Arc detection devices, power conditioners, indoor wiring systems, circuit breakers, solar panels, solar panel accessory modules, and junction boxes

Abstract

The arc detection device (10a) comprises: a current detection unit (20a) having a magnetic core (21) through which a first path (51a) and a second path (52a) connecting a DC power supply (40) and a device (50) pass, and detecting currents flowing in the first path (51a) and the second path (52a) based on a magnetic field generated in the magnetic core (21); a low impedance circuit (11a) having an impedance lower than the impedance of the DC power supply (40) and the impedance of the device (50), connected to the first path (51a) and the second path (52a), and used to bypass a high frequency component flowing to one of the first path (51a) and the second path (52a); and an arc determination unit (30) determining the occurrence of an arc based on the current detected by the current detection unit (20a), wherein in the magnetic core (21), the direction of the DC current flowing in the first path (51a) and the direction of the DC current flowing in the second path (52a) are opposite to each other.

Description

Technical Field

[0001] The invention relates to an arc detection device, a power conditioner, an indoor wiring system, a circuit breaker, a solar panel, a solar panel accessory module and a junction box. Background Art

[0002] In the past, there is a known system that uses an inverter or other device to convert DC power supplied from a PV (Photo Voltaic) panel (solar panel) or the like via wiring into AC power. It is reported that such wiring may be damaged or broken due to external factors, aging, etc. Sometimes, an arc (i.e., arc discharge) occurs due to damage to such wiring or the like. Therefore, an arc detection unit for detecting an arc has been proposed (for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-7765 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The method detects the magnetic field generated in the current sensor by the current flowing in the wiring, and detects the arc based on the current corresponding to the magnetic field. However, in this method, magnetic saturation may occur in the magnetic core of the current sensor, and the arc cannot be accurately detected.

[0008] Therefore, an object of the present invention is to provide an arc detection device or the like that can accurately detect an arc.

[0009] Solutions for solving problems

[0010] One mode of the arc detection device involved in the present invention comprises: a current detection unit, which has a magnetic core through which a first path and a second path connecting a DC power supply to a device pass, and detects the current flowing in the first path and the second path based on the magnetic field generated in the magnetic core; a low-impedance circuit whose impedance is lower than the impedance of the DC power supply and the impedance of the device, the low-impedance circuit is connected to the first path and the second path, and is used to bypass the high-frequency component flowing to one of the first path and the second path; and an arc determination unit, which determines the occurrence of an arc based on the current detected by the current detection unit, wherein, in the magnetic core, the direction of the DC current flowing in the first path is opposite to the direction of the DC current flowing in the second path.

[0011] One aspect of a power conditioner according to the present invention includes the arc detection device described above and a converter that converts output power of the DC power supply.

[0012] One aspect of an indoor wiring system according to the present invention includes the above-mentioned arc detection device, the first path, the second path, and the equipment installed indoors.

[0013] One aspect of a circuit breaker according to the present invention includes the above-described arc detection device, and when it is determined that an arc has occurred, the circuit breaker interrupts the current flowing through the first path and the second path.

[0014] One aspect of a solar panel according to the present invention includes the above-mentioned arc detection device, and the solar panel generates electric power using solar energy.

[0015] One aspect of a solar panel accessory module according to the present invention includes the above-mentioned arc detection device, and the solar panel accessory module is used to convert a signal output from a solar panel.

[0016] One aspect of a junction box according to the present invention includes the above-mentioned arc detection device, and the junction box is used to connect a solar panel and a power conditioner.

[0017] Effects of the Invention

[0018] According to one aspect of the present invention, an arc can be accurately detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1A This is a configuration diagram showing an example of the arc detection device according to the first embodiment.

[0020] Figure 1B This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to the first embodiment.

[0021] Figure 1C This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to the first embodiment.

[0022] Figure 2A This is a configuration diagram showing an example of an arc detection device according to Modification 1 of Embodiment 1.

[0023] Figure 2B This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 1 of Embodiment 1.

[0024] Figure 2CThis is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 1 of Embodiment 1.

[0025] Figure 3A This is a configuration diagram showing an example of an arc detection device according to Modification 2 of Embodiment 1.

[0026] Figure 3B This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 2 of Embodiment 1.

[0027] Figure 3C This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 2 of Embodiment 1.

[0028] Figure 4A This is a configuration diagram showing an example of an arc detection device according to Modification 3 of Embodiment 1.

[0029] Figure 4B This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 3 of Embodiment 1.

[0030] Figure 4C This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 3 of Embodiment 1.

[0031] Figure 5A This is a configuration diagram showing an example of an arc detection device according to Modification 4 of Embodiment 1.

[0032] Figure 5B This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 4 of Embodiment 1.

[0033] Figure 5C This is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device according to Modification 4 of Embodiment 1.

[0034] Fig. 6A This is a configuration diagram showing an example of a solar power generation system according to the second embodiment.

[0035] Figure 6B This is a configuration diagram showing an example of a solar power generation system according to a modification of the second embodiment.

[0036] Fig. 7A This is a configuration diagram showing an example of a solar power generation system according to the third embodiment.

[0037] Figure 7B This is a configuration diagram showing an example of a solar power generation system according to a modification of the third embodiment.

[0038] Fig. 8A This is a configuration diagram showing an example of a solar power generation system according to a fourth embodiment.

[0039] Figure 8B This is a configuration diagram showing an example of a solar power generation system according to a modification of the fourth embodiment.

[0040] Fig. 9A This is a configuration diagram showing an example of a solar power generation system according to the fifth embodiment.

[0041] Fig. 9B This is a configuration diagram showing an example of a solar power generation system according to a modification of the fifth embodiment.

[0042] Fig.10 This is a configuration diagram showing an example of an indoor wiring system according to the sixth embodiment.

[0043] Fig.11 It is a diagram for explaining an application example of the arc detection device according to the present invention. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments to be described below all represent a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, configuration positions of components, and connection forms shown in the following embodiments are examples and are not intended to limit the present invention.

[0045] In addition, each figure is a schematic diagram and does not necessarily illustrate the diagram strictly. In addition, in each figure, the same reference numerals are attached to substantially the same structure, and repeated descriptions are omitted or simplified.

[0046] (Implementation Method 1)

[0047] Figure 1A : is a structural diagram showing an example of the arc detection device 10a according to the first embodiment. Figure 1A A DC power source 40 and a device 50 are also shown.

[0048] The DC power supply 40 is a power supply that generates DC power. The DC power generated by the DC power supply 40 is supplied to the device 50. The DC power supply 40 has a positive electrode and a negative electrode, the positive electrode is connected to the wiring 41a, and the negative electrode is connected to the wiring 42a. The DC power supply 40 supplies DC power to the device 50 via the wirings 41a and 42a.

[0049] Device 50 is a device to which DC power is supplied from DC power supply 40 via wirings 41a and 42a. The type of device 50 is not particularly limited. For example, device 50 may be a converter such as a DC / DC converter, or may be a device such as a lighting fixture, a speaker, or a microphone installed indoors.

[0050] Wiring 41a and 42a connect the DC power supply 40 and the device 50. Wiring 41a is an example of a first wiring connected to one of the positive and negative electrodes of the DC power supply 40. Here, wiring 41a is connected to the positive electrode, which is one of the positive and negative electrodes of the DC power supply 40. Wiring 42a is an example of a second wiring connected to the other of the positive and negative electrodes of the DC power supply 40. Here, wiring 42a is connected to the negative electrode, which is the other of the positive and negative electrodes of the DC power supply 40.

[0051] The wirings 41a and 42a penetrate the magnetic core 21 described later, and the portion (path) of the wiring 41a that penetrates the magnetic core 21 is set as the path 51a, and the portion (path) of the wiring 42a that penetrates the magnetic core 21 is set as the path 52a. The path 51a is a path on the wiring 41a that connects the DC power supply 40 and the device 50, so it can be said that the path 51a also connects the DC power supply 40 and the device 50. The path 51a is an example of a first path connecting the DC power supply 40 and the device 50. The path 52a is a path on the wiring 42a that connects the DC power supply 40 and the device 50, so it can be said that the path 52a also connects the DC power supply 40 and the device 50. The path 52a is an example of a second path connecting the DC power supply 40 and the device 50.

[0052] In the magnetic core 21, the direction of the DC current flowing in the path 51a is opposite to the direction of the DC current flowing in the path 52a. The path 51a is a path on the wiring 41a connected to the positive pole of the DC power supply 40, and the path 52a is a path on the wiring 42a connected to the negative pole of the DC power supply 40. It can be seen from this that the direction of the DC current flowing in the path 51a is opposite to the direction of the DC current flowing in the path 52a. Figure 1A , the direction of the direct current flowing in the path 51 a and the direction of the direct current flowing in the path 52 a are shown by arrows near the magnetic core 21 .

[0053] The arc detection device 10 a is a device for detecting an arc, and includes a low impedance circuit 11 a , a current detection unit 20 a , and an arc determination unit 30 .

[0054] The current detection unit 20 a includes a magnetic core 21 through which the paths 51 a and 52 a pass, and detects the current flowing through the paths 51 a and 52 a based on the magnetic field generated in the magnetic core 21 .

[0055] The magnetic core 21 is an annular shape (here, a circular ring shape) through which wiring can pass, and a magnetic field corresponding to the current is generated in the core due to the current flowing in the wiring that passes through the hole of the magnetic core 21. In addition, the magnetic core 21 is not limited to a circular ring shape, and can also be a rectangular ring shape.

[0056] The current detection unit 20a includes, for example, a Hall element (not shown) that detects a magnetic field generated in the magnetic core 21 and generates a voltage corresponding to the magnetic field generated in the magnetic core 21. The voltage generated by the Hall element is input to the arc determination unit 30 as a signal representing the magnetic field generated in the magnetic core 21, that is, the current flowing in the path penetrating the magnetic core 21.

[0057] The low impedance circuit 11a is a circuit having an impedance lower than the impedance of the DC power supply 40 and the impedance of the device 50. The low impedance circuit 11a is connected to the paths 51a and 52a, and is a circuit for bypassing the high frequency component flowing to one of the paths 51a and 52a. The low impedance circuit 11a is, for example, a capacitor, and has a lower impedance than the capacitance component of the DC power supply 40 and the capacitance component of the device 50. Since the capacitor has a function of blocking the DC component, it is possible to extract only the high frequency component from the signal flowing in the wirings 41a and 42a. The capacitance value of the capacitor is appropriately determined according to the frequency of the high frequency component to be extracted, etc. The low impedance circuit 11a has a lower impedance than the DC power supply 40 and the device 50, so in the wirings 41a and 42a, the high frequency component easily flows to the low impedance circuit 11a.

[0058] Specifically, the low-impedance circuit 11a is arranged on a bypass path 43a connecting a connection point N1a on a wiring 41a and a connection point N2a on a wiring 42a, wherein the connection point N1a on the wiring 41a is located between one of the positive and negative poles of the DC power supply 40 (here the positive pole) and the magnetic core 21, and the connection point N2a on the wiring 42a is located between the magnetic core 21 and the device 50.

[0059] The arc determination unit 30 is realized by, for example, a microcomputer (microcontroller). A microcomputer is a semiconductor integrated circuit having a ROM and a RAM storing programs, a processor (CPU: Central Processing Unit) for executing the programs, a timer, an A / D converter, and a D / A converter. In addition, the arc determination unit 30 may be realized in hardware by a dedicated electronic circuit composed of an A / D converter, a logic circuit, a gate array, and a D / A converter.

[0060] The arc determination unit 30 determines the occurrence of an arc based on the current detected by the current detection unit 20a. For example, the arc determination unit 30 determines the occurrence of an arc in the wiring 41a or 42a by performing frequency analysis on the current detected by the current detection unit 20a. The current on which the high-frequency component generated by the occurrence of an arc is superimposed contains a frequency component caused by the arc, and the occurrence of an arc can be determined by detecting the frequency component.

[0061] Generally, it is considered that the magnetic core 21 is provided in a manner that only one of the wirings 41a and 42a (for example, only the wiring 41a) is passed through, but in this case, a large DC current from the DC power supply 40 flows in the wiring 41a, and there is a possibility that the magnetic core 21 may be magnetically saturated. Therefore, when an arc occurs in the wiring 41a, the high-frequency component caused by the arc superimposed on the DC current flowing in the wiring 41a may not be accurately detected due to the magnetic saturation caused by the DC current.

[0062] In addition, when only the magnetic core 21 is provided so as to be penetrated by both wirings 41a and 42a, since the direction of the current flowing in the wiring 41a is opposite to the direction of the current flowing in the wiring 42a, the magnetic field caused by the DC current flowing in the wiring 41a and the magnetic field caused by the DC current flowing in the wiring 42a can cancel each other out, thereby preventing magnetic saturation. However, the magnetic field generated by the high-frequency component based on the occurrence of the arc is also canceled out, making it difficult to detect the occurrence of the arc.

[0063] Here, the arc detection device 10 has a low-impedance circuit 11a, which is arranged on a bypass path 43a connecting a connection point N1a on a wiring 41a and a connection point N2a on a wiring 42a, wherein the connection point N1a on the wiring 41a is located between one of the positive and negative poles of the DC power supply 40 (here the positive pole) and the magnetic core 21, and the connection point N2a on the wiring 42a is located between the magnetic core 21 and the device 50.

[0064] The low impedance circuit 11a (such as a capacitor) is an element that blocks direct current and allows alternating current (high-frequency component) to pass, and is used to allow the high-frequency component contained in the current flowing through the wiring 41a or 42a to flow to the bypass path 43a. Figure 1B and Figure 1C The principle of how the arc detection device 10a can accurately detect an arc by including such a low impedance circuit 11a will be described.

[0065] Figure 1B and Figure 1C 1 is a diagram showing an example of a current flowing through a wiring when an arc occurs in the arc detection device 10a according to the first embodiment. Figure 1BIn FIG. 4 , it is assumed that an arc occurs in the portion between the positive electrode of the DC power source 40 and the connection point N1a in the wiring 41a. Figure 1C In FIG. 4 , it is assumed that an arc occurs in the portion between the device 50 and the magnetic core 21 in the wiring 42a. Figure 1B and Figure 1C In FIG. 1 , the thick dotted line indicates the flow of high-frequency components generated by the arc.

[0066] As described above, the magnetic field generated in the magnetic core 21 by the DC current flowing in the path 51a and the magnetic field generated by the DC current flowing in the path 52a cancel each other, thereby preventing magnetic saturation. In addition, these DC currents do not flow to the bypass path 43a due to the low impedance circuit 11a (capacitor) that blocks the DC current.

[0067] First, for Figure 1B As shown, the principle of accurately detecting an arc when an arc occurs in the portion between the positive electrode of the DC power supply 40 and the connection point N1a in the wiring 41a will be described.

[0068] The high-frequency component caused by the arc flows to the bypass path 43a at the connection point N1a. This is because the high-frequency component does not flow in the path 51a connecting the connection point N1a and the device 50, but flows in the bypass path 43a provided with the low-impedance circuit 11a. Then, the high-frequency component flows in the path 52a connecting the connection point N2a and the DC power supply 40. In this way, the bypass path 43a becomes a path that bypasses the path 51a, and the high-frequency component flows in the path 52a at the magnetic core 21, while it does not flow in the path 51a. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51a and the magnetic field corresponding to the DC current flowing in the path 52a cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 52a is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0069] Next, for Figure 1C As shown, the principle of accurately detecting an arc when an arc occurs in the portion between the device 50 and the magnetic core 21 in the wiring 42a will be described.

[0070] The high-frequency component caused by the arc flows in the path 51a at the magnetic core 21, and flows to the bypass path 43a at the connection point N1a. This is because the high-frequency component does not flow in the path connecting the connection point N1a to the DC power supply 40, but flows in the bypass path 43a provided with the low-impedance circuit 11a. Then, the high-frequency component flows in the path connecting the connection point N2a to the device 50. In this way, the bypass path 43a becomes a path that bypasses the path 52a, and the high-frequency component flows in the path 51a at the magnetic core 21, while it does not flow in the path 52a. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51a and the magnetic field corresponding to the DC current flowing in the path 52a cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 51a is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0071] As described above, the arc detection device 10a involved in this embodiment includes: a current detection unit 20a, which has a magnetic core 21 through which a first path (for example, path 51a) and a second path (for example, path 52a) connecting a DC power supply 40 and a device 50 are penetrated, and the current flowing in the first path and the second path is detected based on the magnetic field generated in the magnetic core 21; a low-impedance circuit 11a whose impedance is lower than the impedance of the DC power supply 40 and the impedance of the device 50, the low-impedance circuit 11a is connected to the first path and the second path, and is used to bypass the high-frequency component flowing to one of the first path and the second path; and an arc determination unit 30, which determines the occurrence of an arc based on the current detected by the current detection unit 20a, wherein, in the magnetic core 21, the direction of the DC current flowing in the first path is opposite to the direction of the DC current flowing in the second path.

[0072] Thus, since both the first path and the second path through which the DC currents in opposite directions flow pass through the magnetic core 21, the magnetic field caused by the DC current flowing in the first path and the magnetic field caused by the DC current flowing in the second path generated in the magnetic core 21 cancel each other out, thereby preventing magnetic saturation. In addition, since the low impedance circuit 11a is provided to bypass the high-frequency components caused by the arc flowing to any one of the first path and the second path, the high-frequency components caused by the arc can be prevented from being canceled out. Therefore, the arc can be accurately detected.

[0073] For example, the DC power supply 40 may supply power to the device 50 via a first wiring (e.g., wiring 41a) and a second wiring (e.g., wiring 42a), the first wiring being connected to one of the positive and negative electrodes of the DC power supply 40, the second wiring being connected to the other of the positive and negative electrodes of the DC power supply, the first path being a path on the first wiring, and the second path being a path on the second wiring.

[0074] Thus, by using the first wiring and the second wiring respectively connected to electrodes of different polarities, the direction of the DC current flowing in the first path of the first wiring and the direction of the DC current flowing in the second path of the second wiring can be set to opposite directions.

[0075] For example, the low-impedance circuit 11a may be arranged on a bypass path 43a connecting a connection point on a first wiring (e.g., connection point N1a) and a connection point on a second wiring (e.g., connection point N2a), wherein the connection point on the first wiring is located between one of the positive and negative poles of the DC power supply 40 and the magnetic core 21, and the connection point on the second wiring is located between the magnetic core 21 and the device 50.

[0076] Thus, by utilizing the bypass path 43a to connect a connection point in the first wiring that is closer to the DC power supply 40 than the magnetic core 21 and a connection point in the second wiring that is closer to the device 50 than the magnetic core 21 via the low impedance circuit 11a, a high-frequency component flowing to one of the first path and the second path can be bypassed.

[0077] (Variation 1 of Implementation Example 1)

[0078] In the first embodiment, the following example is described: the low impedance circuit 11a is provided on the bypass path 43a connecting the connection point N1a on the wiring 41a and the connection point N2a on the wiring 42a, wherein the connection point N1a on the wiring 41a is located between the positive pole of the DC power supply 40 and the magnetic core 21, and the connection point N2a on the wiring 42a is located between the magnetic core 21 and the device 50, but the present invention is not limited to this example. In the first variant of the first embodiment, the following example is described: the low impedance circuit is provided on the bypass path connecting the connection point on the first wiring and the connection point on the second wiring, wherein the connection point on the first wiring is located between the negative pole of the DC power supply 40 and the magnetic core 21, and the connection point on the second wiring is located between the magnetic core 21 and the device 50.

[0079] Figure 2A : is a structural diagram showing an example of an arc detection device 10b according to a first modification of the first embodiment. Figure 2A Also shown is a DC power source 40 and a device 50.

[0080] The DC power source 40 has a positive electrode and a negative electrode. The positive electrode is connected to the wiring 41 b and the negative electrode is connected to the wiring 42 b. The DC power source 40 supplies DC power to the device 50 via the wirings 41 b and 42 b.

[0081] The device 50 is a device to which DC power is supplied from the DC power supply 40 via the wirings 41 b and 42 b.

[0082] Wiring 41b and 42b connect the DC power supply 40 and the device 50. Wiring 42b is an example of a first wiring connected to one of the positive and negative electrodes of the DC power supply 40. Here, wiring 42b is connected to the negative electrode, which is one of the positive and negative electrodes of the DC power supply 40. Wiring 41b is an example of a second wiring connected to the other of the positive and negative electrodes of the DC power supply 40. Here, wiring 41b is connected to the positive electrode, which is the other of the positive and negative electrodes of the DC power supply 40.

[0083] The wirings 41b and 42b penetrate the magnetic core 21, and the portion (path) of the wiring 41b that penetrates the magnetic core 21 is set as the path 51b, and the portion (path) of the wiring 42b that penetrates the magnetic core 21 is set as the path 52b. The path 51b is a path on the wiring 41b that connects the DC power supply 40 and the device 50, so it can be said that the path 51b also connects the DC power supply 40 and the device 50. The path 51b is an example of a second path connecting the DC power supply 40 and the device 50. The path 52b is a path on the wiring 42b that connects the DC power supply 40 and the device 50, so it can be said that the path 52b also connects the DC power supply 40 and the device 50. The path 52b is an example of a first path connecting the DC power supply 40 and the device 50.

[0084] In the magnetic core 21, the direction of the DC current flowing in the path 51b is opposite to the direction of the DC current flowing in the path 52b. The path 51b is a path on the wiring 41b connected to the positive electrode of the DC power supply 40, and the path 52b is a path on the wiring 42b connected to the negative electrode of the DC power supply 40. It can be seen from this that the direction of the DC current flowing in the path 51b is opposite to the direction of the DC current flowing in the path 52b. Figure 2A , the direction of the direct current flowing in the path 51 b and the direction of the direct current flowing in the path 52 b are indicated by arrows near the magnetic core 21 .

[0085] The arc detection device 10 b is a device for detecting an arc, and includes a low impedance circuit 11 b , a current detection unit 20 b , and an arc determination unit 30 .

[0086] The current detection unit 20 b includes a magnetic core 21 through which the paths 51 b and 52 b pass, and detects the current flowing through the paths 51 b and 52 b based on the magnetic field generated in the magnetic core 21 .

[0087] The current detection unit 20b includes, for example, a Hall element (not shown) that detects a magnetic field generated in the magnetic core 21 and generates a voltage corresponding to the magnetic field generated in the magnetic core 21. The voltage generated by the Hall element is input to the arc determination unit 30 as a signal representing the magnetic field generated in the magnetic core 21, that is, the current flowing in the path penetrating the magnetic core 21.

[0088] The low impedance circuit 11b is a circuit having an impedance lower than the impedance of the DC power supply 40 and the impedance of the device 50. The low impedance circuit 11b is connected to the paths 51b and 52b, and is a circuit for bypassing the high-frequency component flowing to one of the paths 51b and 52b. The low impedance circuit 11b is, for example, a capacitor, and has a lower impedance than the capacitance component of the DC power supply 40 and the capacitance component of the device 50. Since the capacitor has a function of blocking the DC component, it is possible to extract only the high-frequency component from the signal flowing in the wirings 41b and 42b. The capacitance value of the capacitor is appropriately determined according to the frequency of the high-frequency component to be extracted, etc. The low impedance circuit 11b has a lower impedance than the DC power supply 40 and the device 50, so in the wirings 41b and 42b, the high-frequency component easily flows to the low impedance circuit 11b.

[0089] Specifically, the low impedance circuit 11b is arranged on a bypass path 43b that connects a connection point N2b on a wiring 42b and a connection point N1b on a wiring 41b, wherein the connection point N2b on the wiring 42b is located between one of the positive and negative poles (here the negative pole) of the DC power supply 40 and the magnetic core 21, and the connection point N1b on the wiring 41b is located between the magnetic core 21 and the device 50.

[0090] The arc determination unit 30 determines the occurrence of an arc based on the current detected by the current detection unit 20b. For example, the arc determination unit 30 determines the occurrence of an arc in the wiring 41b or 42b by performing a frequency analysis on the current detected by the current detection unit 20b.

[0091] The low impedance circuit 11b (such as a capacitor) is an element that blocks direct current and allows alternating current (high frequency component) to pass, and is used to make the high frequency component contained in the current flowing through the wiring 41b or 42b flow to the bypass path 43b. Figure 2B and Figure 2C The principle of how the arc detection device 10b can accurately detect an arc by including such a low impedance circuit 11b will be described.

[0092] Figure 2B and Figure 2C 1 is a diagram showing an example of current flowing in a wiring when an arc occurs in the arc detection device 10b according to the first modification of the first embodiment. Figure 2BIn FIG. 4 , it is assumed that an arc occurs in the portion between the positive electrode of the DC power supply 40 and the connection point N1b in the wiring 41b. Figure 2C In FIG. 4 , it is assumed that an arc occurs in the portion between the device 50 and the connection point N1b in the wiring 41b. Figure 2B and Figure 2C In FIG. 1 , the thick dotted line indicates the flow of high-frequency components generated by the arc.

[0093] As described above, the magnetic field generated in the magnetic core 21 by the DC current flowing in the path 51b and the magnetic field generated by the DC current flowing in the path 52b cancel each other, thereby preventing magnetic saturation. In addition, these DC currents do not flow to the bypass path 43b due to the low impedance circuit 11b (capacitor) that blocks the DC current.

[0094] First, for Figure 2B As shown, the principle of accurately detecting an arc when an arc occurs in the portion between the positive electrode of the DC power supply 40 and the connection point N1b in the wiring 41b will be described.

[0095] The high-frequency component caused by the arc flows in the path 51b at the magnetic core 21, and flows to the bypass path 43b at the connection point N1b. This is because the high-frequency component does not flow in the path connecting the connection point N1b and the device 50, but flows in the bypass path 43b provided with the low-impedance circuit 11b. Then, the high-frequency component flows in the path connecting the connection point N2a and the DC power supply 40. In this way, the bypass path 43b becomes a path that bypasses the path 52b, and the high-frequency component flows in the path 51b at the magnetic core 21, while it does not flow in the path 52b. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51b and the magnetic field corresponding to the DC current flowing in the path 52b cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 51b is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0096] Next, for Figure 2C As shown, the principle of accurately detecting an arc when an arc occurs in the portion between the device 50 and the connection point N1b in the wiring 41b will be described.

[0097] The high-frequency component caused by the arc flows to the bypass path 43b at the connection point N1b. This is because the high-frequency component does not flow in the path 51b connecting the connection point N1b and the DC power supply 40, but flows in the bypass path 43b provided with the low-impedance circuit 11b. Then, the high-frequency component flows in the path 52b connecting the connection point N2b and the device 50. In this way, the bypass path 43b becomes a path that bypasses the path 51b, and the high-frequency component flows in the path 52b at the magnetic core 21, while it does not flow in the path 51b. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51b and the magnetic field corresponding to the DC current flowing in the path 52b cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 52b is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0098] In this way, even when the low impedance circuit 11b is set on the bypass path 43b that connects the connection point N2b on the wiring 42b located between the negative pole of the DC power supply 40 and the magnetic core 21 with the connection point N1b on the wiring 41b located between the magnetic core 21 and the device 50, the arc can be accurately detected.

[0099] (Variation 2 of Implementation Example 1)

[0100] In the first embodiment, the following example is described: the path 51a passing through the magnetic core 21 is a path on the wiring 41a connected to one of the positive and negative poles of the DC power supply 40 (for example, the positive pole), and the path 52a passing through the magnetic core 21 is a path on the wiring 42a connected to the other of the positive and negative poles of the DC power supply 40 (for example, the negative pole), but the present invention is not limited to this example. In the second variation of the first embodiment, an example is described in which the two paths passing through the magnetic core 21 are paths on the first wiring connected to one of the positive and negative poles of the DC power supply 40.

[0101] Figure 3A : is a structural diagram showing an example of an arc detection device 10c according to a second modification of the first embodiment. Figure 3A A DC power source 40 and a device 50 are also shown.

[0102] The DC power source 40 has a positive electrode and a negative electrode. The positive electrode is connected to the wiring 41 c and the negative electrode is connected to the wiring 42 c. The DC power source 40 supplies DC power to the device 50 via the wirings 41 c and 42 c.

[0103] The device 50 is a device to which DC power is supplied from the DC power supply 40 via the wirings 41 c and 42 c.

[0104] Wiring 41c and 42c connect the DC power supply 40 and the device 50. Wiring 41c is an example of a first wiring connected to one of the positive and negative electrodes of the DC power supply 40. Here, wiring 41c is connected to the positive electrode, which is one of the positive and negative electrodes of the DC power supply 40. Wiring 42c is an example of a second wiring connected to the other of the positive and negative electrodes of the DC power supply 40. Here, wiring 42c is connected to the negative electrode, which is the other of the positive and negative electrodes of the DC power supply 40.

[0105] The wiring 41c penetrates the magnetic core 21. Specifically, the wiring 41c extends from one side of the magnetic core 21 (at Figure 3A The left side of the magnetic core 21) to the other side (in Figure 3A The wiring 41c passes through the magnetic core 21 (the right side of the magnetic core 21) and then turns back, and passes through the magnetic core 21 from the other side of the magnetic core 21 to the one side. The portion (path) of the wiring 41c that passes through the magnetic core 21 from the one side to the other side is set as a path 51c, and the portion (path) of the wiring 41c that passes through the magnetic core 21 from the other side to the one side is set as a path 52c. Paths 51c and 52c are paths on the wiring 41c that connect the DC power supply 40 to the device 50, so it can be said that paths 51c and 52c also connect the DC power supply 40 to the device 50. Path 51c is an example of a first path that connects the DC power supply 40 to the device 50, and path 52c is an example of a second path that connects the DC power supply 40 to the device 50.

[0106] In the magnetic core 21, the direction of the DC current flowing in the path 51c is opposite to the direction of the DC current flowing in the path 52c. Both paths 51c and 52c are paths on the wiring 41c. The path 51c passes through the magnetic core 21 from the one side to the other side, and the path 52c passes through the magnetic core 21 from the other side to the one side. It can be known that the direction of the DC current flowing in the path 51c at the magnetic core 21 is opposite to the direction of the DC current flowing in the path 52c. Figure 3A , the direction of the direct current flowing in the path 51 c and the direction of the direct current flowing in the path 52 c are indicated by arrows near the magnetic core 21 .

[0107] The arc detection device 10 c is a device for detecting an arc, and includes a low impedance circuit 11 c , a current detection unit 20 c , and an arc determination unit 30 .

[0108] The current detection unit 20 c includes a magnetic core 21 through which the paths 51 c and 52 c pass, and detects the current flowing through the paths 51 c and 52 c based on the magnetic field generated in the magnetic core 21 .

[0109] The current detection unit 20c includes, for example, a Hall element (not shown) that detects a magnetic field generated in the magnetic core 21 and generates a voltage corresponding to the magnetic field generated in the magnetic core 21. The voltage generated by the Hall element is input to the arc determination unit 30 as a signal representing the magnetic field generated in the magnetic core 21, that is, the current flowing in the path penetrating the magnetic core 21.

[0110] The low impedance circuit 11c is a circuit having an impedance lower than the impedance of the DC power supply 40 and the impedance of the device 50. The low impedance circuit 11c is connected to the paths 51c and 52c, and is a circuit for bypassing the high-frequency component flowing to one of the paths 51c and 52c. The low impedance circuit 11c is, for example, a capacitor, and has a lower impedance than the capacitance component of the DC power supply 40 and the capacitance component of the device 50. Since the capacitor has a function of blocking the DC component, it is possible to extract only the high-frequency component from the signal flowing in the wiring 41c. The capacitance value of the capacitor is appropriately determined according to the frequency of the high-frequency component to be extracted, etc. The low impedance circuit 11c has a lower impedance than the DC power supply 40 and the device 50, so that in the wiring 41c, the high-frequency component easily flows to the low impedance circuit 11c.

[0111] Specifically, the low impedance circuit 11c is provided on a bypass path 43c connecting a connection point N1c at the folded portion and a connection point N2c on a wiring 41c located between the one side of the magnetic core 21 and the device 50.

[0112] The arc determination unit 30 determines the occurrence of an arc based on the current detected by the current detection unit 20c. For example, the arc determination unit 30 determines the occurrence of an arc in the wiring 41c or 42c by performing frequency analysis on the current detected by the current detection unit 20c.

[0113] The low impedance circuit 11c (for example, a capacitor) is an element that blocks direct current and allows alternating current (high-frequency component) to pass, and is used to allow the high-frequency component contained in the current flowing through the wiring 41c to flow to the bypass path 43c. Figure 3B and Figure 3C The principle of how the arc detection device 10c can accurately detect an arc by including such a low impedance circuit 11c will be described.

[0114] Figure 3B and Figure 3C 1 is a diagram showing an example of current flowing in wiring when an arc occurs in the arc detection device 10c according to the second modification of the first embodiment. Figure 3B In FIG. 4 , it is assumed that an arc occurs in the portion between the positive electrode of the DC power source 40 and the above-mentioned one side of the magnetic core 21 in the wiring 41c. Figure 3CIn FIG. 4 , it is assumed that an arc occurs in the portion between the device 50 and the connection point N2c in the wiring 41c. Figure 3B and Figure 3C In FIG. 1 , the thick dotted line indicates the flow of high-frequency components generated by the arc.

[0115] As described above, the magnetic field generated in the magnetic core 21 by the DC current flowing in the path 51c and the magnetic field generated by the DC current flowing in the path 52c cancel each other, thereby preventing magnetic saturation. In addition, these DC currents do not flow to the bypass path 43c due to the low impedance circuit 11c (capacitor) that blocks the DC current.

[0116] First, for Figure 3B As shown, the principle of accurately detecting the arc when an arc occurs in the portion between the positive electrode of the DC power supply 40 and the above-mentioned one side of the magnetic core 21 in the wiring 41c will be described.

[0117] The high-frequency component caused by the arc flows in the path 51c at the magnetic core 21, and flows to the bypass path 43c at the connection point N1c. This is because the high-frequency component does not flow in the path 52c, but flows in the bypass path 43c provided with the low-impedance circuit 11c. Then, the high-frequency component flows in the path connecting the connection point N2c and the device 50. In this way, the bypass path 43c becomes a path that bypasses the path 52c, and the high-frequency component flows in the path 51c at the magnetic core 21, while it does not flow in the path 52c. Therefore, in the magnetic core 21, the magnetic field corresponding to the direct current flowing in the path 51c and the magnetic field corresponding to the direct current flowing in the path 52c cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 51c is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0118] Next, for Figure 3C As shown, the principle of accurately detecting an arc when an arc occurs in the portion between the device 50 and the connection point N2c in the wiring 41c will be described.

[0119] The high-frequency component caused by the arc flows to the bypass path 43c at the connection point N2c. This is because the high-frequency component does not flow in the path 52c, but flows in the bypass path 43c provided with the low-impedance circuit 11c. Then, the high-frequency component flows in the path 51c connecting the connection point N1c and the DC power supply 40. In this way, the bypass path 43c becomes a path that bypasses the path 52c, and the high-frequency component flows in the path 51c at the magnetic core 21, while it does not flow in the path 52c. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51c and the magnetic field corresponding to the DC current flowing in the path 52c cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 51c is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0120] As described above, the DC power supply 40 supplies power to the device 50 via the first wiring (e.g., wiring 41c) and the second wiring (e.g., wiring 42c), the first wiring is connected to one of the positive and negative poles of the DC power supply 40, and the second wiring is connected to the other of the positive and negative poles of the DC power supply 40, the first path (e.g., path 51c) and the second path (e.g., path 52c) are paths on the first wiring, the first wiring passes through the magnetic core 21 from one side of the magnetic core 21 to the other side on the first path and then turns back, and passes through the magnetic core 21 from the above-mentioned other side to the above-mentioned one side of the magnetic core 21 on the second path.

[0121] Thus, by allowing the first wiring to penetrate once, then turn back and penetrate again, the direction of the direct current flowing in the first path of the first wiring and the direction of the direct current flowing in the second path of the first wiring can be set in opposite directions.

[0122] For example, the low impedance circuit 11c can be set on a bypass path 43c that connects the connection point (e.g., connection point N1c) at the above-mentioned returned portion with the connection point (e.g., connection point N2c) on the first wiring, and the connection point on the first wiring (e.g., connection point N2c) is located between the above-mentioned side of the magnetic core 21 and the device 50.

[0123] Thus, by utilizing the bypass path 43c to connect the connection point on the first wiring where the first wiring returns after passing through the magnetic core 21 once when viewed from the DC power supply 40 and the connection point on the first wiring where the first wiring passes through the magnetic core 21 again via the low impedance circuit 11c, the high-frequency component flowing to the second path can be bypassed.

[0124] (Variation 3 of Implementation Example 1)

[0125] In the second variation of the first embodiment, the following example is described: the low impedance circuit 11c is provided on the bypass path 43c connecting the connection point N1c at the return portion of the wiring 41c with the connection point N2c on the wiring 41c located between the one side of the magnetic core 21 and the device 50, but the present invention is not limited to this example. In the third variation of the first embodiment, the following example is described: the low impedance circuit is provided on the bypass path connecting the connection point at the return portion of the first wiring connected to one of the positive and negative electrodes of the DC power supply 40 with the connection point on the first wiring located between the one side of the magnetic core 21 and the positive and negative electrodes of the DC power supply 40.

[0126] Figure 4A 1 is a structural diagram showing an example of an arc detection device 10d according to a third modification of the first embodiment. Figure 4A A DC power source 40 and a device 50 are also shown.

[0127] The DC power source 40 has a positive electrode and a negative electrode. The positive electrode is connected to the wiring 41 d and the negative electrode is connected to the wiring 42 d. The DC power source 40 supplies DC power to the device 50 via the wirings 41 d and 42 d.

[0128] The device 50 is a device to which DC power is supplied from the DC power supply 40 via the wirings 41 d and 42 d.

[0129] Wiring 41d and 42d connect the DC power supply 40 and the device 50. Wiring 41d is an example of a first wiring connected to one of the positive and negative electrodes of the DC power supply 40. Here, wiring 41d is connected to the positive electrode, which is one of the positive and negative electrodes of the DC power supply 40. Wiring 42d is an example of a second wiring connected to the other of the positive and negative electrodes of the DC power supply 40. Here, wiring 42d is connected to the negative electrode, which is the other of the positive and negative electrodes of the DC power supply 40.

[0130] The wiring 41d penetrates the magnetic core 21. Specifically, the wiring 41d extends from one side of the magnetic core 21 (at Figure 4A The left side of the magnetic core 21) to the other side (in Figure 4AThe wiring 41d passes through the magnetic core 21 (the right side of the magnetic core 21) and then turns back, and passes through the magnetic core 21 from the other side of the magnetic core 21 to the one side. The portion (path) of the wiring 41d that passes through the magnetic core 21 from the one side to the other side is set as a path 51d, and the portion (path) of the wiring 41d that passes through the magnetic core 21 from the other side to the one side is set as a path 52d. Paths 51d and 52d are paths on the wiring 41d that connect the DC power supply 40 to the device 50, so it can be said that paths 51d and 52d also connect the DC power supply 40 to the device 50. Path 51d is an example of a first path that connects the DC power supply 40 to the device 50, and path 52d is an example of a second path that connects the DC power supply 40 to the device 50.

[0131] In the magnetic core 21, the direction of the DC current flowing in the path 51d is opposite to the direction of the DC current flowing in the path 52d. Both the paths 51d and 52d are paths on the wiring 41d. The path 51d passes through the magnetic core 21 from the one side to the other side, and the path 52d passes through the magnetic core 21 from the other side to the one side. It can be known that the direction of the DC current flowing in the path 51d at the magnetic core 21 is opposite to the direction of the DC current flowing in the path 52d. Figure 4A , the direction of the direct current flowing in the path 51 d and the direction of the direct current flowing in the path 52 d are indicated by arrows near the magnetic core 21 .

[0132] The arc detection device 10 d is a device for detecting an arc, and includes a low impedance circuit 11 d , a current detection unit 20 d , and an arc determination unit 30 .

[0133] The current detection unit 20 d includes a magnetic core 21 through which the paths 51 d and 52 d pass, and detects the current flowing through the paths 51 d and 52 d based on the magnetic field generated in the magnetic core 21 .

[0134] The current detection unit 20d includes, for example, a Hall element (not shown) that detects a magnetic field generated in the magnetic core 21 and generates a voltage corresponding to the magnetic field generated in the magnetic core 21. The voltage generated by the Hall element is input to the arc determination unit 30 as a signal representing the magnetic field generated in the magnetic core 21, that is, the current flowing in the path penetrating the magnetic core 21.

[0135] The low impedance circuit 11d is a circuit having an impedance lower than the impedance of the DC power supply 40 and the impedance of the device 50. The low impedance circuit 11d is connected to the paths 51d and 52d, and is a circuit for bypassing the high-frequency component flowing to one of the paths 51d and 52d. The low impedance circuit 11d is, for example, a capacitor, and has a lower impedance than the capacitance component of the DC power supply 40 and the capacitance component of the device 50. Since the capacitor has a function of blocking the DC component, it is possible to extract only the high-frequency component from the signal flowing in the wiring 41d. The capacitance value of the capacitor is appropriately determined according to the frequency of the high-frequency component to be extracted, etc. The low impedance circuit 11d has a lower impedance than the DC power supply 40 and the device 50, so that in the wiring 41d, the high-frequency component easily flows to the low impedance circuit 11d.

[0136] Specifically, the low impedance circuit 11d is arranged on a bypass path 43d that connects the connection point N1d at the above-mentioned returned portion with the connection point N2d on the wiring 41d, and the connection point N2d on the wiring 41d is located between the above-mentioned side of the magnetic core 21 and one of the positive and negative poles of the DC power supply 40 (for example, the positive pole).

[0137] The arc determination unit 30 determines the occurrence of an arc based on the current detected by the current detection unit 20d. For example, the arc determination unit 30 determines the occurrence of an arc in the wiring 41d or 42d by performing frequency analysis on the current detected by the current detection unit 20d.

[0138] The low impedance circuit 11d (for example, a capacitor) is an element that blocks direct current and allows alternating current (high-frequency component) to pass, and is used to allow the high-frequency component contained in the current flowing through the wiring 41d to flow to the bypass path 43d. Figure 4B and Figure 4C The principle of how the arc detection device 10d can accurately detect an arc by including such a low impedance circuit 11d will be described.

[0139] Figure 4B and Figure 4C 1 is a diagram showing an example of current flowing in a wiring when an arc occurs in an arc detection device 10d according to Modification 3 of Embodiment 1. Figure 4B In FIG. 4 , it is assumed that an arc occurs in the portion between the positive electrode of the DC power supply 40 and the connection point N2d in the wiring 41d. Figure 4C In FIG. 4 , it is assumed that an arc occurs in the portion between the device 50 and the above-mentioned one side of the magnetic core 21 in the wiring 41 d. Figure 4B and Figure 4C In FIG. 1 , the thick dotted line indicates the flow of high-frequency components generated by the arc.

[0140] As described above, the magnetic field generated in the magnetic core 21 by the DC current flowing in the path 51d and the magnetic field generated by the DC current flowing in the path 52d cancel each other, thereby preventing magnetic saturation. In addition, these DC currents do not flow to the bypass path 43d due to the low impedance circuit 11d (capacitor) that blocks the DC current.

[0141] First, for Figure 4B The principle of accurately detecting an arc when an arc occurs in the portion between the positive electrode of the DC power supply 40 and the connection point N2d in the wiring 41d as shown will be described.

[0142] The high-frequency component caused by the arc flows to the bypass path 43d at the connection point N2d. This is because the high-frequency component does not flow in the path 52d, but flows in the bypass path 43d provided with the low-impedance circuit 11d. Then, the high-frequency component flows in the path 52d connecting the connection point N1d and the device 50. In this way, the bypass path 43d becomes a path that bypasses the path 51d, and the high-frequency component flows in the path 52d at the magnetic core 21, while it does not flow in the path 51d. Therefore, in the magnetic core 21, the magnetic field corresponding to the direct current flowing in the path 51d and the magnetic field corresponding to the direct current flowing in the path 52d cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 52d is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0143] Next, for Figure 4C As shown, the principle of accurately detecting the arc when an arc occurs in the portion between the device 50 and the above-mentioned one side of the magnetic core 21 in the wiring 41d will be described.

[0144] The high-frequency component caused by the arc flows in the path 52d at the magnetic core 21, and flows to the bypass path 43d at the connection point N1d. This is because the high-frequency component does not flow in the path 51d, but flows in the bypass path 43d provided with the low-impedance circuit 11d. Then, the high-frequency component flows in the path connecting the connection point N2d and the DC power supply 40. In this way, the bypass path 43d becomes a path that bypasses the path 51d, and the high-frequency component flows in the path 52d at the magnetic core 21, while it does not flow in the path 51d. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51d and the magnetic field corresponding to the DC current flowing in the path 52d cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 52d is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0145] As described above, the low impedance circuit 11d can be set on a bypass path 43d that connects a connection point (e.g., connection point N1d) at a returned portion of a first wiring (e.g., wiring 41d) and a connection point on the first wiring (e.g., connection point N2d), and the connection point on the first wiring is located between one side of the magnetic core 21 and one of the positive and negative poles of the DC power supply 40.

[0146] Thus, by utilizing the bypass path 43d to connect the connection point on the first wiring where the first wiring returns after passing through the magnetic core 21 once when viewed from the DC power supply 40 and the connection point on the first wiring before the first wiring passes through the magnetic core 21 via the low impedance circuit 11d, the high-frequency component flowing to the first path can be bypassed.

[0147] (Variation 4 of Implementation Example 1)

[0148] In the second and third variants of the first embodiment, the following example is described: the low impedance circuit is provided on the bypass path connecting the connection point at the return portion of the first wiring with the connection point on the first wiring located on one side of the magnetic core 21 and the DC power supply 40 or the device 50, but the present invention is not limited to this example. In the fourth variant of the first embodiment, the following example is described: the low impedance circuit is provided on the bypass path connecting the connection point at the return portion of the first wiring connected to one of the positive and negative electrodes of the DC power supply 40 with the connection point on the second wiring.

[0149] Figure 5A 1 is a structural diagram showing an example of an arc detection device 10e according to a fourth modification of the first embodiment. Figure 5A Also shown is a DC power source 40 and a device 50.

[0150] The DC power source 40 has a positive electrode and a negative electrode. The positive electrode is connected to the wiring 41 e and the negative electrode is connected to the wiring 42 e. The DC power source 40 supplies DC power to the device 50 via the wirings 41 e and 42 e.

[0151] The device 50 is a device to which DC power is supplied from the DC power supply 40 via the wirings 41 e and 42 e.

[0152] Wiring 41e and 42e connect the DC power supply 40 and the device 50. Wiring 41e is an example of a first wiring connected to one of the positive and negative electrodes of the DC power supply 40. Here, wiring 41e is connected to the positive electrode, which is one of the positive and negative electrodes of the DC power supply 40. Wiring 42e is an example of a second wiring connected to the other of the positive and negative electrodes of the DC power supply 40. Here, wiring 42e is connected to the negative electrode, which is the other of the positive and negative electrodes of the DC power supply 40.

[0153] The wiring 41e penetrates the magnetic core 21. Specifically, the wiring 41e extends from one side of the magnetic core 21 (at Figure 5A The left side of the magnetic core 21) to the other side (in Figure 5A The wiring 41e (the right side of the core 21) passes through the core 21 and then turns back, and passes through the core 21 from the other side of the core 21 to the one side. The portion (path) of the wiring 41e that passes through the core 21 from the one side to the other side is set as a path 51e, and the portion (path) of the wiring 41e that passes through the core 21 from the other side to the one side is set as a path 52e. Paths 51e and 52e are paths on the wiring 41e that connect the DC power supply 40 to the device 50, so it can be said that paths 51e and 52e also connect the DC power supply 40 to the device 50. Path 51e is an example of a first path that connects the DC power supply 40 to the device 50, and path 52e is an example of a second path that connects the DC power supply 40 to the device 50.

[0154] In the magnetic core 21, the direction of the DC current flowing in the path 51e is opposite to the direction of the DC current flowing in the path 52e. Both paths 51e and 52e are paths on the wiring 41e. The path 51e passes through the magnetic core 21 from the one side to the other side, and the path 52e passes through the magnetic core 21 from the other side to the one side. It can be known that the direction of the DC current flowing in the path 51e at the magnetic core 21 is opposite to the direction of the DC current flowing in the path 52e. Figure 5A , the direction of the direct current flowing in the path 51e and the direction of the direct current flowing in the path 52e are indicated by arrows near the magnetic core 21.

[0155] The arc detection device 10 e is a device for detecting an arc, and includes a low impedance circuit 11 e , a current detection unit 20 e , and an arc determination unit 30 .

[0156] The current detection unit 20 e includes a magnetic core 21 through which the paths 51 e and 52 e pass, and detects the current flowing through the paths 51 e and 52 e based on the magnetic field generated in the magnetic core 21 .

[0157] The current detection unit 20e includes, for example, a Hall element (not shown) that detects a magnetic field generated in the magnetic core 21 and generates a voltage corresponding to the magnetic field generated in the magnetic core 21. The voltage generated by the Hall element is input to the arc determination unit 30 as a signal representing the magnetic field generated in the magnetic core 21, that is, the current flowing in the path penetrating the magnetic core 21.

[0158] The low impedance circuit 11e is a circuit having an impedance lower than the impedance of the DC power supply 40 and the impedance of the device 50. The low impedance circuit 11e is connected to the paths 51e and 52e, and is a circuit for bypassing the high-frequency component flowing to one of the paths 51e and 52e. The low impedance circuit 11e is, for example, a capacitor, and has an impedance lower than the capacitance component of the DC power supply 40 and the capacitance component of the device 50. Since the capacitor has a function of blocking the DC component, it is possible to extract only the high-frequency component from the signal flowing in the wirings 41e and 42e. The capacitance value of the capacitor is appropriately determined according to the frequency of the high-frequency component to be extracted, etc. The low impedance circuit 11e has a lower impedance than the DC power supply 40 and the device 50, so in the wirings 41e and 42e, the high-frequency component easily flows to the low impedance circuit 11e.

[0159] Specifically, the low impedance circuit 11e is provided on the bypass path 43e connecting the connection point N1e at the above-mentioned turned-back portion and the connection point N2e on the wiring 42e.

[0160] The arc determination unit 30 determines the occurrence of an arc based on the current detected by the current detection unit 20e. For example, the arc determination unit 30 determines the occurrence of an arc in the wiring 41e or 42e by performing frequency analysis on the current detected by the current detection unit 20e.

[0161] The low impedance circuit 11e (such as a capacitor) is an element that blocks direct current and allows alternating current (high-frequency component) to pass, and is used to allow the high-frequency component contained in the current flowing through the wirings 41e and 42e to flow to the bypass path 43e. Figure 5B and Figure 5C The principle of how the arc detection device 10e can accurately detect an arc by including such a low impedance circuit 11e will be described.

[0162] Figure 5B and Figure 5C 1 is a diagram showing an example of current flowing in wiring when an arc occurs in the arc detection device 10e according to the fourth modification of the first embodiment. Figure 5B In FIG. 4 , it is assumed that an arc occurs in the portion between the positive electrode of the DC power source 40 and the above-mentioned one side of the magnetic core 21 in the wiring 41e. Figure 5C In FIG. 4 , it is assumed that an arc occurs in the portion between the device 50 and the above-mentioned one side of the magnetic core 21 in the wiring 41e. Figure 5B and Figure 5C In FIG. 1 , the thick dotted line indicates the flow of high-frequency components generated by the arc.

[0163] As described above, the magnetic field generated in the magnetic core 21 by the DC current flowing in the path 51e and the magnetic field generated by the DC current flowing in the path 52e cancel each other, thereby preventing magnetic saturation. In addition, these DC currents do not flow to the bypass path 43e due to the low impedance circuit 11e (capacitor) that blocks the DC current.

[0164] First, for Figure 5B As shown, the principle of accurately detecting the arc when an arc occurs in the portion between the positive electrode of the DC power supply 40 and the above-mentioned one side of the magnetic core 21 in the wiring 41e will be described.

[0165] The high-frequency component caused by the arc flows in the path 51e at the magnetic core 21, and flows to the bypass path 43e at the connection point N1e. This is because the high-frequency component does not flow in the path 52e, but flows in the bypass path 43e provided with the low-impedance circuit 11e. Then, the high-frequency component flows in the wiring 42e connecting the connection point N2e and the DC power supply 40. In this way, the bypass path 43e becomes a path that bypasses the path 52e, and the high-frequency component flows in the path 51e at the magnetic core 21, while it does not flow in the path 52e. Therefore, in the magnetic core 21, the magnetic field corresponding to the DC current flowing in the path 51e and the magnetic field corresponding to the DC current flowing in the path 52e cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 51e is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0166] Next, for Figure 5C As shown, the principle of accurately detecting the arc when an arc occurs in the portion between the device 50 and the above-mentioned one side of the magnetic core 21 in the wiring 41e will be described.

[0167] The high-frequency component caused by the arc flows in the path 52e at the magnetic core 21, and flows to the bypass path 43e at the connection point N1e. This is because the high-frequency component does not flow in the path 51e, but flows in the bypass path 43e provided with the low-impedance circuit 11e. Then, the high-frequency component flows in the path connecting the connection point N2e and the device 50. In this way, the bypass path 43e becomes a path that bypasses the path 51e, and the high-frequency component flows in the path 52e at the magnetic core 21, while it does not flow in the path 51e. Therefore, in the magnetic core 21, the magnetic field corresponding to the direct current flowing in the path 51e and the magnetic field corresponding to the direct current flowing in the path 52e cancel each other, and a magnetic field corresponding to the high-frequency component flowing in the path 52e is generated. This magnetic field is output to the arc determination unit 30 as a voltage signal by the Hall element, for example, and the arc determination unit 30 can determine that an arc has occurred based on the voltage signal.

[0168] As described above, the low impedance circuit 11e can be set on the bypass path 43e that connects the connection point (e.g., connection point N1e) at the return portion of the first wiring (e.g., wiring 41e) and the connection point (e.g., connection point N2e) on the second wiring (e.g., wiring 42e).

[0169] Thus, by utilizing the bypass path 43e to connect the connection point on the first wiring at the part where the first wiring returns after passing through the magnetic core 21 once when viewed from the DC power supply 40 with the connection point on the second wiring via the low impedance circuit 11e, the high-frequency component flowing to one of the first path and the second path can be bypassed.

[0170] (Implementation Method 2)

[0171] The arc detection device of the present invention can also be installed in a power conditioner in a solar power generation system. Fig. 6A to explain.

[0172] Fig. 6A This is a configuration diagram showing an example of a solar power generation system 1 a according to the second embodiment.

[0173] The solar power generation system 1 a includes a solar panel 41 , storage batteries 54 , 55 , and 56 , DC / DC converters 51 , 52 , and 53 , and a power conditioner 60 a .

[0174] The solar panel 41 generates direct current power by utilizing solar power generation. The direct current power generated by the solar panel 41 is supplied to the power conditioner 60a.

[0175] The battery 54 stores the DC power from the DC / DC converter 51, the battery 55 stores the DC power from the DC / DC converter 52, and the battery 56 stores the DC power from the DC / DC converter 53. For example, the batteries 54, 55, and 56 may be mounted in electric vehicles, electric bicycles, etc., or may be used to supply power to household appliances, etc.

[0176] The DC / DC converters 51, 52, and 53 are voltage converters that step up or step down the DC voltage of the supplied DC power and output it. The DC / DC converter 51 steps up or steps down the DC power supplied from the power conditioner 60a and outputs it to the battery 54. The DC / DC converter 52 steps up or steps down the DC power supplied from the power conditioner 60a and outputs it to the battery 55. The DC / DC converter 53 steps up or steps down the DC power supplied from the power conditioner 60a and outputs it to the battery 56.

[0177] The power conditioner 60a has a function of converting the DC power supplied from the solar panel 41 into AC power. In addition, the power conditioner 60a has a function of supplying the DC power supplied from the solar panel 41 to a storage battery or the like without converting the DC power supplied from the solar panel 41 into AC power. The power conditioner 60a includes a DC / DC converter 61, an inverter 62, and an arc detection device 10a.

[0178] The DC / DC converter 61 steps up or steps down the DC power supplied from the solar panel 41, and outputs it to the DC / DC converters 51, 52, and 53, and the inverter 62. Since the DC power is output from the DC / DC converter 61, the DC / DC converter 61 can be regarded as a DC power supply. That is, the DC / DC converter 61 is an example of a DC power supply. The DC / DC converter 61 has a positive electrode and a negative electrode, the positive electrode is connected to the wiring 110, and the negative electrode is connected to the wiring 120.

[0179] Wiring 110 and 120 connects DC / DC converter 61 to DC / DC converters 51, 52, and 53. DC / DC converters 51, 52, and 53 are examples of devices connected to DC / DC converter 61 via wiring 110 and 120. Wiring 110 is an example of a first wiring connected to one of the positive and negative electrodes of DC / DC converter 61. Here, wiring 110 is connected to the positive electrode, which is one of the positive and negative electrodes of DC / DC converter 61. Wiring 120 is an example of a second wiring connected to the other of the positive and negative electrodes of DC / DC converter 61. Here, wiring 120 is connected to the negative electrode, which is the other of the positive and negative electrodes of DC / DC converter 61.

[0180] Wiring 110 is a wiring that branches from the positive electrode of DC / DC converter 61 to each of DC / DC converters 51, 52, and 53. The point in wiring 110 that branches from the positive electrode of DC / DC converter 61 to DC / DC converters 51, 52, and 53 is referred to as branch point N3.

[0181] In wiring 110, the path before the branch connecting the branch point N3 and the positive pole of the DC / DC converter 61 is set as path 110a, the path after the branch connecting the branch point N3 and the DC / DC converter 51 is set as path 110c, the path after the branch connecting the branch point N3 and the DC / DC converter 52 is set as path 110d, and the path after the branch connecting the branch point N3 and the DC / DC converter 53 is set as path 110b.

[0182] Wiring 120 is a wiring that branches from the negative electrode of DC / DC converter 61 to each of DC / DC converters 51, 52, and 53. The point in wiring 120 that branches from the negative electrode of DC / DC converter 61 to DC / DC converters 51, 52, and 53 is defined as branch point N4.

[0183] In wiring 120, the path before the branch connecting the branch point N4 and the negative pole of the DC / DC converter 61 is set as path 120a, the path after the branch connecting the branch point N4 and the DC / DC converter 51 is set as path 120c, the path after the branch connecting the branch point N4 and the DC / DC converter 52 is set as path 120d, and the path after the branch connecting the branch point N4 and the DC / DC converter 53 is set as path 120b.

[0184] The wirings 110 and 120 penetrate the magnetic core 21, and the portion (path) of the wiring 110 that penetrates the magnetic core 21 is the path 110a, and the portion (path) of the wiring 120 that penetrates the magnetic core 21 is the path 120a. The path 110a is a path on the wiring 110 that connects the DC / DC converter 61 with the DC / DC converters 51, 52, and 53, so it can be said that the path 110a also connects the DC / DC converter 61 with the DC / DC converters 51, 52, and 53. The path 110a is an example of a first path that connects the DC / DC converter 61 with the DC / DC converters 51, 52, and 53. The path 120a is a path on the wiring 120 that connects the DC / DC converter 61 with the DC / DC converters 51, 52, and 53, so it can be said that the path 120a also connects the DC / DC converter 61 with the DC / DC converters 51, 52, and 53. The path 120 a is an example of a second path connecting the DC / DC converter 61 with the DC / DC converters 51 , 52 , and 53 .

[0185] The inverter 62 converts the DC power supplied from the DC / DC converter 61 into AC power and outputs it. The inverter 62 uses, for example, the MPPT (Maximum Power Point Tracking) method to adjust the current and voltage of the DC power supplied from the DC / DC converter 61 to the maximum power. For example, the inverter 62 converts the DC power into AC power with a voltage of 100V and a frequency of 50Hz or 60Hz. This AC power can be used by household appliances and the like.

[0186] The arc detection device 10a has the same function as the arc detection device in Embodiment 1, and corresponds to Embodiment 1 except that the paths penetrating the magnetic core 21 are paths 110a and 120a, so detailed description is omitted. Embodiment 2 also has the same effect as Embodiment 1 in that it can accurately detect arcs.

[0187] As described above, the power conditioner 60a includes the arc detection device 10a and the converter (for example, the inverter 62) that converts the output power of the direct current power source (for example, the DC / DC converter 61).

[0188] In this way, the arc detection device 10a can be provided in the power conditioner 60a, so that the power conditioner 60a that can accurately detect the arc can be provided.

[0189] In addition, wirings 110 and 120 are branched wirings (referred to as branch wirings), and there may be a situation where an arc occurs in the path before the branch and in each of the multiple paths after the branch of the branch wiring. However, since the path before the branch (specifically, path 110a) passes through the magnetic core 21 possessed by the arc detection device 10a, no matter where the arc occurs in the multiple paths after the branch (for example, paths 110b, 110c, 110d, 120b, 120c and 120d), the high-frequency component caused by the arc flows in the path before the branch that passes through the magnetic core 21, and therefore the arc can be detected based on the current detected by the current detection unit 20a that detects the current flowing in the path passing through the magnetic core 21.

[0190] (Variation of Implementation Example 2)

[0191] In the second embodiment, an example in which the path before branching passes through the magnetic core 21 provided in the current detection unit 20a is described, but the invention is not limited to this example. Figure 6B Provide explanation.

[0192] Figure 6B This is a diagram showing a configuration of an example of a solar power generation system 1aa according to a modification of the second embodiment.

[0193] The solar power generation system 1aa is different from the solar power generation system 1a according to Embodiment 2 in that a power conditioner 60aa is provided instead of the power conditioner 60a. Other points are the same as those of the solar power generation system 1a according to Embodiment 2, and thus description thereof is omitted.

[0194] The power conditioner 60aa is different from the power conditioner 60a according to the second embodiment in that an arc detection device 10aa is provided instead of the arc detection device 10a. The other points are the same as the power conditioner 60a according to the second embodiment, and thus the description thereof is omitted.

[0195] The arc detection device 10aa includes current detection units 20aa, 20ab, and 20ac, and an arc determination unit 30a.

[0196] The current detection unit 20aa has the same function as the current detection unit 20a involved in the first embodiment, except that the path passing through the magnetic core 21 is the path 110c and 120c, and other aspects correspond to the first embodiment, and detailed description is omitted. The current detection unit 20ab has the same function as the current detection unit 20a involved in the first embodiment, except that the path passing through the magnetic core 21 is the path 110d and 120d, and other aspects correspond to the first embodiment, and detailed description is omitted. The current detection unit 20ac has the same function as the current detection unit 20a involved in the first embodiment, except that the path passing through the magnetic core 21 is the path 110b and 120b, and other aspects correspond to the first embodiment, and detailed description is omitted.

[0197] The arc determination unit 30a is realized by, for example, a microcomputer similarly to the arc determination unit 30, but may be realized by hardware using a dedicated electronic circuit.

[0198] The arc determination unit 30a determines the occurrence of an arc based on the currents detected by the current detection units 20aa, 20ab, and 20ac. For example, the arc determination unit 30a determines the occurrence of an arc in the path 110c or 120c by performing a frequency analysis on the current detected by the current detection unit 20aa, determines the occurrence of an arc in the path 110d or 120d by performing a frequency analysis on the current detected by the current detection unit 20ab, and determines the occurrence of an arc in the path 110b or 120b by performing a frequency analysis on the current detected by the current detection unit 20ac.

[0199] Thus, no matter where an arc occurs in the plurality of branched paths (e.g., paths 110b, 110c, 110d, 120b, 120c, and 120d), the branched paths all pass through the magnetic core 21, so the arc can be detected based on the current detected by the current detection unit 20aa, 20ab, or 20ac. In particular, it is possible to determine in which branched path the arc has occurred.

[0200] (Implementation method 3)

[0201] In the second embodiment, an example in which the arc detection device 10a according to the first embodiment is provided in the power conditioner 60a is described. However, the arc detection device 10c according to the second modification of the first embodiment may be provided in the power conditioner. Fig. 7A to explain.

[0202] Fig. 7A This is a configuration diagram showing an example of a solar power generation system 1b according to the third embodiment.

[0203] The solar power generation system 1b is different from the solar power generation system 1a according to Embodiment 2 in that a power conditioner 60b is provided instead of the power conditioner 60a. Other points are the same as those of the solar power generation system 1a according to Embodiment 2, and thus description thereof is omitted.

[0204] The power conditioner 60b is different from the power conditioner 60a according to the second embodiment in that an arc detection device 10c is provided instead of the arc detection device 10a. The other points are the same as the power conditioner 60a according to the second embodiment, and thus the description thereof is omitted.

[0205] The arc detection device 10c has the same function as the arc detection device in the second variant of the first embodiment, and corresponds to the second variant of the first embodiment except that the path penetrating the magnetic core 21 is the path 110a, so the detailed description is omitted. The third embodiment also has the same effect as the second variant of the first embodiment in that it can accurately detect arcs.

[0206] (Variation of Implementation Example 3)

[0207] In the third embodiment, an example in which the path before branching passes through the magnetic core 21 provided in the current detection unit 20c is described, but the present invention is not limited to this example. Figure 7B to explain.

[0208] Figure 7B This is a diagram showing a configuration of an example of a solar power generation system 1ba according to a modification of the third embodiment.

[0209] The solar power generation system 1ba is different from the solar power generation system 1b according to the third embodiment in that a power conditioner 60ba is provided instead of the power conditioner 60b. Other points are the same as those of the solar power generation system 1b according to the third embodiment, and thus description thereof is omitted.

[0210] The power conditioner 60ba is different from the power conditioner 60b according to the third embodiment in that an arc detection device 10ca is provided instead of the arc detection device 10c. Other points are the same as those of the power conditioner 60b according to the third embodiment, and thus description thereof is omitted.

[0211] The arc detection device 10ca includes current detection units 20ca, 20cb, and 20cc, and an arc determination unit 30a.

[0212] The current detection unit 20ca has the same function as the current detection unit 20c according to the second modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110c, and the other aspects correspond to the second modification of the first embodiment, and detailed description is omitted. The current detection unit 20cb has the same function as the current detection unit 20c according to the second modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110d, and the other aspects correspond to the second modification of the first embodiment, and detailed description is omitted. The current detection unit 20cc has the same function as the current detection unit 20c according to the second modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110b, and the other aspects correspond to the second modification of the first embodiment, and detailed description is omitted.

[0213] The arc determination unit 30a determines the occurrence of an arc based on the currents detected by the current detection units 20ca, 20cb, and 20cc. For example, the arc determination unit 30a determines the occurrence of an arc in the path 110c or 120c by performing a frequency analysis on the current detected by the current detection unit 20ca, determines the occurrence of an arc in the path 110d or 120d by performing a frequency analysis on the current detected by the current detection unit 20cb, and determines the occurrence of an arc in the path 110b or 120b by performing a frequency analysis on the current detected by the current detection unit 20cc.

[0214] Thus, no matter where an arc occurs in the plurality of branched paths (e.g., paths 110b, 110c, 110d, 120b, 120c, and 120d), the branched paths all pass through the magnetic core 21, so the arc can be detected based on the current detected by the current detection unit 20ca, 20cb, or 20cc. In particular, it is possible to determine in which branched path the arc has occurred.

[0215] (Implementation 4)

[0216] In the second embodiment, an example in which the arc detection device 10a according to the first embodiment is provided in the power conditioner 60a is described. However, the arc detection device 10d according to the third modification of the first embodiment may be provided in the power conditioner. Fig. 8A to explain.

[0217] Fig. 8A This is a configuration diagram showing an example of a solar power generation system 1c according to the fourth embodiment.

[0218] The solar power generation system 1c is different from the solar power generation system 1a according to Embodiment 2 in that a power conditioner 60c is provided instead of the power conditioner 60a. Other points are the same as those of the solar power generation system 1a according to Embodiment 2, and thus description thereof is omitted.

[0219] The power conditioner 60c is different from the power conditioner 60a according to the second embodiment in that an arc detection device 10d is provided instead of the arc detection device 10a. The other points are the same as the power conditioner 60a according to the second embodiment, and thus the description thereof is omitted.

[0220] The arc detection device 10d has the same function as the arc detection device in the third variant of the first embodiment, and corresponds to the third variant of the first embodiment except that the path penetrating the magnetic core 21 is the path 110a, so the detailed description is omitted. The fourth embodiment also has the same effect as the third variant of the first embodiment in that it can accurately detect arcs.

[0221] (Variation of Implementation Example 4)

[0222] In the fourth embodiment, an example in which the path before branching passes through the magnetic core 21 provided in the current detection unit 20d is described, but the present invention is not limited to this example. Figure 8B to explain.

[0223] Figure 8B This is a diagram showing a configuration of an example of a solar power generation system 1ca according to a modification of the fourth embodiment.

[0224] The solar power generation system 1ca is different from the solar power generation system 1c according to the fourth embodiment in that a power conditioner 60ca is provided instead of the power conditioner 60c. Other points are the same as those of the solar power generation system 1c according to the fourth embodiment, and thus description thereof is omitted.

[0225] The power conditioner 60ca is different from the power conditioner 60c according to the fourth embodiment in that an arc detection device 10da is provided instead of the arc detection device 10d. Other points are the same as the power conditioner 60c according to the fourth embodiment, and thus description thereof is omitted.

[0226] The arc detection device 10da includes current detection units 20da, 20db, and 20dc, and an arc determination unit 30a.

[0227] The current detection unit 20da has the same function as the current detection unit 20d involved in the third modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110c, and other aspects correspond to the third modification of the first embodiment, and detailed description is omitted. The current detection unit 20db has the same function as the current detection unit 20d involved in the third modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110d, and other aspects correspond to the third modification of the first embodiment, and detailed description is omitted. The current detection unit 20dc has the same function as the current detection unit 20d involved in the third modification of the first embodiment, except that the path passing through the magnetic core 21 is the path 110b, and other aspects correspond to the third modification of the first embodiment, and detailed description is omitted.

[0228] The arc determination unit 30a determines the occurrence of an arc based on the currents detected by the current detection units 20da, 20db, and 20dc. For example, the arc determination unit 30a determines the occurrence of an arc in the path 110c or 120c by performing a frequency analysis on the current detected by the current detection unit 20da, determines the occurrence of an arc in the path 110d or 120d by performing a frequency analysis on the current detected by the current detection unit 20db, and determines the occurrence of an arc in the path 110b or 120b by performing a frequency analysis on the current detected by the current detection unit 20dc.

[0229] Thus, no matter where an arc occurs in the plurality of branched paths (e.g., paths 110b, 110c, 110d, 120b, 120c, and 120d), the branched paths all pass through the magnetic core 21, so the arc can be detected based on the current detected by the current detection unit 20da, 20db, or 20dc. In particular, it is possible to determine in which branched path the arc has occurred.

[0230] (Implementation 5)

[0231] In the second embodiment, an example in which the arc detection device 10a according to the first embodiment is provided in the power conditioner 60a is described. However, the arc detection device 10e according to the fourth modification of the first embodiment may be provided in the power conditioner. Fig. 9A to explain.

[0232] Fig. 9A This is a configuration diagram showing an example of a solar power generation system 1d according to the fifth embodiment.

[0233] The solar power generation system 1d is different from the solar power generation system 1a according to Embodiment 2 in that a power conditioner 60d is provided instead of the power conditioner 60a. Other points are the same as those of the solar power generation system 1a according to Embodiment 2, and thus description thereof is omitted.

[0234] The power conditioner 60d is different from the power conditioner 60a according to the second embodiment in that an arc detection device 10e is provided instead of the arc detection device 10a. The other points are the same as the power conditioner 60a according to the second embodiment, and thus the description thereof is omitted.

[0235] The arc detection device 10e has the same function as the arc detection device in the fourth variant of the first embodiment, and corresponds to the fourth variant of the first embodiment except that the path penetrating the magnetic core 21 is the path 110a, so the detailed description is omitted. The fifth embodiment also has the same effect as the fourth variant of the first embodiment in that an arc can be accurately detected.

[0236] (Variation of Implementation Example 5)

[0237] In Embodiment 5, an example in which the path before branching passes through the magnetic core 21 provided in the current detection unit 20e is described, but the invention is not limited to this example. Fig. 9B to explain.

[0238] Fig. 9B This is a diagram showing a configuration of an example of a solar power generation system 1 da according to a modification of the fifth embodiment.

[0239] The solar power generation system 1da is different from the solar power generation system 1d according to the fifth embodiment in that a power conditioner 60da is provided instead of the power conditioner 60d. Other points are the same as those of the solar power generation system 1d according to the fifth embodiment, and thus description thereof is omitted.

[0240] The power conditioner 60da is different from the power conditioner 60d according to the fifth embodiment in that an arc detection device 10ea is provided instead of the arc detection device 10e. The other points are the same as those of the power conditioner 60d according to the fifth embodiment, and thus description thereof is omitted.

[0241] The arc detection device 10ea includes current detection units 20ea, 20eb, and 20ec, and an arc determination unit 30a.

[0242] The current detection unit 20ea has the same function as the current detection unit 20e involved in the modification example 4 of the first embodiment, except that the path passing through the magnetic core 21 is the path 110c, and other aspects correspond to the modification example 4 of the first embodiment, and detailed description is omitted. The current detection unit 20eb has the same function as the current detection unit 20e involved in the modification example 4 of the first embodiment, except that the path passing through the magnetic core 21 is the path 110d, and other aspects correspond to the modification example 4 of the first embodiment, and detailed description is omitted. The current detection unit 20ec has the same function as the current detection unit 20e involved in the modification example 4 of the first embodiment, except that the path passing through the magnetic core 21 is the path 110b, and other aspects correspond to the modification example 4 of the first embodiment, and detailed description is omitted.

[0243] The arc determination unit 30a determines the occurrence of an arc based on the currents detected by the current detection units 20ea, 20eb, and 20ec. For example, the arc determination unit 30a determines the occurrence of an arc in the path 110c or 120c by performing a frequency analysis on the current detected by the current detection unit 20ea, determines the occurrence of an arc in the path 110d or 120d by performing a frequency analysis on the current detected by the current detection unit 20eb, and determines the occurrence of an arc in the path 110b or 120b by performing a frequency analysis on the current detected by the current detection unit 20ec.

[0244] Thus, no matter where an arc occurs in the plurality of branched paths (e.g., paths 110b, 110c, 110d, 120b, 120c, and 120d), the branched paths all pass through the magnetic core 21, so the arc can be detected based on the current detected by the current detection unit 20ea, 20eb, or 20ec. In particular, it is possible to determine in which branched path the arc has occurred.

[0245] (Implementation method 6)

[0246] Arc detection devices can also be installed in indoor wiring systems. Fig.10 to explain.

[0247] Fig.10 : is a structural diagram showing an example of an indoor wiring system 2 involved in Embodiment 6. Fig.10 A system power supply 43 connected to the indoor wiring system 2 is also shown.

[0248] The system power supply 43 is a power supply for supplying AC power generated by a power plant or the like.

[0249] The indoor wiring system 2 includes an AC / DC converter 42, wirings 111 and 121, lighting fixtures 57, 58 and 59, and an arc detection device 10a. The AC / DC converter 42, wirings 111 and 121, lighting fixtures 57, 58 and 59, and the arc detection device 10a are installed indoors in a facility such as a single-family house, a multi-family house, a building, or a factory.

[0250] The AC / DC converter 42 is a power converter that receives AC power from the system power supply 43, converts the supplied AC power into DC power, and outputs the DC power. Since the AC / DC converter 42 outputs DC power, the AC / DC converter 42 can be regarded as a DC power source.

[0251] AC / DC converter 42 converts AC power supplied from system power supply 43 into DC power and outputs it to lighting fixtures 57, 58, and 59. AC / DC converter 42 has a positive electrode and a negative electrode. The positive electrode is connected to wiring 111, and the negative electrode is connected to wiring 121.

[0252] The wirings 111 and 121 connect the AC / DC converter 42 to the lighting devices 57, 58, and 59. The lighting devices 57, 58, and 59 are examples of devices connected to the AC / DC converter 42 via the wirings 111 and 121. The wiring 111 is an example of a first wiring connected to one of the positive and negative electrodes of the AC / DC converter 42. Here, the wiring 111 is connected to the positive electrode, which is one of the positive and negative electrodes of the AC / DC converter 42. The wiring 121 is an example of a second wiring connected to the other of the positive and negative electrodes of the AC / DC converter 42. Here, the wiring 121 is connected to the negative electrode, which is the other of the positive and negative electrodes of the AC / DC converter 42.

[0253] Like the wiring 110 in Embodiment 2, etc., the wiring 111 is a wiring that branches from the positive pole of the AC / DC converter 42 to each of the lighting fixtures 57, 58, and 59. Like the wiring 120 in Embodiment 2, etc., the wiring 121 is a wiring that branches from the negative pole of the AC / DC converter 42 to each of the lighting fixtures 57, 58, and 59.

[0254] Furthermore, the device is not limited to a lighting device, and any device installed indoors is not particularly limited. For example, the device may be a speaker or a microphone.

[0255] The wirings 111 and 121 pass through the magnetic core 21, and the paths before the branches of the wirings 111 and 121 pass through the magnetic core 21. The path before the branches of the wiring 111 is an example of a first path connecting the AC / DC converter 42 to the lighting fixtures 57, 58, and 59. The path before the branches of the wiring 121 is an example of a second path connecting the AC / DC converter 42 to the lighting fixtures 57, 58, and 59.

[0256] The arc detection device 10a has the same function as the arc detection device in the first embodiment, and corresponds to the first embodiment except that the path penetrating the magnetic core 21 is the path before the branching of the wirings 111 and 121, so the detailed description is omitted. The sixth embodiment also has the effect of being able to accurately detect arcs in the same manner as the first embodiment.

[0257] As described above, the indoor wiring system 2 includes the arc detection device 10a, the first path (e.g., the path before the branch of the wiring 111), the second path (e.g., the path before the branch of the wiring 121), and equipment installed indoors (e.g., lighting fixtures 57, 58, and 59).

[0258] In this way, the arc detection device 10a can be provided in the indoor wiring system 2, so that the indoor wiring system 2 capable of accurately detecting an arc can be provided.

[0259] In addition, similar to Embodiment 2, wirings 111 and 121 are branch wirings, and there may be a situation where an arc occurs in the path before the branch and in each of the multiple paths after the branch of the branch wiring. However, since the path before the branch passes through the magnetic core 21 possessed by the arc detection device 10a, no matter where the arc occurs in the multiple paths after the branch, the high-frequency component caused by the arc flows in the path before the branch that passes through the magnetic core 21, and therefore the arc can be detected based on the current detected by the current detection unit 20a that detects the current flowing in the path passing through the magnetic core 21.

[0260] In addition, similarly to the modified example of the second embodiment, in the indoor wiring system 2, an arc detection device may be provided in each branched path.

[0261] Furthermore, the arc detection devices according to Modifications 1 to 4 of Embodiment 1 may be provided in an indoor wiring system.

[0262] (Other embodiments)

[0263] As mentioned above, although the arc detection device etc. which concern on embodiment were demonstrated, this invention is not limited to the said embodiment.

[0264] For example, a low impedance circuit can also be realized by using a capacitor provided in a device connected to a DC power supply.

[0265] For example, in Modifications 2 to 4 of Embodiment 1, an example is described in which the first wiring that passes through the magnetic core 21 once and then turns back and passes through the magnetic core 21 again is connected to the positive pole of the DC power supply 40, but the first wiring may be connected to the negative pole of the DC power supply 40. In other words, the first wiring connected to the negative pole, which is one of the positive pole and the negative pole of the DC power supply 40, may turn back and pass through the magnetic core 21 again after passing through the magnetic core 21 once.

[0266] For example, in the above-mentioned embodiment, the arc detection device is applied to a solar power generation system (specifically, a power conditioner) and an indoor wiring system, but the application examples are not limited to these. Fig.11 Another application example of the arc detection device according to the present invention (that is, an arc detection device capable of accurately detecting an arc) will be described.

[0267] Fig.11 It is a diagram for explaining an application example of the arc detection device according to the present invention.

[0268] The arc detection device involved in the present invention can be applied to various components in a system that converts DC power supplied from a solar panel 310 via wiring into AC power using a power conditioner 500. Here, a plurality of (for example, three) structures in which a plurality of (for example, three) solar panels 310 are connected in series using a wiring 600 (string) are arranged to form a solar cell array 300. The plurality of wirings 600 are brought together through a junction box 400 and connected to a power conditioner 500. The DC power source is the solar panel 310, and the first path and the second path are the wiring 600.

[0269] For example, the circuit breaker 410 is provided for each wiring 600, and here, the circuit breaker 410 is provided in the junction box 400. In addition, the circuit breaker 410 may not be provided in the junction box 400. For example, the circuit breaker 410 may be provided between the junction box 400 and the solar cell array 300, or may be provided between the junction box 400 and the power conditioner 500 in a manner not provided for each wiring 600.

[0270] The solar panel 310 has, for example, a solar panel auxiliary module 320 for converting a signal output from the solar panel 310. The solar panel auxiliary module 320 is, for example, a DC / DC converter that optimizes the amount of power generated by each solar panel 310. In addition, the solar panel 310 may not have the solar panel auxiliary module 320.

[0271] For example, the circuit breaker 410 may include an arc detection device. When it is determined that an abnormality has occurred, the circuit breaker 410 interrupts the current flowing through the wiring 600 .

[0272] For example, the solar panel 310 or the solar panel auxiliary module 320 may include an arc detection device. When it is determined that an arc has occurred, the solar panel 310 or the solar panel auxiliary module 320 stops output to the wiring 600 .

[0273] In addition, for example, junction box 400 may include an arc detection device. When it is determined that an arc has occurred, junction box 400 interrupts the current flowing through wiring 600 via circuit breaker 410 or the like, for example.

[0274] In addition, the arc detection device involved in the present invention is not limited to this, and can be fully applied to systems that require arc detection.

[0275] In this way, the circuit breaker 410 may also include an arc detection device, and when it is determined that an arc has occurred, the circuit breaker 410 cuts off the current flowing in the first path and the second path. In addition, the solar panel 310 may also include an arc detection device, which uses solar energy to generate electricity. In addition, the solar panel auxiliary module 320 may also include an arc detection device, which is used to convert the signal output from the solar panel 310. In addition, the junction box 400 may also include an arc detection device, which connects the solar panel 310 to the power conditioner 500.

[0276] For example, the arc determination unit included in the arc detection device may be realized as software in a general-purpose computer such as a personal computer.

[0277] In addition, various modifications that can be conceived by those skilled in the art to the embodiments and embodiments achieved by arbitrarily combining components and functions in the embodiments without departing from the gist of the present invention are also included in the present invention.

[0278] Description of Reference Numerals

[0279] 1a, 1aa, 1b, 1ba, 1c, 1ca, 1d, 1da: solar power generation system; 2: indoor wiring system; 10a, 10aa, 10b, 10c, 10ca, 10d, 10da, 10e, 10ea: arc detection device; 11a, 11b, 11c, 11d, 11e: low impedance circuit; 20a, 20aa, 20ab, 20ac, 20b, 20c, 20ca, 20cb, 20cc , 20d, 20da, 20db, 20dc, 20e, 20ea, 20eb, 20ec: current detection unit; 21: magnetic core; 30, 30a: arc determination unit; 40: DC power supply; 41, 310: solar panel; 41a, 41b, 41c, 41d, 41e, 42a, 42b, 42c, 42d, 42e, 110, 111, 120, 121, 600: wiring; 42: AC / DC converter; 43: system power supply; 43a, 43b, 43c, 43d, 43e: bypass path; 50: device; 51, 52, 53, 61: DC / DC converter; 51a, 51b, 51c, 51d, 51e, 52a, 52b, 52c, 52d, 52e, 110a, 110b, 110c, 110d, 120a, 120b, 120c, 120d: path; 54, 55, 56: battery; 57, 58, 59: lighting fixtures; 60a, 60aa, 60b, 60ba, 60c, 60ca, 60d, 60da, 500: power conditioner; 62: inverter; 300: solar cell array; 320: solar panel accessory module; 400: junction box; 410: circuit breaker; N1a, N1b, N1c, N1d, N1e, N2a, N2b, N2c, N2d, N2e: connection points; N3, N4: branch points.

Claims

1. An arc detection device, comprising: a current detection unit having a magnetic core through which a first path and a second path connecting a DC power supply to a device pass, and detecting currents flowing in the first path and the second path based on a magnetic field generated in the magnetic core; a low impedance circuit having an impedance lower than that of the DC power supply and the device, the low impedance circuit being connected to the first path and the second path and configured to bypass a high frequency component flowing to one of the first path and the second path; as well as an arc determination unit that determines the occurrence of an arc based on the current detected by the current detection unit, Wherein, in the magnetic core, the direction of the direct current flowing in the first path is opposite to the direction of the direct current flowing in the second path, The DC power supply supplies power to the device via a first wiring and a second wiring, the first wiring being connected to one of a positive electrode and a negative electrode of the DC power supply, and the second wiring being connected to the other of a positive electrode and a negative electrode of the DC power supply, The first path is a path on the first wiring, The second path is a path on the second wiring, The low-impedance circuit is arranged on a bypass path connecting a connection point on the first wiring and a connection point on the second wiring, wherein the connection point on the first wiring is located between one of the positive and negative poles of the DC power supply and the magnetic core, and the connection point on the second wiring is located between the magnetic core and the device.

2. An arc detection device, comprising: a current detection unit having a magnetic core through which a first path and a second path connecting a DC power supply to a device pass, and detecting currents flowing in the first path and the second path based on a magnetic field generated in the magnetic core; a low impedance circuit having an impedance lower than that of the DC power supply and the device, the low impedance circuit being connected to the first path and the second path and configured to bypass a high frequency component flowing to one of the first path and the second path; as well as an arc determination unit that determines the occurrence of an arc based on the current detected by the current detection unit, Wherein, in the magnetic core, the direction of the direct current flowing in the first path is opposite to the direction of the direct current flowing in the second path, The DC power supply supplies power to the device via a first wiring and a second wiring, the first wiring being connected to one of a positive electrode and a negative electrode of the DC power supply, and the second wiring being connected to the other of a positive electrode and a negative electrode of the DC power supply, The first path and the second path are paths on the first wiring, The first wiring penetrates the magnetic core from one side to the other side on the first path and then turns back, and penetrates the magnetic core from the other side to the one side on the second path. The low impedance circuit is provided on a bypass path connecting a connection point at the folded portion and a connection point on the first wiring, the connection point on the first wiring being located between the one side of the magnetic core and the device.

3. An arc detection device, comprising: a current detection unit having a magnetic core through which a first path and a second path connecting a DC power supply to a device pass, and detecting currents flowing in the first path and the second path based on a magnetic field generated in the magnetic core; a low impedance circuit having an impedance lower than that of the DC power supply and the device, the low impedance circuit being connected to the first path and the second path and configured to bypass a high frequency component flowing to one of the first path and the second path; as well as an arc determination unit that determines the occurrence of an arc based on the current detected by the current detection unit, Wherein, in the magnetic core, the direction of the direct current flowing in the first path is opposite to the direction of the direct current flowing in the second path, The DC power supply supplies power to the device via a first wiring and a second wiring, the first wiring being connected to one of a positive electrode and a negative electrode of the DC power supply, and the second wiring being connected to the other of a positive electrode and a negative electrode of the DC power supply, The first path and the second path are paths on the first wiring, The first wiring penetrates the magnetic core from one side to the other side on the first path and then turns back, and penetrates the magnetic core from the other side to the one side on the second path. The low impedance circuit is provided on a bypass path connecting a connection point at the folded portion with a connection point on the first wiring, and the connection point on the first wiring is located between the one side of the magnetic core and one of the positive and negative electrodes of the DC power supply.

4. An arc detection device, comprising: a current detection unit having a magnetic core through which a first path and a second path connecting a DC power supply to a device pass, and detecting currents flowing in the first path and the second path based on a magnetic field generated in the magnetic core; a low impedance circuit having an impedance lower than that of the DC power supply and the device, the low impedance circuit being connected to the first path and the second path and configured to bypass a high frequency component flowing to one of the first path and the second path; as well as an arc determination unit that determines the occurrence of an arc based on the current detected by the current detection unit, Wherein, in the magnetic core, the direction of the direct current flowing in the first path is opposite to the direction of the direct current flowing in the second path, The DC power supply supplies power to the device via a first wiring and a second wiring, the first wiring being connected to one of a positive electrode and a negative electrode of the DC power supply, and the second wiring being connected to the other of a positive electrode and a negative electrode of the DC power supply, The first path and the second path are paths on the first wiring, The first wiring penetrates the magnetic core from one side to the other side on the first path and then turns back, and penetrates the magnetic core from the other side to the one side on the second path. The low impedance circuit is provided on a bypass path connecting a connection point at the turned-back portion and a connection point on the second wiring.

5. A power regulator comprising: The arc detection device according to any one of claims 1 to 4; and A converter converts the output power of the DC power supply.

6. An indoor wiring system comprising: The arc detection device according to any one of claims 1 to 4; the first path; the second path; and The device is arranged indoors.

7. A circuit breaker, A method of providing an arc detection device according to any one of claims 1 to 4, When it is determined that an arc has occurred, the circuit breaker interrupts the current flowing through the first path and the second path.

8. A solar panel, A method of providing an arc detection device according to any one of claims 1 to 4, The solar panel utilizes solar energy to generate electricity.

9. A solar panel accessory module, A method of providing an arc detection device according to any one of claims 1 to 4, The solar panel auxiliary module is used to convert the signal output from the solar panel.

10. A junction box, A method of providing an arc detection device according to any one of claims 1 to 4, The junction box is used to connect the solar panel to the power conditioner.

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