A photovoltaic grid system access structure and cable clamp

Abstract

The utility model relates to the technical field of power grid. A kind of photovoltaic power grid system access structure includes distributed photovoltaic, for converting solar energy into electric energy;Inverter, which is connected with distributed photovoltaic;Reactive power compensation device, for adjusting power caused by photovoltaic output fluctuation;Energy storage device, for photovoltaic cooperative operation, suppresses power generation fluctuation, participates in peak shaving and frequency modulation;Double-winding transformer, through circuit breaker respectively with inverter, reactive power compensation device and energy storage device connection;User bus, through circuit breaker and double-winding transformer connection, for user internal load;Common bus, through circuit breaker and double-winding transformer connection, for public power grid.Through above-mentioned structure, solve the problem that photovoltaic power grid operation risk can appear intermittency and volatility.A kind of cable clamp includes S-shaped fixing part, B-shaped limiting part, clamping groove and limiting plate.The cable is fixed during wiring process, which reduces the separation of the cable to some extent and improves the safety.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic power grid technology, and in particular to a photovoltaic power grid system access structure and cable clamp. Background Technology

[0002] In current distributed photovoltaic grid-connected systems, the intermittency and fluctuation of photovoltaic output can easily cause voltage overruns at the point of common coupling (such as exceeding ±10% of the rated range) and harmonic distortion, leading to frequent shutdowns of sensitive user equipment (corresponding to the failure to meet the "flash-free" requirement in the diagram). In addition, insufficient grid connection point protection configuration results in delayed fault isolation and lag in dispatch response, further exacerbating the risks to grid operation.

[0003] In addition, photovoltaic cables in photovoltaic power grids need to be fixed during the wiring process, but most of the existing fixing methods are ineffective and there is also a risk of them coming loose. Utility Model Content

[0004] The primary objective of this invention is to provide a photovoltaic power grid system access structure that can address the operational risks of photovoltaic power grids.

[0005] The second objective of this invention is to provide a cable clamp that addresses the problem of poor fixation of photovoltaic cables during the wiring process in photovoltaic power grids.

[0006] In a first aspect, this utility model provides a photovoltaic grid system access structure, including:

[0007] Distributed photovoltaics are used to convert solar energy into electricity.

[0008] Inverter, which is connected to the distributed photovoltaic system;

[0009] Reactive power compensation devices are used to adjust the power output caused by fluctuations in photovoltaic power generation.

[0010] Energy storage devices are used for photovoltaic coordinated operation to smooth power generation fluctuations and participate in peak shaving and frequency regulation;

[0011] The dual-winding transformer is connected to the inverter, reactive power compensation device and energy storage device respectively through circuit breakers;

[0012] The user busbar is connected to the double-winding transformer via a circuit breaker and is used for user internal loads;

[0013] The common busbar, connected to the double-winding transformer via a circuit breaker, is used for the public power grid.

[0014] In some feasible implementations, the inverter, the reactive power compensation device, and the energy storage device are each connected to a circuit breaker before being connected to the line, and are connected to the double-winding transformer through the circuit breaker after being connected to the line.

[0015] In some feasible embodiments, the output terminals of multiple dual-winding transformers are connected to a grid connection point circuit breaker, which is connected to the user bus.

[0016] In some feasible implementations, the grid connection point circuit breaker is also connected to a common busbar via a circuit breaker.

[0017] In some feasible implementations, both the user bus and the common bus are connected to circuit breakers / load switches.

[0018] Secondly, this utility model provides a cable clamp for use in the aforementioned photovoltaic grid system access structure for cables. The cable clamp includes an S-shaped fixing member, a B-shaped limiting member, a slot, and a limiting plate.

[0019] One end of the S-shaped fixing member and the extended end of the B-shaped limiting member form an integral structure. The extended end is provided with the slot. The side of the B-shaped limiting member near the extended end is arc-shaped as a limiting plate. The limiting plate is rotatably connected to the B-shaped limiting member. The limiting plate can rotate to a set angle and can be pulled into the slot to prevent the cable stuck in the B-shaped limiting member from detaching from the B-shaped limiting member.

[0020] In some feasible embodiments, the B-shaped limiting member includes a support plate, a first arc-shaped plate, a second arc-shaped plate, and the limiting plate; one end of the support plate is connected to one end of the first arc-shaped plate, and the other end is connected to one end of the S-shaped fixing member; the end of the first arc-shaped plate away from the support plate is connected to one end of the second arc-shaped plate; the end of the second arc-shaped plate away from the first arc-shaped plate is rotatably connected to the limiting plate; wherein the area enclosed by the support plate and the first arc-shaped plate is used to insert a first cable, and the area enclosed by the second arc-shaped plate, the limiting plate, and the support plate is used to insert a second cable.

[0021] In some feasible embodiments, the limiting plate has an arc-shaped structure.

[0022] In some possible implementations, the slot is a U-shaped structure, with one side wall of the U-shape extending along its length and the end of the side wall having a certain curvature so as to move toward the other side wall to form a slot.

[0023] In some possible implementations, the end of the S-shaped fastener away from the support plate is spaced a certain distance from the support plate.

[0024] The beneficial effects of this utility model are as follows: A photovoltaic grid system access structure includes distributed photovoltaic (PV) systems for converting solar energy into electrical energy; an inverter connected to the distributed PV systems; a reactive power compensation device for adjusting power output fluctuations caused by PV power output fluctuations; an energy storage device for PV coordinated operation, smoothing power generation fluctuations, and participating in peak shaving and frequency regulation; a dual-winding transformer connected to the inverter, reactive power compensation device, and energy storage device respectively via circuit breakers; a user bus connected to the dual-winding transformer via circuit breakers for user internal loads; and a common bus connected to the dual-winding transformer via circuit breakers for the public power grid. This structure addresses the intermittency and volatility issues that may arise during the operation of the photovoltaic grid. A cable clamp includes an S-shaped fixing member, a B-shaped limiting member, a slot, and a limiting plate. One end of the S-shaped fixing member and the extended end of the B-shaped limiting member form an integral structure. The extended end is provided with a slot. The curved portion of the B-shaped limiting member near the extended end serves as a limiting plate, which is rotatably connected to the B-shaped limiting member. The limiting plate can rotate to a set angle and be pulled into the slot to prevent the cable inserted into the B-shaped limiting member from detaching. This structure secures the cable during wiring, reducing the risk of cable detachment and improving safety. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a logic diagram of a photovoltaic power grid system access structure according to the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of a cable clamp according to the present invention;

[0028] Figure 3 This is a schematic diagram of a cable clamp for inserting a cable according to the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Circuit breaker; 2. Inverter; 3. Dual-winding transformer; 4. Load switch;

[0031] 5. S-shaped fastener; 6. B-shaped limiting component; 61. Extension end; 62. Support plate; 63. First arc plate; 64. Second arc plate; 65. Limiting plate; 66. Rotating shaft; 7. Slot; 71. First side wall; 72. Second side wall; 73. Groove; 81. First cable; 82. Second cable. Detailed Implementation

[0032] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0033] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] like Figure 1 As shown, in the first aspect, this utility model provides a photovoltaic power grid system access structure, including distributed photovoltaic, inverter 2, reactive power compensation device, energy storage device, dual-winding transformer 3, user bus and common bus.

[0036] Among them, distributed photovoltaic (PV) systems are used to convert solar energy into electrical energy; there are multiple distributed PV systems. Inverter 2 is connected to the distributed PV system and is arranged on its circuitry. Reactive power compensation devices, such as SVG (Static Var Generator) and capacitor banks, are used to adjust power output fluctuations caused by PV power generation fluctuations. Energy storage devices, such as bidirectional inverter 2 and BMS (Battery Management System), are used for PV-coordinated operation to smooth power generation fluctuations and participate in peak shaving and frequency regulation. Dual-winding transformer 3 is connected to inverter 2, the reactive power compensation device, and the energy storage device via circuit breaker 1. The user busbar, connected to dual-winding transformer 3 via circuit breaker 1, is used for user internal loads. The public busbar, connected to dual-winding transformer 3 via circuit breaker 1, is used for the public power grid.

[0037] In one embodiment, the inverter 2, the reactive power compensation device, and the energy storage device are each connected to a circuit breaker 1 before being connected to the line, and are connected to the double-winding transformer 3 through the circuit breaker 1 after being connected to the line.

[0038] The circuit breaker 1 connected to the distributed photovoltaic system is designed to be easy to install and operate, interlockable, with a clear breaking point, grounding function, capable of interrupting fault current, and equipped with undervoltage tripping and overvoltage detection closing functions. The breaking capacity of the equipment should be selected based on the short-circuit current level, with a certain margin. For 10 kV systems, a 20 kA or 25 kA circuit breaker is generally recommended. Circuit breaker 1 should ideally have remote control, remote monitoring, and remote telemetry functions and meet the requirements of the corresponding communication protocols.

[0039] In one embodiment, the output terminals of multiple double-winding transformers 3 are connected to the grid connection point circuit breaker 1 via circuit breaker 1, and the grid connection point circuit breaker 1 is connected to the user bus.

[0040] If the photovoltaic system outputs low-voltage AC power (e.g., 400V) through inverter 2, it needs to be stepped up to 10kV through a double-winding transformer 3 to match the voltage level of the public power grid or the user's 10kV bus (complying with the grid connection voltage requirements of GB / T 19964-2012) and reduce line transmission losses. In other words, it is deployed between the output of inverter 2 and the grid connection point to realize the conversion of low-voltage photovoltaic AC power to 10kV grid voltage.

[0041] In one embodiment, the circuit breaker 1 at the grid connection point is also connected to the common bus.

[0042] A dedicated photovoltaic grid-connected circuit breaker 1 shall be installed at the grid connection point. Circuit breaker 1 shall have undervoltage tripping, overvoltage tripping, and voltage detection closing functions. The undervoltage tripping setting should preferably be set to 20%UN for 10 seconds, the overvoltage tripping setting should preferably be set to 135%UN, and the voltage detection closing setting should preferably be set to greater than 85%UN. It shall also have residual current protection. The breaking capacity of the equipment shall be selected according to the short-circuit current level, with a certain margin. Circuit breaker 1, which is used in conjunction with the energy meter to achieve grid connection and off-grid control, shall also meet the technical requirements of "Q / GDW 11421-2020 Technical Specification for External Circuit Breakers for Energy Meters".

[0043] In one embodiment, circuit breakers / load switches 4 are connected to both the user bus and the common bus.

[0044] The user bus is connected to a circuit breaker 1 / load switch 4, which quickly cuts off the fault current when a short circuit or overload occurs on the user side to prevent it from affecting the photovoltaic equipment. It supports manual / automatic tripping, which facilitates the maintenance of the photovoltaic system.

[0045] Circuit breaker 1 / load switch 4 are connected to the common busbar to isolate public power grid faults (such as 10kV line short circuits), prevent reverse power supply from the user side from causing the accident to escalate, control the switching of reactive power compensation equipment, and maintain the stability of the common busbar voltage.

[0046] like Figure 2 and Figure 3 As shown, in a second aspect, this utility model provides a cable clamp for use in the aforementioned photovoltaic grid system access structure. In photovoltaic grid systems, the securing of cables after installation is crucial to prevent accidents and ensure the cables are firmly secured after wiring. Therefore, this utility model provides a cable clamp comprising an S-shaped fixing member 5, a B-shaped limiting member 6, a slot 7, and a limiting plate 65.

[0047] The cable clamp has a certain width. Figure 2 and Figure 3 The middle view is a side view, so the width is not shown. The width can be set as needed, such as 3cm, 5cm or 7cm.

[0048] One end of the S-shaped fixing member 5 and the extended end 61 of the B-shaped limiting member 6 form an integrated structure. The extended end 61 is provided with a slot 7. The arc-shaped part of the B-shaped limiting member 6 near the extended end 61 is a limiting plate 65. The limiting plate 65 and the B-shaped limiting member 6 are rotatably connected by a rotating shaft 66. The limiting plate 65 can be rotated to a set angle and pulled into the slot 7 to prevent the cable stuck in the B-shaped limiting member 6 from detaching from the B-shaped limiting member 6.

[0049] In one embodiment, the B-shaped limiting member 6 includes a support plate 62, a first arc-shaped plate 63, a second arc-shaped plate 64, and a limiting plate 65; one end of the support plate 62 is connected to one end of the first arc-shaped plate 63, and the other end is connected to one end of the S-shaped fixing member 5; the end of the first arc-shaped plate 63 away from the support plate 62 is connected to one end of the second arc-shaped plate 64; the end of the second arc-shaped plate 64 away from the first arc-shaped plate 63 is rotatably connected to the limiting plate 65; wherein, the area enclosed by the support plate 62 and the first arc-shaped plate 63 is used to insert the first cable 81, and the area enclosed by the second arc-shaped plate 64, the limiting plate 65, and the support plate 62 is used to insert the second cable 82.

[0050] The S-shaped fastener 5, the support plate 62, the first arc-shaped plate 63, and the second arc-shaped plate 64 are integrated into one structure, thereby improving strength.

[0051] In one embodiment, the slot 7 is a U-shaped structure, with the first sidewall 71 of the U-shape extending along its length and the end of the sidewall having a certain curvature so as to approach the second sidewall 72 to form a slot 73.

[0052] The limiting plate 65 has an arc-shaped structure with the arc direction facing outward. The distance between the end of the second arc-shaped plate 64 away from the first arc-shaped plate 63 and the slot 7 is less than the length of the limiting plate 65. However, during the assembly process, since the S-shaped fastener 5, the support plate 62, the first arc-shaped plate 63, and the second arc-shaped plate 64 are all made of metal materials, such as iron, they have a certain degree of ductility. This ductility can be used to allow the end of the limiting plate 65 away from the second arc-shaped plate 64 to enter the slot 7 along the slot 73. Since the slot 73 of the slot 7 has an arc-shaped structure, the limiting plate 65 can be easily inserted into the slot 7.

[0053] The arc-shaped structure of the limiting plate 65 faces outward. Thus, the second cable 82, which is trapped in the area enclosed by the second arc-shaped plate 64, must first break through the arc-shaped structure of the limiting plate 65 before it can release the interlock between the limiting plate 65 and the slot 7. Therefore, to a certain extent, it prevents the cable from separating from the cable clamp.

[0054] In one embodiment, the end of the S-shaped fastener 5 that is away from the support plate 62 is spaced a certain distance from the support plate 62.

[0055] The S-shaped fastener 5 and the support plate 62 are spaced a certain distance apart, which can be easily inserted into the outwardly extending edge of the channel steel, etc. In addition, the interface of the S-shaped fastener can also be inserted into other cables for fixation.

[0056] In one embodiment, the first arc plate 63 and the second arc plate 64 are connected, and the corresponding support plate 62 is provided with a triangular rubber protrusion to facilitate the deformation of the rubber material to facilitate the insertion of the first cable 81. It also facilitates the connection between the first arc plate 63 and the second arc plate 64 to prevent the first cable 81 and the second cable 82 from sticking together, and can also limit the position of the first cable 81 to a certain extent.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A photovoltaic grid system interconnection structure, characterized by, The application relates to a photovoltaic grid system access structure. Distributed photovoltaic for converting solar energy into electric energy; Inverter connected with the distributed photovoltaic; Reactive power compensation device for adjusting power caused by photovoltaic output fluctuation; Energy storage device for photovoltaic cooperative operation, power fluctuation smoothing, peak shaving and frequency modulation; Double-winding transformer connected with the inverter, the reactive power compensation device and the energy storage device through breakers; User bus connected with the double-winding transformer through a breaker for user internal load; Common bus connected with the double-winding transformer through a breaker for public power grid.

2. The photovoltaic grid-tie architecture of claim 1, wherein, The inverter, the reactive power compensation device and the energy storage device are respectively connected with breakers before parallel connection and connected with the double-winding transformer through breakers after parallel connection.

3. The photovoltaic grid-tie architecture of claim 1, wherein, Outputs of a plurality of the double-winding transformers are connected with a grid connection point breaker through breakers, and the grid connection point breaker is connected with the user bus.

4. The photovoltaic grid-tie architecture of claim 3, wherein, The grid connection point breaker is also connected with the common bus through a breaker.

5. The photovoltaic grid-tie architecture of claim 1, wherein, Breakers / load switches are connected with the user bus and the common bus.

6. A cable clamp, characterized in that The cable clamp applied to the photovoltaic grid system access structure in any one of claims 1-5 comprises an S-shaped fixing piece, a B-shaped limiting piece, a clamping groove and a limiting plate. One end of the S-shaped fixing piece and an extended end of the B-shaped limiting piece form an integrated structure, the extended end is provided with the clamping groove, and a part of the side of the B-shaped limiting piece close to the extended end is arc-shaped as the limiting plate, and the limiting plate is rotationally connected with the B-shaped limiting piece, wherein the limiting plate can be rotated to a set angle and pulled into the clamping groove to prevent the cable clamped in the B-shaped limiting piece from being separated from the B-shaped limiting piece.

7. The cable clamp of claim 6, wherein, The B-shaped limiting piece comprises a supporting plate, a first arc-shaped plate, a second arc-shaped plate and the limiting plate; one end of the supporting plate is connected with one end of the first arc-shaped plate, the other end is connected with one end of the S-shaped fixing piece, one end of the first arc-shaped plate away from the supporting plate is connected with one end of the second arc-shaped plate, and one end of the second arc-shaped plate away from the first arc-shaped plate is rotationally connected with the limiting plate, wherein the surrounding area of the supporting plate and the first arc-shaped plate is used for clamping a first cable, and the surrounding area of the second arc-shaped plate, the limiting plate and the supporting plate is used for clamping a second cable.

8. The cable clamp of claim 7, wherein, The limiting plate is arc-shaped.

9. The cable clamp of claim 8, wherein, The clamping groove is concave-shaped, one side wall of the concave-shaped structure extends along the length, and the end of the side wall has a certain curvature so as to be close to the other side wall, thereby forming a notch.

10. The cable clamp of claim 7, wherein, The end of the S-shaped fixing piece away from the supporting plate is spaced apart from the supporting plate by a certain distance.

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