CN219458661U

CN219458661U - Full-amount internet roof distributed photovoltaic power station electricity theft prevention management system

Info

Publication number: CN219458661U
Application number: CN202320425635.0U
Authority: CN
Inventors: 石凤武; 申彦民
Original assignee: Hebei Branch Of Huaneng New Energy Co ltd
Current assignee: Hebei Branch Of Huaneng New Energy Co ltd
Priority date: 2023-03-08
Filing date: 2023-03-08
Publication date: 2023-08-01
Anticipated expiration: 2033-03-08

Abstract

The utility model relates to the technical field of electricity theft prevention, in particular to an electricity theft prevention management system of a full-amount internet-surfing roof distributed photovoltaic power station, which is characterized in that a photovoltaic module is connected in series and then connected into a DC input loop of an inverter, and the inverter is connected into a grid-connected distribution box switch through an output loop and then connected into a power distribution network through a kilowatt-hour meter and a knife switch; comprising the following steps: the system comprises a first low-voltage current transformer, a second low-voltage current transformer and a line differential protection device, wherein the first low-voltage current transformer is connected to an outgoing line of an inverter, the second low-voltage current transformer is connected to an incoming line of an electric meter, the first low-voltage current transformer and the second low-voltage current transformer are electrically connected with the line differential protection device, and the line differential protection device is electrically connected with a grid-connected distribution box switch. According to the differential protection principle, the current vector differences at two ends are compared, when the set action value is reached, the action element is started, the grid-connected distribution box switch is disconnected, the power generation of the power station is stopped, and the electricity stealing behavior of the full-amount internet roof distributed photovoltaic power station can be fundamentally stopped.

Description

Full-amount internet roof distributed photovoltaic power station electricity theft prevention management system

Technical Field

The utility model relates to the technical field of electricity theft prevention, in particular to an electricity theft prevention management system for a full-amount internet surfing roof distributed photovoltaic power station.

Background

The electric energy is an indispensable energy use mode for human production and life at present, and is produced by an electric power company, transmitted to users through various transmission lines and power transformation devices, and the users pay the cost to maintain the electric power production of the electric power company, so that a virtuous circle is realized.

The roof distributed photovoltaic is particularly used for a photovoltaic power generation facility which is characterized in that the roof of a user building is in a grid connection mode and is divided into three modes of spontaneous self-use, surplus internet surfing and full internet surfing, and balance adjustment is performed in a power distribution system. Roof distributed photovoltaic power generation is a novel power generation and energy comprehensive utilization mode with wide development prospect, advocates nearby power generation, nearby grid connection, nearby conversion and nearby use principles, can effectively improve the generated energy of a photovoltaic power station with the same scale, and simultaneously effectively solves the problem of power loss in boosting and long-distance transportation.

Aiming at the roof distributed photovoltaic power station on the full network, because the current rural power management is not standard, the behavior of illegal wiring between the kilowatt-hour meter and the inverter in the grid-connected distribution box of the local power station exists in the private of the user; and because the roof distributed photovoltaic power station has the characteristics of small unit capacity and wide distribution area, fewer operation and maintenance personnel are distributed in the sheet area, the behavior of illegal wiring cannot be found in time, and the property loss of the power company is caused.

Disclosure of Invention

The utility model aims to provide a full-capacity internet-surfing roof distributed photovoltaic power station electricity stealing prevention management system, which is used for collecting currents at an outgoing line of an inverter and an incoming line of an electric meter through a low-voltage transformer, comparing current vector differences at two ends according to a differential protection principle, starting an action element when a set action value is reached, switching off a grid-connected distribution box switch, and stopping power station power generation so as to solve the problem of illegal wiring of the full-capacity internet-surfing roof distributed photovoltaic power station.

The embodiment of the utility model is realized by the following technical scheme: a full-amount internet roof distributed photovoltaic power station electricity theft prevention management system is characterized in that a photovoltaic module is connected in series and then connected into an inverter direct current input loop, and the inverter is connected into a grid-connected distribution box switch through an output loop and then connected into a power distribution network through an electric meter and a knife switch;

the anti-theft management system comprises: the system comprises a first low-voltage current transformer, a second low-voltage current transformer and a line differential protection device, wherein the first low-voltage current transformer is connected to an outgoing line of an inverter, the second low-voltage current transformer is connected to an incoming line of an electric meter, the first low-voltage current transformer and the second low-voltage current transformer are electrically connected with the line differential protection device, and the line differential protection device is electrically connected with a grid-connected distribution box switch.

According to a preferred embodiment, the first low-voltage current transformer and the second low-voltage current transformer are connected to the phase of an ac line A, B, C.

According to a preferred embodiment, the grid-connected distribution box switch is open.

According to a preferred embodiment, the line differential protection device is connected to the knife switch.

According to a preferred embodiment, a protection box is installed on the local grid-connected distribution box side, and the line differential protection device is arranged in the protection box.

According to a preferred implementation mode, a distributed photovoltaic protection switch is further connected between the grid-connected distribution box switch and the kilowatt-hour meter.

According to a preferred embodiment, the distributed photovoltaic protection switch uses a residual current recloser circuit breaker as a main body.

The technical scheme of the embodiment of the utility model has at least the following advantages and beneficial effects: according to the utility model, the current at the outgoing line of the inverter and the incoming line of the kilowatt-hour meter is collected through the low-voltage transformer, the current vector difference at two ends is compared according to the differential protection principle, when the set action value is reached, the action element is started, the grid-connected distribution box switch is disconnected, the power generation of the power station is stopped, and the electricity stealing behavior of the full-capacity internet-surfing roof distributed photovoltaic power station can be fundamentally stopped.

Drawings

Fig. 1 is a schematic circuit wiring diagram of an anti-electricity-theft management system provided in embodiment 1 of the present utility model;

fig. 2 is a grid-connected wiring diagram of a conventional roof-top distributed photovoltaic power station provided in embodiment 1 of the present utility model;

icon: the system comprises a 1-inverter, a 2-first low-voltage current transformer, a 3-grid-connected distribution box switch, a 4-distributed photovoltaic protection switch, a 5-second low-voltage current transformer, a 6-kilowatt-hour meter, a 7-knife switch, an 8-line differential protection device and 9-illegal wiring.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Example 1

Referring to fig. 1, fig. 1 is a schematic circuit wiring diagram of an anti-electricity-theft management system for a full-capacity internet-surfing roof distributed photovoltaic power station provided by an embodiment of the utility model.

In the full-online roof distributed photovoltaic power station electricity theft prevention management system provided by the utility model, after roof distributed photovoltaic module strings are connected into a direct current input loop of an inverter 1, the inverter 1 inverts current into alternating current 380V and then is connected into a grid-connected distribution box switch 3 through an output loop, and then the grid-connected distribution box switch is connected into a power distribution network through a distributed photovoltaic protection switch 4, an electric meter 6 and a knife switch 7 in sequence, wherein the distributed photovoltaic protection switch 4 adopts a residual current reclosing circuit breaker as a main body and has a reclosing function. Referring to fig. 2, the current rural power management is not standard, and the illegal wiring 9 between the kilowatt-hour meter 6 and the inverter 1 in the grid-connected distribution box of the local power station is used by users, so that the loss of the network-connected electric quantity of the power station is caused.

The anti-electricity-theft management system provided in this embodiment includes: a first low-voltage current transformer 2CT1, a second low-voltage current transformer 5CT2, and a line differential protection device 8; the line differential protection device 8 is a differential current vector difference between both ends of an input CT (current transformer), and when a set operation value is reached, an operation element is activated. A device with a protection range between the two ends of the input CT.

In this embodiment, the first low-voltage current transformer 2CT1 is connected to the phase A, B, C of the ac line where the inverter 1 appears, and the second low-voltage current transformer 5CT2 is connected to the phase A, B, C of the ac line where the watt-hour meter 6 is connected; the outgoing lines of the secondary coil protection terminals of the first low-voltage current transformer 2CT1 and the second low-voltage current transformer 5CT2 are connected to a line differential protection device 8, wherein CT1 is line incoming line current, CT2 is line outgoing line current, the line differential protection device 8 is electrically connected with a grid-connected distribution box switch 3, and when a set action value is reached, an action element is started to control the grid-connected distribution box switch 3 to be tripped. Specifically, when no electricity stealing behavior exists in the power station alternating current loop, the current at two ends is consistent, the vector sum is zero, the action element of the line differential protection device 8 does not act, and normal power generation is not affected; when electricity stealing behavior exists between the power station alternating current loop inverter 1 and the kilowatt-hour meter 6, the vector sum of current at two ends is not zero, the action element of the differential protection device acts, the grid-connected distribution box switch 3 is tripped, the island protection action of the inverter 1 is performed, the power station stops generating electricity, the protection is not reset, and the grid-connected distribution box switch 3 cannot be switched on; the background monitoring personnel can screen according to the abnormal power station, and inform nearby operation and maintenance personnel to process in time. In addition, when the power grid fails, the circuit differential protection device 8 loses power, and cannot realize the differential protection function, at the moment, the power station is disconnected from the reset switch, the power station does not generate electricity, and the power stealing behavior cannot be performed.

In this embodiment, the grid-connected distribution box switch 3 is a line-controlled air switch, and the line differential protection device 8 is connected to the knife switch 7 by using an AC 220V working voltage.

Further, a protection box is installed on the side of the local grid-connected distribution box, and the line differential protection device 8 is arranged in the protection box.

In summary, the current at the outgoing line of the inverter and the incoming line of the kilowatt-hour meter is collected through the low-voltage transformer, the current vector difference at two ends is compared according to the differential protection principle, when the set action value is reached, the action element is started, the grid-connected distribution box switch is disconnected, the power generation of the power station is stopped, and the electricity stealing behavior of the full-capacity internet-surfing roof distributed photovoltaic power station can be fundamentally stopped.

The above is only a preferred embodiment of the present utility model, and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. The full-online roof distributed photovoltaic power station electricity theft prevention management system is characterized in that a direct current input loop of an inverter (1) is connected after a photovoltaic module is connected in series, and the inverter (1) is connected into a grid-connected distribution box switch (3) through an output loop and then is connected into a power distribution network through a kilowatt-hour meter (6) and a knife switch (7);

the anti-theft management system comprises: the low-voltage power supply system comprises a first low-voltage current transformer (2), a second low-voltage current transformer (5) and a circuit differential protection device (8), wherein the first low-voltage current transformer (2) is connected to an outgoing line of an inverter (1), the second low-voltage current transformer (5) is connected to an incoming line of a kilowatt-hour meter (6), the first low-voltage current transformer (2) and the second low-voltage current transformer (5) are electrically connected with the circuit differential protection device (8), and the circuit differential protection device (8) is electrically connected with a grid-connected distribution box switch (3).

2. The full-networking roof-top distributed photovoltaic power station anti-theft management system according to claim 1, wherein the first low-voltage current transformer (2) and the second low-voltage current transformer (5) are connected to the alternating current line A, B, C.

3. The full-online roof-top distributed photovoltaic power station anti-electricity-theft management system according to claim 1, wherein the grid-connected distribution box switch (3) is open.

4. The full-online roof-top distributed photovoltaic power plant anti-theft management system according to claim 1, characterized in that the line differential protection device (8) is connected to the knife switch (7).

5. The full-online roof distributed photovoltaic power station electricity theft prevention management system according to claim 1, wherein a protection box is arranged on the side of the local grid-connected distribution box, and the line differential protection device (8) is arranged in the protection box.

6. The full-networking roof distributed photovoltaic power station electricity theft prevention management system according to any one of claims 1 to 5, wherein a distributed photovoltaic protection switch (4) is further connected between the grid-connected distribution box switch (3) and the kilowatt-hour meter (6).

7. The full-load internet-surfing roof-top distributed photovoltaic power plant anti-theft management system according to claim 6, wherein the distributed photovoltaic protection switch (4) adopts a residual current reclosing circuit breaker as a main body.