Photovoltaic combiner box with in-situ fault display

Abstract

A photovoltaic combiner box with an in-situ fault display function comprises a box body, an indicating lamp group arranged on the surface of the box body, a combiner circuit arranged in the box body, a power supply, an optical coupler isolation module and a controller, the combiner circuit comprises a plurality of photovoltaic branches, and a fuse and an optical coupler isolation module are additionally arranged at the fuse position of each photovoltaic branch. The optocoupler isolation module, the controller and the power supply are connected in series through the fuse; and the indicating lamp group is connected with the controller and is used for displaying the fault state of the photovoltaic branch in situ. When the fuse is fused, the optocoupler isolation module is also disconnected, the optocoupler isolation module loses power, the indicating lamp group is turned off, and power supply isolation is realized during positive and negative electrode monitoring, so that the branch state can be visually and locally seen in real time, and operation and maintenance personnel can observe the operation state of the combiner box of a gaze and a residence when performing other work in a photovoltaic area. And the defects of communication interruption, data acquisition errors and the like of the fault combiner box are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation equipment, in particular to a photovoltaic combiner box with local fault display. Background Art

[0002] The photovoltaic combiner box connects a certain number of photovoltaic cells of the same specifications in series to form photovoltaic strings, and then connects several photovoltaic strings in parallel to the photovoltaic combiner box. After the convergence in the photovoltaic combiner box, it passes through the DC distribution cabinet, photovoltaic inverter, and AC distribution cabinet, and is used in conjunction to form a complete photovoltaic power generation system to achieve grid connection with the city power. In the photovoltaic power generation system, the photovoltaic combiner box is a wiring device that ensures the orderly connection and convergence function of photovoltaic components. This device can ensure that the photovoltaic system is easy to cut off the circuit during maintenance and inspection, and reduce the scope of power outage when a photovoltaic system failure occurs.

[0003] At present, photovoltaic combiner boxes are divided into two types in terms of function: intelligent combiner boxes and non-intelligent combiner boxes. Intelligent combiner boxes have the function of collecting the voltage, current, temperature, and circuit breaker opening and closing status of each branch and transmitting information to the monitoring background through 485 communication. When the equipment is normal, the operation and maintenance personnel can observe the operating status and data of each combiner box in real time through the monitoring background, and can handle any abnormalities at any time. Non-intelligent combiner boxes do not have the above functions, and only have the most basic primary original function of power generation, making it difficult for operation and maintenance personnel to control the operating status of the photovoltaic area.

[0004] As the operating time of photovoltaic power stations increases, smart combiner boxes gradually experience communication loss due to hardware damage such as communication boards, acquisition boards, Hall sensors, and 485 communication lines. Due to the large number and high maintenance costs, on-site personnel conduct special inspections of combiner boxes and troubleshoot faults once a month. This method is not easy to detect combiner box branch faults in a timely manner, resulting in a certain amount of power loss. Summary of the invention

[0005] In view of this, it is necessary to provide a photovoltaic combiner box with local fault display, which has a safe circuit link, no dangerous or harmful voltage is generated, and has low requirements for the combiner box.

[0006] A photovoltaic combiner box with local fault display comprises a box body, an indicator light group arranged on the surface of the box body, a combiner circuit arranged in the box body, a power supply, an optocoupler isolation module and a controller. The combiner circuit comprises multiple photovoltaic branches. A fuse and an optocoupler isolation module are installed at the insurance part of each photovoltaic branch. The optocoupler isolation module, the controller and the power supply are connected in series through the fuse. The indicator light group is connected to the controller to display the fault status of the photovoltaic branch locally.

[0007] Preferably, the bus circuit includes multiple positive poles, multiple negative poles, a positive busbar, a negative busbar and a DC circuit breaker, each positive pole and a negative pole form a photovoltaic branch, multiple positive poles are connected in parallel to the positive busbar and merged into one through the positive busbar, multiple negative poles are connected in parallel to the negative busbar and merged into one through the negative busbar, and the positive busbar and the negative busbar are respectively connected to the DC circuit breaker.

[0008] Preferably, the fuse includes a positive electrode fuse and a negative electrode fuse. The positive electrode is connected to the positive electrode busbar after passing through the positive electrode fuse. The positive electrode busbar is connected to the power supply and the controller respectively. The negative electrode is connected to the negative electrode busbar after passing through the negative electrode fuse.

[0009] Preferably, the positive electrode fuse is connected in series with the controller via an optocoupler isolation module.

[0010] Preferably, the busbar circuit further includes a lightning arrester, which is connected to the positive busbar and the negative busbar and is grounded.

[0011] Preferably, it also includes a communication module for remote communication, and the communication module is connected to the power supply and the controller.

[0012] Preferably, it also includes a data acquisition module for collecting voltage and current signals on each photovoltaic branch, and the data acquisition module is connected to the power supply and the controller.

[0013] Preferably, the indicator light group includes a fuse indicator light and a warning light, the number of the fuse indicator lights matches the number of the positive fuses, and is used to display the status of the photovoltaic branch; the warning light is used to display a combiner box circuit fault.

[0014] In the above-mentioned photovoltaic junction box with on-site fault display, a fuse and an optocoupler isolation module are installed at the insurance part of each photovoltaic branch, and the optocoupler isolation module, the controller and the power supply are connected in series through the fuse. When the fuse blows, the optocoupler isolation module is also disconnected, the optocoupler isolation module loses power, the indicator light group goes out, and the normal path lights up. The power supply is isolated during positive and negative pole monitoring, and the branch status can be intuitively seen. It not only makes up for the defects of communication interruption and data collection errors of the faulty junction box, but also serves as an on-site real-time status display. When the operation and maintenance personnel are doing other work in the photovoltaic area, they can observe the operating status of the junction box within their sight so as to deal with the fault in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attached Figure 1 It is a schematic diagram of the internal structure of a photovoltaic combiner box with local fault display.

[0016] In the figure: controller 1, optocoupler isolation module 2, power supply 3, communication module 4, data acquisition module 5, warning light 6, fuse indicator light 7, positive pole 8, negative pole 9, positive busbar 10, negative busbar 11, DC circuit breaker 12, positive fuse 13, negative fuse 14, lightning arrester 15. DETAILED DESCRIPTION

[0017] Please refer to Figure 1 A photovoltaic combiner box with local fault display includes a box body, an indicator light group arranged on the surface of the box body, a combiner circuit arranged in the box body, a power supply 3, an optical coupling isolation module 2, a communication module 4, a data acquisition module 5 and a controller 1. The indicator light group, the communication module 4, and the data acquisition module 5 are connected to the controller 1, the communication module 4 is used for remote communication, the data acquisition module 5 is used to collect voltage and current signals on each photovoltaic branch and the opening and closing state of the combiner box DC circuit breaker 12, and the indicator light group displays the fault state of the photovoltaic branch locally.

[0018] The confluence circuit includes multiple photovoltaic branches, and a fuse and an optocoupler isolation module 2 are installed at the insurance part of each photovoltaic branch, and the input end of the optocoupler isolation module 2, the controller 1 and the power supply 3 are connected in series through the fuse. The indicator light group includes a fuse indicator light 7 and a warning light 6. The fuse indicator light 7 is used to display the status of the photovoltaic branch; the warning light 6 is used to display the circuit fault of the confluence box, preferably a three-color warning light 6. When the fuse blows, the input end of the optocoupler isolation module 2 is also disconnected, the optocoupler isolation module 2 loses power, the light of the fuse indicator light 7 goes out, and the light of the normal path is on. When monitoring the positive and negative poles, the power supply 3 is isolated, and the branch status can be intuitively seen. At the same time, this signal is connected to the three-color warning light 6, and the red light of the three-color warning light 6 is on if there is a fault. The data acquisition module 5 monitors the opening and closing status of the DC circuit breaker 12 of the combiner box in real time, collects the auxiliary contact signal of the DC circuit breaker 12, and connects it to the three-color warning light 6 through the controller 1 or other electronic components. If the DC circuit breaker 12 trips or the operation and maintenance personnel forget to close the DC circuit breaker 12, the green light of the three-color warning light 6 will be on. The collected voltage and current data will be transmitted to the controller 1. The controller 1 always takes the branch with the largest current as the standard and compares the current of other branches. Through logical judgment, when the current of any branch is lower than the corresponding percentage of the branch with the highest current (set according to the power station situation), the yellow light of the three-color warning light 6 will be on.

[0019] This application is redundant on the original intelligent combiner box to make up for the defects of communication interruption and data collection errors of the faulty combiner box. As a real-time status display on site, the operation and maintenance personnel can observe the operating status of the combiner box within their sight when doing other work in the photovoltaic area, so as to timely troubleshoot the fault. At the same time, it can also be applied to non-intelligent combiner boxes as a plug-in function to more effectively improve the operation and maintenance efficiency.

[0020] The convergence circuit includes multiple positive electrodes 8, multiple negative electrodes 9, positive busbars 10, negative busbars 11, lightning arresters 15, and DC circuit breakers 12. Each positive electrode 8 forms a photovoltaic branch with a negative electrode 9. Multiple positive electrodes 8 are connected in parallel to the positive busbar 10 and converged into one through the positive busbar 10. Multiple negative electrodes 9 are connected in parallel to the negative busbar 11 and converged into one through the negative busbar 11. The positive busbar 10 and the negative busbar 11 are respectively connected to the DC circuit breaker 12, and the output end is connected through the DC circuit breaker 12. The lightning arrester 15 is connected to the positive busbar 10 and the negative busbar 11 and grounded. The positive and negative electrodes 9 are both lightning-proof, and have dual lightning protection functions. The lightning arrester 15 has a lightning counter that can record the number of times the lightning arrester 15 is actuated, and timely understand the intrusion and frequency of lightning disasters.

[0021] The fuse includes a positive pole fuse 13 and a negative pole fuse 14. The positive pole 8 is connected to the positive pole busbar 10 after passing through the positive pole fuse 13. The positive pole busbar 10 is connected to the power supply 3 and the controller 1 respectively. The positive pole fuse 13 is connected in series with the controller 1 through the optical coupling isolation module 2. The negative pole 9 is connected to the negative pole busbar 11 after passing through the negative pole fuse 14.

[0022] Multiple photovoltaic strings are respectively connected to multiple photovoltaic branches (i.e., multiple positive poles 8 and multiple negative poles 9 are respectively connected), and connected in parallel to the junction box. Each positive pole 8 is connected in series with a positive pole fuse 13. Each negative pole 9 is connected in series with a negative pole fuse 14. Since the short-circuit current of multiple photovoltaic strings is greater than the current of a single photovoltaic string, the fuse can be blown to isolate the faulty photovoltaic string, thereby protecting the photovoltaic string. The fuse isolates the faulty photovoltaic string in time, improves the power generation efficiency (when the photovoltaic panel fails and does not generate electricity, it becomes a load that consumes electric energy), and also avoids overcurrent hazards caused by local abnormal wiring due to wrong connection or other reasons during the installation stage.

[0023] The number of fuse indicator lights 7 matches the number of positive fuses 13, and the fuse indicator lights 7 are used to display the status of each photovoltaic branch. The photovoltaic combiner box is preferably a 16-input 1-output combiner box or an 8-input 1-output combiner box.

Claims

1. A photovoltaic combiner box with local fault display, comprising a box body and a combiner circuit arranged in the box body, Features: It also includes an indicator light group arranged on the surface of the box, a power supply arranged in the box, an optocoupler isolation module and a controller. The convergence circuit includes multiple photovoltaic branches. A fuse and an optocoupler isolation module are installed at the insurance part of each photovoltaic branch, and the optocoupler isolation module, the controller and the power supply are connected in series through the fuse; the indicator light group is connected to the controller to display the fault status of the photovoltaic branch on site.

2. The photovoltaic combiner box according to claim 1, Features: The busbar circuit includes multiple positive poles, multiple negative poles, a positive busbar, a negative busbar and a DC circuit breaker. Each positive pole forms a photovoltaic branch with a negative pole. Multiple positive poles are connected in parallel to the positive busbar and are merged into one through the positive busbar. Multiple negative poles are connected in parallel to the negative busbar and are merged into one through the negative busbar. The positive busbar and the negative busbar are respectively connected to the DC circuit breaker.

3. The photovoltaic combiner box according to claim 2, Features: The fuse includes a positive pole fuse and a negative pole fuse. The positive pole is connected to the positive pole busbar after passing through the positive pole fuse. The positive pole busbar is connected to the power supply and the controller respectively. The negative pole is connected to the negative pole busbar after passing through the negative pole fuse.

4. The photovoltaic combiner box according to claim 3, Features: The positive fuse is connected in series with the controller via an optocoupler isolation module.

5. The photovoltaic combiner box according to claim 2, Features: The busbar circuit also includes a lightning arrester, which is connected to the positive busbar and the negative busbar and is grounded.

6. The photovoltaic combiner box according to claim 1, Features: It also includes a communication module for remote communication, and the communication module is connected with a power source and a controller.

7. The photovoltaic combiner box according to claim 1, Features: It also includes a data acquisition module for collecting voltage and current signals on each photovoltaic branch, and the data acquisition module is connected to the power supply and the controller.

8. The photovoltaic combiner box according to claim 1, Features: The indicator light group includes a fuse indicator light and a warning light. The number of the fuse indicator lights matches the number of the positive fuses and is used to display the status of the photovoltaic branch circuit; the warning light is used to display a combiner box circuit fault.

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