Distributed photovoltaic direct current confluence monitoring equipment

Abstract

The utility model provides distributed photovoltaic direct-current confluence monitoring equipment, which comprises a confluence box body and a photovoltaic branch arranged in the confluence box body, and the photovoltaic branch is connected with a photovoltaic breaking switch, a detection circuit and a circuit breaker. The detection circuit is connected with at least one photovoltaic breaking switch; the detection circuit and the circuit breaker are connected in sequence; the circuit breaker is connected with an upper computer. According to the utility model, the real-time monitoring of the state of each photovoltaic branch is realized, and the effective early warning and protection when the photovoltaic branch is abnormal are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation, and in particular to a distributed photovoltaic direct current confluence monitoring device. Background Art

[0002] The relevant photovoltaic busbar equipment is usually equipped with a monitoring device consisting of a set of intelligent modules and acquisition modules. The main function of this intelligent monitoring device is to detect the current and busbar voltage of each branch of photovoltaic power generation, and at the same time detect the operation of the photovoltaic busbar circuit and provide fault alarm information. Moreover, the monitoring device can realize remote monitoring function.

[0003] When the combiner box is in use, it is equipped with devices such as DC fuses, surge protectors and DC arc switches to protect the photovoltaic branches from current confluence. However, if an abnormality occurs in one branch, the photovoltaic currents of other branches will flow to the damaged branch. After the current reaches a certain threshold, the fuse in the DC fuse will be damaged and disconnected, preventing damage to the photovoltaic components in the abnormal circuit. In actual use now, distributed combiner box products are generally installed on roofs or high places, and real-time monitoring and early warning cannot be achieved. Utility Model Content

[0004] Therefore, the technical problem to be solved by the present invention is to solve the problem in the prior art that the distributed junction box cannot monitor each photovoltaic branch in real time, thereby providing a distributed photovoltaic DC junction monitoring device.

[0005] The present invention provides a distributed photovoltaic DC confluence monitoring device, comprising:

[0006] A junction box, a photovoltaic branch installed inside the junction box, the photovoltaic branch is connected with a photovoltaic disconnect switch, a detection circuit and a circuit breaker; the detection circuit is connected to at least one photovoltaic disconnect switch; the detection circuit and the circuit breaker are connected in sequence; the circuit breaker is connected to a host computer.

[0007] Optionally, a distributed photovoltaic DC bus monitoring device further includes:

[0008] The photovoltaic branch is connected with an anti-reverse diode, a leakage protection switch, a fuse and an MPPT module; the anti-reverse diode is located on one side of the circuit breaker; the leakage protection switch is located on the other side of the circuit breaker; the fuse is located on the upper side of the anti-reverse diode, and the fuse is located on the lower side of the photovoltaic disconnect switch; the MPPT module is located on the lower side of the anti-reverse diode.

[0009] Optionally, in a distributed photovoltaic DC bus current monitoring device, the detection circuit comprises:

[0010] A monitoring device and a DC chopper; the monitoring device is connected to at least one photovoltaic disconnect switch; the monitoring device, the DC chopper and the circuit breaker are connected in sequence.

[0011] Optionally, the detection circuit further includes: a display screen;

[0012] The display screen is connected to the DC chopper to display detection data.

[0013] Optionally, it also includes: a lightning protection device;

[0014] The lightning protection device is arranged between the monitoring device and the photovoltaic disconnect switch; the output end of each photovoltaic disconnect switch is connected to the lightning protection device.

[0015] Optionally, the monitoring device comprises: a sampling unit and a gateway;

[0016] The sampling unit is connected to the gateway; the gateway is wirelessly connected to the host computer.

[0017] Optionally, it also includes: a meter;

[0018] The meter is installed inside the combiner box, and the meter is connected to the sampling unit.

[0019] Optionally, it further comprises: a wire hole;

[0020] The wire-through hole is installed on the top of the combiner box, and the circuit breaker and the host computer are connected through the wire-through hole.

[0021] Optionally, it further includes: a bus terminal;

[0022] The bus terminal is installed at the bottom of the bus box, and the bus terminal is connected to the output end of the photovoltaic array.

[0023] Optionally, the circuit breaker is connected to the host computer via an RS485 communication cable.

[0024] The technical solution of the utility model has the following advantages:

[0025] The embodiment of the utility model provides a distributed photovoltaic DC convergence monitoring device, which realizes real-time monitoring of the status of each photovoltaic branch by connecting a photovoltaic disconnect switch, a detection circuit and a circuit breaker to the photovoltaic branch, and the circuit breaker is connected to a host computer. By transmitting real-time monitoring data of the photovoltaic branch to the host computer, when a harmful electric arc exists in the photovoltaic branch, the fault of the photovoltaic branch can be quickly understood, and the fault circuit can be cut off by the circuit breaker, effectively preventing safety hazards such as fire caused by electric arc, and realizing effective early warning and protection of abnormal photovoltaic branches. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of a specific example of a distributed photovoltaic DC bus monitoring device in an embodiment of the utility model;

[0028] Figure 2 It is a structural schematic diagram of another specific example of a distributed photovoltaic DC bus monitoring device in an embodiment of the present utility model.

[0029] In the figure, 1-merger box; 2-photovoltaic disconnect switch; 3-detection circuit; 4-circuit breaker; 5-anti-reverse diode; 6-leakage protection switch; 7-fuse; 8-MPPT module; 9-monitoring and monitoring device; 10-DC chopper; 11-lightning protection device; 12-meter; 13-wire hole; 14-merger terminal. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper end", "interior", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The utility model provides a distributed photovoltaic DC confluence monitoring device, such as Figure 1-2 As shown, the device comprises:

[0035] A junction box 1, a photovoltaic branch installed inside the junction box 1, a photovoltaic disconnect switch 2, a detection circuit 3 and a circuit breaker 4 are connected to the photovoltaic branch; the detection circuit 3 is connected to at least one photovoltaic disconnect switch 2; the detection circuit 3 and the circuit breaker 4 are connected in sequence; and the circuit breaker 4 is connected to a host computer.

[0036] Specifically, the circuit breaker 4 is connected to the host computer via an RS485 (a serial communication interface standard) communication cable; the photovoltaic disconnect switch 2 can be PV-170M.

[0037] Furthermore, a photovoltaic disconnect switch 2, a detection circuit 3 and a circuit breaker 4 are connected to the photovoltaic branch. The detection current is used to perform real-time detection of the current, bus voltage, bus-to-ground leakage current, box temperature, lightning arrester status, circuit breaker status, etc. of each photovoltaic branch. Based on the detection data, FR-DCMG (DC arc detector) detects in real time whether there is a harmful arc in each photovoltaic branch. Once a harmful arc exists, an alarm signal is immediately issued, and the tripping device on the circuit breaker 4 is driven to cut off the fault circuit, thereby effectively preventing safety hazards such as fire caused by arcs.

[0038] Furthermore, the FR-DCMG may be arranged in the detection circuit 3 or in the host computer.

[0039] Furthermore, a bracket is provided on the upper side of the photovoltaic disconnect switch 2 to support the installation layout of the equipment in the combiner box.

[0040] The embodiment of the utility model provides a distributed photovoltaic DC convergence monitoring device, which realizes real-time monitoring of the status of each photovoltaic branch by connecting a photovoltaic disconnect switch, a detection circuit and a circuit breaker to the photovoltaic branch, and the circuit breaker is connected to a host computer. By transmitting real-time monitoring data of the photovoltaic branch to the host computer, when a harmful electric arc exists in the photovoltaic branch, the fault of the photovoltaic branch can be quickly understood, and the fault circuit can be cut off by the circuit breaker, effectively preventing safety hazards such as fire caused by electric arc, and realizing effective early warning and protection of abnormal photovoltaic branches.

[0041] In an optional embodiment, it also includes:

[0042] The photovoltaic branch is connected with an anti-reverse diode 5, a leakage protection switch 6, a fuse 7 and an MPPT (Maximum power point tracking) module 8; the anti-reverse diode 5 is located on one side of the circuit breaker 4; the leakage protection switch 6 is located on the other side of the circuit breaker 4; the fuse 7 is located on the upper side of the anti-reverse diode 5, and the fuse 7 is located on the lower side of the photovoltaic disconnect switch 2; the MPPT module 8 is located on the lower side of the anti-reverse diode 5.

[0043] Specifically, the MPPT module 8 may be of the EPSOLAR / MT-5 type or the like.

[0044] Furthermore, the leakage current condition is monitored in real time by the leakage protection switch 6 .

[0045] In an optional embodiment, the detection circuit 3 comprises:

[0046] Monitoring and monitoring device 9 and DC chopper 10; the monitoring and monitoring device 9 is connected to at least one photovoltaic disconnect switch 2; the monitoring and monitoring device 9, the DC chopper 10 and the circuit breaker 4 are connected in sequence.

[0047] Specifically, the DC chopper 10 may be a LT8705 DC-DC model.

[0048] Furthermore, since there are differences in photovoltaic direct drive access, the use of an inverter to directly convert AC equipment cannot eliminate the differences. Therefore, a DC chopper 10 is used to eliminate the access differences.

[0049] In an optional embodiment, the detection circuit 3 further includes: a display screen;

[0050] The display screen is connected to the DC chopper 10 to display the detection data.

[0051] Specifically, the display screen can adopt LCD (Liquid Crystal Display) to display the detected voltage, current, temperature, power generation and other data through LCD, and LCD supports the bar graph display of current, making the interface more user-friendly.

[0052] In an optional embodiment, it also includes: a lightning protection device 11;

[0053] The lightning protection device 11 is arranged between the monitoring device 9 and the photovoltaic disconnect switch 2 ; the output end of each photovoltaic disconnect switch 2 is connected to the lightning protection device 11 .

[0054] Specifically, the lightning protection device 11 can be classified according to voltage levels, for example, it can be classified according to 800V / DC (volts / direct current) and 1000V / DC.

[0055] In an optional embodiment, the monitoring device 9 includes: a sampling unit and a gateway;

[0056] The sampling unit is connected to the gateway; the gateway is connected to the host computer wirelessly.

[0057] Specifically, the gateway and the sampling unit are connected via RS485 or a network cable. The sampling unit collects relevant information such as current, voltage, temperature and humidity, and then transmits it to the gateway. The gateway transmits it to the host computer via industrial wireless.

[0058] Furthermore, the fuse 7 can be used to access the bus string detection of 24 channels (ie, 24 photovoltaic branches), and the detection data of the first 20 bus strings can be transmitted to the gateway via wireless.

[0059] Furthermore, for multiple devices, each device is connected by wire, and a photovoltaic DC bus monitoring device is set up for each device. Each photovoltaic DC bus monitoring device is used as a wireless network node to form a wireless communication network at the same frequency. The wireless network node can send data to the gateway, the gateway manages the entire network, and uploads the collected monitoring data to the host computer via RS485.

[0060] Furthermore, the sampling unit includes a temperature sensor and an electric energy meter. The temperature sensor is arranged on the heat sink of the anti-reverse diode 5 to collect the box temperature; the electric energy meter can collect the current, bus voltage and bus-to-ground leakage current of each photovoltaic branch.

[0061] In an optional embodiment, it further includes: a meter 12;

[0062] The meter 12 is installed inside the combiner box 1 , and the meter 12 is connected to the sampling unit.

[0063] In an optional embodiment, it further includes: a wire hole 13;

[0064] The wire hole 13 is installed on the top of the combiner box 1, and the circuit breaker 4 and the host computer are connected through the wire hole 13.

[0065] Specifically, other external devices may also be connected through the wire hole 13 .

[0066] In an optional embodiment, it further includes: a bus terminal 14;

[0067] The bus terminal 14 is installed at the bottom of the bus box 1 , and the bus terminal 14 is connected to the output end of the photovoltaic array.

[0068] Specifically, each MPPT module 8 corresponds to each monocrystalline silicon cell assembly in the photovoltaic array, and is connected to the photovoltaic array via a bus terminal 14 .

[0069] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A distributed photovoltaic DC bus monitoring device, characterized in that: include: A junction box, a photovoltaic branch installed inside the junction box, the photovoltaic branch is connected with a photovoltaic disconnect switch, a detection circuit and a circuit breaker; the detection circuit is connected to at least one photovoltaic disconnect switch; the detection circuit and the circuit breaker are connected in sequence; the circuit breaker is connected to a host computer.

2. A distributed photovoltaic DC bus monitoring device according to claim 1, characterized in that: Also includes: The photovoltaic branch is connected with an anti-reverse diode, a leakage protection switch, a fuse and an MPPT module; the anti-reverse diode is located on one side of the circuit breaker; the leakage protection switch is located on the other side of the circuit breaker; the fuse is located on the upper side of the anti-reverse diode, and the fuse is located on the lower side of the photovoltaic disconnect switch; the MPPT module is located on the lower side of the anti-reverse diode.

3. A distributed photovoltaic DC bus monitoring device according to claim 1, characterized in that: The detection circuit comprises: A monitoring device and a DC chopper; the monitoring device is connected to at least one photovoltaic disconnect switch; the monitoring device, the DC chopper and the circuit breaker are connected in sequence.

4. A distributed photovoltaic DC bus monitoring device according to claim 3, characterized in that: The detection circuit further includes: a display screen; The display screen is connected to the DC chopper to display detection data.

5. A distributed photovoltaic DC bus monitoring device according to claim 3, characterized in that: Also includes: Lightning protection devices; The lightning protection device is arranged between the monitoring device and the photovoltaic disconnect switch; The output end of each photovoltaic disconnect switch is connected to the lightning protection device.

6. A distributed photovoltaic DC bus monitoring device according to claim 3, characterized in that: The monitoring device comprises: a sampling unit and a gateway; The sampling unit is connected to the gateway; the gateway is wirelessly connected to the host computer.

7. A distributed photovoltaic DC bus monitoring device according to claim 6, characterized in that: Also includes: Meters; The meter is installed inside the combiner box, and the meter is connected to the sampling unit.

8. A distributed photovoltaic DC bus monitoring device according to claim 1, characterized in that: Also includes: Cable hole; The wire-through hole is installed on the top of the combiner box, and the circuit breaker and the host computer are connected through the wire-through hole.

9. A distributed photovoltaic DC bus monitoring device according to claim 1, characterized in that: Also includes: Bus terminal; The bus terminal is installed at the bottom of the bus box, and the bus terminal is connected to the output end of the photovoltaic array.

10. A distributed photovoltaic DC bus monitoring device according to claim 1, characterized in that: The circuit breaker is connected to the host computer via an RS485 communication cable.

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