CN107968329A - Grid-connected access case and its access system - Google Patents

Abstract

The invention discloses a kind of grid-connected access case and its access system, it belongs to technical field of photovoltaic power generation.It solve in the prior art tradition access case existing for measuring difficulties, power grid incoming call cannot automatic power transmission the defects of.Including ammeter box and grid connection box; isolation board is equipped between ammeter box and grid connection box; ammeter box is located at the top of grid connection box; isolation board is equipped with threading hole; electric energy meter is equipped with ammeter box; line bank is mounted with above grid connection box, the first breaker, Surge Protector, protector with automatic reconnection for leakage of electricity, inverter switching device and fuse type disconnector are equipped with grid connection box；One end of first breaker is connected with Surge Protector, and the other end is connected by line bank with electric energy meter；Protector with automatic reconnection for leakage of electricity is connected with electric energy meter and fuse type disconnector respectively by line bank；One end of inverter switching device is connected by line bank with electric energy meter, and the other end is connected with inverter.Present invention is mainly used on photovoltaic generating system.

Description

Photovoltaic grid-connected access box and its access system

Technical field:

The invention belongs to the technical field of photovoltaic power generation, and in particular relates to a photovoltaic grid-connected access box and an access system thereof.

Background technique:

As one of the emerging clean and efficient energy sources, photovoltaic power generation has become an effective way to promote the application of clean energy and can gradually replace some old power generation devices and technologies. However, in the process of promoting residential photovoltaic grid-connected power generation, since the photovoltaic power generation device used does not have a dedicated control and metering device, only temporary metering solutions can be used during the grid-connected construction process, which is likely to cause heavy and repetitive labor ; and there were no clear standards and professional personnel for the initial grid connection, which caused many technical defects and potential safety hazards, such as how to completely isolate the power grid from photovoltaic power generation for power outage maintenance, how to automatically cut off the power when the grid is out of power, and how to automatically power off when the grid is powered on. Power transmission to achieve photovoltaic power generation can be put into use for power generation in the first time.

Invention content:

In order to solve the problems of measurement difficulties in the traditional access box in the prior art and the inability to automatically transmit electricity from the power grid, the present invention provides a photovoltaic grid-connected access box and its access system that are different from the prior art. Accurate and convenient system maintenance.

In order to achieve the above object, the present invention is achieved by adopting the following technical solutions:

A photovoltaic grid-connected access box, including a meter box and a grid-connected box, an isolation plate is provided between the meter box and the grid-connected box, the meter box is located above the grid-connected box, and a threading hole is provided on the isolation plate. An electric energy meter is installed in the electric meter box, and a terminal block is installed and fixed above the grid-connected box. The first circuit breaker, surge protector, automatic reclosing leakage protector, and inverter switch are installed in the grid-connected box. and a fuse type isolating switch; one end of the first circuit breaker is connected to the surge protector, and the other end is connected to the electric energy meter through a terminal block; the automatic reclosing leakage protector is respectively separated from the electric energy meter and the fuse type The switch is connected; one end of the inverter switch is connected to the electric energy meter through a terminal block, and the other end is connected to the inverter.

Further, a concentrator is arranged in the meter box, and the concentrator is connected with the electric energy meter.

Further, the grid-connected box is provided with a second circuit breaker, and the second circuit breaker is respectively connected to the first circuit breaker, the electric energy meter and the inverter switch.

Further, the grid-connected box is also provided with a lightning arrester switch and a lightning arrester, one end of the lightning arrester is grounded, the other end is connected to one end of the lightning arrester switch, and the other end of the lightning arrester switch is respectively connected to the inverter switch and the electric energy meter through a terminal block. connect.

Further, the electric energy meter is a three-phase intelligent electric energy meter.

Further, the length, width and height of the photovoltaic grid-connected box are 120cm, 70cm and 140cm respectively, the material of the photovoltaic grid-connected box is stainless steel, and the front of the photovoltaic grid-connected box is set There are three doors.

Further, a transparent window is provided on the door of the electric meter box.

The access system of the photovoltaic grid-connected access box includes a photovoltaic grid-connected access box, an inverter, a distribution transformer, a drop-out fuse, a third circuit breaker, and a fourth circuit breaker. One end of the inverter is connected to the photovoltaic The board is connected, the other end is connected to the photovoltaic grid-connected access box, the photovoltaic grid-connected access box is connected to one end of the distribution transformer, the other end of the distribution transformer is connected to the drop-out fuse, and the drop-out fuse is connected to the user 10kV On the bus, a third circuit breaker is installed between the 10kV bus of the user and the 10kV line of the public grid, and a fourth circuit breaker is installed between the 10kV line of the public grid and the 10kV bus of the public grid.

Compared with prior art, the beneficial effect of the present invention is:

1. The surge protector protects against direct, indirect lightning or instantaneous overvoltage surges; adding arresters and arrester switches is equivalent to adding double protection to prevent one of the components from malfunctioning and causing serious consequences;

2. The electric energy meter is a three-phase intelligent electric energy meter, which fully guarantees the accuracy of measurement;

3. There is a concentrator in the meter box, which can make the system maintenance convenient;

4. Fusible isolating switch can ensure the safety of circuit maintenance personnel;

5. There is a transparent window on the door of the meter box, so that the meter can be observed at any time without opening the door.

Description of drawings:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the front view of the present invention;

Fig. 3 is a schematic diagram of system solution access in the present invention.

In the figure: 1. Meter box; 2. Isolation plate; 3. First circuit breaker; 4. Second circuit breaker; 5. Surge protector; 6. Lightning arrester switch; 7. Lightning arrester; 8. Automatic reclosing leakage protection 9. Inverter switch; 10. Grid-connected box; 11. Fused isolating switch; 12. Wiring block; 13. Concentrator; 14. Energy meter; 15. Transparent window; 16. Box door; 17. Photovoltaic 18. Inverter; 19. Photovoltaic grid-connected access box; 20. Distribution transformer; 21. Drop-out fuse; 22. User 10kV busbar; 23. Third circuit breaker; 24. Public grid 10kV line ; 25. The fourth circuit breaker; 26. The 10kV busbar of the public power grid.

Detailed ways:

The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

Example 1:

As shown in Figure 1, a photovoltaic grid-connected access box includes a meter box 1 and a grid-connected box 10, an isolation plate 2 is provided between the meter box 1 and the grid-connected box 10, and the meter box 1 is located at the side of the grid-connected box 10. On the top, the isolation plate 2 is provided with a threading hole, the electric meter box 1 is provided with an electric energy meter 14, and a terminal block 12 is installed and fixed above the network box 10, and the first circuit breaker 3 and a surge protector are arranged in the network box 10 5. Automatic reclosing leakage protector 8, inverter switch 9 and fuse type isolating switch 11; one end of the first circuit breaker 3 is connected to the surge protector 5, and the other end is connected to the electric energy meter 14 through the terminal block 12; automatic The reclosing leakage protector 8 is connected to the electric energy meter 14 and the fuse type isolating switch 11 respectively through the terminal block 12;

Example 2:

A photovoltaic grid-connected access box, the meter box 1 is provided with a concentrator 13, the concentrator 13 is connected to the electric energy meter 14; the grid-connected box 10 is provided with a second circuit breaker 4, and the second circuit breaker 4 is respectively connected to the first The circuit breaker 3, the electric energy meter 14 and the inverter switch 9 are connected. Other parts are identical with embodiment 1.

Example 3:

As shown in Figure 2, a photovoltaic grid-connected access box, the grid-connected box 10 is also provided with a lightning arrester switch 6 and a lightning arrester 7, one end of the lightning arrester 7 is grounded, the other end is connected to one end of the lightning arrester switch 6, and the lightning arrester switch 6 The other end is respectively connected to the inverter switch 9 and the electric energy meter 14 through the terminal block 12; the electric energy meter 14 is a three-phase intelligent electric energy meter; the length, width and height of the photovoltaic grid-connected access box 19 are 120cm, 70cm and 140cm respectively The photovoltaic grid-connected access box 19 is made of stainless steel, and the front of the photovoltaic grid-connected access box 19 is provided with three doors 16; the door 16 of the meter box 1 is provided with a transparent window 15. Other parts are identical with embodiment 2.

Example 4:

As shown in Figure 3, an access system using a photovoltaic grid-connected access box includes a photovoltaic grid-connected access box 19, an inverter 18, a distribution transformer 20, a drop-out fuse 21, a third circuit breaker 23 and For the fourth circuit breaker 25, one end of the inverter 18 is connected to the photovoltaic panel 17, and the other end is connected to the photovoltaic grid connection box 19, and the photovoltaic grid connection box 19 is connected to one end of the distribution transformer 20, and the distribution transformer The other end of 20 is connected to the drop-out fuse 21, and the drop-out fuse 21 is connected to the user 10kV busbar 22, and a third circuit breaker 23 is arranged between the user 10kV busbar 22 and the public power grid 10kV line 24, and the public power grid 10kV line 24 A fourth circuit breaker 25 is provided between the 10kV busbar 26 and the public power grid.

The surge protector 5 protects against direct and indirect lightning or instantaneous overvoltage surges; adding the arrester 7 and the arrester switch 6 is equivalent to adding double protection to prevent one of the components from malfunctioning and causing serious consequences.

The watt-hour meter 14 is a three-phase smart watt-hour meter, which fully guarantees the accuracy of measurement. The precision is 0.5S for active power and 2.0 for reactive power. The electricity collection information can be accurately uploaded to the relevant power grid management department.

There is a concentrator 13 inside the meter box 1. The model of the concentrator 13 is DJGZ23-SEA3700, which has rapidity, stability and reliability; it can make the system maintenance convenient, and you can check the relevant information of the network connection point through the background, and support the remote upgrade of the background and remote control.

Fusible isolating switch 11 can be clearly observed when isolating power supply and breaking load, ensuring the safety of circuit maintenance personnel.

The first circuit breaker 3 and the second circuit breaker 4 have overload and short circuit protection functions. When the line has overvoltage, undervoltage, overcurrent, short circuit, neutral line disconnection, leakage, etc., the first circuit breaker 3 or the second circuit breaker will be triggered. 4 trips, and the automatic reclosing leakage protector 8 can guarantee automatic reclosing and energization after a certain time interval and can automatically save tripping information, including tripping cause, voltage, current, leakage current and other information; when a fault occurs, it will alarm, Fault locking and opening indications light up at the same time, and the LCD displays the corresponding fault causes; there is no need to add alarm controllers and alarm horns, reducing the access of lines, that is, reducing the occurrence of faults.

In addition, the automatic reclosing leakage protector 8 also has: 1) undervoltage or overvoltage protection, when the voltage is low or higher than the set value, the protector will automatically disconnect the power supply; when the voltage is normal, it will automatically close and power on; 2) When a short circuit occurs in the line or the current is greater than the rated current, the automatic reclosing leakage protector 8 is disconnected for protection; 3) When the zero and live wires are reversed, it is automatically disconnected to avoid electrical burnout and accidents; 4) Manual closing, when When automatic closing is not required, manual closing can be selected, which operates exactly the same as ordinary circuit breakers and is not subject to electric control and other functions.

The box door 16 of the electric meter box 1 is provided with a transparent window 15, and the electric energy meter 14 can be observed at any time without opening the box door 16.

The photovoltaic grid-connected access box 19 adopts a suspended installation, and the distance from the lower edge to the ground is not less than 2.0m. It can be raised appropriately if there is a need for flood control; Such as copper core, aluminum core or rare earth high-iron aluminum alloy core, or XLPE insulated soft copper wire, if the cable is used to lay in the ground, the wire will enter from the bottom of the photovoltaic grid connection box 19; the photovoltaic grid connection box 19 To go out to the low-voltage side of the distribution transformer 20, use JKTRYJ-1-1×300mm ² overhead insulated conductors or ZC-EFR-0.6/1kV-300 flexible cables.

The low-voltage side of the distribution transformer 20 is connected to the fuse-type isolating switch 11 in the photovoltaic grid-connected box 19, and the photovoltaic panel 17 is connected to the inverter switch 9 in the photovoltaic grid-connected box 19 through the inverter 18. A drop-out fuse 21 is installed between the high-voltage side of the distribution transformer 20 and the user's 10kV bus bar 22 to provide protection and facilitate switching operations.

Claims (8)

1. a kind of grid-connected access case, including ammeter box (1) and grid connection box (10), between ammeter box (1) and grid connection box (10) Equipped with isolation board (2), ammeter box (1) is located at the top of grid connection box (10), and the isolation board (2) is equipped with threading hole, the electricity Electric energy meter (14) is equipped with electricity box (1), line bank (12) is mounted with above the grid connection box (10), it is characterised in that：Institute State and the first breaker (3), Surge Protector (5), protector with automatic reconnection for leakage of electricity (8), inverter are equipped with grid connection box (10) Switch (9) and fuse type disconnector (11)；One end of first breaker (3) is connected with Surge Protector (5), the other end It is connected by line bank (12) with electric energy meter (14)；The protector with automatic reconnection for leakage of electricity (8) passes through line bank (12) difference It is connected with electric energy meter (14) and fuse type disconnector (11)；One end of the inverter switching device (9) by line bank (12) with Electric energy meter (14) connects, and the other end is connected with inverter (18).

2. grid-connected access case according to claim 1, it is characterised in that：Concentrator is equipped with the ammeter box (1) (13), the concentrator (13) is connected with electric energy meter (14).

3. grid-connected access case according to claim 2, it is characterised in that：It is disconnected that second is equipped with the grid connection box (10) Road device (4), second breaker (4) are connected with the first breaker (3), electric energy meter (14) and inverter switching device (9) respectively.

4. grid-connected access case according to claim 3, it is characterised in that：It is additionally provided with the grid connection box (10) lightning-arrest Device electric brake (6) and arrester (7), one end ground connection of the arrester (7), the other end are connected with the one end of arrester electric brake (6), The other end of arrester electric brake (6) is connected with inverter switching device (9) and electric energy meter (14) respectively by line bank (12).

5. grid-connected access case according to claim 4, it is characterised in that：The electric energy meter (14) is three-phase intelligent electricity Can table.

6. grid-connected access case according to claim 5, it is characterised in that：The grid-connected access case (19) Length is respectively 120cm, 70cm and 140cm, and the material of the grid-connected access case (19) is stainless steel, described The front of grid-connected access case (19) is equipped with three fan chamber doors (16).

7. grid-connected access case according to claim 6, it is characterised in that：On the chamber door (16) of the ammeter box (1) Equipped with transparency window (15).

8. using the access system of the grid-connected access case as described in claim 1-7：It is characterized in that：Including grid-connected It is disconnected to access case (19), inverter (18), distribution transformer (20), fuse switch (21), the 3rd breaker (23) and the 4th Road device (25), one end of the inverter (18) are connected with photovoltaic plate (17), and the other end connects with grid-connected access case (19) Connect, grid-connected access case (19) is connected with one end of distribution transformer (20), and the other end of distribution transformer (20) is with falling Formula fuse (21) connects, and fuse switch (21) is connected on user 10kV busbares (22), user 10kV busbares (22) with The 3rd breaker (23), public electric wire net 10kV circuits (24) and public electric wire net 10kV are equipped between public electric wire net 10kV circuits (24) The 4th breaker (25) is equipped between busbar (26).