Photovoltaic grid-connected metering cabinet

Abstract

The utility model relates to a photovoltaic grid-connected metering cabinet, which belongs to the technical field of electric power system equipment and comprises a cabinet body, and a plurality of wire outlet holes are arranged at the bottom end of the cabinet body. Three layers of partition plates are sequentially arranged in the cabinet body from top to bottom, the internal space of the cabinet body is sequentially divided into a first cavity, a second cavity, a third cavity and a fourth cavity from top to bottom by the three layers of partition plates, a knife switch is arranged in the first cavity, a load control mutual inductor is arranged in the second cavity, a metering mutual inductor is arranged in the third cavity, and the metering mutual inductor is arranged in the fourth cavity. A photovoltaic circuit breaker and an anti-islanding device are arranged in the fourth cavity, and the knife switch, the load control mutual inductor, the metering mutual inductor, the photovoltaic circuit breaker and the anti-islanding device are sequentially connected in series and then externally connected with a UPS. And the online monitoring device is used for monitoring electric energy quality and is externally connected with an upper computer. According to the utility model, the safety and reliability of the metering cabinet in the daily use process are improved.

Description

Technical Field

[0001] The utility model relates to a photovoltaic grid-connected metering cabinet, belonging to the technical field of power system equipment. Background Art

[0002] The meter cabinet is a device for installing special electric energy meters for power supply companies. The device includes current transformers that provide current signals for the electric energy meters, voltage transformers that provide voltage signals for the electric energy meters, etc.

[0003] Photovoltaic power generation uses AC and DC inverters. Since the inverter converts DC power into AC power by turning on and off semiconductor power switches, harmonic problems will occur in this link, causing random fluctuations in output power, resulting in grid frequency deviation, voltage fluctuations and flicker, etc. Harmonic problems are the main problem of photovoltaic power generation.

[0004] For example, when voltage and frequency fluctuations occur in the photovoltaic power generation grid, the existing metering cabinets will cause shocks to the power grid and overload, which will not only damage the power grid equipment but also threaten the lives of maintenance personnel. Therefore, improvements are urgently needed. Utility Model Content

[0005] In order to overcome the shortcomings of existing metering cabinets that may cause impact on the power grid and overload when fluctuations in voltage, frequency, etc. occur during photovoltaic power generation grid connection, the utility model designs a photovoltaic grid-connected metering cabinet, which improves the safety and reliability of the metering cabinet in daily use.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A photovoltaic grid-connected metering cabinet comprises a cabinet body, wherein a plurality of outlet holes are arranged at the bottom of the cabinet body; three layers of partitions are arranged in sequence from top to bottom in the cabinet body, and the three layers of partitions divide the internal space of the cabinet body into chamber one, chamber two, chamber three and chamber four in sequence from top to bottom; a knife switch is arranged in chamber one, a load control mutual inductor is arranged in chamber two, a metering mutual inductor is arranged in chamber three, a photovoltaic circuit breaker and an anti-islanding device are arranged in chamber four, and the knife switch, the load control mutual inductor, the metering mutual inductor, the photovoltaic circuit breaker and the anti-islanding device are connected in series in sequence and then externally connected to a UPS power supply; and an online monitoring device for monitoring power quality and externally connected to a host computer is also included.

[0008] Furthermore, a wire clamping mechanism is provided at the position of each wire outlet hole at the bottom of the cabinet, and the wire clamping mechanism includes an elastic sleeve and a clamping mechanism for squeezing the elastic sleeve toward the cabinet; the elastic sleeve is a bowl-shaped structure, and a wire clamping hole is opened through the middle of the elastic sleeve, and a plurality of elastic sheets integrally arranged with the elastic sleeve are evenly arranged along the circumference of the side wall of the wire clamping hole, and a clamping inclined surface is provided at the free end of the elastic sheet, and a plurality of clamping rods corresponding to each elastic sheet one by one and evenly arranged around the outer edge of the wire outlet hole are fixed to the bottom of the cabinet, and a top connecting inclined surface adapted to the clamping inclined surface is provided at the end of the clamping rod.

[0009] Furthermore, the clamping mechanism includes at least two fixing screws and clamping nuts matched with each fixing screw. One end of the fixing screw is arranged inside the elastic sleeve and fixed on the cabinet outside the wire outlet hole, and the other end is movable through the elastic sleeve and threadedly connected with the clamping nut.

[0010] Furthermore, the length of the cabinet is 800 mm.

[0011] Furthermore, the width of the cabinet is 1000 mm.

[0012] Furthermore, the height of the cabinet is 2200 mm.

[0013] Compared with the prior art, the utility model has the following characteristics and beneficial effects:

[0014] The utility model collects grid-connected voltage, frequency and grid incoming current signals by installing an anti-islanding device. When an islanding phenomenon occurs, the grid-connected point can be quickly cut off to quickly disconnect it from the grid side. At the same time, an online monitoring device is configured to perform real-time monitoring of voltage harmonics, voltage fluctuations and flickers, frequency deviations, voltage imbalances and voltage sags / swells / short-term interruptions. The provision of the anti-islanding device and the online monitoring device provides a guarantee for the reliable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side perspective view of the utility model;

[0016] Figure 2 It is the front view of the utility model;

[0017] Figure 3 It is a bottom view of the utility model;

[0018] Figure 4 It is a circuit connection diagram of the utility model;

[0019] Figure 5 This is a schematic diagram of the installation of the wire clamping mechanism of the utility model;

[0020] Figure 6It is a three-dimensional structural schematic diagram of the elastic sleeve of the utility model;

[0021] Figure 7 It is a schematic diagram of the cooperation between the elastic sheet and the pressing rod 14 of the utility model.

[0022] The accompanying drawings are marked as follows: 1. knife switch; 2. load control transformer; 3. metering transformer; 4. photovoltaic circuit breaker; 5. anti-islanding device; 6. cabinet; 7. partition; 8. wire outlet hole; 9. UPS power supply; 10. elastic sleeve; 11. fixing screw; 12. clamping nut; 13. elastic sheet; 131. clamping bevel; 14. clamping rod; 141. top connection bevel; 15. wire clamping hole; 16. wire clamping mechanism. DETAILED DESCRIPTION

[0023] The present invention will be described in more detail below in conjunction with the embodiments.

[0024] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 The photovoltaic grid-connected metering cabinet of this embodiment includes a cabinet body 6, and a plurality of outlet holes 8 are arranged at the bottom of the cabinet body 6; three layers of partitions 7 are arranged in sequence from top to bottom in the cabinet body 6, and the three layers of partitions 7 divide the internal space of the cabinet body 6 into chamber one, chamber two, chamber three and chamber four from top to bottom in sequence, a knife switch 1 is arranged in chamber one, a load control mutual inductor 2 is arranged in chamber two, a metering mutual inductor 3 is arranged in chamber three, and a photovoltaic circuit breaker 4 and an anti-islanding device 5 are arranged in chamber four, and the knife switch 1, the load control mutual inductor 2, the metering mutual inductor 3, the photovoltaic circuit breaker 4 and the anti-islanding device 5 are connected in series in sequence and then externally connected to a UPS power supply 9; and an online monitoring device for monitoring power quality and externally connected to a host computer is also included.

[0025] Specifically, the knife switch 1 is used to isolate and disconnect the current to ensure the safety of circuit and equipment maintenance;

[0026] Load control transformer 2 is a measuring device specially used to measure the electrical quantity of current or voltage, which is convenient for subsequent measurement and recording;

[0027] The photovoltaic circuit breaker 4 has the function of automatically closing when there is power and automatically opening when there is a power outage. It also has the functions of fault-proof closing, overload and short-circuit protection;

[0028] The anti-islanding device 5 can accurately detect the voltage and frequency of the grid connection point. When the voltage and frequency fluctuate and are greater than the customized value, the tripping output will be activated to disconnect the grid connection switch. When an islanding phenomenon occurs, the grid connection point can be quickly cut off, so that the device can be quickly disconnected from the grid side, thereby ensuring the safety of the power station and related maintenance personnel;

[0029] The online monitoring device is specifically used to monitor voltage harmonics, voltage fluctuations and flicker, frequency deviation, voltage imbalance and voltage sag / swell / short interruption in real time, and transmit the monitoring data to the host computer for storage and display.

[0030] See also Figure 5 , Figure 6 and Figure 7 A wire clamping mechanism 16 is provided at the bottom of the cabinet 6 at the position of each wire outlet hole 8, and the wire clamping mechanism 16 includes an elastic sleeve 10 and a clamping mechanism for squeezing the elastic sleeve 10 toward the cabinet 6; the elastic sleeve 10 is a bowl-shaped structure, and a wire clamping hole 15 is opened through the middle of the elastic sleeve 10, and a plurality of elastic sheets 13 integrally provided with the elastic sleeve 10 are uniformly provided along the circumferential direction on the side wall of the wire clamping hole 15, and a clamping inclined surface 131 is provided at the free end of the elastic sheet 13, and a plurality of clamping rods 14 corresponding to each elastic sheet 13 and uniformly arranged around the outer edge of the wire outlet hole 8 are fixed to the bottom of the cabinet 6, and a top connecting inclined surface 141 adapted to the clamping inclined surface 131 is provided at the end of the clamping rod 14.

[0031] Furthermore, the clamping mechanism includes at least two fixing screws 11 and a clamping nut 12 matched with each fixing screw 11. One end of the fixing screw 11 is arranged inside the elastic sleeve 10 and fixed on the cabinet 6 outside the wire outlet hole 8, and the other end is movably penetrated through the elastic sleeve 10 and threadedly connected with the clamping nut 12.

[0032] Specifically, when the cable is output from the outlet hole 8, the elastic sleeve 10 is squeezed by twisting the clamping nut 12, so that the elastic sheet 13 fixed on the elastic sleeve 10 is close to the clamping rod 14, that is, the clamping bevel 131 and the top bevel 141 are in contact with each other and face each other, and the elastic sheet 13 clamps the output cable under the action of the squeezing force, thereby preventing the line from being pulled by external force, thereby ensuring the stability of the cable connection of the cabinet 6; when disassembling, pull out the elastic sleeve 10, and the elastic sheet 13 can return to its position under the action of the elastic force.

[0033] Furthermore, the length of the cabinet 6 is 800 mm.

[0034] Furthermore, the width of the cabinet 6 is 1000 mm.

[0035] Furthermore, the height of the cabinet 6 is 2200 mm.

[0036] The working principle of the utility model is as follows: by installing an anti-islanding device 5 to collect grid-connected voltage, frequency and grid incoming current signals, when an islanding phenomenon occurs, the grid-connected point can be quickly cut off to quickly disconnect it from the grid side, and an online monitoring device is configured at the same time to perform real-time monitoring of voltage harmonics, voltage fluctuations and flickers, frequency deviations, voltage imbalances and voltage sags / swells / short-term interruptions. By setting up the anti-islanding device 5 and the online monitoring device, a guarantee is provided for the reliable operation of the power grid.

[0037] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate directions or positional relationships based on the directions 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Claims

1. A photovoltaic grid-connected metering cabinet, characterized in that: The invention comprises a cabinet (6), wherein a plurality of outlet holes (8) are arranged at the bottom of the cabinet (6); three layers of partitions (7) are arranged in sequence from top to bottom in the cabinet (6); the three layers of partitions (7) divide the internal space of the cabinet (6) into chamber one, chamber two, chamber three and chamber four in sequence from top to bottom; a knife switch (1) is arranged in chamber one, a load control mutual inductor (2) is arranged in chamber two, a metering mutual inductor (3) is arranged in chamber three, and a photovoltaic circuit breaker (4) and an anti-islanding device (5) are arranged in chamber four; and the knife switch (1), the load control mutual inductor (2), the metering mutual inductor (3), the photovoltaic circuit breaker (4) and the anti-islanding device (5) are connected in series in sequence and then externally connected to a UPS power supply (9); It also includes an online monitoring device for monitoring power quality and externally connected to a host computer.

2. A photovoltaic grid-connected metering cabinet according to claim 1, characterized in that: The bottom of the cabinet (6) is provided with a wire clamping mechanism (16) at the position of each wire outlet hole (8), and the wire clamping mechanism (16) comprises an elastic sleeve (10) and a clamping mechanism for pressing the elastic sleeve (10) towards the cabinet (6); the elastic sleeve (10) is a bowl-shaped structure, and a wire clamping hole (15) is provided through the middle of the elastic sleeve (10), and a plurality of elastic sheets (13) integrally arranged with the elastic sleeve (10) are evenly arranged along the circumference of the side wall of the wire clamping hole (15), and a clamping inclined surface (131) is provided at the free end of the elastic sheet (13); a plurality of clamping rods (14) corresponding to each elastic sheet (13) and evenly arranged around the outer edge of the wire outlet hole (8) are fixed to the bottom of the cabinet (6), and a top connecting inclined surface (141) adapted to the clamping inclined surface (131) is provided at the end of the clamping rod (14).

3. A photovoltaic grid-connected metering cabinet according to claim 2, characterized in that: The clamping mechanism comprises at least two fixing screws (11) and a clamping nut (12) matched with each fixing screw (11); one end of the fixing screw (11) is arranged inside the elastic sleeve (10) and fixed on the cabinet (6) outside the wire outlet hole (8); the other end movably passes through the elastic sleeve (10) and is threadedly connected with the clamping nut (12).

4. A photovoltaic grid-connected metering cabinet according to claim 1, characterized in that: The length of the cabinet (6) is 800 mm.

5. A photovoltaic grid-connected metering cabinet according to claim 4, characterized in that: The width of the cabinet (6) is 1000 mm.

6. A photovoltaic grid-connected metering cabinet according to claim 5, characterized in that: The height of the cabinet (6) is 2200 mm.

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