Photovoltaic grid-connected cabinet

Abstract

The invention belongs to the technical field of photovoltaic grid-connected cabinets, and particularly relates to a photovoltaic grid-connected cabinet. The interior of the cabinet body is divided into a plurality of function zones, adjacent function zones are mutually independent, the metering zone and the photovoltaic communication equipment zone are located above the incoming line disconnecting link zone, the photovoltaic switch zone, the protection zone and the residual current operated protector are located below the incoming line disconnecting link zone, the residual current operated protector is located above the protection zone, and the residual current operated protector is located above the protection zone. The current mutual inductance area is located behind the incoming line disconnecting link area, the incoming line disconnecting link area is electrically connected with the residual current operated protector through a copper bar, the residual current operated protector is in circuit connection with the photovoltaic switch area, the current mutual inductance area is sleeved outside the copper bar, and the current mutual inductance area is in circuit connection with the metering area. According to the photovoltaic grid-connected cabinet disclosed by the invention, functional partitions are designed in a standard manner, the partitions are reasonable, the wiring layout is reasonable, and photovoltaic grid connection is safer and more reliable; and a photovoltaic communication equipment space is reserved to adapt to new technology development.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic grid-connected cabinets, and in particular relates to a photovoltaic grid-connected cabinet. Background Art

[0002] With the continuous development of photovoltaic power generation technology, more and more photovoltaic power generation is connected to the power grid. At present, there is no unified standard for low-voltage photovoltaic grid-connected metering cabinets, and the quality is uneven, which is mainly reflected in the fuzzy partitions inside the cabinet, the irregular installation positions of the metering energy meter and the transformer, and the incomplete isolation of the distribution part from the metering part; in addition, since the low-voltage photovoltaic grid-connected metering cabinet needs to connect multiple devices such as photovoltaic components, inverters and energy meters, and the communication protocols used between different devices may be different, it is not conducive to the realization of interconnection and online regulation. The functions need to be improved urgently to facilitate the realization of online power quality monitoring, load balancing and energy optimization. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a photovoltaic grid-connected cabinet.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows: a photovoltaic grid-connected cabinet comprises: a cabinet body, wherein the interior of the cabinet body is divided into a plurality of functional zones, and adjacent functional zones are relatively independent of each other, and the functional zones comprise: a metering zone, a current mutual induction zone, a photovoltaic switch zone, a protection zone, an incoming knife switch zone, a photovoltaic communication equipment zone and a residual current operated protector; the metering zone and the photovoltaic communication equipment zone are located above the incoming knife switch zone, the photovoltaic switch zone, the protection zone and the residual current operated protector are located below the incoming knife switch zone, the residual current operated protector is located above the protection zone, and the current mutual induction zone is located behind the incoming knife switch zone; the incoming knife switch zone is electrically connected to the residual current operated protector through a copper busbar, the residual current operated protector is circuit-connected to the photovoltaic switch zone, the current mutual induction zone is sleeved outside the copper busbar, the current mutual induction zone is circuit-connected to the metering zone, the metering zone is connected to the photovoltaic communication equipment zone, the metering zone and the photovoltaic communication equipment zone are circuit-connected to the photovoltaic switch zone respectively, a flexible control device is arranged in the photovoltaic communication equipment zone, one end of the protection zone is connected between the residual current operated protector and the photovoltaic switch zone, and the other side is connected to the grounding device outside the cabinet body through a grounding wire.

[0005] Furthermore, the photovoltaic communication equipment area includes a protocol converter and an interface converter, and the protocol converter and the interface converter are communicatively connected with each other.

[0006] Furthermore, the photovoltaic communication equipment area adopts a flexible control method, the steps are as follows: S1. Each data acquisition device is connected to the interface converter, and the data acquisition device includes but is not limited to a current transformer, a light sensor and a temperature sensor; S2, the protocol converter converts the collected data into a unified protocol format; S3. Combine real-time data and control objectives to formulate control strategies, convert them into control instructions through protocol converters, and then adjust the power generation output of the photovoltaic system through interface converters.

[0007] Furthermore, the control target in step S3 includes but is not limited to power generation prediction or power supply balance.

[0008] Furthermore, the grid-side incoming lines are connected from the incoming line switch area, and the photovoltaic-side outgoing lines are connected from the photovoltaic switch area.

[0009] Furthermore, the cabinet is divided into a front area and a rear area by a vertical virtual plate. The metering area, photovoltaic switch area, protection area, incoming line switch area, photovoltaic communication equipment area and residual current action protector are located in the front area, and the current mutual inductance area is located in the rear area.

[0010] Furthermore, the copper busbar connected to the incoming knife switch area has a middle body located in the rear area and two ends bent toward the front area.

[0011] Furthermore, an electric meter and a junction box are installed in the metering area, the electric meter and the junction box are connected by wires, and the electric meter is connected to the photovoltaic switch area.

[0012] Furthermore, an isolating switch, an anti-islanding protection device, a surge protector and an anti-electromagnetic interference device are provided in the protection zone, and the isolating switch, the anti-islanding protection device, the surge protector and the anti-electromagnetic interference device are connected in parallel.

[0013] Furthermore, the voltage line is connected to the copper busbar, and the current line is connected to the transformer in the current mutual inductance area.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: a photovoltaic grid-connected cabinet is provided, with standardized functional zoning design, including a metering area, a current mutual inductance area, a photovoltaic switch area, a protection area, an incoming knife switch area and a residual current action protector, and space for photovoltaic communication equipment is reserved to adapt to the development of new technologies; reasonable zoning, the grid side and the photovoltaic side can be relatively independent, and the distribution part and the metering part are completely isolated; a metering current mutual inductance area is designed behind the photovoltaic grid-connected cabinet, making photovoltaic grid connection safer and more reliable; an interface converter can convert different interface standards, and a protocol converter can convert different communication protocols to improve the compatibility of data transmission, so as to facilitate the realization of online power quality monitoring, load balancing and energy optimization utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the front view of the interior of the photovoltaic grid-connected cabinet; Figure 2 This is the rear view of the interior of the photovoltaic grid-connected cabinet; Figure 3 This is the left view inside the photovoltaic grid-connected cabinet; Figure 4This is the front view of the interior of the photovoltaic grid-connected cabinet in Example 3.

[0016] In the figure: 1. cabinet, 2. vertical virtual plate, 4. metering area, 5. current mutual inductance area, 6. photovoltaic switch area, 7. protection area, 8. incoming knife switch area, 9. photovoltaic communication equipment area, 10. residual current action protector, 11. front area, 12. rear area, 13. isolation board, 14. mutual inductance copper bus, 401. electric meter, 402. junction box, 701. isolating switch, 702. anti-islanding protection device, 703. surge protector, 704. anti-electromagnetic interference device, 901. protocol converter, 902. interface converter. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0018] Combination Figure 1 Understand, combine Figure 1-3 It is understood that a photovoltaic grid-connected cabinet comprises: a cabinet body 1, wherein the cabinet body 1 is internally divided into a plurality of functional partitions, and adjacent functional partitions are relatively independent of each other, and the functional partitions include: a metering area 4, a current mutual induction area 5, a photovoltaic switch area 6, a protection area 7, an incoming knife switch area 8, a photovoltaic communication equipment area 9 and a residual current action protector 10; the metering area 4 and the photovoltaic communication equipment area 9 are located above the incoming knife switch area 8, the photovoltaic switch area 6, the protection area 7 and the residual current action protector 10 are located below the incoming knife switch area 8, the residual current action protector 10 is located above the protection area 7, and the current mutual induction area 5 is located behind the incoming knife switch area 8; The gate area 8 is electrically connected to the residual current action protector 10 through the copper busbar, the residual current action protector 10 is connected to the photovoltaic switch area 6 in circuit, the current mutual inductance area 5 is sleeved outside the copper busbar, the current mutual inductance area 5 is connected to the metering area 4 in circuit, the metering area 4 is connected to the photovoltaic communication equipment area 9, the metering area 4 and the photovoltaic communication equipment area 9 are respectively connected to the photovoltaic switch area 6 in circuit, one end of the protection area 7 is connected between the residual current action protector 10 and the photovoltaic switch area 6, and the other side is connected to the grounding device outside the cabinet 1 through the grounding wire; the cabinet 1 is well prepared with wiring reserved holes, which can make the overall wiring layout reasonable and meet the conditions for padlock sealing. The photovoltaic grid-connected cabinet is designed with standardized functional zoning and reasonable zoning. The grid side and the photovoltaic side can be relatively independent, the distribution part and the metering part can be completely isolated, the mutual interference is reduced, and the metering accuracy is high; improve the safety performance of the grid-connected cabinet. Reserve space for photovoltaic communication equipment to adapt to the development of new technologies and provide support for online power quality monitoring.

[0019] Furthermore, the photovoltaic communication equipment area 9 includes a protocol converter 901 and an interface converter 902, and the protocol converter 901 and the interface converter 902 are connected in communication. The interface converter 902 can convert different interface standards, and the protocol converter 901 converts different communication protocols to improve the compatibility of data transmission, so as to facilitate the realization of online power quality monitoring, load balancing and energy optimization.

[0020] Further, the photovoltaic communication equipment area 9 adopts a flexible control method, the steps are as follows: S1. Each data acquisition device is connected to the interface converter 902. The data acquisition device includes but is not limited to a current transformer, a light sensor and a temperature sensor; S2, the protocol converter 901 converts the collected data into a unified protocol format; S3. Combine real-time data and control objectives to formulate a control strategy. The core of the control strategy is to formulate a prediction curve, which is carried out through data processing: the previous current value is used as a reference curve relative to light and temperature, and then the current value is predicted on the reference curve with the measured light and temperature values, and then the influence factor is obtained by the predicted current value and the measured current value, and the reference curve is corrected to obtain a prediction curve, and finally the next current value and power generation are predicted by the prediction curve. Usually, when environmental factors such as light or temperature fluctuate greatly, it is necessary to re-prepare the reference curve and the corresponding prediction curve, otherwise, it can be continuously used; formulate the next execution signal according to the control strategy, and convert it into a control instruction through the protocol converter 901, and then adjust the power generation output of the photovoltaic system through the interface converter 902.

[0021] Furthermore, the control target in step S3 includes but is not limited to power generation prediction or power supply balance.

[0022] In one embodiment, the grid side incoming line is connected from the incoming line switch area 8, and the photovoltaic side outgoing line is connected from the photovoltaic switch area 6. Clearly distinguishing the grid side and the photovoltaic side is conducive to the wiring operation and is not prone to errors.

[0023] In one embodiment, in combination Figure 3 It is understood that the cabinet 1 is divided into a front area 11 and a rear area 12 by a vertical virtual plate 2, the metering area 4, the photovoltaic switch area 6, the protection area 7, the incoming knife switch area 8, the photovoltaic communication equipment area 9 and the residual current action protector 10 are located in the front area 11, and the current mutual inductance area 5 is located in the rear area 12. The metering current mutual inductance area is designed behind the photovoltaic grid-connected cabinet to make the photovoltaic grid-connected more safe and reliable.

[0024] In one embodiment, the copper bar connected to the incoming switch area 8 has a central body located in the rear area 12 and two ends bent toward the front area 11. By improving the copper bar structure, the current mutual inductance area is installed in the rear area 12 to reduce interference with the power distribution part.

[0025] In one embodiment, an electric meter 401 and a junction box 402 are installed in the metering area 4 , the electric meter 401 and the junction box 402 are connected by wires, and the electric meter 401 is connected to the photovoltaic switch area 6 .

[0026] In one embodiment, an isolating switch 701, an anti-islanding protection device 702, a surge protector 703 and an anti-electromagnetic interference device 704 are provided in the protection zone 7, and the isolating switch 701, the anti-islanding protection device 702, the surge protector 703 and the anti-electromagnetic interference device 704 are connected in parallel. Multiple protection measures are used in combination to provide the safety and reliability of the photovoltaic grid-connected cabinet.

[0027] In one embodiment, the voltage line is connected to the copper busbar, and the current line is connected to the transformer in the current mutual inductance area 5 .

[0028] Example 1: Combination Figure 1-3It is understood that a photovoltaic grid-connected cabinet includes: a cabinet body 1, the cabinet body 1 is divided into multiple functional areas, and the adjacent functional areas are relatively independent of each other, and the functional areas include: a metering area 4, a current mutual induction area 5, a photovoltaic switch area 6, a protection area 7, an incoming knife switch area 8, a photovoltaic communication equipment area 9 and a residual current action protector 10; the metering area 4 and the photovoltaic communication equipment area 9 are located above the incoming knife switch area 8, the photovoltaic switch area 6, the protection area 7 and the residual current action protector 10 are located below the incoming knife switch area 8, the residual current action protector 10 is located above the protection area 7, and the current mutual induction area 5 is located behind the incoming knife switch area 8; the incoming knife switch area 8 is electrically connected to the residual current action protector 10 through a mutual induction copper bus 14, the residual current action protector 10 is circuit-connected to the photovoltaic switch area 6, the current mutual induction area 5 is sleeved outside the mutual induction copper bus 14, the current mutual induction area 5 is circuit-connected to the metering area 4, the metering area 4 is connected to the photovoltaic communication equipment area 9, and the metering area 4 and the photovoltaic communication equipment area 9 are respectively circuit-connected to the photovoltaic switch area 6 The photovoltaic communication equipment area 9 allows remote monitoring and management of the photovoltaic power generation system; one end of the protection area 7 is connected between the residual current action protector 10 and the photovoltaic switch area 6, and the other end is connected to the grounding device outside the cabinet 1 through a grounding wire; the cabinet 1 is divided into a front area 11 and a rear area 12 with the vertical virtual plate 2 as the boundary, the metering area 4, the photovoltaic switch area 6, the protection area 7, the incoming knife switch area 8, the photovoltaic communication equipment area 9 and the residual current action protector 10 are located in the front area 11, and the current mutual inductance area 5 is located in the rear area. Area 12, the vertical virtual plate 2 refers to the virtual plate extending to the top and bottom of the cabinet 1 above and below the isolation plate 13, respectively. The isolation plate 13 is a solid plate that isolates the current mutual inductance area 5 from the front area 11; the mutual inductance copper bar 14 connected to the incoming knife switch area 8, the middle body is located in the rear area 12, and the two ends are bent toward the front area 11. The voltage line is connected to the mutual inductance copper bar 14, and the current line is connected to the mutual inductance in the current mutual inductance area 5. The mutual inductance here is used to detect the current value in the power grid and provide necessary feedback for the photovoltaic power generation system. The location of the photovoltaic switch area 6 is the photovoltaic side, and the protection area 7 and the residual current action protector 10 are located in the photovoltaic switch area 6. The location of the grid side is the grid side. The grid side incoming line is connected from the incoming knife switch area 8, and the photovoltaic side outgoing line is connected from the photovoltaic switch area 6.

[0029] Embodiment 2: Based on the structure of embodiment 1, an electric meter 401 and a junction box 402 are installed in the metering area 4, and the electric meter 401 and the junction box 402 are connected by wires. The electric meter 401 is connected to the control terminal of the photovoltaic switch area 6 through a 485 communication line. The electric meter 401 measures the electric power injected into the power grid by the photovoltaic power generation system to achieve electric energy measurement. An isolating switch 701, an anti-islanding protection device 702, a surge protector 703 and an anti-electromagnetic interference device 704 are provided in the protection area 7, and the isolating switch 701, the anti-islanding protection device 702, the surge protector 703 and the anti-electromagnetic interference device 704 are connected in parallel.

[0030] Embodiment 3: Based on the structure of embodiment 1 or 2, combined with Figure 4 It is understood that the photovoltaic communication equipment area 9 includes a protocol converter 901 and an interface converter 902. The protocol converter 901 and the interface converter 902 are connected through a 485 communication line. The protocol converter 901 is connected to the photovoltaic switch area 6 through two 485 lines to obtain a 220V voltage. The interface converter 902 has a side hole reserved for connecting inverters, 4G sticks and other equipment. Among them, the inverter converts the direct current emitted by the photovoltaic panel into alternating current suitable for the alternating current grid; the 4G stick is a portable device that supports 4G network connection and is usually used to provide wireless communication functions. The interface converter 902 can convert different interface standards, and the protocol converter 901 converts different communication protocols to improve the compatibility of data transmission, so as to facilitate the realization of online power quality monitoring, load balancing and energy optimization.

[0031] Photovoltaic communication equipment area 9 adopts a flexible control method, the steps are as follows: S1. Data acquisition: Each data acquisition device is connected to the interface converter 902. The data acquisition device includes but is not limited to a current transformer, a light sensor and a temperature sensor. Among them, the current transformer is used to detect the current value in the power grid and provide necessary feedback for the photovoltaic power generation system; the light sensor is used to detect the light intensity; and the temperature sensor detects the temperature of the photovoltaic module. S2, the protocol converter 901 converts the collected data into a unified protocol format; S3. Combining real-time data and control objectives, formulate control strategies. For example, draw a reference curve based on the values ​​of the past 3 to 5 days, then find the corresponding current values ​​A and B on the reference curve based on the measured light and temperature values, and then combine the measured current value C. Take values ​​multiple times, such as once every 15 minutes, calculate the influencing factors and correct the reference curve to obtain a prediction curve. The prediction curve is used to predict the current values ​​for the next 3 to 7 days, with an allowable error of ±8%, to achieve prediction of power generation; S4. Based on the obtained current value prediction, the controller sends a signal, which is converted into a control instruction through the protocol converter 901, and then the power generation output of the photovoltaic system is adjusted through the interface converter 902.

[0032] By collecting environmental data such as light and temperature, and combining it with the current value in the power grid, the operating status of the photovoltaic system is monitored in real time, and the photovoltaic power generation is predicted; combined with the load conditions in each time period, the power supply balance can be further achieved, and the photovoltaic power generation access to the power grid is effectively used. The interface converter 902 can also be connected to the host computer system, and the power information is transmitted to the cloud for data analysis and comprehensive management through the photovoltaic grid cabinet network. In this way, the operating status of photovoltaic power generation can be monitored in real time and remotely controlled through the photovoltaic grid cabinet.

[0033] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A photovoltaic grid-connected cabinet, comprising: The cabinet (1) is characterized in that: The cabinet (1) is internally divided into a plurality of functional zones, and adjacent functional zones are relatively independent of each other. The functional zones include: a metering zone (4), a current mutual inductance zone (5), a photovoltaic switch zone (6), a protection zone (7), an incoming line switch zone (8), a photovoltaic communication equipment zone (9), and a residual current operated protector (10). The metering area (4) and the photovoltaic communication equipment area (9) are located above the incoming knife switch area (8), the photovoltaic switch area (6), the protection area (7) and the residual current operated protective device (10) are located below the incoming knife switch area (8), the residual current operated protective device (10) is located above the protection area (7), and the current mutual inductance area (5) is located behind the incoming knife switch area (8). The incoming switch area (8) is electrically connected to the residual current operated protector (10) through a copper busbar, the residual current operated protector (10) is connected to the photovoltaic switch area (6) by circuit, the current mutual inductance area (5) is sleeved outside the copper busbar, the current mutual inductance area (5) is connected to the metering area (4) by circuit, the metering area (4) is connected to the photovoltaic communication equipment area (9), the metering area (4) and the photovoltaic communication equipment area (9) are respectively connected to the photovoltaic switch area (6) by circuit, one end of the protection area (7) is connected between the residual current operated protector (10) and the photovoltaic switch area (6), and the other end is connected to the grounding device outside the cabinet (1) by a grounding wire.

2. The photovoltaic grid-connected cabinet according to claim 1, characterized in that: The photovoltaic communication equipment area (9) includes a protocol converter (901) and an interface converter (902), and the protocol converter (901) and the interface converter (902) are communicatively connected.

3. The photovoltaic grid-connected cabinet according to claim 2, characterized in that: The photovoltaic communication equipment area (9) adopts a flexible control method, the steps are as follows: S1. Each data acquisition device is connected to the interface converter (902), and the data acquisition device includes but is not limited to a current transformer, a light sensor and a temperature sensor; S2, the protocol converter (901) converts the collected data into a unified protocol format; S3. Combining the real-time data with the control target, a control strategy is formulated, and the control strategy is converted into a control command through the protocol converter (901), and then the power generation output of the photovoltaic system is adjusted through the interface converter (902).

4. The photovoltaic grid-connected cabinet according to claim 3, characterized in that: The control target in step S3 includes but is not limited to power generation prediction or power supply balance.

5. The photovoltaic grid-connected cabinet according to claim 1 or 2, characterized in that: The grid-side incoming line is connected from the incoming line switch area (8), and the photovoltaic-side outgoing line is connected from the photovoltaic switch area (6).

6. The photovoltaic grid-connected cabinet according to claim 5, characterized in that: The cabinet (1) is divided into a front area (11) and a rear area (12) by a vertical virtual plate (2); a metering area (4), a photovoltaic switch area (6), a protection area (7), an incoming line switch area (8), a photovoltaic communication equipment area (9) and a residual current action protector (10) are located in the front area (11), and a current mutual inductance area (5) is located in the rear area (12).

7. The photovoltaic grid-connected cabinet according to claim 6, characterized in that: The copper bar connected to the incoming knife switch area (8) has a middle body located in the rear side area (12) and two ends bent toward the front side area (11).

8. The photovoltaic grid-connected cabinet according to claim 1, characterized in that: An electric meter (401) and a junction box (402) are installed in the metering area (4), the electric meter (401) and the junction box (402) are connected by wires, and the electric meter (401) is connected to the photovoltaic switch area (6).

9. The photovoltaic grid-connected cabinet according to claim 1, characterized in that: An isolating switch (701), an anti-islanding protection device (702), a surge protector (703) and an anti-electromagnetic interference device (704) are provided in the protection zone (7); the isolating switch (701), the anti-islanding protection device (702), the surge protector (703) and the anti-electromagnetic interference device (704) are connected in parallel.

10. The photovoltaic grid-connected cabinet according to claim 1, characterized in that: The voltage line is connected to the copper busbar, and the current line is connected to the current transformer in the current mutual inductance area (5).

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