Direct current transfer box and photovoltaic power generation system

Abstract

The utility model discloses a DC transfer box and a photovoltaic power generation system, and relates to the field of power generation, a plurality of circuit breakers, a plurality of fuses and a box body are arranged in the DC transfer box, the circuit breakers and the fuses are arranged in the box body, the fuses are connected with the corresponding circuit breakers in series, and the fuses are connected with the box body in series. The common input end is connected with the output end of the corresponding photovoltaic module, and the common output end is connected with the input end of the inverter, so that when the photovoltaic module branch circuit has an arc discharge phenomenon, the corresponding circuit breaker and fuse can be disconnected, and the connection between the photovoltaic module branch circuit with a fault and the inverter can be timely disconnected, thereby avoiding the fire hazard, and improving the safety of the scheme.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of power generation, especially a direct current transfer box and photovoltaic power generation system. BACKGROUND

[0002] In order to reach the purpose of carbon standard, the state supports photovoltaic power generation, and various photovoltaic power stations are more and more, and the safety problem is paid more and more attention. For the roof photovoltaic power station, the occurrence of the inverter fire event in the photovoltaic power station is the more serious safety accident at present. Because the inverter is connected with multiple photovoltaic module branches through the assembly connection line and constitutes the photovoltaic direct current line, once the individual photovoltaic module branch fails, it will lead to the arc phenomenon of the whole photovoltaic direct current line, and if it is not handled in time, it will lead to the burning of the whole photovoltaic direct current line and the surrounding equipment. Because some inverters on the market do not have the function of string off, that is, when the photovoltaic module branch of the photovoltaic direct current line fails, the inverter cannot be automatically disconnected, thereby causing a fire. CONTENT OF THE UTILITY MODEL

[0003] The utility model discloses a direct current transfer box and photovoltaic power generation system, when the photovoltaic module branch appears the arc phenomenon, the circuit breaker and the fuse arranged between the output end of the photovoltaic module branch and the input end of the inverter will be disconnected, and the connection of the fault photovoltaic module branch and the inverter is disconnected in time, the fire situation is avoided, and the safety of the scheme is improved.

[0004] In order to solve the above technical problems, the utility model provides a direct current transfer box, which comprises: N circuit breakers, N fuses, a box body, each circuit breaker and each fuse are arranged in the box body,

[0005] The first end of each fuse is connected with the positive output end of N photovoltaic module branches one by one, and is used for disconnecting when the corresponding photovoltaic module branch appears overvoltage or overcurrent condition;

[0006] The first end of each circuit breaker is connected with the second end of each fuse one by one, and the second end is connected with the positive input end of the inverter, and is used for disconnecting when the corresponding fuse is disconnected;

[0007] The negative input end of the inverter is connected with the negative output end of each photovoltaic module branch.

[0008] Optionally, it further comprises:

[0009] The input end of the positive copper bar is connected with the second end of each circuit breaker, and the output end is connected with the positive input end of the inverter;

[0010] A negative copper bar, input ends of the negative copper bar are connected with negative output ends of the photovoltaic module branches respectively, and output ends are connected with negative input ends of the inverter.

[0011] Optionally, the application further comprises:

[0012] N voltage sensors, each of the voltage sensors is connected with a positive output end of each of the photovoltaic module branches correspondingly, and is used for collecting a voltage value of each of the photovoltaic module branches.

[0013] Optionally, the application further comprises:

[0014] N first display devices, each of the first display devices is connected with each of the voltage sensors correspondingly, and is used for displaying the voltage value of the corresponding photovoltaic module branch.

[0015] Optionally, the application further comprises:

[0016] N current sensors, each of the current sensors is connected with a positive output end of each of the photovoltaic module branches correspondingly, and is used for collecting a current value of each of the photovoltaic module branches.

[0017] Optionally, the application further comprises:

[0018] N second display devices, each of the second display devices is connected with each of the current sensors correspondingly, and is used for displaying the current value of the corresponding photovoltaic module branch.

[0019] Optionally, the application further comprises N switches and N alarm devices.

[0020] A first end of a coil of each of the switches is connected with a second end of each of the fuses correspondingly, a second end of the coil is connected with a first end of each of the circuit breakers correspondingly, a static contact is connected with a direct current power supply, a movable contact is connected with a power supply end of each of the alarm devices correspondingly, and is used for controlling the movable contact and the static contact to be closed when the corresponding fuse and / or circuit breaker is disconnected.

[0021] Each of the alarm devices is used for giving corresponding alarm when the corresponding movable contact and the static contact are closed.

[0022] Optionally, the alarm device is a sound alarm device and / or a display alarm device, the power supply end of the sound alarm device and / or the display alarm device is connected with the movable contact of the corresponding switch, and is used for giving corresponding sound alarm and / or display alarm when the movable contact and the static contact of the corresponding switch are closed.

[0023] Optionally, the application further comprises:

[0024] N one-way conducting devices, the input end of each one-way conducting device is connected with the second end of each circuit breaker in one-to-one correspondence, and the output end is connected with the positive input end of the inverter.

[0025] To solve the above technical problems, the utility model also provides a kind of photovoltaic power generation system, comprising: the direct current adapter box, inverter and N photovoltaic assembly branch as described above, the input end of the direct current adapter box is connected with the positive output end of each photovoltaic assembly branch, the output end of the direct current adapter box is connected with the positive input end of the inverter, and the negative input end of the inverter is connected with the negative output end of each photovoltaic assembly branch.

[0026] The utility model discloses a kind of direct current adapter box and photovoltaic power generation system, several circuit breakers are provided in direct current adapter box, several fuses, box, each circuit breaker and each fuse are arranged in box, fuse and corresponding circuit breaker are mutually connected in series, and common input end is connected with corresponding photovoltaic assembly output end, common output end is connected with the input end of inverter, when photovoltaic assembly branch appears arc phenomenon, corresponding circuit breaker and fuse will be disconnected, to disconnect the connection of fault photovoltaic assembly branch and inverter in time, avoid causing fire situation, improve the security of scheme. BRIEF DESCRIPTION OF DRAWINGS

[0027] To more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be simply introduced below, and obviously, the drawings in the following description are only the embodiment of the utility model, and for ordinary skilled person in the art, other drawings can be obtained according to the provided drawings without creating labor.

[0028] Figure 1 The structure diagram of the direct current adapter box provided by the utility model is shown;

[0029] Figure 2 The structure diagram of the photovoltaic power generation system provided by the utility model is shown;

[0030] Figure 3 The electrical connection diagram of the fuse and circuit breaker provided by the utility model is shown;

[0031] Figure 4 The box structure diagram of the direct current adapter box provided by the utility model is shown;

[0032] Figure 5 The structure diagram of another photovoltaic power generation system provided by the utility model is shown. DETAILED DESCRIPTION

[0033] The utility model discloses a core provides a kind of direct current switch cabinet and photovoltaic power generation system, when the arc phenomenon appears in photovoltaic module branch, the circuit breaker and fuse arranged between the output end of photovoltaic module branch and the input end of inverter are disconnected, in time disconnect the connection of fault photovoltaic module branch and inverter, avoid causing fire condition, improve the security of scheme.

[0034] To make the purpose, technical scheme and advantages of the utility model embodiment clearer, the technical scheme in the utility model embodiment will be clearly and completely described below in conjunction with the drawings in the utility model embodiment. Obviously, the described embodiments are part of the embodiments of the utility model, not all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0035] Please refer to Figure 1 , Figure 1 The utility model provides a kind of direct current switch cabinet structural schematic diagram. The direct current switch cabinet includes: N circuit breaker 1, N fuse 2, box 3, each circuit breaker 1 and each fuse 2 are set in box 3.

[0036] The first end of each fuse 2 is connected with the positive output end of N photovoltaic module branches one by one, for disconnecting when the corresponding photovoltaic module branch appears overvoltage or overcurrent condition;

[0037] The first end of each circuit breaker 1 is connected with the second end of each fuse 2 one by one, and the second end is connected with the positive input end of inverter, for disconnecting when the corresponding fuse 2 is disconnected;

[0038] The negative input end of inverter is connected with the negative output end of each photovoltaic module branch.

[0039] In the utility model, considering that photovoltaic module branch in photovoltaic power station can occur fault, and lead to arc phenomenon, serious fire can occur, so as to be able to disconnect photovoltaic module branch in time fault, the scheme not only increases fuse 2 and is set between each photovoltaic module branch and inverter connection line, to ensure the reliability of disconnecting, additionally set circuit breaker 1, when any photovoltaic module branch appears overvoltage or overcurrent fault, the fuse 2 of photovoltaic module branch corresponding will disconnect, at this moment, circuit breaker 1 will also disconnect, at this moment, fault photovoltaic module branch cannot be connected with inverter, so arc phenomenon will not appear, ensure the security of scheme.

[0040] It should be noted that some inverters on the market do not have the function of string shutdown, that is, when the branch of the direct current line fails, the inverter cannot automatically disconnect, thereby causing a fire. The positive output end of the photovoltaic module branch is connected with the input end of the fuse 2, the output end of the fuse 2 is connected with the circuit breaker 1, the circuit breaker 1 is electrically connected with the inverter, and the negative pole of the photovoltaic module branch is directly connected with the inverter. When the photovoltaic module line fails, the direct current transfer box will automatically trip, so that the positive and negative poles of the photovoltaic module branch cannot form a loop, there is no current, and a fire will not occur. The direct current transfer box protects each photovoltaic module branch connected by the direct current transfer box through the fuse 2 and the circuit breaker 1. When arc occurs in a photovoltaic module branch, the corresponding circuit breaker 1 and fuse 2 will automatically disconnect, so as to timely disconnect the connection between the faulty photovoltaic module branch and the inverter, avoid causing a fire, and improve the safety of the scheme.

[0041] It should also be noted that the connection relationship between each circuit breaker 1 and each fuse 2 in the direct current transfer box and the inverter and each photovoltaic module branch is as shown in Figure 2 , wherein PV+ is the positive output end of the photovoltaic module branch, and PV- is the negative output end of the photovoltaic module branch. The positive input end of the direct current transfer box is connected with PV+, the negative input end of the direct current transfer box is connected with PV-, one end of the fuse 2 is connected with the positive input end of the direct current transfer box, the other end of the fuse 2 is connected with the circuit breaker 1, and the circuit breaker 1 is connected with the positive output end of the direct current transfer box. The positive output end of the direct current transfer box is connected with the positive input end of the inverter, the negative input end of the direct current transfer box is connected with the negative output end of the direct current transfer box, and the negative output end of the direct current transfer box is connected with the negative input end of the inverter. Specifically, the electrical wiring diagram inside the direct current transfer box is as shown in Figure 3 , wherein PV1+ to PV24+ are the positive output ends of the photovoltaic module branches respectively. The structure of the box body 3 of the direct current transfer box is as shown in Figure 4 , and the structure of the photovoltaic power generation system is as shown in Figure 5 .

[0042] The embodiment provides a direct current transfer box, the direct current transfer box is provided with N circuit breakers 1, N fuses 2 and a box body 3. Each circuit breaker 1 and each fuse 2 are arranged in the box body 3. The fuse 2 and the corresponding circuit breaker 1 are connected in series, the common input end is connected with the corresponding photovoltaic module output end, and the common output end is connected with the input end of the inverter. When arc occurs in any photovoltaic module branch, the corresponding circuit breaker 1 and fuse 2 will be disconnected, so as to timely disconnect the connection between the faulty photovoltaic module branch and the inverter, avoid causing a fire, and improve the safety of the scheme.

[0043] On the basis of the above embodiments:

[0044] As an optional embodiment, further comprising:

[0045] The positive copper bar has an input end connected with the second end of each circuit breaker 1 and an output end connected with the positive input end of the inverter.

[0046] The negative copper bar has an input end connected with the negative output end of each photovoltaic module branch and an output end connected with the negative input end of the inverter.

[0047] In the utility model, considering that when any photovoltaic module branch appears overvoltage or overcurrent fault, arc phenomenon will be caused soon, so as to make the fuse 2 and the circuit breaker 1 find the fault condition of the corresponding photovoltaic module branch faster and disconnect in time, the positive copper bar and the negative copper bar are additionally arranged, the power transmission efficiency of the photovoltaic module branch to the inverter is improved through the positive copper bar and the negative copper bar, so that the fuse 2 and the circuit breaker 1 can find the fault condition of the corresponding photovoltaic module branch faster and disconnect the electrical connection between the fault photovoltaic module branch and the inverter in time, and the safety and reliability of the scheme are improved.

[0048] As an optional embodiment, further comprising:

[0049] The N voltage sensors are connected with the positive output end of each photovoltaic module branch one by one and are used for collecting the voltage value of each photovoltaic module branch.

[0050] In the utility model, considering that in actual application, the fuse 2 has a fusing interval, that is, when the voltage value transmitted by the photovoltaic module branch needs to reach a certain interval, the fuse 2 will be normally disconnected, but if the minimum value of the fusing interval needs to be small enough to ensure that arc phenomenon does not occur, it is necessary to put forward higher requirements for the material selection of the fuse 2, so as to improve practicability, the voltage sensor is additionally arranged at the positive output end of each photovoltaic module branch, the voltage value of the photovoltaic module branch is monitored in real time through the voltage sensor, so as to control the circuit breaker 1 to be turned off in advance and avoid the occurrence of arc phenomenon.

[0051] As an optional embodiment, further comprising:

[0052] The N first display devices are connected with the voltage sensors one by one and are used for displaying the voltage value of the corresponding photovoltaic module branch.

[0053] The utility model discloses, in order to let user or maintenance personnel timely observe each photovoltaic assembly branch's voltage change situation, and then timely control circuit breaker 1 disconnect, so this scheme increases and set uped first display device, each display device is used to show the voltage value of corresponding photovoltaic assembly branch, so that the observation of user and maintenance personnel, improved the practicability of scheme.

[0054] As an optional embodiment, further comprising:

[0055] N current sensors, each current sensor is connected with the positive output end of each photovoltaic assembly branch one by one, for collecting the current value of each photovoltaic assembly branch.

[0056] In the utility model, considering in actual application, because there is the fusing interval of fuse 2, namely when the current value of photovoltaic assembly branch transmission needs to reach certain interval, fuse 2 will normally disconnect, but if in order to guarantee that arc phenomenon does not occur, need to guarantee that the minimum value of this fusing interval is small enough, this needs to put forward higher demand to the material selection of fuse 2, so as to improve practicability, this scheme increases and sets uped current sensor at the positive output end of each photovoltaic assembly branch, and the current value of photovoltaic assembly branch is monitored in real time through current sensor, so as to control circuit breaker 1 off in advance, and arc phenomenon is avoided.

[0057] As an optional embodiment, further comprising:

[0058] N second display devices, each second display device is connected with each current sensor one by one, for showing the current value of corresponding photovoltaic assembly branch.

[0059] In the utility model, in order to let user or maintenance personnel timely observe each photovoltaic assembly branch's current change situation, and then timely control circuit breaker 1 disconnect, so this scheme increases and set uped second display device, each display device is used to show the current value of corresponding photovoltaic assembly branch, so that the observation of user and maintenance personnel, improved the practicability of scheme.

[0060] As an optional embodiment, further comprising: N switches and N alarm devices;

[0061] The first end of the coil of each switch is connected with the second end of each fuse 2 one by one, the second end of the coil is connected with the first end of each circuit breaker 1 one by one, the static contact is connected with the direct current power supply, the moving contact is connected with the power supply end of each alarm device one by one, for controlling the moving contact and static contact to close when corresponding fuse 2 and / or circuit breaker 1 disconnect;

[0062] Each alarm device is used to issue corresponding alarm when corresponding moving contact and static contact close.

[0063] The utility model discloses, in order to let user or maintenance personnel timely observe each photovoltaic assembly branch's fault condition, and then timely control circuit breaker 1 disconnect, so this scheme increases and sets up N switches and N alarm devices, and the coil of each switch is connected with corresponding photovoltaic assembly branch and inverter, and the static contact and the movable contact of switch are connected direct current power supply and corresponding alarm device respectively, when corresponding photovoltaic assembly branch appears the fault, the coil of corresponding switch loses electricity, at this moment, the movable contact of switch and static contact close, and alarm device gets electricity and sends corresponding alarm, can timely inform user corresponding photovoltaic assembly branch failure, improved the security of scheme.

[0064] As an optional embodiment, the alarm device is a sound alarm device and / or a display alarm device, and a power supply end of the sound alarm device and / or the display alarm device is connected with the movable contact of the corresponding switch, for sending corresponding sound alarm and / or display alarm when the movable contact and the static contact of the corresponding switch are closed.

[0065] In the utility model, the alarm device can be a sound alarm device, a display alarm device, or both, so that users can choose different alarm devices according to actual conditions, improving the practicability of the scheme.

[0066] As an optional embodiment, the utility model further comprises:

[0067] The N one-way conduction devices are connected with the second ends of the N circuit breakers 1 one by one at the input ends, and connected with the positive input end of the inverter at the output ends.

[0068] In the utility model, the structure of the circuit breaker 1 is composed of a coil and a contact, one end of the coil is connected with the fuse 2, and the other end is connected with the inverter. When the corresponding connected photovoltaic assembly branch fails, the fuse 2 is disconnected at this time. In order to ensure that the circuit breaker 1 is also disconnected, the coil of the circuit breaker 1 needs to be stably powered off. Because the inverter may have a current backflow situation, in order to ensure that the current of the inverter does not flow back into the coil of the circuit breaker 1, causing the coil of the circuit breaker 1 to lose power, the utility model increases and sets up a one-way conduction device between the coil of the circuit breaker 1 and the inverter, that is, a corresponding one-way conduction device is set between the second end of the circuit breaker 1 and the inverter. The one-way conduction device ensures that the current of the inverter does not flow back into the coil of the circuit breaker 1, ensuring that the circuit breaker 1 can be disconnected in time when the photovoltaic assembly branch fails, improving the safety and reliability of the scheme.

[0069] It should be noted that in actual application, the circuit breaker 1 is generally composed of a coil, a movable contact and a fixed contact, wherein the coil is connected with the second end of the corresponding fuse 2 and the positive input end of the inverter respectively, the movable contact is connected with the second end of the fuse 2 or the positive input end of the inverter, and the fixed contact is connected with the positive input end of the inverter or the second end of the fuse 2; and the unidirectional conduction device can be a diode or other unidirectional conduction device, which is not particularly limited in the present application.

[0070] The utility model also provides a kind of photovoltaic power generation system corresponding embodiment, comprising: the direct current adapter box, inverter and N photovoltaic assembly branch as described above, the input end of direct current adapter box is connected with the positive output end of each photovoltaic assembly branch, the output end of direct current adapter box is connected with the positive input end of inverter, and the negative input end of inverter is connected with the negative output end of each photovoltaic assembly branch.

[0071] The photovoltaic power generation system provided in the embodiment corresponds to the above-mentioned direct current adapter box, and therefore has the same beneficial effects as the above-mentioned direct current adapter box.

[0072] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0073] The above detailed description of the technical solutions provided by the present application, the principle and implementation mode of the present application are described in this paper, the above example is only used to help understand the method and core idea of the present application; At the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed, and the above description should not be understood as the limitation of the present application.

Claims

1. A DC transfer box, characterized in that include: N circuit breakers, N fuses, and an enclosure, wherein each circuit breaker and each fuse is housed within the enclosure; The first end of each fuse is connected to the positive output end of N photovoltaic module branches in a one-to-one correspondence, and is used to disconnect when the corresponding photovoltaic module branch experiences overvoltage or overcurrent. The first terminal of each circuit breaker is connected to the second terminal of each fuse in a one-to-one correspondence. The second terminal of each circuit breaker is connected to the positive input terminal of the inverter, and is used to disconnect when the corresponding fuse is opened. The negative input terminal of the inverter is connected to the negative output terminal of each photovoltaic module branch.

2. The DC transfer box of claim 1, wherein Also includes: The positive copper busbar has its input terminal connected to the second terminal of each circuit breaker and its output terminal connected to the positive input terminal of the inverter. The negative electrode copper busbar has its input terminal connected to the negative output terminal of each photovoltaic module branch, and its output terminal connected to the negative input terminal of the inverter.

3. The DC transfer box of claim 1, wherein, Also includes: N voltage sensors are connected one-to-one with the positive output terminal of each photovoltaic module branch to collect the voltage value of each photovoltaic module branch.

4. The DC transfer box of claim 3, wherein Also includes: N first display devices, each of which is connected to a voltage sensor in a one-to-one correspondence, are used to display the voltage value of the corresponding photovoltaic module branch.

5. The DC transfer box of claim 1, wherein, Also includes: N current sensors are connected one-to-one with the positive output terminal of each photovoltaic module branch to collect the current value of each photovoltaic module branch.

6. The DC transfer box of claim 5, wherein, Also includes: N second display devices are connected one-to-one with each of the current sensors to display the current value of the corresponding photovoltaic module branch.

7. The DC transfer box of claim 1, wherein, It also includes: N switches and N alarm devices; The first end of the coil of each switch is connected to the second end of each fuse, and the second end of the coil is connected to the first end of each circuit breaker. The stationary contact is connected to a DC power supply, and the moving contact is connected to the power supply terminal of each alarm device. This is used to control the moving contact and the stationary contact to close when the corresponding fuse and / or circuit breaker is open. Each of the alarm devices is used to issue a corresponding alarm when the corresponding moving contact and the corresponding stationary contact are closed.

8. The DC transfer box of claim 7, wherein, The alarm device is an audible alarm device and / or a display alarm device. The power supply terminal of the audible alarm device and / or the display alarm device is connected to the moving contact of the corresponding switch, and is used to issue a corresponding audible alarm and / or display alarm when the moving contact and the stationary contact of the corresponding switch are closed.

9. The DC transfer box of any of claims 1 to 8, characterized in that Also includes: There are N unidirectional conducting devices, the input terminal of each unidirectional conducting device is connected to the second terminal of each circuit breaker in a one-to-one correspondence, and the output terminal of each device is connected to the positive input terminal of the inverter.

10. A photovoltaic power system, characterized by, include: As described in any one of claims 1 to 9, the DC adapter box, inverter, and N photovoltaic module branches are all connected to the positive output terminal of each of the photovoltaic module branches, the output terminal of the DC adapter box is connected to the positive input terminal of the inverter, and the negative input terminal of the inverter is connected to the negative output terminal of each of the photovoltaic module branches.

Images