Photovoltaic group cascade fault arc breaking device

Abstract

The utility model relates to the field of photovoltaics, in particular to a photovoltaic group cascade fault arc breaking device, which comprises a fault arc sensing unit used for detecting a circuit, obtaining an arc sensing signal and outputting the arc sensing signal; the fault arc detection main control unit is used for receiving the arc sensing signal, carrying out data processing, judging whether an arc exists or not, and outputting a corresponding trigger signal; and the breaking unit is electrically connected to the circuit, receives the control of the trigger signal, and performs tripping and breaking control on the circuit. The AFCI equipment has the advantages of being small in size, capable of being flexibly assembled and adaptive to a high-voltage direct-current system as pure AFCI equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic, in particular to a photovoltaic string level fault arc breaking device. BACKGROUND

[0002] In a photovoltaic system, there is a safety hazard of arc fault in high-voltage direct current, and a simple emergency trip device can only be manually disconnected after the arc causes a visible disaster, missing the best protective tripping opportunity. Therefore, the trip device with fault arc detection function can timely identify the fault existing in the high-voltage circuit and timely trip to ensure the safe operation of the photovoltaic system.

[0003] The arc detection device used in the photovoltaic system is generally divided into two categories: one is the AFDD device, and the other is the other device with AFCI function; the AFDD device usually only has detection function, and the trip function is not integrated; the other device with AFCI function such as photovoltaic inverter and photovoltaic combiner box, such device not only has large volume, but also cannot be installed as pure AFCI device. Therefore, a small volume, flexible assembly and high-voltage direct current system adapted AFCI device is needed for system level access. CONTENT OF THE INVENTION

[0004] In order to improve the problem of large volume and difficult assembly of the device with AFCI function, the present application provides a photovoltaic string level fault arc breaking device.

[0005] The photovoltaic string level fault arc breaking device provided by the present application adopts the following technical scheme:

[0006] A photovoltaic string level fault arc breaking device comprises:

[0007] A fault arc sensing unit is used for detecting a circuit, obtaining an arc sensing signal and outputting;

[0008] A fault arc detection master control unit receives the arc sensing signal and performs data processing, judges whether there is an arc, and outputs a corresponding trigger signal;

[0009] A breaking unit is electrically connected to the circuit, receives the control of the trigger signal, and performs trip breaking control on the circuit.

[0010] By adopting the above technical scheme, the breaking unit is controlled by detection, calculation and control to control the on-off of the circuit, realizing an independent pure AFCI device. In the case that the user only needs AFCI function and does not need other functions such as photovoltaic inverter, the number of components is reduced, the volume is greatly reduced, and the assembly is more convenient.

[0011] Optionally, the emergency stop unit is further included for triggering by a user, and directly outputting the trigger signal to the breaking unit.

[0012] By adopting the above technical scheme, if detection or calculation fails, the user can actively disconnect the circuit through the emergency stop unit, thereby playing a role in safety guarantee.

[0013] Optionally, the high-voltage power supply unit is further included and electrically connected to the input end of the breaking unit, converts a high-voltage direct-current signal of the circuit into a low-voltage direct-current signal, and the output end of the high-voltage power supply unit is electrically connected to the fault arc detection master control unit, the emergency stop unit and the breaking unit to supply power.

[0014] By adopting the above technical scheme, the high-voltage input is directly converted into a low-voltage direct-current output by the high-voltage power supply unit to supply power to other units, without the need for additional power supply to supply power to other units, which is convenient and fast.

[0015] Optionally, the fault arc self-checking unit is further included and used to output a self-checking signal to the fault arc detection master control unit, the fault arc detection master control unit outputs an analog fault signal to the fault arc sensing unit after receiving the self-checking signal, and the fault arc detection master control unit judges whether self-checking is successful through the arc sensing signal returned by the fault arc sensing unit.

[0016] By adopting the above technical scheme, self-checking is realized through the fault arc self-checking unit, so as to check whether detection and calculation fail, thereby ensuring normal operation of the system.

[0017] Optionally, the indication unit is further included, the fault arc detection master control unit outputs different indication signals according to different arc sensing signals, and the indication unit receives the indication signals and displays different indications for the user to view.

[0018] By adopting the above technical scheme, different colors, colors with different frequencies or displays are provided through the indication unit to directly prompt the user.

[0019] Optionally, the wireless alarm unit is further included and receives the trigger signal to wirelessly output an alarm signal to the user.

[0020] By adopting the above technical scheme, the user is remotely warned to realize timely prompting and reduce the probability of additional economic loss caused by long-term closing of the circuit output.

[0021] Optionally, the fault arc self-checking unit further includes a wireless self-checking subunit, the wireless self-checking subunit is used to receive a remote self-checking signal wirelessly input by the user, and the fault arc self-checking unit outputs the self-checking signal through the remote self-checking signal.

[0022] By adopting the technical scheme, the user can remotely perform self-checking, which is convenient and fast.

[0023] Optionally, the breaking unit comprises:

[0024] a breaking subunit, configured to trip and break the input;

[0025] an automatic control subunit, configured to receive the trigger signal and then trip and break the input through the breaking subunit;

[0026] a manual control subunit, configured to be manually controlled by the user to control the breaking subunit to trip and break;

[0027] an automatic reset subunit, configured to receive the trigger signal and control the breaking subunit to close.

[0028] By adopting the technical scheme, the manual breaking, automatic breaking and automatic closing can be supported, which is convenient, fast and efficient.

[0029] In summary, the present application has at least one of the following beneficial technical effects:

[0030] 1. The number of components is reduced, the volume is greatly reduced, and the assembly is more convenient.

[0031] 2. The manual breaking, automatic breaking and automatic closing can be supported, which is convenient, fast and efficient. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a module schematic diagram of a photovoltaic string-level fault arc breaking device in Embodiment 1 of the present application.

[0033] Figure 2 is a module schematic diagram of a highlighted fault arc self-checking unit of a photovoltaic string-level fault arc breaking device in Embodiment 2 of the present application.

[0034] Figure 3 is a module schematic diagram of the highlighted breaking unit 12.

[0035] Legend: 1, fault arc sensing unit; 11, fault arc detection master control unit; 12, breaking unit; 121, breaking subunit; 122, automatic control subunit; 123, manual control subunit; 124, automatic reset subunit; 2, emergency stop unit; 21, high-voltage power supply unit; 3, fault arc self-checking unit; 31, indication unit; 312, wireless self-checking subunit; 32, wireless alarm unit. DETAILED DESCRIPTION

[0036] The following will be described in detail in combination with the accompanying drawings. Figures 1-3Further details of the application are provided below.

[0037] Embodiment 1 of the present application discloses a photovoltaic string level fault arc breaking device. Referring to Figure 1 , the photovoltaic string level fault arc breaking device comprises a fault arc sensing unit 1, a fault arc detection master control unit 11, a breaking unit 12, an emergency stop unit 2, a high-voltage power supply unit 21, a fault arc self-checking unit 3, an indication unit 31, and a wireless alarm unit 32. In this embodiment, the breaking unit 12 has four input terminals, and the four input terminals are connected to four photovoltaic cables respectively, which are named PV1-IN, PV2-IN, PV3-IN, and PV4-IN respectively. The four output terminals are PV1-OUT, PV2-OUT, PV3-OUT, and PV4-OUT respectively. Each photovoltaic cable usually has a voltage of 300V-1500V and a current of 0A-20A, and in other embodiments, the number of input terminals can be different.

[0038] Referring to Figure 1 , PV1-IN, PV2-IN, PV3-IN, and PV4-IN are electrically connected to the input terminals of the breaking unit 12, and the four output terminals of the breaking unit 12 are electrically connected to the input terminals of the fault arc sensing unit 1. The fault arc sensing unit 1 detects the four inputs to obtain an arc sensing signal and outputs it. The output terminals of the fault arc sensing unit 1 output PV1-OUT, PV2-OUT, PV3-OUT, and PV4-OUT respectively.

[0039] Referring to Figure 1 , the input terminal of the high-voltage power supply unit 21 takes power from any photovoltaic cable. In this embodiment, the input terminal of the high-voltage power supply unit 21 is connected in parallel to PV1-IN, and converts the high-voltage direct current signal of the photovoltaic cable into a low-voltage direct current signal of 24V as output. The output terminal of the high-voltage power supply unit 21 is electrically connected to the fault arc detection master control unit 11, the emergency stop unit 2, and the breaking unit 12 to supply power.

[0040] Referring to Figure 1 , the emergency stop unit 2 can be a button that receives power supply from the high-voltage power supply unit 21. When the user presses the emergency stop unit 2, the emergency stop unit 2 can conduct an output trigger signal to the breaking unit 12, and the breaking unit 12 will trip and break all the circuits of the connected photovoltaic cables, i.e., all the inputs of the input terminals will be disconnected.

[0041] Referring to Figure 1The fault arc detection master control unit 11 receives the arc sensing signal output by the fault arc sensing unit 1, compares the arc sensing signal with the preset arc threshold, judges whether there is an arc, and if so, outputs a trigger signal to the breaking unit 12 to disconnect the circuit of the corresponding photovoltaic cable, and if not, does not act. The fault arc detection master control unit 11 can use an MCU, a CPU, or a processor with data processing capability composed of an MCU and a CPU.

[0042] Referring to Figure 1 The fault arc self-checking unit 3 outputs a self-checking signal to the fault arc detection master control unit 11, and after receiving the self-checking signal, the fault arc detection master control unit 11 performs a self-checking function. The fault arc detection master control unit 11 simulates a simulated fault signal of a fault arc, and outputs it to the fault arc sensing unit 1. The fault arc detection master control unit 11 judges whether the self-checking is successful through the arc sensing signal returned by the fault arc sensing unit 1, that is, if the received arc sensing signal indicates that there is an arc, it means that the self-checking is successful, and the fault arc detection master control unit 11 and the fault arc sensing unit 1 are functioning normally.

[0043] Referring to Figure 1 The indicating unit 31 can use multiple LED lights, or lights with color changing ability, or instruments and equipment with display capability, such as a display screen. When the fault arc detection master control unit 11 receives different arc sensing signals, it will get different indication signals, such as the existence of one arc sensing signal, two arc sensing signals, three arc sensing signals, or four arc sensing signals. At this time, different indication signals will be generated. The indicating unit 31 receives the indication signal and displays it differently according to different indication signals, such as emitting red light, yellow light, flashing red light, flashing yellow light, or directly displaying which fault.

[0044] Referring to Figure 1 The wireless alarm unit 32 receives the trigger signal output by the fault arc detection master control unit 11 to form an alarm signal, and then outputs the alarm signal wirelessly to the cloud platform through wifi or 4G or 5G. Users can view it on the cloud platform through terminal devices such as mobile phones and computers.

[0045] The implementation principle of the photovoltaic string level fault arc breaking device according to an embodiment of the present application is as follows: when a fault occurs in the photovoltaic cable, the fault arc detection master control unit 11 detects the arc sensing signal detected by the fault arc sensing unit 1, outputs a trigger signal to the breaking unit 12 to trip and break the corresponding photovoltaic cable, controls the indicating unit 31 to indicate the user, and remotely outputs a warning to the user through the wireless alarm unit 32.

[0046] Embodiment 2:

[0047] Different from embodiment 1, referring to Figure 2 , the fault arc self-checking unit 3 comprises a wireless self-checking subunit 312, which is a unit for receiving a cloud platform remote control signal, for example, a functional unit such as Bluetooth, WIFI, 4G or 5G, and a user remotely outputs a remote self-checking signal, which is received by the wireless self-checking subunit 312, and then controls the fault arc self-checking unit 3 to output a self-checking signal.

[0048] Referring to Figure 3 , the breaking unit 12 comprises a breaking subunit 121, an automatic control subunit 122, a manual control subunit 123 and an automatic reset subunit 124, the breaking subunit 121 can adopt an electromagnetic release or other devices with release function, the automatic control subunit 122 is an electromagnetic part for controlling the electromagnetic release to release, that is, by controlling the size of the coil current to control the strength of the magnetic field, thereby realizing electromagnetic release. The manual control subunit 123 can adopt, for example, a handle, which is directly connected to the release part to realize manual release. The automatic reset subunit 124 is used to control the direction of the coil current, thereby controlling the direction of the magnetic field, controlling the magnetic pole orientation, realizing the change of the direction, that is, positive release and reverse reset, thereby realizing automatic closing, or other devices can also be adopted.

[0049] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: all equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A photovoltaic string-level fault arc interruption device, comprising: The application relates to a fault arc detection device, which comprises the following parts: a fault arc sensing unit (1) for detecting a circuit, obtaining an arc sensing signal and outputting the same; a fault arc detection master control unit (11) for receiving the arc sensing signal and processing data, judging whether an arc exists and outputting a corresponding trigger signal; a breaking unit (12) electrically connected to the circuit, receiving the trigger signal and controlling the circuit to perform a tripping breaking control.

2. A photovoltaic string-level fault current arc interruption device according to claim 1, wherein: The device further comprises an emergency stop unit (2) for being triggered by a user to directly output the trigger signal to the breaking unit (12).

3. A photovoltaic string-level fault current arc interruption device according to claim 2, wherein: The device further comprises a high-voltage power supply unit (21) electrically connected to the input end of the breaking unit (12) to convert a high-voltage direct-current signal of the circuit into a low-voltage direct-current signal, and the output end of the high-voltage power supply unit (21) is electrically connected to the fault arc detection master control unit (11), the emergency stop unit (2) and the breaking unit (12) to supply power.

4. A photovoltaic string-level fault current arc mitigation device according to claim 1, wherein: The device further comprises a fault arc self-checking unit (3) for outputting a self-checking signal to the fault arc detection master control unit (11), the fault arc detection master control unit (11) outputs an analog fault signal to the fault arc sensing unit (1) after receiving the self-checking signal, and the fault arc detection master control unit (11) judges whether the self-checking is successful through the arc sensing signal returned by the fault arc sensing unit (1).

5. A photovoltaic string-level fault current arc mitigation device according to claim 1, wherein: The device further comprises an indicating unit (31), the fault arc detection master control unit (11) outputs different indicating signals according to different arc sensing signals, and the indicating unit (31) receives the indicating signals and displays different signals for a user to view.

6. A photovoltaic string-level fault current arc mitigation device according to claim 1, wherein: The device further comprises a wireless alarm unit (32) for receiving the trigger signal and wirelessly outputting an alarm signal to a user.

7. A photovoltaic string-level fault current arc interruption device according to claim 4, wherein: The fault arc self-checking unit (3) further comprises a wireless self-checking subunit (312) for receiving a remote self-checking signal wirelessly input by a user and controlling the fault arc self-checking unit (3) to output the self-checking signal through the remote self-checking signal.

8. A photovoltaic string-level fault current arc mitigation device according to claim 1, wherein, The breaking unit (12) comprises: a breaking subunit (121) for tripping breaking an input; an automatic control subunit (122) for receiving the trigger signal and then tripping breaking the input through the breaking subunit (121); a manual control subunit (123) for being manually controlled by a user to control the breaking subunit (121) to trip and break; an automatic reset subunit (124) for receiving the trigger signal and controlling the breaking subunit (121) to close.

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