String inverter and integrated dc switch device for pv input side

Abstract

The application discloses a kind of group string photovoltaic inverter and PV input side DC switch integrated device thereof, it is related to group string photovoltaic inverter technical field, PV input side DC switch integrated device includes: PV input board, its one side is located on inverter box;DC air switch, it includes DC air switch operating mechanism, handle vertically arranged on DC air switch operating mechanism, multiple switch units stacked on the one side of DC air switch operating mechanism and air switch pin, the opposite sides of each switch unit are respectively provided with air switch pin;Lightning protection board, for preventing DC side surge caused by lightning stroke or power grid failure, DC air switch is clamped between the other side of PV input board and lightning protection board, and each air switch pin is connected with PV input board and lightning protection board respectively.The device not only helps to reduce the manufacturing cost of group string photovoltaic inverter and the labor intensity of operator, but also can improve the assembly efficiency of group string photovoltaic inverter.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of string PV inverter, more particularly, to a PV input side DC switch integrated device. BACKGROUND

[0002] In the prior art, the competition of string PV inverter is increasingly fierce, and the string PV inverter is constantly developed in the direction of reducing cost and improving power density. In order to match the power, the number of PV terminals connected to the input side of the string PV inverter is increasing. However, the current DC switch wire connection scheme is very complicated, which is not conducive to space compression, assembly, space control and cost control.

[0003] Taking 320kW commonly used in ground photovoltaic power station as an example, 72 cables are needed before and after the DC switch, and each end of the cable needs to be crimped with a terminal. Each end of the cable needs to be locked with one screw, and a total of about 144 screws need to be fixed. Moreover, the cable has a bending radius limit, which requires a large assembly space, which limits the volume compression of the string PV inverter. At the same time, each connection point of the string PV inverter needs to be manually confirmed and locked, which is easy to cause misoperation and cause assembly quality problems. That is, the existing string PV inverter has the problems of high cost, low assembly efficiency, time-consuming and laborious, etc.

[0004] In summary, how to provide a string PV inverter with low manufacturing cost, high assembly efficiency and low labor intensity of operators is a problem that needs to be solved by the technical personnel in the field at present. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a PV input side DC switch integrated device, which not only helps to reduce the manufacturing cost and labor intensity of operators of the string PV inverter, but also improves the assembly efficiency of the string PV inverter.

[0006] Another purpose of the present application is to provide a string PV inverter comprising the PV input side DC switch integrated device.

[0007] In order to achieve the above purpose, the present application provides the following technical solutions:

[0008] A PV input side DC switch integrated device, comprising:

[0009] A PV input board is arranged on one side of the inverter box;

[0010] The DC air switch comprises a DC air switch operating mechanism, a handle vertically arranged on the DC air switch operating mechanism, a plurality of switch units stacked on one side of the DC air switch operating mechanism, and air switch pins arranged on opposite sides of each switch unit.

[0011] The lightning protection plate is used to prevent DC side surge caused by lightning strike or power grid failure, the DC air switch is arranged between the other side of the PV input plate and the lightning protection plate, and each air switch pin is connected with the PV input plate and the lightning protection plate.

[0012] In an embodiment, the periphery of the PV input plate and the periphery of the lightning protection plate are connected by studs, and the DC air switch is arranged between the PV input plate and the lightning protection plate.

[0013] In an embodiment, the PV input plate and the lightning protection plate are both welded with the air switch pins.

[0014] Or one of the PV input plate and the lightning protection plate is welded with the air switch pins, and the other is fixed with the air switch pins by screws.

[0015] Or the PV input plate and the lightning protection plate are both fixed with the air switch pins by screws.

[0016] In an embodiment, the PV input plate is provided with a PV positive terminal, a PV negative terminal, a Y capacitor for DC side EMI improvement, and a branch Hall for current sampling, the PV positive terminal and the PV negative terminal are used to connect photovoltaic panels to form a complete circuit loop.

[0017] In an embodiment, the lightning protection plate is provided with a lightning protection device, an MPPT Hall, and a wiring terminal, the lightning protection device is used for lightning protection of the inverter, the MPPT Hall is used for sampling MPPT current, and the wiring terminal is used for conducting connection with MMPT power.

[0018] In an embodiment, the PV input plate and the lightning protection plate are both PCBA plates.

[0019] In an embodiment, the air switch pins are welded or fixed by screws on opposite sides of the switch unit.

[0020] In an embodiment, the PV input plate and the lightning protection plate are distributed in parallel.

[0021] A string type photovoltaic inverter comprises the PV input side DC switch integrated device of any one of the above.

[0022] In an embodiment, the PV input panel of the PV input side DC switch integrated device is arranged on an inverter box.

[0023] In use of the PV input side DC switch integrated device, first, a handle is arranged vertically on the DC air switch operating mechanism. Then, a plurality of switch units are arranged in a stacked manner on one side of the DC air switch operating mechanism. After that, the PV input panel, the DC air switch and the lightning protection panel are fixedly connected by the stud, so that the DC air switch is arranged between the PV input panel and the lightning protection panel. Subsequently, the air switch pins are arranged on opposite sides of each switch unit, and the air switch pins are connected to the corresponding PV input panel and lightning protection panel, so as to realize power transmission from the PV input panel to the lightning protection panel. Finally, the PV input panel is fixed on the inverter box, so as to complete the assembly of the PV input side DC switch integrated device and the inverter box.

[0024] The device can realize current conduction through the DC air switch only, i.e. the power is transmitted from the PV input panel to the DC air switch, and the power is transmitted from the DC air switch to the lightning protection panel, without the need of cables, which can effectively reduce the material (cable) cost, and effectively save the bending space of the cable layout, so as to make the device compact in structure and small in space occupation. Moreover, each air switch pin of the DC air switch needs to be fixed by a screw only, which can help to reduce the assembly time, and compared with the traditional scheme that the two ends of the cable need to be locked by screws, the number of screws can be saved by half, so as to effectively reduce the labor intensity of the operator, and reduce the material (screw) and labor cost.

[0025] In summary, the PV input side DC switch integrated device can help to reduce the production cost and labor intensity of the string type photovoltaic inverter, and improve the assembly efficiency of the string type photovoltaic inverter.

[0026] In addition, the application further provides a string type photovoltaic inverter comprising the PV input side DC switch integrated device. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without any creative labor.

[0028] Figure 1 Structure diagram of the PV input side DC switch integrated device installed on the inverter box;

[0029] Figure 2Structure diagram of the PV input plate and the lightning protection plate both being welded with the air switch pin;

[0030] Figure 3 is a top view of Figure 2 ;

[0031] Figure 4 is a side view of Figure 2 ;

[0032] Figure 5 Structure diagram of the PV input plate and the lightning protection plate both being fixed with the air switch pin through screws;

[0033] Figure 6 is a top view of Figure 5 ;

[0034] Figure 7 is a side view of Figure 5 .

[0035] Figures 1-7 In the drawings:

[0036] 100 is an inverter box, 200 is a PV input plate, 300 is a stud, 400 is a DC air switch, 410 is a handle, 420 is a switch unit, 430 is an air switch pin, 440 is a DC air switch operating mechanism, 500 is a lightning protection plate, and 600 is a screw. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0038] The core of the present application is to provide a PV input side DC switch integrated device which not only helps to reduce the manufacturing cost and the labor intensity of an operating personnel of a string type photovoltaic inverter, but also improves the assembly efficiency of the string type photovoltaic inverter. Another core of the present application is to provide a string type photovoltaic inverter comprising the above-mentioned PV input side DC switch integrated device.

[0039] As shown in Figure 1 , the present embodiment provides a PV input side DC switch integrated device, which comprises:

[0040] The PV input plate 200 is arranged on one side of the inverter box 100;

[0041] The DC air switch 400 comprises a DC air switch operating mechanism 440, a handle 410 vertically arranged on the DC air switch operating mechanism 440, a plurality of switch units 420 stacked on one side of the DC air switch operating mechanism 440, and air switch pins 430 arranged on opposite sides of each switch unit 420;

[0042] The lightning protection plate 500 is used to prevent DC side surges caused by lightning strikes or power grid failures. The DC air switch 400 is arranged between the other side of the PV input plate 200 and the lightning protection plate 500, and each air switch pin 430 is connected to the PV input plate 200 and the lightning protection plate 500.

[0043] It should be noted that the DC air switch 400 composed of the DC air switch operating mechanism 440, the handle 410, and the switch units 420 is a DC air switch, which is a switching device used to protect circuits. When overloads, short circuits, or other faults occur in the circuit, the DC air switch 400 can automatically cut off the circuit to prevent damage to electrical equipment and ensure personnel safety. Moreover, the PV input plate 200 can be connected to the DC input end of the photovoltaic string, the lightning protection plate 500 can be connected to the DC output end of the photovoltaic string, and power transmission from the PV input plate 200 to the lightning protection plate 500 can be achieved through the air switch pins 430 of the DC air switch 400.

[0044] In actual application, the shape, structure, size, material, type, etc. of the PV input plate 200, the DC air switch 400, and the lightning protection plate 500 can be determined according to actual conditions and actual needs.

[0045] When using the PV input side DC switch integrated device provided by the present application, first, the handle 410 can be vertically arranged on the DC air switch operating mechanism 440. Then, a plurality of switch units 420 are arranged on one side of the DC air switch operating mechanism 440. After that, the PV input plate 200, the DC air switch 400, and the lightning protection plate 500 can be fixedly connected through studs, so that the DC air switch 400 is arranged between the PV input plate 200 and the lightning protection plate 500. Subsequently, the air switch pins 430 can be arranged on opposite sides of each switch unit 420, and each air switch pin 430 can be connected to the corresponding PV input plate 200 and lightning protection plate 500 to achieve power transmission from the PV input plate 200 to the lightning protection plate 500. Finally, the PV input plate 200 is fixed on the inverter box 100 to complete the assembly operation of the PV input side DC switch integrated device and the inverter box 100.

[0046] The device can realize the conduction of current only through the DC air switch 400, that is, the power is conducted from the PV input plate 200 to the DC air switch 400, and the power is conducted from the DC air switch 400 to the lightning protection plate 500, and the process does not need to pass through the cable, which not only can effectively reduce the material (cable) cost, but also can effectively save the bending space of the cable wiring, so that the device structure is compact and occupies small space. Moreover, each air switch pin 430 of the DC air switch 400 needs to be fixed by a screw at most, which helps to reduce the assembly time, and compared with the traditional scheme that the cable needs to be locked by a screw at both ends, the number of screws can be saved by half, the labor intensity of the operator is effectively reduced, and the material (screw) and labor cost are reduced.

[0047] In summary, the PV input side DC switch integrated device provided by the application not only helps to reduce the manufacturing cost and labor intensity of the string type photovoltaic inverter, but also improves the assembly efficiency of the string type photovoltaic inverter.

[0048] In one embodiment, as shown in Figures 1 to 7 The four sides of the PV input plate 200 and the four sides of the lightning protection plate 500 are connected by the stud 300, and the DC air switch 400 is arranged between the PV input plate 200 and the lightning protection plate 500.

[0049] In one embodiment, the PV input plate 200 and the lightning protection plate 500 are welded with the air switch pin 430, that is, the air switch pin welding hole can be arranged on the PV input plate 200 and the lightning protection plate 500, so as to fix the air switch pin 430 of the DC air switch 400 by welding;

[0050] or one of the PV input plate 200 and the lightning protection plate 500 is welded with the air switch pin 430, and the other is fixed with the air switch pin 430 by the screw 600, so as to fix the air switch pin 430 of the DC air switch 400 by the fixed and welded mode of the screw 600;

[0051] or the PV input plate 200 and the lightning protection plate 500 are fixed with the air switch pin 430 by the screw 600, that is, the air switch pin fixing hole can be arranged on the PV input plate 200 and the lightning protection plate 500, so as to fix the air switch pin 430 of the DC air switch 400 by the screw 600 passing through the air switch pin fixing hole.

[0052] In one embodiment, the PV input plate 200 is provided with a PV positive terminal, a PV negative terminal, a Y capacitor for improving the DC side EMI (Electro Magnetic Interference, electromagnetic interference), and a branch Hall for current sampling, and the PV positive terminal and the PV negative terminal are used to connect the photovoltaic plate to form a complete circuit loop.

[0053] It should be noted that the PV positive terminal is a connection point for outputting the positive pole of direct current, the PV negative terminal is a connection point for outputting the negative pole of direct current, and the PV positive terminal and the PV negative terminal together constitute a complete circuit loop, so that the electric energy can be normally transmitted. The Y capacitor is used to improve the electromagnetic interference on the direct current side, wherein the electromagnetic interference refers to the phenomenon that electromagnetic waves generated by the internal circuit or component of an electronic device during operation are radiated to the surrounding environment, or the electromagnetic interference is propagated through conductors such as power lines or signal lines to affect the normal operation of other devices. The branch Hall is a sensor based on the Hall effect, and its working principle is that when current passes through a conductor located in a magnetic field, the magnetic field will generate a force on the electrons in the conductor perpendicular to the direction of motion of the electrons, thereby generating a potential difference at both ends of the conductor, that is, the branch Hall can sample the current.

[0054] In an embodiment, the lightning protection plate 500 is provided with a lightning protection device (with a protection function), an MPPT (Maximum Power Point Tracking) Hall and a wiring terminal. The lightning protection device is used for lightning protection of the inverter, the MPPT Hall is used for sampling the MPPT current, and the wiring terminal is used for conducting connection with the MMPT power.

[0055] It should be noted that MPPT is a power regulation technology, and its main purpose is to maximize the output power of a power generation device and deliver these powers to the power grid or battery storage system. The MPPT Hall generally refers to a Hall current sensor used in the MPPT system. The Hall current sensor is a sensor based on the Hall effect, and its working principle is that when current passes through a conductor located in a magnetic field, the magnetic field will generate a force on the electrons in the conductor perpendicular to the direction of motion of the electrons, thereby generating a potential difference at both ends of the conductor.

[0056] In an embodiment, the PV input plate 200 and the lightning protection plate 500 are both PCBA plates. That is, the PV input plate 200 and the lightning protection plate 500 refer to the PCBA plates before and after the direct current switch, and do not limit the specific types of the PV input plate 200 and the lightning protection plate 500.

[0057] In an embodiment, the air switch pin 430 is welded or fixed by the screw 600 on the opposite sides of the switch unit 420. That is, the air switch pin 430 can be fixed on the opposite sides of the switch unit 420 by using the welding scheme and the screw 600 fixing scheme.

[0058] In an embodiment, as shown in FIG. 6, the air switch pin 430 is welded on the opposite sides of the switch unit 420. Figure 1As shown, the PV input plate 200 and the lightning protection plate 500 are distributed in parallel. Therefore, the positions of the air break lead pins 430 on the upper and lower sides of each switch unit 420 directly reach the PV input plate 200 and the lightning protection plate 500, having a fool-proof effect and controllable quality. Moreover, compared with the traditional scheme, the parallel distribution of the PV input plate 200 and the lightning protection plate 500 in the present application can make the device structure more compact and the required occupied space more saved.

[0059] In order to further illustrate the assembling method of the PV input side DC switch integrated device provided by the present application, the assembling method is described as follows.

[0060] First, the PV input plate 200, the DC air break 400 and the lightning protection plate 500 are fixed together through the stud 300 (single-pass hexagonal stud), and then the air break lead pin 430 is fixed through welding or through the screw 600, so as to realize the power transmission from the PV input plate 200 to the lightning protection plate 500. Compared with the traditional scheme, the power is conducted from the PV input plate 200 to the DC air break 400, and then from the DC air break 400 to the lightning protection plate 500, and the conducting process does not require a cable.

[0061] That is, the device can realize power conduction without cable connection, saves the bending space of cable wiring, makes the device structure more compact and occupies less space. Moreover, each air break lead pin 430 of the device only needs to be fixed once by a screw, compared with the traditional scheme that the two ends of the cable need to be locked by a screw, saving half the number of screws 600. Moreover, the traditional scheme has many cables with similar sizes and relatively unstable positions, and workers need to distinguish them one by one through labels, which is time-consuming and laborious, and does not have a fool-proof function. However, each air break lead pin 430 of the present application directly connects the PV input plate 200 and the lightning protection plate 500, has a fool-proof function and controllable quality.

[0062] In addition to the above-mentioned PV input side DC switch integrated device, the present application also provides a string-type photovoltaic inverter comprising the PV input side DC switch integrated device disclosed in the above-mentioned embodiments. The string-type photovoltaic inverter is one of the core devices of a photovoltaic power generation system, mainly used for converting the direct current generated by a photovoltaic module into alternating current and realizing grid-connected or off-grid power supply. The structures of other parts of the string-type photovoltaic inverter can refer to the prior art, and will not be described herein.

[0063] In an embodiment, the inverter box 100 is further included, and the PV input plate 200 of the PV input side DC switch integrated device is arranged on the inverter box 100.

[0064] In addition, it should be noted that the "vertical" and other indications of orientation or position relationship in the present application are based on the orientation or position relationship shown in the drawings, and are only for the convenience of simplifying the description and facilitating understanding, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0065] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other. Any combination of all the embodiments provided by the present application is within the protection scope of the present application, and is not described here.

[0066] The string-type photovoltaic inverter and the PV input side DC switch integrated device thereof provided by the present application are described in detail above. The principles and implementation manners of the present application are described by applying specific examples in this paper. The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. A PV input side DC switch integrated device, characterized by, The application relates to a PV input plate (200) arranged on one side of an inverter box (100), a DC air switch (400) comprising a DC air switch operating mechanism (440), a handle (410) vertically arranged on the DC air switch operating mechanism (440), a plurality of switch units (420) stacked on one side of the DC air switch operating mechanism (440), and air switch pins (430) arranged on opposite sides of each switch unit (420), a lightning protection plate (500) for preventing DC side surges caused by lightning strikes or power grid failures, the DC air switch (400) being arranged between the other side of the PV input plate (200) and the lightning protection plate (500), and each air switch pin (430) being connected with the PV input plate (200) and the lightning protection plate (500), the periphery of the PV input plate (200) being connected with the periphery of the lightning protection plate (500) through studs (300), and the DC air switch (400) being arranged between the PV input plate (200) and the lightning protection plate (500), the lightning protection plate (500) being provided with a lightning protection device, an MPPT hall and a wiring terminal, the lightning protection device being used for lightning protection of the inverter, the MPPT hall being used for sampling of MPPT current, and the wiring terminal being used for conduction connection with MMPT power, the PV input plate (200) and the lightning protection plate (500) being parallelly distributed, the positions of the air switch pins (430) on the upper and lower sides of each switch unit (420) being directly to the PV input plate (200) and the lightning protection plate (500), and having a fool-proof effect. The PV input plate (200) and the lightning protection plate (500) are welded with the air switch pins (430); or one of the PV input plate (200) and the lightning protection plate (500) is welded with the air switch pins (430), and the other is fixedly connected with the air switch pins (430) through screws (600); or the PV input plate (200) and the lightning protection plate (500) are fixedly connected with the air switch pins (430) through screws (600).

2. The PV input-side DC switching integrated device according to claim 1, characterized by, The PV input plate (200) is provided with a PV positive terminal, a PV negative terminal, a Y capacitor for DC side EMI improvement and a branch hall for current sampling, the PV positive terminal and the PV negative terminal being used for connection with photovoltaic plates to form a complete circuit loop. The PV input plate (200) and the lightning protection plate (500) are PCBA plates. The air switch pins (430) are welded or fixed on the opposite sides of the switch units (420) through the screws (600).

3. The PV input-side DC switching integrated device according to claim 1, characterized by, The application further relates to the PV input side DC switch integrated device.

4. The PV input-side DC switching integrated device according to any one of claims 1 to 3, characterized by The application further relates to an inverter box (100), and the PV input plate (200) of the PV input side DC switch integrated device is arranged on the inverter box (100).

5. The PV input-side DC switching integrated device according to any one of claims 1 to 3, characterized by ​ 6. A string inverter, comprising: ​ 7. The string inverter of claim 6, wherein, ​

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