Power supply system

Abstract

Provided is a power supply system capable of specifying the location where series arc discharge or parallel arc discharge occurs. The noise detection mechanism is provided in the positive electrode-side wiring section or the negative electrode-side wiring section, and is positioned closer to the power supply module than a connection section with the bypass wiring section, and the arc determination section is configured so as to determine that the series arc discharge occurs closer to the power supply module than the bypass wiring section by satisfying the following conditions (1) or (2). (1) The series switching unit is located closer to the power supply module than the bypass wiring unit, and when the arc detection unit detects the series arc discharge, the series switching unit is in an off state, and the parallel switching unit is in an off state, the noise detection mechanism detects a predetermined current noise or high-frequency noise. (2) The series switching unit is located closer to the power conversion device than the bypass wiring unit, and when the arc detection unit detects the series arc discharge and the parallel switching unit is in an off state, the noise detection means detects a predetermined current noise or high-frequency noise.

Description

Technical Field

[0001] The present invention relates to a power supply system including a power supply module such as a solar cell module and a power conversion device. Background Art

[0002] Conventionally, in a solar power generation system, a solar cell module and a power conversion device are provided, and the power conversion device can convert the DC power generated by the solar cell module into AC power and supply it to a commercial power supply system.

[0003] In an existing solar power generation system, after several years of installation, fires occasionally occur. The main causes of such fires are mostly cable jamming during construction, damage to the cable, poor contact at the connector part being left unattended, and arc discharge occurring at these parts as they age.

[0004] If this arc discharge is roughly classified according to the location where it occurs in the circuit, it can be classified into series arc discharge and parallel arc discharge.

[0005] Series arc discharge occurs when current passes through a wire in a series circuit, and parallel arc discharge occurs when current passes between two wires that have been connected in parallel in a parallel circuit.

[0006] Series arc discharge can be extinguished by cutting off the series circuit. In contrast, parallel arc discharge can be extinguished by short-circuiting the parallel circuit to make the voltage difference between the ends of the wires 0V. The corresponding methods are different according to the type of arc discharge.

[0007] Therefore, conventionally, in order to extinguish arc discharge, it is necessary to determine whether the arc discharge is series arc discharge or parallel arc discharge and then extinguish the arc by a method corresponding to the determined arc discharge, resulting in a problem of delayed response to arc discharge.

[0008] Therefore, in Patent Document 1, a protection method capable of extinguishing both series arc discharge and parallel arc discharge is proposed.

[0009] Specifically, the protection method of Patent Document 1 is as follows: First, when arc discharge is detected by an arc detection unit in a solar cell string, series arc extinguishing control for cutting off the series circuit through which current flows from the power conversion circuit via the power conditioning system to the solar cell string using a series switch, and parallel arc extinguishing control for forming a parallel circuit through which current flows to the string without passing through the power conversion circuit using a parallel switch are executed.

[0010] After the series arc extinguishing control and the parallel arc extinguishing control, in a state where the series circuit is cut off by the series switch and the parallel circuit is formed by the parallel switch, when arc discharge is detected by the arc detection unit, the occurrence of series arc discharge in the solar cell string is detected. After the series arc extinguishing control and the parallel arc extinguishing control, in a state where both the series circuit and the parallel circuit are cut off by the series switch and the parallel switch, when arc discharge is detected by the arc detection unit, the occurrence of parallel arc discharge in the solar cell string is detected.

[0011] Then, when the series arc discharge in the solar cell string is detected, the parallel circuit is cut off by the parallel switch. When the parallel arc discharge in the solar cell string is detected, the parallel circuit is made conductive by the parallel switch.

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-80747

[0013] However, when arc discharge occurs, if its severity is high, it may be necessary to immediately maintain the occurrence site of the arc discharge. In addition, even if the severity is low, during regular maintenance, it is necessary to maintain the occurrence site of the arc discharge.

[0014] However, in the protection method of Patent Document 1, the occurrence site of the arc discharge cannot be determined, and during maintenance, it is necessary to check all parts between the solar cell string and the power conversion circuit. Summary of the Invention

[0015] Therefore, an object of the present invention is to provide a power supply system capable of determining the occurrence site of series arc discharge or parallel arc discharge.

[0016] One aspect of the present invention for solving the above problems is a power supply system, which includes a power supply module, a power conversion device, an arc detection unit, a positive-side wiring portion, a negative-side wiring portion, a bypass wiring portion, a series switch portion, a parallel switch portion, and an arc determination unit. The power supply module is connected to the power conversion device via the positive-side wiring portion and the negative-side wiring portion. The arc detection unit can detect series arc discharge in a portion on the power supply module side of the power conversion device and has a noise detection mechanism. The bypass wiring portion connects the positive-side wiring portion and the negative-side wiring portion. The series switch portion is provided in the positive-side wiring portion or the negative-side wiring portion. The parallel switch portion is provided in the middle of the bypass wiring portion and is connected in parallel with the power conversion device. The noise detection mechanism is provided in the positive-side wiring portion or the negative-side wiring portion and is located on the power supply module side of the connection portion with the bypass wiring portion. The arc determination unit determines that the series arc discharge occurs on the power supply module side of the bypass wiring portion when the following condition (1) or (2) is satisfied.

[0017] (1) The series switch portion is on the power supply module side of the bypass wiring portion. When the arc detection unit detects series arc discharge, the series switch portion is in the closed state and the parallel switch portion is in the closed state, and the noise detection mechanism detects a specified current noise or a specified high-frequency noise.

[0018] (2) The series switch portion is on the power conversion device side of the bypass wiring portion. When the arc detection unit detects series arc discharge and the parallel switch portion is in the closed state, the noise detection mechanism detects a specified current noise or a specified high-frequency noise.

[0019] According to this aspect, it is possible to determine whether series arc discharge occurs on the power supply module side of the bypass wiring portion, so that the occurrence location of the series arc discharge can be determined, and subsequent maintenance work and the like become easy.

[0020] Preferably, the arc determination unit determines that the series arc discharge occurs on the power conversion device side of the bypass wiring portion when the following condition (3) or (4) is satisfied.

[0021] (3) The series switch portion is on the power supply module side of the bypass wiring portion. When the arc detection unit detects series arc discharge, the series switch portion is in the closed state and the parallel switch portion is in the closed state, and the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise.

[0022] (4) The above-mentioned series switch section is on the side of the power conversion device closer to the power conversion device than the above-mentioned detour wiring section. When the series arc discharge is detected by the above-mentioned arc detection section and the above-mentioned parallel switch section is in the closed state, the above-mentioned noise detection mechanism does not detect the specified current noise and the specified high-frequency noise.

[0023] According to this aspect, the occurrence location of the series arc discharge can be determined more accurately, and subsequent maintenance operations and the like become easier.

[0024] Preferably, the above-mentioned arc detection section is configured to be able to detect the parallel arc discharge of the part on the side of the power supply module closer to the power supply module than the above-mentioned power conversion device. When the above-mentioned arc detection section detects the parallel arc discharge, the above-mentioned series switch section is in the closed state and the above-mentioned parallel switch section is in the open state, and when the above-mentioned noise detection mechanism does not detect the specified current noise and the specified high-frequency noise, the above-mentioned arc determination section determines that the parallel arc discharge occurs on the side of the power supply module closer to the power supply module than the above-mentioned detour wiring section.

[0025] According to this aspect, even when the parallel arc discharge occurs, it is possible to determine whether the parallel arc discharge occurs on the side of the power supply module closer to the power supply module than the detour wiring section. Therefore, the occurrence location of the parallel arc can be determined, and subsequent maintenance operations and the like become easier.

[0026] More preferably, when the above-mentioned arc detection section detects the parallel arc discharge, the above-mentioned series switch section is in the closed state and the above-mentioned parallel switch section is in the open state, and when the above-mentioned noise detection mechanism detects the specified current noise or the specified high-frequency noise, the above-mentioned arc determination section determines that the parallel arc discharge occurs on the side of the power conversion device closer to the power conversion device than the above-mentioned detour wiring section.

[0027] According to this aspect, the occurrence location of the parallel arc can be determined more accurately, and subsequent maintenance operations and the like become easier.

[0028] One aspect of the present invention is a power supply system, which includes a power supply module, a power conversion device, an arc detection unit, a positive-side wiring section, a negative-side wiring section, a bypass wiring section, a series switch section, a parallel switch section, and an arc determination section. The power supply module is connected to the power conversion device via the positive-side wiring section and the negative-side wiring section. The arc detection unit can detect parallel arc discharge in a portion on the power supply module side relative to the power conversion device and has a noise detection mechanism. The bypass wiring section connects the positive-side wiring section and the negative-side wiring section. The series switch section is provided in the positive-side wiring section or the negative-side wiring section. The parallel switch section is provided in the middle of the bypass wiring section and is connected in parallel with the power conversion device. The noise detection mechanism is provided in the positive-side wiring section or the negative-side wiring section and is located on the power supply module side relative to the connection portion with the bypass wiring section. When the arc detection unit detects parallel arc discharge, the series switch section is in the closed state, and the parallel switch section is in the open state, and when the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise, the arc determination section determines that the parallel arc discharge occurs on the power supply module side relative to the bypass wiring section.

[0029] According to this aspect, it is possible to determine whether parallel arc discharge occurs on the power supply module side relative to the bypass wiring section, so that the location where the parallel arc occurs can be determined, and subsequent maintenance operations and the like become easier.

[0030] Preferably, it is configured that when the arc detection unit detects parallel arc discharge, the series switch section is in the closed state, and the parallel switch section is in the open state, and when the noise detection mechanism detects a specified current noise or a specified high-frequency noise, the arc determination section determines that the parallel arc discharge occurs on the power conversion device side relative to the bypass wiring section.

[0031] According to this aspect, the location where the parallel arc occurs can be more accurately determined, and subsequent maintenance operations and the like become easier.

[0032] For the above aspects, as long as they are within the technical scope of the present invention, they can be subordinate to each other among the aspects, a part of the structure can be cited, and a part of the structure can be replaced.

[0033] According to the power supply system of the present invention, the location where series arc discharge or parallel arc discharge occurs can be determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a block diagram during normal operation of the power supply system according to the first embodiment of the present invention.

[0035] Figure 2 is Figure 1 a flowchart of an arc interruption operation of a power supply system of

[0036] Figure 3 is Figure 2 an explanatory diagram of the state of a switch unit in an arc interruption operation of a power supply system of Figure 3 (a) of Figure 2 is a block diagram in steps S1-3 and S1-9 of Figure 3 (b) of Figure 2 is a block diagram in step S1-6 of

[0037] Figure 4 is a block diagram of a power supply system according to another embodiment of the present invention, where Figure 4 (a) of Figure 4 is a block diagram when the series switch unit is in the closed state and the parallel switch unit is in the closed state

[0038] Figure 5 is a flowchart of an arc interruption operation of a power supply system according to another embodiment of the present invention.

[0039] Figure 6 is a flowchart of an arc interruption operation of a power supply system according to still another embodiment of the present invention. Detailed Embodiment

[0040] Hereinafter, embodiments of the present invention will be described in detail.

[0041] As Figure 1 such, a power supply system 1 according to a first embodiment of the present invention includes a power supply module 2, a power conversion device 3, an arc detection unit 5, a positive-side wiring unit 6, a negative-side wiring unit 7, a bypass wiring unit 8, a measurement wiring unit 9, a series switch unit 10 (series arc interruption unit), a parallel switch unit 11 (parallel arc short-circuit unit), and an arc determination unit 12 as main components, and can connect a system power supply unit 100 to the power conversion device 3.

[0042] The power supply system 1 supplies the power generated by the power supply module 2 to the system power supply unit 100 connected to the power conversion device 3.

[0043] (Power Supply Module 2)

[0044] The power supply module 2 is a power generation module that generates power using renewable energy, such as a solar cell module or a fuel cell module, or a power storage module such as a secondary battery, and can supply the generated power to the system power supply unit 100 via the power conversion device 3.

[0045] The power supply module 2 of this embodiment uses a solar cell module that converts light energy into electrical energy.

[0046] The power supply module 2 is formed by connecting a plurality of solar cell unit groups in series or in series and in parallel, and each solar cell unit group is configured such that a plurality of solar cell units are connected in series.

[0047] As Figure 1 such, the power supply module 2 includes a positive-side terminal 21a connected to the positive-side of each solar cell unit group, and a negative-side terminal 21b connected to the negative-side of each solar cell unit group.

[0048] (Power conversion device 3)

[0049] The power conversion device 3 converts DC power into AC power, and includes a boost converter section that boosts the power generated by the power supply module 2, and an inverter that converts the boosted power from DC power into AC power.

[0050] (Arc detection section 5)

[0051] The arc detection section 5 is a section that detects arc discharge when arc discharge occurs in a portion on the power supply module 2 side relative to the connection terminals 31a and 31b of the power conversion device 3.

[0052] That is, for the arc detection section 5, not only the power supply module 2 becomes an object of arc discharge detection, but also wiring components that connect the power supply module 2 to the connection terminals 31a and 31b, etc., become objects of arc discharge detection.

[0053] As Figure 1 such, the arc detection section 5 mainly includes a noise detection section 15 (noise detection mechanism) and a voltage measurement section 16.

[0054] The noise detection section 15 is a section that detects current noise or high-frequency noise at the noise detection position 48 of the negative-side wiring section 7.

[0055] The voltage measurement section 16 is provided in the middle of the measurement wiring section 9 and measures the voltage between the positive-side wiring section 6 and the negative-side wiring section 7.

[0056] (Positive-side wiring section 6)

[0057] The positive-side wiring section 6 is a wiring section that connects the positive-side terminal 21a of the power supply module 2 to the positive-side connection terminal 31a of the power conversion device 3.

[0058] (Negative-side wiring section 7)

[0059] The negative-side wiring portion 7 is a wiring portion that connects the negative-side terminal 21b of the power supply module 2 to the negative-side connection terminal 31b of the power conversion device 3.

[0060] (Detour wiring portion 8)

[0061] The detour wiring portion 8 is a wiring portion that connects the middle of the positive-side wiring portion 6 to the middle of the negative-side wiring portion 7, and is a wiring portion that bypasses the power conversion device 3 when viewed from the power supply module 2 side.

[0062] That is, the detour wiring portion 8 is connected to the middle of the positive-side wiring portion 6 via the connection portion 40, and is connected to the middle of the negative-side wiring portion 7 via the connection portion 41.

[0063] (Measurement wiring portion 9)

[0064] The measurement wiring portion 9 is a wiring portion that connects the middle of the positive-side wiring portion 6 to the middle of the negative-side wiring portion 7, is connected to the middle of the positive-side wiring portion 6 via the connection portion 45, and is connected to the middle of the negative-side wiring portion 7 via the connection portion 46.

[0065] (Series switch portion 10)

[0066] The series switch portion 10 is provided in the middle of the positive-side wiring portion 6, and is a series arc cut-off portion that cuts off the conduction between the power supply module 2 and the power conversion device 3 when series arc discharge occurs.

[0067] The series switch portion 10 can conduct between the power supply module 2 and the power conversion device 3 by being set to the closed state, and can cut off the conduction between the power supply module 2 and the power conversion device 3 by being set to the open state.

[0068] (Parallel switch portion 11)

[0069] The parallel switch portion 11 is provided in the middle of the detour wiring portion 8, and is a parallel arc short-circuit portion that shorts the positive-side wiring portion 6 and the negative-side wiring portion 7 to short-circuit between the power supply module 2 and the power conversion device 3 when parallel arc discharge occurs.

[0070] The parallel switch portion 11 can conduct and short-circuit the positive-side wiring portion 6 and the negative-side wiring portion 7 by being set to the closed state, and can cut off the conduction between the positive-side wiring portion 6 and the negative-side wiring portion 7 by being set to the open state.

[0071] (Arc determination portion 12)

[0072] The arc determination portion 12 is a part that determines whether the arc discharge is series arc discharge or parallel arc discharge.

[0073] Next, the positional relationship of each component of the power supply system 1 of the present embodiment will be described.

[0074] As Figure 1 shown, the measurement wiring portion 9 is configured such that the voltage measurement portion 16 is provided in the middle, the connection portion 45 with the positive electrode side wiring portion 6 is provided on the positive electrode side terminal 21a side of the power supply module 2 (the upstream side in the current flow direction) with respect to the connection portion 40 (connection part) of the bypass wiring portion 8 with the positive electrode side wiring portion 6, and is provided on the positive electrode side terminal 21a side of the power supply module 2 (the upstream side in the current flow direction) with respect to the series switch portion 10. That is, the series switch portion 10 is located between the connection portion 45 of the measurement wiring portion 9 and the connection portion 40 of the bypass wiring portion 8.

[0075] The measurement wiring portion 9 is configured such that the connection portion 46 with the negative electrode side wiring portion 7 is provided on the negative electrode side terminal 21b side of the power supply module 2 with respect to the connection portion 41 (connection part) of the bypass wiring portion 8 with the negative electrode side wiring portion 7, and is provided on the negative electrode side terminal 21b side of the power supply module 2 with respect to the noise detection position 48 of the noise detection portion 15. That is, the noise detection position 48 of the noise detection portion 15 at the negative electrode side wiring portion 7 is located between the connection portion 46 of the measurement wiring portion 9 and the connection portion 41 of the bypass wiring portion 8.

[0076] Next, the arc interruption operation of the power supply system 1 of the present embodiment will be described according to the Figure 2 flowchart.

[0077] The arc interruption operation is performed in parallel with the normal operation of supplying the power generated by the power supply module 2 to the system power supply unit 100 via the power conversion device 3.

[0078] That is, in principle, the arc interruption operation is based on the state of the normal operation. That is, as Figure 1 shown, it is based on the state where the series switch portion 10 is in the closed state and the parallel switch portion 11 is in the open state.

[0079] In the arc interruption operation, first, it is determined whether the noise detection portion 15 detects a prescribed current noise or a prescribed high-frequency noise (hereinafter also simply referred to as noise) at the noise detection position 48 of the negative electrode side wiring portion 7 (step S1-1). When the noise detection portion 15 detects noise (Yes in step S1-1), it is determined whether the voltage between the connection portions 45 and 46 measured by the voltage measurement portion 16 is equal to or higher than the first arc threshold (step S1-2).

[0080] The first arc threshold at this time is the threshold that serves as the determination criterion for the occurrence of series arc discharge, and can be appropriately changed according to the minimum operating input voltage in the power conversion device 3, etc. For example, a value exceeding 0V and less than 40V is preferably used.

[0081] In step S1-2, when the voltage between the connection parts 45 and 46 is equal to or higher than the first arc threshold (Yes in step S1-2), the arc determination unit 12 determines that series arc discharge has occurred, and as shown in Figure 3 (a) of, the parallel switch unit 11 is changed to the closed state (step S1-3), and it is determined whether noise is detected by the noise detection unit 15 (step S1-4).

[0082] In step S1-4, when the noise detection unit 15 detects noise, that is, when the noise continues (Yes in step S1-4), the arc determination unit 12 determines that the series arc discharge that has occurred is a supply-side series arc discharge that occurred on the side of the power supply module 2 closer than the detour wiring part 8, as shown in Figure 3 (b) of, the series switch unit 10 is changed to the open state, and the parallel switch unit 11 is changed to the open state (step S1-6), and the conduction between the power supply module 2 and the power conversion device 3 is cut off to extinguish the supply-side series arc discharge.

[0083] On the other hand, in step S1-4, when the noise detection unit 15 does not detect noise, that is, when the noise has disappeared (No in step S1-4), the arc determination unit 12 determines that the series arc discharge that has occurred is a conversion-side series arc discharge that occurred on the side of the power conversion device 3 closer than the detour wiring part 8 (step S1-7), and moves to step S1-6 to cut off the conduction between the power supply module 2 and the power conversion device 3 to extinguish the conversion-side series arc discharge.

[0084] When the noise detection unit 15 detects noise (Yes in S1-1) and the voltage is less than the first arc threshold (No in step S1-2), the arc determination unit 12 determines that parallel arc discharge has occurred between the positive-side wiring part 6 and the negative-side wiring part 7, and this parallel arc discharge is a conversion-side parallel arc discharge that occurred on the side of the power conversion device 3 closer than the detour wiring part 8 (step S1-8), as shown in Figure 3 (a) of, the series switch unit 10 is changed (maintained) to the closed state, and the parallel switch unit 11 is changed to the closed state (step S1-9), and the positive-side wiring part 6 and the negative-side wiring part 7 are conducted through the detour wiring part 8 to extinguish the conversion-side parallel arc discharge.

[0085] When the noise detection unit 15 does not detect noise in step S1-1 (No in step S1-1), and the voltage between the connection parts 45 and 46 measured by the voltage measurement unit 16 is below the second arc threshold (Yes in step S1-10), the arc determination unit 12 determines that a parallel arc discharge has occurred between the positive-side wiring part 6 and the negative-side wiring part 7. This parallel arc discharge is a supply-side parallel arc discharge that occurs on the power supply module 2 side of the detour wiring part 8 (step S1-11). Then, it moves to step S1-9, and the positive-side wiring part 6 and the negative-side wiring part 7 are made conductive through the detour wiring part 8 to extinguish the supply-side parallel arc discharge.

[0086] The second arc threshold at this time is the threshold for determining the occurrence of parallel arc discharge, and it can be appropriately changed according to the minimum operating input voltage in the power conversion device 3, etc. The second arc threshold can be the same value as the first arc threshold or a different value.

[0087] When the noise detection mechanism does not detect noise in step S1-1 (No in step S1-1), and the voltage between the connection parts 45 and 46 measured by the voltage measurement unit 16 exceeds the second arc threshold (No in step S1-10), the arc determination unit 12 determines that no arc discharge has occurred, and returns to step S1-1.

[0088] According to the power supply system 1 of the present embodiment, the noise detection unit 15 is provided in the negative-side wiring part 7 and is located on the power supply module 2 side of the connection part 41 with the detour wiring part 8. The series switch part 10 is on the power supply module 2 side of the detour wiring part 8. The arc determination unit 12 determines that the series arc discharge is a supply-side series arc discharge that occurs on the power supply module 2 side of the detour wiring part 8 on the condition that the noise detection unit 15 and the voltage measurement unit 16 of the arc detection unit 5 detect a series arc discharge, and the series switch part 10 is in the closed state and the parallel switch part 11 is in the closed state. Therefore, the location where the series arc occurs can be determined, and subsequent maintenance operations and the like become easy.

[0089] According to the power supply system 1 of the present embodiment, the arc determination unit 12 determines that the series arc discharge is a conversion-side series arc discharge that occurs on the power conversion device 3 side of the detour wiring part 8 on the condition that the noise detection unit 15 and the voltage measurement unit 16 of the arc detection unit 5 detect a series arc discharge, and the series switch part 10 is in the closed state and the parallel switch part 11 is in the closed state, and the noise detection unit 15 does not detect a specified current noise and a specified high-frequency noise. Therefore, the location where the series arc occurs can be determined more accurately, and subsequent maintenance operations and the like become easy.

[0090] In the power supply system 1 according to the present embodiment, in a state where the noise detection unit 15 and the voltage measurement unit 16 of the arc detection unit 5 detect a parallel arc discharge, the series switch unit 10 is in a closed state, and the parallel switch unit 11 is in an open state. When the noise detection unit 15 does not detect a specified current noise and a specified high-frequency noise, the arc determination unit 12 determines that the parallel arc discharge is a supply-side parallel arc discharge occurring on the power supply module 2 side relative to the detour wiring unit 8. Therefore, even when a parallel arc discharge occurs, it is possible to determine whether the parallel arc discharge occurs on the power supply module 2 side relative to the detour wiring unit 8, so that the location where the parallel arc occurs can be determined, and subsequent maintenance operations and the like become easier.

[0091] In the power supply system 1 according to the present embodiment, in a state where the arc detection unit 5 detects a parallel arc discharge, the series switch unit 10 is in a closed state, and the parallel switch unit 11 is in an open state. When the noise detection unit 15 detects a specified current noise or a specified high-frequency noise, the arc determination unit 12 determines that the parallel arc discharge is a conversion-side parallel arc discharge occurring on the power conversion device 3 side relative to the detour wiring unit 8. Therefore, it is possible to more accurately determine the location where the parallel arc occurs, and subsequent maintenance operations and the like become easier.

[0092] In the above embodiment, the series switch unit 10 is provided on the power supply module 2 side relative to the detour wiring unit 8, but the present invention is not limited thereto. As Figure 4 shown in (a), the series switch unit 10 may also be provided on the power conversion device 3 side relative to the detour wiring unit 8. That is, the series switch unit 10 may also be provided on the downstream side in the direction of the electric current flow of the positive electrode side wiring unit 6 relative to the detour wiring unit 8. In this case, in steps S1-3 and S1-9, similar to the above embodiment, as Figure 4 shown in (a), the series switch unit 10 may be made to be in a closed state, but as Figure 4 shown in (b), the series switch unit 10 may be made to be in an open state.

[0093] In the above embodiment, after the noise is detected by the noise detection unit 15 in step S1-1, the voltage between the connection parts 45 and 46 measured by the voltage measurement unit 16 is measured in step S1-2, but the present invention is not limited thereto.

[0094] As Figure 5 shown, the voltage between the connection parts 45 and 46 measured by the voltage measurement unit 16 may also be measured in step S2-1, and then the noise may be detected by the noise detection unit 15 in step S2-2 or step S2-3.

[0095] At this time, when the voltage in step S2-1 is above the third arc threshold and noise is detected in step S2-2, move to step S1-3. When the voltage in step S2-1 is above the third arc threshold and no noise is detected in step S2-2, return to step S2-1.

[0096] In addition, when the voltage in step S2-1 is less than the third arc threshold and noise is detected in step S2-3, move to step S1-8. On the other hand, when the voltage in step S2-1 is less than the third arc threshold and no noise is detected in step S2-3, move to step S2-4. In step S2-4, if the arc determination unit 12 determines that supply-side parallel arc discharge has occurred on the power supply module 2 side compared to the detour wiring section 8, or although it is normal but in a state of insufficient sunlight, move to step S1-9.

[0097] The above-mentioned third arc threshold can be appropriately changed according to the minimum operating input voltage in the power conversion device 3, etc.

[0098] In the above-described embodiment, the case where the power supply system 1 includes one power supply module 2 has been described, but the present invention is not limited thereto. The power supply system 1 may also include two or more power supply modules 2.

[0099] In the above-described embodiment, the series switch section 10 is provided only on the positive electrode side wiring section 6, but the present invention is not limited thereto. The series switch section 10 may also be provided on the negative electrode side wiring section 7.

[0100] In the above-described embodiment, the connection portion 46 between the measurement wiring section 9 and the negative electrode side wiring section 7 is provided on the power supply module 2 side with respect to the connection portion 41 between the detour wiring section 8 and the negative electrode side wiring section 7, but the present invention is not limited thereto. The connection portion 46 between the measurement wiring section 9 and the negative electrode side wiring section 7 may also be provided on the power conversion device 3 side with respect to the connection portion 41 between the detour wiring section 8 and the negative electrode side wiring section 7.

[0101] In the above-described embodiment, in step S1-8, when it is determined by the arc determination unit 12 that parallel arc discharge has occurred between the positive electrode side wiring section 6 and the negative electrode side wiring section 7, and this parallel arc discharge occurs after the conversion side parallel arc discharge on the power conversion device 3 side compared to the detour wiring section 8, move to step S1-9 to extinguish the conversion side parallel arc discharge, but the present invention is not limited thereto. As Figure 6 such, it is also possible to move to step S1-6 after step S1-8 to make the series switch section 10 in the open state to extinguish the conversion side parallel arc discharge. Thus, even when parallel arc discharge and series arc discharge are misjudged in step S1-2, arc extinguishing can be performed.

[0102] For the above-described embodiments, as long as they are within the technical scope of the present invention, the respective components can be freely replaced and added between the embodiments.

[0103] Description of Reference Numerals

[0104] 1... Power supply system; 2... Power supply module; 3... Power conversion device; 5... Arc detection unit; 6... Positive-side wiring part; 7... Negative-side wiring part; 8... Detour wiring part; 10... Series switch part; 11... Parallel switch part; 12... Arc determination unit; 15... Noise detection unit (noise detection mechanism); 40, 41... Connection part (connection portion).

Claims

1. A power supply system, wherein, it has a power supply module, a power conversion device, an arc detection unit, a positive-side wiring portion, a negative-side wiring portion, a detour wiring portion, a series switch portion, a parallel switch portion, and an arc determination unit, the power supply module is connected to the power conversion device via the positive-side wiring portion and the negative-side wiring portion, the arc detection unit can detect series arc discharge in a portion on the power supply module side relative to the power conversion device, and has a noise detection mechanism, the detour wiring portion connects the positive-side wiring portion and the negative-side wiring portion, the series switch portion is provided in the positive-side wiring portion or the negative-side wiring portion, the parallel switch portion is provided midway in the detour wiring portion and is connected in parallel with the power conversion device, the noise detection mechanism is provided in the positive-side wiring portion or the negative-side wiring portion and is located on the power supply module side relative to the connection portion with the detour wiring portion, the arc determination unit determines that the series arc discharge occurs on the power supply module side relative to the detour wiring portion by satisfying the following condition (1) or (2), (1) When the series switch portion is on the power supply module side relative to the detour wiring portion, and when the arc detection unit detects series arc discharge, the series switch portion is in the closed state and the parallel switch portion is in the closed state, the noise detection mechanism detects a specified current noise or a specified high-frequency noise, (2) When the series switch portion is on the power conversion device side relative to the detour wiring portion, and when the arc detection unit detects series arc discharge and the parallel switch portion is in the closed state, the noise detection mechanism detects a specified current noise or a specified high-frequency noise.

2. The power supply system according to claim 1, wherein, the arc determination unit determines that the series arc discharge occurs on the power conversion device side relative to the detour wiring portion by satisfying the following condition (3) or (4), (3) When the series switch portion is on the power supply module side relative to the detour wiring portion, and when the arc detection unit detects series arc discharge, the series switch portion is in the closed state and the parallel switch portion is in the closed state, the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise, (4) When the series switch portion is on the power conversion device side relative to the detour wiring portion, and when the arc detection unit detects series arc discharge and the parallel switch portion is in the closed state, the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise.

3. The power supply system according to claim 1 or 2, wherein, the arc detection unit can detect parallel arc discharge in a portion on the power supply module side relative to the power conversion device, When the arc detection unit detects a parallel arc discharge, and when the series switch unit is in the closed state and the parallel switch unit is in the open state, if the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise, the arc determination unit determines that the parallel arc discharge occurs on the power supply module side relative to the detour wiring section.

4. The power supply system according to claim 3, wherein, When the arc detection unit detects a parallel arc discharge, and when the series switch unit is in the closed state and the parallel switch unit is in the open state, if the noise detection mechanism detects a specified current noise or a specified high-frequency noise, the arc determination unit determines that the parallel arc discharge occurs on the power conversion device side relative to the detour wiring section.

5. A power supply system, wherein, it includes a power supply module, a power conversion device, an arc detection unit, a positive electrode side wiring section, a negative electrode side wiring section, a detour wiring section, a series switch unit, a parallel switch unit, and an arc determination unit. The power supply module is connected to the power conversion device via the positive electrode side wiring section and the negative electrode side wiring section. The arc detection unit can detect a parallel arc discharge in a part on the power supply module side relative to the power conversion device, and has a noise detection mechanism. The detour wiring section connects the positive electrode side wiring section and the negative electrode side wiring section. The series switch unit is provided in the positive electrode side wiring section or the negative electrode side wiring section. The parallel switch unit is provided in the middle of the detour wiring section and is connected in parallel with the power conversion device. The noise detection mechanism is provided in the positive electrode side wiring section or the negative electrode side wiring section, and is located on the power supply module side relative to the connection part with the detour wiring section. When the arc detection unit detects a parallel arc discharge, and when the series switch unit is in the closed state and the parallel switch unit is in the open state, if the noise detection mechanism does not detect a specified current noise and a specified high-frequency noise, the arc determination unit determines that the parallel arc discharge occurs on the power supply module side relative to the detour wiring section.

6. The power supply system according to claim 5, wherein, When the arc detection unit detects a parallel arc discharge, and when the series switch unit is in the closed state and the parallel switch unit is in the open state, if the noise detection mechanism detects a specified current noise or a specified high-frequency noise, the arc determination unit determines that the parallel arc discharge occurs on the power conversion device side relative to the detour wiring section.

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