Current collection circuit device of photovoltaic power station

Abstract

The utility model discloses a current collection circuit device of a photovoltaic power station, which relates to the technical field of photovoltaic power stations and comprises a current collection circuit cabinet, a plurality of cable branch boxes, a plurality of box inversion all-in-one machines, a plurality of centralized confluence cabinets and a plurality of photovoltaic string units. Wherein the current collection circuit cabinet is respectively connected in series with each cable branch box, and the plurality of cable branch boxes are connected in parallel; each cable branch box is connected in series with one box inversion all-in-one machine; each box inversion all-in-one machine is connected in series with one centralized confluence cabinet, and a plurality of centralized confluence cabinets connected with the same box inversion all-in-one machine are connected in parallel; and each centralized confluence cabinet is connected with a plurality of photovoltaic string units. According to the utility model, the condition that the whole current collection line is out of work when equipment such as a single box transformer substation or a part of box transformer substations is overhauled can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power stations, in particular to a collector line device for a photovoltaic power station. Background Art

[0002] This section aims to provide background or context for the embodiments of the utility model described in the claims. The description herein is not admitted to be prior art merely because it is included in this section.

[0003] At present, renewable energy is developing rapidly. As an important part of it, photovoltaic power stations are being laid out and constructed on a large scale at an unprecedented speed and scale. The current existing collector line devices are connected to the overhead line through the cable outlet of the string inverter, or adopt the 66kV tree - chain collector line topology form. When constructing these existing collector line devices, factors such as construction cost, construction efficiency, and power generation effect are mostly considered, and the impact on power transmission during equipment maintenance is not considered. However, under the existing photovoltaic power station collector line structure, when some of its equipment is maintained, one or more collector lines will be taken out of service, which has a great impact on the power generation efficiency of the photovoltaic power station. Summary of the Utility Model

[0004] The embodiment of the utility model provides a collector line device for a photovoltaic power station to avoid the situation that the entire collector line is taken out of service when maintaining a single unit or some box - type transformers and other equipment. The device includes: one collector line cabinet, multiple cable branch boxes, multiple box - inverter integrated machines, multiple centralized converging cabinets, and multiple photovoltaic string units; wherein,

[0005] The collector line cabinet is respectively connected in series with each cable branch box, and the multiple cable branch boxes are connected in parallel;

[0006] Each cable branch box is connected in series with one box - inverter integrated machine;

[0007] Each box - inverter integrated machine is respectively connected in series with one centralized converging cabinet, and the multiple centralized converging cabinets connected to the same box - inverter integrated machine are connected in parallel;

[0008] Each centralized converging cabinet is connected to multiple photovoltaic string units.

[0009] Further, the box - inverter integrated machine includes: a fuse and a disconnector.

[0010] Further, in each box - inverter integrated machine, the fuse and the disconnector are connected in series and are connected in series to the high - voltage side of the box - inverter integrated machine.

[0011] Further, the cable branch box is configured with a circuit breaker, a three - position isolating and grounding switch, a live - line indicator, and a lightning arrester.

[0012] Further, the circuit breaker in each cable distribution box is connected in series with the three-position disconnector and is connected to the live display and the lightning arrester; among them, the live display and the lightning arrester are connected in parallel to the ground.

[0013] The embodiment of the present utility model can avoid the problem that when the line on the opposite side is energized during operation under the existing structure of the collector line of the photovoltaic power station, the high-voltage side of the box inverter integrated machine on the collector line of the photovoltaic power station is all energized or de-energized; in the collector line device of the photovoltaic power station in the embodiment of the present utility model, each cable distribution box is connected in series with a box inverter integrated machine. During maintenance, it is only necessary to determine the box transformer branch where the equipment or component to be repaired and operated is located, and then perform a switching operation on the corresponding cable distribution box of the box transformer branch, thus avoiding the situation where the entire collector line exits the operation when repairing a single or part of the box transformers and other equipment, and avoiding the situation of affecting the power transmission of the power station during maintenance. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0015] Figure 1 It is a structural diagram of the existing collector line of the photovoltaic power station;

[0016] Figure 2 It is a structural diagram of the collector line device of the photovoltaic power station in the embodiment of the present utility model. Detailed Embodiment

[0017] To make the purpose, technical solutions and advantages of the embodiments of the present utility model clearer, the following will further describe the embodiments of the present utility model in detail with reference to the drawings. Herein, the illustrative embodiments of the present utility model and their descriptions are used to explain the present utility model, but not to limit the present utility model.

[0018] In the technical solution of this application, the acquisition, storage, use, processing, etc. of data all comply with the relevant regulations of national laws and regulations.

[0019] First, a brief introduction to the technical terms involved in the present utility model is given.

[0020] The collector line cabinet, usually used in the power system, especially in the field of renewable energy such as wind farms and photovoltaic power stations, is an electrical device for concentrating, collecting and distributing electric energy. Its main function is to converge the electric energy generated by multiple power source points (such as multiple wind turbines or solar arrays), then step up the voltage through a transformer, and finally uniformly transmit it to the power grid.

[0021] The integrated box inverter, also known as the integrated inverter-booster or the integrated photovoltaic box inverter, is an integrated device in a solar photovoltaic system. It integrates multiple components that were traditionally separated into one unit or container to simplify the installation and maintenance process and improve overall efficiency.

[0022] The centralized current collection cabinet: plays a crucial role in a photovoltaic power generation system. It is mainly used to collect the currents generated by multiple photovoltaic arrays (formed by paralleling multiple photovoltaic string units), and then transmit them to the inverter or subsequent power processing equipment through a unified line.

[0023] The photovoltaic string unit: is formed by paralleling multiple photovoltaic strings or by connecting multiple photovoltaic modules in series. In a photovoltaic power generation system or a microgrid, it plays the role of converting solar energy into electrical energy.

[0024] Figure 1 Shown in the figure is the structure diagram of the current collection line of an existing photovoltaic power station. As Figure 1 shown, the current collection line cabinet is connected to the high-voltage side of the integrated box inverter B1, the integrated box inverter B1 is connected to the high-voltage side of the integrated box inverter B2, and the integrated box inverter B n-1 is connected to the high-voltage side of the integrated box inverter B n . Under this current collection line structure, only all the high-voltage sides of the integrated box inverters are either fully charged or fully uncharged. During maintenance, the entire current collection line is taken out of service, and the scope of influence of the maintenance operation is relatively wide, reducing the power generation of the photovoltaic power station.

[0025] To solve the above problems, an embodiment of the present utility model provides a current collection line device for a photovoltaic power station. The device includes: one current collection line cabinet, multiple cable branch boxes, multiple integrated box inverters, multiple centralized current collection cabinets, and multiple photovoltaic string units; wherein,

[0026] The current collection line cabinet is respectively connected in series with each cable branch box, and multiple cable branch boxes are connected in parallel;

[0027] Each cable branch box is connected in series with one integrated box inverter;

[0028] Each integrated box inverter is respectively connected in series with one centralized current collection cabinet, and multiple centralized current collection cabinets connected to the same integrated box inverter are connected in parallel;

[0029] Each centralized current collection cabinet is connected to multiple photovoltaic string units.

[0030] Refer to Figure 2 , Figure 2 Shown in the figure is the structure diagram of the current collection line device for a photovoltaic power station in an embodiment of the present utility model. The device includes: multiple photovoltaic string units, multiple centralized current collection cabinets / cases (HL nj ), multiple integrated box inverters (Bn ) 1# to n# cable distribution boxes and one collector line cabinet. The collector line cabinet is connected in series with 1# to n# cable distribution boxes respectively, and 1# to n# cable distribution boxes are connected in parallel with each other. 1# to n# cable distribution boxes are connected in series with box inverter integrated machines B1 to B n in series. Box inverter integrated machine B1 is connected in series with m centralized busbar cabinets / boxes HL 11 to HL 1m in series, where the centralized busbar cabinets / boxes HL 11 to HL 1m are connected in parallel; Box inverter integrated machine B n is connected in series with j centralized busbar cabinets / boxes HL n1 to HL nj in series, where the centralized busbar cabinets / boxes HL n1 to HL nj are connected in parallel, where m and j have no quantitative relationship and can be configured according to the actual situation. The centralized busbar cabinets / boxes HL 11 are connected to a photovoltaic string units; The centralized busbar cabinets / boxes HL nj are connected to d photovoltaic string units. Among them, the number of photovoltaic string units connected to each centralized busbar cabinet / box needs to be determined according to the electrical parameters of the inverter. For example, if the output current of each photovoltaic string unit is 20A and the maximum allowable current on the DC side of the inverter is 3160A, then the maximum number of photovoltaic module units on this branch is 3160 / 20 = 158. If a 16-in-1 centralized busbar box is used, then 10 centralized busbar boxes are configured to connect 16×8 + 15×2 photovoltaic string units.

[0031] In the embodiment of the present utility model, the photovoltaic power station can be a 35kV photovoltaic power station.

[0032] In one embodiment, the box inverter integrated machine includes: fuse, disconnector, etc., and overcurrent protection is carried out by using a fuse.

[0033] Furthermore, the fuse and the disconnector in each box inverter integrated machine are connected in series and are connected in series to the high-voltage side of the box inverter integrated machine.

[0034] In one embodiment, the cable distribution box is configured with a circuit breaker, a three-position isolating earthing switch, a live-line indicator, a lightning arrester, etc. The circuit breaker is characterized in that it is not configured with any protection device and is only used for manual opening and closing operations during maintenance, and can only make the branch of the box transformer work or stop working.

[0035] Furthermore, the circuit breaker and the three-position isolating switch in each cable distribution box are connected in series and are connected to the live-line indicator and the lightning arrester; among them, the live-line indicator and the lightning arrester are connected in parallel to the ground.

[0036] During the maintenance of the photovoltaic power station collector line device in the embodiment of the present utility model, the specific maintenance operation process is as follows:

[0037] 1. Determine the box-type transformer branch where the equipment or component to be repaired is located;

[0038] 2. Determine the cable branch box number of the box-type transformer branch;

[0039] 3. Manually trip the circuit breaker of the cable branch box;

[0040] 4. The three-position isolating earthing switch of the cable branch box changes from the closing position to the isolating position;

[0041] 5. The three-position isolating earthing switch of the cable branch box changes from the isolating position to the earthing position;

[0042] 6. Perform the repair operation on the equipment.

[0043] When the collector line device of the photovoltaic power station in the embodiment of the present utility model is restarted, the operations are as follows:

[0044] 1. The three-position isolating earthing switch changes from the earthing position to the isolating position;

[0045] 2. The three-position isolating earthing switch changes from the isolating position to the closing position;

[0046] 3. Manually close the above-mentioned circuit breaker;

[0047] 4. The box-type transformer branch where the repaired equipment or component is located resumes operation.

[0048] For example, assume Figure 2 the medium-voltage inverter integrated machine B1 needs to be repaired, then the specific repair operations are as follows:

[0049] 1. Determine the box-type transformer branch where the component to be repaired is located: The medium-voltage inverter integrated machine B1 to be repaired is in the 1# box-type transformer branch;

[0050] 2. Determine the cable branch box number of the box-type transformer branch: The 1# cable branch box controls the operation or withdrawal of the 1# box-type transformer branch;

[0051] 3. Manually trip the circuit breaker of the 1# cable branch box;

[0052] 4. The three-position isolating earthing switch of the 1# cable branch box changes from the closing position to the isolating position;

[0053] 5. The three-position isolating earthing switch of the 1# cable branch box changes from the isolating position to the earthing position;

[0054] 6. Perform the repair operation on the medium-voltage inverter integrated machine B1.

[0055] After the maintenance of the integrated box inverter B1 is completed, the following operations shall be performed:

[0056] 1. The three-position isolating grounding switch of the 1# cable distribution box is switched from the grounding position to the isolating position;

[0057] 2. The three-position isolating grounding switch of the 1# cable distribution box is switched from the isolating position to the closing position;

[0058] 3. Manually close the circuit breaker of the 1# cable distribution box;

[0059] 4. The 1# box transformer branch operates normally.

[0060] In the embodiment of the present utility model, aiming at the problem that when replacing and maintaining the integrated box inverter in the existing collector line structure of a photovoltaic power station, one or more collector lines are taken out of service, affecting the power generation efficiency of the photovoltaic power station, a collector line device for a photovoltaic power station is proposed. The specific advantages are as follows:

[0061] 1. Avoid the problem that when the line on the opposite side of the station is energized under the existing collector line structure, all or none of the high-voltage sides of the integrated box inverters on the collector line of the photovoltaic power station are energized. In the embodiment of the present utility model, the collector line device of the photovoltaic power station can realize local switching on and off of a single box transformer, avoiding the situation that the entire collector line is taken out of service when maintaining a single or some integrated box inverters (box transformers) and other equipment, thus affecting the power transmission of the power station.

[0062] 2. In the embodiment of the present utility model, the collector line device of the photovoltaic power station uses the fuse inside the box transformer for overcurrent protection, avoiding duplicate protection configuration and reducing the construction and operation costs of the photovoltaic power station.

[0063] In the above specific embodiments, the purpose, technical solutions and beneficial effects of the present utility model are further described in detail. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A photovoltaic power station collector circuit device, characterized in that: include: One power collection line cabinet, multiple cable branch boxes, multiple box-inverter integrated machines, multiple centralized junction cabinets, and multiple photovoltaic string units; among them, The collector circuit cabinet is connected in series with each cable branch box, and multiple cable branch boxes are connected in parallel; Each cable branch box is connected in series with a box-inverter integrated machine; Each box inverter is connected in series with a centralized combiner cabinet, and multiple centralized combiner cabinets connected to the same box inverter are connected in parallel; Each centralized combiner cabinet is connected to multiple photovoltaic string units.

2. The photovoltaic power station collector line device according to claim 1, characterized in that: The box-type inverter is equipped with a fuse and an isolating switch.

3. The photovoltaic power station collector circuit device according to claim 2, characterized in that: The fuse in each box inverter is connected in series with the isolating switch and connected in series to the high voltage side of the box inverter.

4. The photovoltaic power station collector circuit device according to claim 1, characterized in that: The cable branch box is equipped with: a circuit breaker, a three-position isolating grounding switch, a live display, and a lightning arrester.

5. The photovoltaic power station collector circuit device according to claim 4, characterized in that in, The circuit breaker in each cable branch box is connected in series with the three-position isolating switch, and is connected to the live display and lightning arrester; the live display and lightning arrester are connected in parallel to the ground.

6. The photovoltaic power station collector circuit device according to claim 1, characterized in that: The circuit breaker of the cable branch box is used for manual opening and closing operations during the maintenance of the photovoltaic power station collector line device, and can make the box transformer branch work or stop working.

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