, and reaches the voltage value V1 during the switching time T1. Then, the voltage of the detection object 1 is controlled by the power supply unit 110 to be constant during the steady-state period Ts.

[0113] It should be noted that the charging period Tc is the period during which the power supply unit 110 supplies the voltage V before the voltage of the detection object 1 reaches the voltage value V1, and the steady-state period Ts is the period during which the power supply unit 110 continues to supply the voltage V of the voltage value V1 even after the voltage of the detection object 1 reaches the voltage value V1.

[0114] On the other hand, Figure 4 As shown in (a), the leakage current of the detection object 1 is kept constant during the charging period Tc. Then, when the voltage of the detection object 1 reaches the voltage value V1 during the switching time T1, the leakage current of the detection object 1 is lower than the current value I1 during the steady-state period Ts and is kept constant at a specific current value.

[0115] exist Figure 4 In the example shown in (a), temporary changes in the electrical signal occur during each of the charging period Tc and the steady-state period Ts. The voltage change represented by the solid line and the current change represented by the dotted line follow Ohm's law, so the directions of the changes are opposite to each other.

[0116] Therefore, during the charging period Tc, the leakage current of the detection object 1 is substantially constant, so the current variation of the detection object 1 is smaller than the voltage variation. On the other hand, during the steady-state period Ts, the voltage value of the detection object 1 is substantially constant, so the voltage variation of the detection object 1 is smaller than the current variation.

[0117] like Figure 4 As shown in (a), during the charging period Tc, when the voltage of the detection object 1 temporarily decreases during the variation period Tv during the sampling period Tp, the leakage current of the detection object 1 temporarily increases. Therefore, the measurement signal Vmi temporarily decreases in the same manner as the temporary decrease in the voltage of the detection object 1. It should be noted that Figure 2 As shown, the polarity of the measurement signal Vmi in the first embodiment is inverted by the IV conversion circuit 141 .

[0118] At this time, if Figure 4 As shown in (b), the first hold signal Vh3 further rises from the time point when the measurement signal Vmi temporarily rises, and then shows +1 [V].

[0119] On the other hand, Figure 4 As shown in (c), the second hold signal Vh4 representing the peak value of the differential signal (Vh3-Vmi) obtained by subtracting the measurement signal Vmi from the first hold signal Vh3 rises from 0 [V] and is maintained at +0.1 [V] after the first hold signal Vh3 reaches +1 [V].

[0120] Therefore, even if the measurement signal Vmi varies within the sampling period Tp, the second hold signal Vh4 continues to indicate +0.1 [V], so that the voltage variation of the detection target 1 can be accurately detected.

[0121] That is, in the variation detection circuit 150 of the first embodiment, even when the variation period Tv of the measurement signal Vmi due to a short circuit in the detection target object 1 is shorter than the sampling period Tp, the variation of the measurement signal Vmi can be detected without shortening the sampling period Tp. Therefore, it is possible to determine whether a short circuit that may occur in the detection target object 1 exists while a voltage is supplied to the detection target object 1.

[0122] As described above, the short-circuit detection device 100 includes the variation detection circuit 150 , and thereby can detect the variation of the measurement signal Vmi during the charging period Tc in which the detection target object 1 is charged.

[0123] Moreover, if Figure 4 As shown in (a), the inventors found that since the voltage V of the voltage value V1 is continuously supplied even after the charging period Tc, a short circuit occurs in the detection object 1. Even in such a steady-state period Ts in which the voltage of the detection object 1 is maintained at the voltage value V1, the change of the measurement signal Vmi can be detected by the change detection circuit 150 in the same manner as in the charging period Tc.

[0124] Therefore, the short-circuit detection device 100 can detect the variation of the measurement signal Vmi not only in the charging period Tc but also in the steady period Ts by using the variation detection circuit 150 .

[0125] Next, refer to Figure 5 , the operation of the change detection circuit 130 is described.

[0126] Figure 5 1 is a timing chart for explaining a method for detecting changes in the measurement signal Vmv during the charging period Tc. Figure 5 In, with Figure 4 Likewise, for easy understanding, even when a short circuit is detected in the detection target 1 , the voltage continues to be supplied to the detection target 1 .

[0127] exist Figure 5 In (a) of FIG. 1 , the time change of the measurement signal Vmv is indicated by a solid line, and the time change of the leakage current output from the detection target 1 is indicated by a dotted line. Figure 5 (b) shows the time variation of the first hold signal Vh1. Figure 5 (c) shows the time variation of the second hold signal Vh2. Figure 5 The horizontal axes of (a) to (c) are a common time axis and represent the elapsed time from the time when charging of the detection target object 1 is started.

[0128] like Figure 5As shown in (a) of FIG. 1 , in the charging period Tc, when the voltage of the detection object 1 temporarily decreases during the variation period Tv within the sampling period Tp, the measurement signal Vmv temporarily decreases.

[0129] At this time, if Figure 5 As shown in (b), the first hold signal Vh3 rises until just before the measurement signal Vmv turns to fall, and then shows +1 [V].

[0130] On the other hand, Figure 5 As shown in (c) of FIG. 1 , the second hold signal Vh2 indicating the peak value of the differential signal (Vh1 −Vmv) obtained by subtracting the measurement signal Vmv from the first hold signal Vh1 continues to indicate +0.2 [V].

[0131] Therefore, even if the measurement signal Vmv varies within the sampling period Tp, the second hold signal Vh2 continues to indicate +0.2 [V], so that the voltage variation of the detection target 1 can be accurately detected.

[0132] Note that the method of detecting the change in the measurement signal Vmv during the charging period Tc has been described, but the change in the measurement signal Vmv during the steady period Ts in which the voltage of the detection target 1 is maintained at the voltage value V1 can also be detected in the same manner.

[0133] In this way, the fluctuation detection circuit 130 can detect the fluctuation of the measurement signal Vmv not only in the steady-state period Ts but also in the charging period Tc in which the detection target object 1 is charged.

[0134] Next, refer to Figure 6 and Figure 7 , the operation of the short-circuit detection device 100 is described.

[0135] Figure 6 2 is a flowchart showing a short circuit detection method performed by the short circuit detection device 100. First, the operation reception unit 400 of the short circuit detection device 100 outputs the supply instruction signal to the processing unit 200 according to, for example, a user's input operation.

[0136] In step S1, when receiving the supply command signal, the processing unit 200 of the short-circuit detection device 100 drives the power supply unit 110 to charge the detection object 1. The processing unit 200 of the first embodiment sets the upper limit value acquired from the internal memory in the current limiter 111, and drives the constant voltage source 112. Then, the processing unit 200 supplies current or voltage to the detection object 1 until the voltage of the detection object 1 reaches a predetermined voltage value V1.

[0137] In step S2, the processing unit 200 supplies a constant voltage V to the detection object 1 during the charging period Tc until the voltage of the detection object 1 reaches the voltage value V1. Thus, the detection object 1 is charged and the voltage of the detection object 1 is maintained at the voltage value V1. At this time, the current limiter 111 limits the current output from the constant voltage source 112 to the upper limit value. And, during the steady-state period Ts after the voltage of the detection object 1 reaches the voltage value V1, the processing unit 200 supplies the voltage V of the voltage value V1 to the detection object 1.

[0138] In step S3 , the voltage measuring unit 120 and the current measuring unit 140 in the short-circuit detection device 100 measure a signal generated in the detection object 1 by the power supply unit 110 .

[0139] In the first embodiment, the voltage measuring unit 120 measures the magnitude of the voltage generated between the two electrodes of the detection object 1 and generates a measurement signal Vmv indicating the magnitude of the measured voltage. At the same time, the current measuring unit 140 measures the magnitude of the leakage current output from the negative electrode (-) of the detection object 1 and generates a measurement signal Vmi indicating the magnitude of the measured leakage current.

[0140] In step S4, the processing unit 200 performs a supply stop process of stopping the supply of voltage when a short circuit in the detection object 1 is detected based on at least one of the measurement signals Vmv and Vmi generated in step S3 during at least the steady-state period Ts within the detection period. Figure 7 The details of the supply stop processing will be described later.

[0141] When the process of step S4 is completed, a series of processing procedures related to the short-circuit detection method are completed.

[0142] Figure 7 This is a flowchart showing an example of a processing procedure related to the supply stop processing executed in step S4.

[0143] In step S41 , the fluctuation detection circuits 130 and 150 detect fluctuations in the measurement signals Vmv and Vmi caused by the short circuit in the detection target 1 based on the measurement signals Vmv and Vmi generated by the voltage measurement unit 120 and the current measurement unit 140 , respectively.

[0144] In a first embodiment, if Figure 2As shown in FIG. 1 , the fluctuation detection circuit 150 holds the peak value of the measurement signal Vmi from the IV conversion circuit 141, and generates a first held signal Vh3 indicating the held peak value. Then, the fluctuation detection circuit 150 generates a differential signal obtained by subtracting the measurement signal Vmi from the first held signal Vh3, and holds the peak value of the generated differential signal. Thus, the fluctuation detection circuit 150 generates a second held signal Vh4 indicating the held peak value.

[0145] At the same time, the change detection circuit 130 holds the peak value of the measurement signal Vmv indicating the magnitude of the voltage generated between the two electrodes of the detection object 1 in the same manner as the change detection circuit 150, and generates a first hold signal Vh1 indicating the held peak value. Then, the change detection circuit 130 generates a differential signal obtained by subtracting the measurement signal Vmv from the first hold signal Vh1, and holds the peak value of the generated differential signal. Thus, the change detection circuit 130 generates a second hold signal Vh2 indicating the held peak value.

[0146] In step S42 , the processing unit 200 determines whether a short circuit has occurred in the detection object 1 based on the fluctuation detection signals ( Vh1 to Vh4 ) output from the fluctuation detection circuits 130 and 150 .

[0147] The processing unit 200 of the first embodiment determines whether the second held signal Vh2 output from the fluctuation detection circuit 130 exceeds the voltage threshold, and determines whether the second held signal Vh4 output from the fluctuation detection circuit 150 exceeds the current threshold.

[0148] In step S43 , the processing unit 200 determines that a short circuit has occurred in the detection object 1 when the second hold signal Vh2 output from the fluctuation detection circuit 130 exceeds the voltage threshold or when the second hold signal Vh4 output from the fluctuation detection circuit 150 exceeds the current threshold.

[0149] In step S44 , the processing unit 200 determines that a short circuit does not occur in the detection target 1 when the second hold signal Vh2 does not exceed the voltage threshold and the second hold signal Vh4 does not exceed the current threshold.

[0150] In this way, in steps S41 to S44 , the processing unit 200 detects the occurrence of a short circuit in the detection target 1 based on the measurement signals Vmv and Vmi.

[0151] In step S45, the processing unit 200 stops the voltage supply from the power supply unit 110 when a short circuit is detected in the detection object 1. The processing unit 200 of the first embodiment immediately stops the voltage supply to the detection object 1 when it is determined in step S43 that a short circuit has occurred in the detection object 1.

[0152] In step S46, when the processing unit 200 does not detect a short circuit in the detection object 1, the power supply unit 110 continues to supply voltage, and determines whether the time elapsed from the start of the voltage supply to the detection object 1 exceeds a specified value. The specified value here is a time predetermined to specify the measurement time of the insulation resistance R, etc., and is determined to be, for example, several seconds.

[0153] Then, the processing unit 200 returns to step S42 when the elapsed time is less than the prescribed value, and proceeds to step S45 to stop supplying voltage to the detection target 1 when the elapsed time exceeds the prescribed value.

[0154] When the processing of step S45 is completed, a series of processing procedures related to the supply stop processing executed in step S4 are completed, and the process returns to step S45. Figure 5 It should be noted that the processing of steps S43 and S44 may also be omitted.

[0155] Next, refer to Fig. 8A and Figure 8B , the operation of the processing unit 200 when a short circuit occurs in the detection target object 1 is described.

[0156] Fig. 8A This is a diagram for explaining a method of controlling a voltage supplied to the detection target object 1 when the occurrence of a short circuit is detected within the charging period Tc.

[0157] Fig. 8A 2 shows the temporal change of the voltage generated between the two electrodes of the detection object 1 , and shows the elapsed time from the time when the charging of the detection object 1 is started.

[0158] like Fig. 8A As shown, at time point Td in charging period Tc, the variation of measurement signal Vmv indicating the magnitude of voltage between electrodes of detection target 1 is detected by variation detection circuit 130. Thus, the variation detection signal output from variation detection circuit 130 exceeds the voltage threshold.

[0159] Therefore, the processing unit 200 determines that a short circuit has occurred in the detection object 1, and immediately stops the voltage supplied from the power supply unit 110 to the detection object 1. As a result, the voltage supplied to the two electrodes of the detection object 1 is sharply reduced, thereby suppressing the influence on the characteristics or performance of the detection object 1 and shortening the time required for detection.

[0160] Figure 8B This is a diagram for explaining a method of controlling a voltage supplied to the detection target object 1 when the occurrence of a short circuit is detected in the steady-state period Ts.

[0161] and Fig. 8A same, Figure 8B 2 shows the temporal change of the voltage generated between the two electrodes of the detection object 1 , and shows the elapsed time from the time when the charging of the detection object 1 is started.

[0162] like Figure 8B As shown, at the time point Td in the steady-state period Ts, the variation of the measurement signal Vmv indicating the magnitude of the voltage between the two electrodes of the detection object 1 is detected by the variation detection circuit 130 .

[0163] As a result, the fluctuation detection signal output from the fluctuation detection circuit 130 exceeds the voltage threshold, and therefore the processing unit 200 determines that a short circuit has occurred in the detection target 1 and immediately stops the voltage supplied from the power supply unit 110 .

[0164] exist Fig. 8A and Figure 8B In the description, an example is described in which the operation of the power supply unit 110 is stopped when a change in the measurement signal Vmv is detected, but the operation of the power supply unit 110 may be stopped when a change in the measurement signal Vmi indicating the magnitude of the leakage current of the detection target 1 is detected.

[0165] As described above, the short-circuit detection device 100 of the first embodiment determines in real time whether a short circuit exists in the detection object 1 while supplying voltage to the detection object 1 , and promptly stops supplying voltage to the detection object 1 when determining that a short circuit has occurred.

[0166] It should be noted that, in the above-mentioned first embodiment, an example of monitoring both the measurement signals Vmv and Vmi to detect signal changes when determining whether a short circuit has occurred in the detection object 1 has been described, but the short-circuit detection device 100 may also monitor only one of the measurement signals Vmv and Vmi to determine whether a short circuit has occurred.

[0167] For example, when a short circuit occurs in the detection object 1 during the steady-state period Ts, the measurement signal Vmi indicating the leakage current from the detection object 1 is more likely to show fluctuations than the measurement signal Vmv indicating the voltage between the two electrodes of the detection object 1. Therefore, the short-circuit detection device 100 may stop supplying current or voltage based only on the measurement signal Vmi of the leakage current during the steady-state period Ts. In this case, the reduction in the detection accuracy of the short circuit can be suppressed, and the calculation load of the processing unit 200 can be reduced.

[0168] In the first embodiment, a voltage is supplied to the detection object 1 using the constant voltage source 112 so that the detection object 1 is charged with a constant current and the voltage of the detection object 1 is maintained at the voltage value V1. However, the present invention is not limited to this.

[0169] For example, a constant current source that performs constant current control to control the output current so that the current value is constant may be used as the power supply unit 110, or the detection object 1 may be charged and the voltage of the detection object 1 may be maintained at the voltage value V1 by supplying current from the constant current source to the detection object 1.

[0170] Alternatively, the detection object 1 may be charged by the constant current source during the charging period Tc, and the voltage of the detection object 1 may be maintained at the voltage value V1 by the constant voltage source 112 during the steady-state period Ts.

[0171] Furthermore, although the HPF circuit 150A is provided in each of the fluctuation detection circuits 130 and 150 in the first embodiment, the HPF circuit 150A may be eliminated. Even in such a case, the voltage supply to the detection target 1 can be stopped when a short circuit is detected in the detection target 1 .

[0172] Next, the effects achieved by the first embodiment will be described.

[0173] In the first embodiment, the short-circuit detection device 100 is a device for detecting a short circuit occurring in a secondary battery as a detection object 1. The short-circuit detection device 100 includes: a charging unit that supplies a current or a voltage to the detection object 1 for charging until a predetermined charging end condition is satisfied; and a power supply unit 110 as a supply unit that supplies a voltage of a predetermined voltage value V1 after the charging. In addition, the short-circuit detection device 100 includes a voltage measuring unit 120 and a current measuring unit 140 as a measuring unit that measures a signal generated in the detection object 1 by the power supply unit 110.

[0174] The short circuit detection device 100 includes a fluctuation detection circuit 130, a fluctuation detection circuit 150, and a processing unit 200 as a stop processing unit. The stop processing unit stops supplying voltage when the short circuit is detected based on the signal measured by at least one of the voltage measuring unit 120 and the current measuring unit 140, at least during a steady-state period Ts during which the power supply unit 110 supplies a voltage having a predetermined voltage value V1.

[0175] In addition, the short circuit detection method for detecting a short circuit occurring in the secondary battery of the detection object 1 as the first embodiment includes: a charging step (S1) of supplying a current or voltage to the detection object 1 for charging until the above-mentioned specified charging end condition is met; and a supply step (S2) of supplying a voltage of a specified voltage value V1. Moreover, the short circuit detection method includes a measuring step (S3) of measuring a signal generated in the detection object 1 by the supply step (S2). Moreover, the short circuit detection method includes the following stop processing step (S4): at least during the steady state period Ts, when the above-mentioned short circuit is detected based on the above-mentioned signal measured by the measuring step (S3), the supply of voltage is stopped.

[0176] The program of the first embodiment is a program for causing a computer (100) for detecting a short circuit occurring in the detection object 1 to execute the charging step (S1), supply step (S2), measurement step (S3) and stop processing step (S4). The program is recorded in a processing unit 200 having a computer-readable recording medium.

[0177] According to these configurations, the short-circuit detection device 100, the short-circuit detection method, or the program of the first embodiment supplies voltage to the detection object 1 until a predetermined charging end condition is satisfied even after the charging period Tc during which a current or voltage is supplied to the detection object 1 for charging. Furthermore, when a short circuit is detected in the detection object 1 at least after the charging period Tc, the voltage supplied to the detection object 1 is stopped.

[0178] When a short circuit occurs in the detection object 1, the short circuit may affect the characteristics or performance of the detection object 1. For example, when a short circuit occurs multiple times, the influence caused by the short circuit may accumulate on the detection object 1 each time a short circuit occurs, and there is a concern that the yield of the detection object 1 may be reduced.

[0179] As a countermeasure, the short-circuit detection device 100, the short-circuit detection method or the program of the first embodiment stops the voltage supplied to the detection object 1 when the occurrence of a short circuit is detected at least after the charging period Tc. As a result, the influence of the short circuit on the detection object 1 is not accumulated, so the influence on the characteristics or performance of the detection object 1 can be suppressed. In addition, since it is possible to avoid further continuous supply of a voltage that becomes a load to the detection object 1 that has a short circuit, the influence on the characteristics or performance of the detection object 1 can also be suppressed.

[0180] In this way, the short-circuit detection device 100, the short-circuit detection method or the program of the first embodiment can detect a short circuit generated in the detection object 1 not only during the charging period Tc but also after the charging period Tc, and can suppress a reduction in the yield of the detection object 1. In addition, compared with a configuration in which a voltage is continuously supplied to the detection object 1 until a predetermined time has passed even after the charging period Tc, the time required to detect a short circuit can be shortened.

[0181] In the short-circuit detection device 100 of the first embodiment, the predetermined charging end condition is when the voltage of the detection target 1 reaches the voltage value V1.

[0182] Furthermore, in the charging step ( S1 ) of the short-circuit detection method or program of the first embodiment, the predetermined charging end condition is when the voltage of the detection target object 1 reaches the voltage value V1 .

[0183] According to this configuration, the short-circuit detection device 100, the short-circuit detection method or the program of the first embodiment supplies a voltage of voltage value V1 after the voltage of the detection object 1 reaches voltage value V1, thereby minimizing the influence of the internal impedance of the detection object 1 on the charging voltage of the detection object 1.

[0184] Furthermore, the processing unit 200 of the short-circuit detection device 100 of the first embodiment immediately stops supplying current or voltage when a short circuit is detected in the detection object 1 during the charging period Tc and the steady-state period Ts, and continues supplying current or voltage when no short circuit is detected.

[0185] According to this configuration, the short-circuit detection device 100, the short-circuit detection method or the program of the first embodiment stops the supply of current or voltage immediately after detecting a short circuit in the detection object 1. Therefore, compared with a configuration in which the supply is stopped after a specified time has passed since the short circuit was detected, the effect of the supply of current or voltage on the detection object 1 can be reduced.

[0186] In addition, the short circuit detection device 100, the short circuit detection method or the program of the first embodiment can shorten the time required for detecting a short circuit compared to the configuration in which the current or voltage is continuously supplied to the detection object 1 until a predetermined time has passed. In addition, when the short circuit of a plurality of detection objects 1 is inspected one by one in sequence, the supply of voltage or current is stopped when a short circuit is detected for each detection object 1, so that the timing of starting the next inspection can be advanced. Therefore, the time for inspecting all the detection objects 1 can be shortened.

[0187] In addition, the short-circuit detection device 100 of the first embodiment includes an HPF circuit 150A as a filter processing unit, and the HPF circuit 150A extracts a predetermined high-frequency component caused by a short circuit in the detection target object 1 from the measurement signal Vmi or Vmv. In addition, the processing unit 200 includes a stop control unit that stops the supply of current or voltage by the power supply unit 110 when the fluctuation component (Vh2, Vh4) of the extraction signal output from the HPF circuit 150A exceeds a threshold value.

[0188] According to this configuration, in the extraction signal generated by the HPF circuit 150A, low-frequency components other than the predetermined high-frequency components in the measurement signal Vmi or Vmv are attenuated, so that the rise or fall of the variable component caused by the low-frequency component can be suppressed. Therefore, the false detection of the short circuit in the detection object 1 is reduced, so the reduction in detection accuracy can be suppressed.

[0189] Therefore, the current or voltage supplied to the detection target 1 can be accurately stopped, so the reduction in the yield of the detection target 1 can be further improved.

[0190] Furthermore, the HPF circuit 150A as the filter processing unit of the first embodiment is a high-pass filter circuit that processes an analog signal.

[0191] According to this configuration, a continuous extraction signal is generated by analog processing, so compared with a configuration in which a sampled extraction signal is generated by digital processing, it is possible to avoid missing a short circuit caused by sampling processing. Therefore, it is possible to suppress the influence of voltage supply on the detection object 1 and shorten the detection time.

[0192] In the first embodiment, the voltage measuring unit 120 constitutes a voltage measuring means for measuring a voltage signal (Vmv) generated in the detection target 1 , and the current measuring unit 140 constitutes a current measuring means for measuring a current signal (Vmi) output from the detection target 1 .

[0193] Furthermore, the processing unit 200 as the stop processing means stops the supply of current or voltage by the power supply unit 110 when a short circuit is detected based on the measurement signal Vmv indicating the voltage signal measured by the voltage measurement unit 120. At the same time, the processing unit 200 stops the supply of current or voltage by the power supply unit 110 when a short circuit is detected based on the measurement signal Vmi indicating the current signal measured by the current measurement unit 140.

[0194] According to this configuration, the short-circuit detection device 100 monitors the two measurement signals Vmi and Vmv, which are the voltage signal and the current signal generated in the detection target 1 , and thus can improve the accuracy of short-circuit detection.

[0195] Furthermore, in the first embodiment, the short-circuit detection device 100 includes the fluctuation detection circuits 130 and 150 including the maximum value holding circuit 150B and the fluctuation holding circuit 150C as the above-mentioned stop processing unit.

[0196] For example, the maximum value holding circuit 150B is a first holding circuit that holds the peak value of the measurement signal Vmi from the current measuring unit 140 and outputs a first holding signal Vh3 indicating the peak value of the held measurement signal Vmi. Furthermore, the variation holding circuit 150C is a second holding circuit that holds the peak value of a differential signal indicating the difference between the measurement signal Vmi and the first holding signal Vh3 and outputs a second holding signal Vh4 indicating the peak value of the held differential signal.

[0197] Furthermore, the processing unit 200 configures a determination unit that determines whether or not the measurement signals Vmi and Vmv have changed based on the second hold signal Vh4 output from the change hold circuit 150C.

[0198] According to this configuration, the second hold signals Vh2 and Vh4 are signals representing the fluctuation components of the measurement signals Vmv and Vmi, respectively, so the fluctuations of the measurement signals Vmv and Vmi can be determined with high accuracy. Thus, a short circuit can be accurately detected, thereby suppressing the influence of the power supply unit 110 on the detection object 1 and shortening the detection time.

[0199] (Second Embodiment)

[0200] Next, refer to Fig. 9 , the structure of the short-circuit detection device 100 according to the second embodiment will be described.

[0201] The short-circuit detection device 100 of the second embodiment deletes the fluctuation detection circuits 130 and 150, and detects fluctuations of the measurement signals Vmv and Vmi in the processing unit 200. The other configurations are the same or equivalent to those of the first embodiment.

[0202] Fig. 9 It is a block diagram showing the functional configuration of the processing unit 200 according to the second embodiment.

[0203] The processing unit 200 of the second embodiment includes a power supply control unit 210 , a digital detection unit 220 , and an immediate stop unit 230 as functional components.

[0204] The power supply control unit 210 controls the operation of the current limiter 111 and the constant voltage source 112 constituting the power supply unit 110 to supply voltage to the detection object 1. Specifically, when receiving the supply instruction signal from the operation receiving unit 400, the power supply control unit 210 controls the current limiter 111 so that the output current of the constant voltage source 112 does not exceed the upper limit value, and controls the constant voltage source 112 to supply the voltage V to the detection object 1.

[0205] The digital detection unit 220 is a detection unit that detects the change in the measurement signals Vmv and Vmi caused by the short circuit. In particular, the digital detection unit 220 is a digital processing unit that detects the change in the measurement signals Vmv and Vmi by processing the digital signal obtained by sampling the measurement signals Vmv and Vmi.

[0206] The digital detection unit 220 of the second embodiment includes a threshold holding unit 221 , an HPF processing unit 222 , and a short-circuit determination unit 223 .

[0207] The threshold value holding unit 221 is a memory that holds a threshold value for determining whether a short circuit has occurred in the detection object 1. In the threshold value holding unit 221 of the second embodiment, a voltage threshold value related to the measurement signal Vmv output from the voltage measuring unit 120 and a current threshold value related to the measurement signal Vmi output from the current measuring unit 140 are held. The current threshold value and the voltage threshold value are determined in advance by experiments or simulations.

[0208] The HPF processing unit 222 constitutes a filter processing unit that extracts a predetermined high-frequency component generated by a short circuit in the detection target object 1 from the measurement signals Vmv and Vmi. The HPF processing unit 222 is implemented by a processor that extracts the predetermined high-frequency component by digital processing.

[0209] In the second embodiment, the HPF processing unit 222 has the same function as the HPF circuit 150A. The HPF processing unit 222 acquires measurement data obtained by sampling the measurement signals Vmv and Vmi by the AD converter 160, and performs high-pass filter processing on the measurement data.

[0210] The HPF processing unit 222 outputs the measurement data after the high-pass filter processing to the short-circuit determination unit 223. The measurement data output from the HPF processing unit 222 is processed into an extraction signal including a fluctuation component accompanying a short circuit in the detection target object 1.

[0211] The short-circuit determination unit 223 constitutes determination means for determining whether or not at least one of the measurement signals Vmv and Vmi has changed based on the measurement data output from the HPF processing unit 222 .

[0212] In the second embodiment, the short circuit determination unit 223 determines whether the measurement data based on the measurement signal Vmv exceeds the voltage threshold. If the short circuit determination unit 223 determines that the measurement data exceeds the voltage threshold, it determines that a short circuit has occurred in the detection object 1, and if the measurement data does not exceed the voltage threshold, it determines that a short circuit has not occurred in the detection object 1.

[0213] Furthermore, the short circuit determination unit 223 determines whether the measurement data based on the measurement signal Vmi exceeds the current threshold value. If the short circuit determination unit 223 determines that the measurement data exceeds the voltage threshold value, it determines that a short circuit has occurred in the detection object 1, and if the measurement data does not exceed the voltage threshold value, it determines that a short circuit has not occurred in the detection object 1.

[0214] The short-circuit determination unit 223 outputs a determination result indicating whether a short circuit has occurred in the detection target object 1 to the immediate stop unit 230 .

[0215] The immediate stop unit 230 constitutes a stop control means for stopping the supply of current or voltage by the power supply unit 110 when the measurement data output from the HPF processing unit 222 exceeds a threshold value.

[0216] The immediate stop unit 230 of the second embodiment issues a command to the power supply control unit 210 to continue or stop supplying voltage to the detection target object 1 based on the determination result from the short-circuit determination unit 223 .

[0217] Specifically, when the short circuit determination unit 223 determines that a short circuit has occurred, the immediate stop unit 230 instructs the power supply control unit 210 to immediately stop the voltage supply. As a result, the power supply control unit 210 stops the voltage supplied from the constant voltage source 112 to the detection target 1.

[0218] On the other hand, when the short circuit determination unit 223 determines that a short circuit has not occurred, the immediate stop unit 230 instructs the power supply control unit 210 to continue the voltage supply. Thus, the power supply control unit 210 continues to supply voltage from the constant voltage source 112 to the detection target 1 .

[0219] Next, the effects achieved by the second embodiment will be described.

[0220] The short-circuit detection device 100 of the second embodiment includes: a power supply unit 110 that supplies a current or a voltage to the detection object 1 until the voltage of the detection object 1 reaches a predetermined voltage value V1; and a voltage measuring unit 120 and a current measuring unit 140 that measure a signal generated by the power supply unit 110 in the detection object 1. In addition, the short-circuit detection device 100 includes a processing unit 200 that stops the supply of current or voltage by the power supply unit 110 when a short circuit in the detection object 1 is detected based on the signal measured by at least one of the voltage measuring unit 120 and the current measuring unit 140.

[0221] According to this configuration, the short circuit detection device 100 of the second embodiment stops the current or voltage supplied to the detection object 1 when a short circuit is detected in the detection object 1, similarly to the first embodiment. This can suppress a reduction in the yield of the detection object 1 and shorten the time required for short circuit detection.

[0222] In addition, the processing unit 200 of the second embodiment includes an HPF processing unit 222 as a filter processing unit, and the HPF processing unit 222 extracts a predetermined high-frequency component caused by a short circuit in the measurement signals Vmv and Vmi. In addition, the processing unit 200 includes an immediate stop unit 230 as a stop control unit, and the immediate stop unit 230 stops the supply of current or voltage by the power supply unit 110 when the measurement data indicating the fluctuation component of the extraction signal output from the HPF processing unit 222 exceeds a threshold value.

[0223] In the processing unit 200 , the HPF processing unit 222 is a processor that extracts the above-mentioned predetermined high-frequency component by digital processing.

[0224] According to this configuration, the processor extracts the above-mentioned predetermined high-frequency component in the measurement signals Vmv and Vmi, thereby reducing Figure 1 The analog components of the fluctuation detection circuits 130 and 150 shown in FIG. 1 can reduce the cost of the analog components and the mounting area of ​​the analog components in the short-circuit detection device 100 .

[0225] In addition, since the signal delay in the fluctuation detection circuits 130 and 150 can be shortened, when a short circuit is detected in the detection object 1 , the voltage supply to the detection object 1 can be stopped promptly.

[0226] (Third Embodiment)

[0227] Next, the configuration of the short-circuit detection device according to the third embodiment will be described.

[0228] The short circuit detection device 100 of the third embodiment includes the functional configuration of the processing unit 200 of the second embodiment in addition to the configuration of the first embodiment.

[0229] That is, the short-circuit detection device 100 of the third embodiment has a method for executing analog processing in order to detect the changes of the measurement signals Vmv and Vmi. Figure 1 The change detection circuits 130 and 150 and the digital processing Fig. 9 The digital detection unit 220 is provided.

[0230] In the third embodiment, the voltage measuring unit 120 outputs the measurement signal Vmv to the fluctuation detection circuit 130 for analog processing, and outputs the measurement signal Vmv to the AD converter 160 for digital processing. Similarly, the current measuring unit 140 outputs the measurement signal Vmi to the fluctuation detection circuit 150 for analog processing, and outputs the measurement signal Vmi to the AD converter 160 for digital processing.

[0231] As described above, the short-circuit detection device 100 according to the third embodiment uses both digital processing and analog processing in the process of detecting the changes in the measurement signals Vmv and Vmi.

[0232] Next, refer to Fig. 10A and Fig. 10B , the digital processing and analog processing of the short-circuit detection device 100 according to the third embodiment will be described.

[0233] Fig. 10A This is a diagram for explaining the operation of the digital detection unit 220 according to the third embodiment.

[0234] Fig. 10A (a) shows an example of the change in the voltage generated between the two electrodes of the detection object 1. Fig. 10A (b) shows the processing of the HPF processing unit 222 to represent Fig. 10A The measurement signal Vmv of the voltage between the two electrodes of the detection target 1 shown in (a) is an output signal after high-pass filtering is performed.

[0235] Here, for easy understanding, changes in signals when a voltage is continuously supplied to the detection target 1 even when a short circuit is detected in the detection target 1 are shown.

[0236] like Fig. 10A As shown in (b), the HPF processing unit 222 extracts the predetermined high frequency component caused by the short circuit in the measurement signal Vmv. Then, the short circuit determination unit 223 determines that a short circuit has occurred in the detection object 1 at the time point Td when the variation component of the extracted signal exceeds the first voltage threshold Thv1.

[0237] In a third embodiment, if Figure 8B As shown, when it is determined that a short circuit has occurred in the detection object 1 , the immediate stop unit 230 stops the operation of the power supply unit 110 to immediately stop the voltage supply to the detection object 1 .

[0238] exist Fig. 10A In the description above, an example is described in which a short circuit occurring in the detection object 1 is detected based on the measurement signal Vmv. However, the measurement signal Vmi indicating the magnitude of the leakage current of the detection object 1 is also processed by the digital detection unit 220 in the same manner.

[0239] Fig. 10B This is a diagram for explaining the operation of the fluctuation detection circuit 130 according to the third embodiment.

[0240] Fig. 10B (a) shows the Fig. 10A (a) Changes in the voltage between the two electrodes of the same detection object 1. Fig. 10B (b) shows the expression from Fig. 10B The peak hold circuit 151 that holds the peak value of the voltage measurement signal Vmv shown in (a) outputs the first held signal Vh1.

[0241] Fig. 10B (c) shows the second held signal Vh2 output from the peak hold circuit 153 that holds the peak value of the difference signal indicating the difference between the measurement signal Vmv and the first held signal Vh1.

[0242] like Fig. 10B As shown in (c), the change of the measurement signal Vmv is detected by the change detection circuit 130. Then, the short circuit determination unit 223 determines that a short circuit has occurred in the object 1 at the time point Td when the detected change component of the second hold signal Vh2 exceeds the second voltage threshold Thv2.

[0243] Then, when it is determined by the short circuit determination unit 223 that a short circuit has occurred in the detection target object 1, as shown in FIG. Figure 8B As shown, the immediate stop unit 230 stops the operation of the power supply unit 110 to immediately stop the voltage supply to the detection target 1 .

[0244] exist Fig. 10B In the description, an example is described in which a short circuit occurring in the detection object 1 is detected based on the measurement signal Vmv. However, the measurement signal Vmi indicating the magnitude of the leakage current of the detection object 1 is also analog-processed by the fluctuation detection circuit 150.

[0245] As described above, in the third embodiment, by using both analog processing and digital processing to detect changes in each of the measurement signals Vmv and Vmi, it is possible to reduce missed detection of short circuits.

[0246] When digital processing and analog processing are used together, from the perspective of reducing the impact on the detection object 1, the voltage supply to the detection object 1 may be stopped at the timing when a short circuit is detected in either processing. On the other hand, from the perspective of suppressing false detection, the voltage supply to the detection object 1 may be stopped only when a short circuit is detected by both digital processing and analog processing.

[0247] Next, the effects achieved by the third embodiment will be described.

[0248] The short-circuit detection device 100 according to the third embodiment includes a digital detection unit 220 and fluctuation detection circuits 130 and 150 as the detection means.

[0249] The digital detection unit 220 constitutes a digital processing unit that detects changes in the measurement signals Vmv and Vmi by processing digital signals obtained by sampling the measurement signals Vmv and Vmi.

[0250] The change detection circuit 130 constitutes an analog processing unit that detects a change in the voltage signal by processing the analog signal (Vmv) indicating the magnitude of the voltage signal of the detection object 1 measured by the voltage measurement unit 120. The change detection circuit 150 constitutes an analog processing unit that detects a change in the current signal by processing the analog signal (Vmv) indicating the magnitude of the current signal of the detection object 1 measured by the current measurement unit 140.

[0251] According to this configuration, even if temporary fluctuations due to sampling processing are missed in the digital detection unit 220, fluctuations in the measurement signals Vmv and Vmi are accurately detected in the fluctuation detection circuits 130 and 150. Therefore, the voltage supply to the detection target 1 can be stopped accurately.

[0252] In addition, if Figure 4 As shown in FIG. 1 , when the measurement signal Vmi gradually decreases from the switching time T1 during the steady-state period Ts, the change detection circuit 150 may miss detection when the peak values ​​of the peak holding circuits 151 and 153 are reset. Even in such a case, since the change of the measurement signal Vmi is accurately detected in the digital detection unit 220, the voltage supply to the detection object 1 can be accurately stopped.

[0253] Thus, by using digital processing and analog processing together, even if a short circuit is missed in one process, the short circuit can be correctly detected in the other process, thereby improving the detection accuracy. Therefore, the supply of voltage or current to the detection object 1 can be stopped more accurately, thereby suppressing the reduction of the yield of the detection object 1 and shortening the time required for the detection of the short circuit.

[0254] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0255] For example, in the first to third embodiments, as a method of stopping the supply of current or voltage to the detection object 1, an example of stopping the operation of the power supply unit 110 is described, but the present invention is not limited thereto. For example, a switch for switching the connection state between the detection object 1 and the power supply unit 110 may be pre-configured, and when the processing unit 200 detects a short circuit in the detection object 1, the switch is switched from the power-on state to the power-off state.

[0256] Furthermore, in the first to third embodiments, an example in which changes in each of the two measurement signals Vmv and Vmi are detected is described, but only a change in one of the measurement signals may be detected.

[0257] also, Figure 2 The circuit configuration of the IV conversion circuit 141 shown is an example, and the circuit configuration is not limited to this as long as it has the function of converting the input current into a voltage corresponding to the current value. Figure 2 The circuit configuration of the subtraction circuit 152 shown is just an example and is not limited to this.

[0258] Furthermore, in the first to third embodiments, the positive electrode (+) of the detection object 1 is connected to the connection terminal 101 of the short-circuit detection device 100, and the negative electrode (-) of the detection object 1 is connected to the connection terminal 102 of the short-circuit detection device 100. However, it is also possible that any one of the positive electrode (+) and the negative electrode (-) of the detection object 1 and the housing constituting the detection object 1 are connected to the connection terminals 101 and 102 of the short-circuit detection device 100, respectively.

[0259] This application claims priority based on Japanese Patent Application No. 2022-165670 filed with the Japan Patent Office on October 14, 2022, the entire contents of which are incorporated into this specification by reference.

[0260] Description of Reference Numerals

[0261] 1: Detection object;

[0262] 110: power supply unit (charging unit, supply unit);

[0263] 120: voltage measuring unit (measuring unit, voltage measuring unit);

[0264] 140: current measuring unit (measuring unit, current measuring unit);

[0265] 130, 150: change detection circuit (stop processing unit, detection unit, analog processing unit);

[0266] 150A: HPF circuit (filter processing unit);

[0267] 150B: maximum value holding circuit (first holding circuit);

[0268] 150C: variable holding circuit (second holding circuit);

[0269] 200: Processing unit (stop processing unit, detection unit, determination unit);

[0270] 220: digital detection unit (detection unit, digital processing unit);

[0271] 222: HPF processing unit (filter processing unit).

Claims

1. A short circuit detection device for detecting a short circuit occurring in a secondary battery as a detection object, wherein: The short circuit detection device comprises: a charging unit that supplies current or voltage to the detection object to charge it until a predetermined charging end condition is met; a supply unit that supplies a voltage of a prescribed voltage value after the charging; a measuring unit for measuring a signal generated in the detection object by the supply unit; as well as The stop processing unit stops supply of the voltage when the short circuit is detected based on the signal measured by the measuring unit at least during a period when the supply unit supplies the voltage of the predetermined voltage value.

2. The short circuit detection device according to claim 1, wherein: The charging end condition is that the voltage of the detection object reaches the predetermined voltage value.

3. The short circuit detection device according to claim 1 or 2, wherein: The stop processing unit immediately stops the charging or stops the supply of the voltage when the short circuit is detected, and continues the charging or continues the supply of the voltage when the short circuit is not detected.

4. The short circuit detection device according to any one of claims 1 to 3, wherein: The stop processing unit comprises: a filtering processing unit for extracting a predetermined high-frequency component caused by the short circuit in the signal; and The stop control unit stops the supply of the current or the voltage by the supply unit when the fluctuation component of the extraction signal output from the filter processing unit exceeds a threshold value.

5. The short circuit detection device according to claim 4, wherein: The filter processing unit is a processor that extracts the prescribed high-frequency component by digital processing.

6. The short circuit detection device according to claim 4, wherein: The filtering processing unit is a high-pass filtering circuit.

7. The short circuit detection device according to any one of claims 1 to 6, wherein: The stop processing unit includes a detection unit configured to detect a change in the signal measured by the measurement unit caused by the short circuit. The detection unit comprises: a digital processing unit for detecting a change of the signal by processing a digital signal obtained by sampling the signal; and The analog processing unit detects a change in the signal by processing an analog signal indicating the magnitude of the signal.

8. The short-circuit detection device according to any one of claims 1 to 7, wherein: The measuring unit comprises: a voltage measuring unit for measuring a voltage signal generated in the detection object; and a current measuring unit for measuring a current signal output from the detection object; The stop processing unit stops the supply of the current or the voltage by the supply unit when the short circuit is detected based on the voltage signal, and The stop processing unit stops supply of the current or the voltage by the supply unit when the short circuit is detected based on the current signal.

9. The short circuit detection device according to any one of claims 1 to 8, wherein: The stop processing unit comprises: a first holding circuit that holds a peak value of a measurement signal from the measurement unit and outputs a first holding signal indicating the held peak value of the measurement signal; a second holding circuit that holds a peak value of a differential signal indicating a difference between the measurement signal and the first held signal, and outputs a second held signal indicating a peak value of the held differential signal; and The determination unit determines whether or not the measurement signal has changed based on the second hold signal output from the second hold circuit.

10. A short circuit detection method for detecting a short circuit occurring in a secondary battery as a detection object, wherein: The short circuit detection method comprises: a charging step of supplying current or voltage to the detection object to charge the object until a predetermined charging end condition is met; a supplying step of supplying a voltage of a prescribed voltage value after the charging; a measuring step of measuring a signal generated in the detection object by the supplying step; and The stop processing step stops supply of the voltage when the short circuit is detected based on the signal measured in the measuring step at least during the period when the voltage of the predetermined voltage value is supplied in the supplying step.

11. A program for causing a computer for detecting a short circuit occurring in a secondary battery as a detection object to execute the following steps: a charging step of supplying current or voltage to the detection object to charge the object until a predetermined charging end condition is met; a supplying step of supplying a voltage of a prescribed voltage value after the charging; a measuring step of measuring a signal generated in the detection object by the supplying step; as well as The stop processing step stops supply of the voltage when the short circuit is detected based on the signal measured in the measuring step at least during the period when the voltage of the predetermined voltage value is supplied in the supplying step.

Images