Direct current side wiring scheme of photovoltaic system

Through the introduction of DC -side switch components in the DC side of the photovoltaic system, the interruption control of solar cells and DC/DC converters is realized, and the problem of inconvenience and current impact and anti -irrigation in existing technologies has been solved. And security.

CN222423248UActive Publication Date: 2025-01-28JIANGSU GUANGHENG NEW ENERGY CO LTD
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Patent Information

Application Number
CN202323412220.9
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2023-12-14
Publication Date
2025-01-28
Estimated Expiration
2033-12-14

AI Technical Summary

Technical Problem

The DC-side wiring scheme of the existing photovoltaic system cannot cut off the connection between the solar cell and the DC/DC converter in the event of a failure, resulting in inconvenient maintenance and prone to current shock and backsinking problems, which damages the capacitor and solar cells.

Method used

Using DC -side switch components, the positive and negative electrodes of solar cells and DC/DC converters are connected through the first and second DC -side switch components to achieve the disassembly control of the DC side. Irrigation.

Benefits of technology

Realize the connection between the solar cell and the DC/DC converter when faulting, facilitate maintenance and replacement, prevent current impact and anti -irrigation, and extend the life of capacitors and solar cells.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model provides a photovoltaic system direct current side wiring scheme, which comprises a solar cell, a direct current side switch assembly and a DC / DC converter which are sequentially cascaded, the direct current side switch assembly comprises a first direct current side switch assembly, and the first direct current side switch assembly is electrically connected between the positive electrode of the solar cell and the positive input end of the DC / DC converter. The first direct current side switch assembly comprises a first switch branch and a second switch branch, the two switch branches are connected in parallel to form a first common end and a second common end, the two common ends are electrically connected with the positive electrode of the solar cell and the positive input end of the DC / DC converter respectively, the first switch branch comprises a first switch and a first resistor which are cascaded, and the second switch branch comprises a second switch and a second resistor which are cascaded. The second switch branch comprises a second switch and a first diode which are cascaded, the cathode of the first diode is electrically connected with the second common end, or the anode of the first diode is electrically connected with the first common end. The direct current side wiring scheme of the photovoltaic system is more convenient and safer to maintain, and has anti-reverse and soft start functions at the same time.
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Description

Technical Field

[0001] The utility model mainly relates to the technical field of photovoltaics, in particular to a DC side wiring scheme for a photovoltaic system. Background Art

[0002] On the DC side of the existing photovoltaic system, the solar cell is directly connected to the DC / DC converter. Since the solar cell is directly connected to the DC / DC converter, this wiring scheme has the following disadvantages: 1. When the solar cell or the DC / DC converter fails and needs to be replaced or repaired, the connection between the two cannot be cut off, which is inconvenient for repair and replacement; 2. Since a large-capacity DC bus capacitor is generally used at the back end of the photovoltaic system DC / DC converter connected to the inverter circuit, it is easy to cause current impact on the bus capacitor at the moment of startup, causing circuit abnormality and damaging the life of the capacitor; 3. When the DC bus voltage is higher than the solar cell voltage, if the DC / DC converter fails, for example, its switch is broken down, it may cause backflow, that is, current flows from the bus capacitor into the solar cell, thereby damaging the solar cell and the system can no longer work. Therefore, the utility model provides a DC side wiring scheme for the photovoltaic system. Utility Model Content

[0003] In order to solve the deficiencies of the prior art, the utility model provides a DC side wiring solution for a photovoltaic system.

[0004] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0005] A photovoltaic system DC side wiring scheme includes a solar cell, a DC / DC converter, and a DC side switch component, wherein the DC side switch component is electrically connected between the solar cell and the DC / DC converter, wherein the DC side switch component includes a first DC side switch component, wherein the first DC side switch component is electrically connected between the positive electrode of the solar cell and the positive input terminal of the DC / DC converter, wherein the first DC side switch component includes a first switch branch and a second switch branch, wherein the first switch branch and the second switch branch are connected in parallel to form a first common terminal and a second common terminal, wherein the first common terminal and the second common terminal are electrically connected to the positive electrode of the solar cell and the positive input terminal of the DC / DC converter, respectively, wherein the first switch branch includes a cascaded first switch and a first resistor, wherein the second switch branch includes a cascaded second switch and a first diode, wherein the cathode of the first diode is electrically connected to the second common terminal, and the anode of the first diode is electrically connected to the first common terminal.

[0006] Preferably, the DC side switch component further includes a second DC side switch component, and the second DC side switch component is electrically connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

[0007] Preferably, the second DC side switch component includes a third switch branch, the third switch branch includes a second diode, and the cathode and anode of the second diode are respectively connected to the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

[0008] Preferably, the DC / DC converter is a boost converter.

[0009] Preferably, the third switch branch further includes a third switch, and the third switch is cascaded with the second diode and electrically connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

[0010] Preferably, the second DC side switch component also includes a fourth switch branch, the fourth switch branch includes a cascaded fourth switch and a second resistor, and the third switch branch and the fourth switch branch are connected in parallel and connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

[0011] Preferably, the resistance value of the first resistor is greater than the resistance value of the second resistor.

[0012] Preferably, the DC side switch assembly further includes a third DC side switch assembly, and the third DC side switch assembly includes a first fuse, and the first fuse is located between the positive pole of the solar cell and the first DC side switch assembly.

[0013] Preferably, the DC side switch assembly further includes a fourth DC side switch assembly, the fourth DC side switch assembly includes a second fuse, and the second fuse is located between the negative pole of the solar cell and the second DC side switch assembly.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] Compared with the DC side wiring scheme of the photovoltaic system in the prior art, the scheme of the utility model cuts off the connection between the solar cell and the DC / DC converter when a fault occurs on the DC side by connecting the DC side switch component, which facilitates the maintenance or replacement of the faulty parts and ensures the safety of the human body during the maintenance process; at the same time, the DC side switch component has soft start and anti-reverse functions, which can improve the performance of the photovoltaic system startup process and effectively prevent current backflow during the steady-state working process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of the DC side wiring scheme of the photovoltaic system in the prior art;

[0017] Figure 2 This is a schematic diagram of the DC side wiring scheme of the photovoltaic system in the first embodiment of the present application;

[0018] Figure 3This is a schematic diagram of the structure of the DC side wiring scheme of the photovoltaic system in the second embodiment of the present application;

[0019] Figure 4 This is a schematic diagram of the structure of the DC side wiring solution of the photovoltaic system in the third embodiment of the present application;

[0020] Figure 5 This is a schematic diagram of the structure of the DC side wiring solution of the photovoltaic system according to the fourth embodiment of the present application;

[0021] Figure 6 This is a schematic diagram of the DC side wiring scheme of a photovoltaic system according to the fifth embodiment of the present application;

[0022] Figure 7 This is a schematic diagram of the structure of the DC side wiring solution of the photovoltaic system according to the sixth embodiment of the present application;

[0023] Figure 8 This is a schematic diagram of the structure of the DC side wiring solution of the photovoltaic system according to the seventh embodiment of the present application;

[0024] Fig. 9 This is a schematic diagram of the structure of the DC side wiring scheme of the photovoltaic system according to the eighth embodiment of the present application.

[0025] The meanings of the reference numerals are as follows:

[0026] BAT Solar Cells M2 Second DC side switch component Con DC / DC Converter SS DC side switch components M1 First DC side switch assembly D2 The second diode C1 First public terminal S3 Third switch C2 Second common terminal S4 Fourth switch S1 First switch R2 Second resistor R1 First resistor F1 First fuse S2 Second switch F2 Second fuse D1 The first diode DETAILED DESCRIPTION

[0027] The utility model is further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the utility model and are not used to limit the scope of the utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by this application.

[0028] The standard parts used in the present invention can all be purchased from the market, special-shaped parts can be customized according to the description in the specification and the drawings, and the specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, and bonding in the prior art. At the same time, in order to clearly express the connection relationship and working principle between the various components, the drawings in the specification are organized and drawn in the form of simple diagrams of the mechanism movement, which will not be described in detail here.

[0029] Example 1

[0030] Please refer to Figure 2A photovoltaic system DC side wiring scheme includes a solar cell BAT, a DC / DC converter SS, and a DC side switch component Con. The DC side switch component Con is electrically connected between the solar cell BAT and the DC / DC converter SS. The connection or disconnection between the solar cell BAT and the DC / DC converter Con is controlled by controlling the DC side switch component SS to be turned on or off, so that when the photovoltaic system DC side works normally, the solar cell BAT is connected to the input end of the DC / DC converter Con to provide DC power for the DC / DC converter Con; when a fault occurs on the photovoltaic system DC side, the connection between the solar cell BAT and the DC / DC converter Con is cut off, so that it is convenient to repair or replace the faulty parts and ensure the safety of human body during the repair process.

[0031] Please refer to Figure 3 The DC side switch component includes a first DC side switch component M1, which is electrically connected between the positive electrode of the solar cell BAT and the positive input terminal of the DC / DC converter; the connection or disconnection between the solar cell BAT and the DC / DC converter Con is controlled by the first DC side switch component M1, thereby controlling the on-off of the DC side of the photovoltaic system.

[0032] Please refer to Figure 4 , Figure 5 The first DC side switch component M1 includes a first switch branch and a second switch branch. The first switch branch and the second switch branch are connected in parallel to form a first common terminal C1 and a second common terminal C2. The first common terminal C1 and the second common terminal C2 are electrically connected to the positive electrode of the solar cell BAT and the positive input terminal of the DC / DC converter Con, respectively. The first switch branch includes a cascaded first switch S1 and a first resistor R1. The second switch branch includes a cascaded second switch S2 and a first diode D1. The cathode of the first diode D1 is electrically connected to the second common terminal C2, or the anode of the first diode D1 is electrically connected to the first common terminal C1.

[0033] In one embodiment of the present application, the DC / DC converter Con is a boost converter.

[0034] Example 2

[0035] Please refer to Figure 6The DC side switch component also includes a second DC side switch component M2, which is electrically connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter. The second DC side switch component M2 includes a third switch branch, which includes a second diode D2, and the cathode and anode of the second diode D2 are respectively connected to the negative electrode of the solar cell BAT and the negative input terminal of the DC / DC converter Con. It can be understood that in steady-state operation, the second diode D2 is added to play a redundant role, that is, when the system is in steady-state operation, when the first diode D1 is damaged, the second diode D2 can still play an anti-reverse role.

[0036] Example 3

[0037] Please refer to Figure 7 The third switch branch further includes a third switch S3, which is cascaded with the second diode D2 and electrically connected between the negative electrode of the solar cell BAT and the negative input terminal of the DC / DC converter Con. It can be understood that due to the addition of the third switch S3, when a fault occurs on the DC side of the photovoltaic system, the connection between the solar cell BAT and the DC / DC converter Con can be cut off by disconnecting the third switch S3, thereby increasing the redundancy of the system.

[0038] Example 4

[0039] Please refer to Figure 8 , the second DC side switch component M2 also includes a fourth switch branch, the fourth switch branch includes a cascaded fourth switch S4 and a second resistor R2, the third switch branch and the fourth switch branch are connected in parallel between the negative electrode of the solar cell BAT and the negative input terminal of the DC / DC converter Con; in one embodiment, the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2; it can be understood that due to the addition of the fourth switch S4 and the second resistor R2, during the soft start process, the first switch S1 or / and the fourth switch S4 can be selected to be turned on, which increases the redundancy of the system, can meet the needs of different scenarios, and improve the system efficiency and adaptability: for example, during soft start, if the impact current is very large, the first switch S1 and the fourth switch S4 can be selected to be turned on at the same time, so that the first resistor R1 and the second resistor R2 are connected to the soft start circuit at the same time, thereby effectively curbing the impact current; if the impact current is large, the first switch S1 can be selected to be turned on, so that the first resistor R1 is connected to the soft start circuit; if the impact current is small, the fourth switch S4 can be selected to be turned on, so that the second resistor R2 is connected to the soft start circuit.

[0040] In one embodiment of the present application, the resistance value of the first resistor is greater than the resistance value of the second resistor.

[0041] Example 5

[0042] Please refer to Fig. 9The DC side switch assembly also includes a third DC side switch assembly M3, and the third DC side switch assembly M3 includes a first fuse F1, and the first fuse F1 is located between the positive electrode of the solar cell and the first DC side switch assembly M1. The first fuse F1 plays a role of safety fuse.

[0043] In other embodiments, the DC side switch assembly further includes a fourth DC side switch assembly M4, the fourth DC side switch assembly M4 includes a second fuse F2, and the second fuse F2 is located between the negative electrode of the solar cell and the second DC side switch assembly M2. The second fuse F2 plays a safety fuse role, and together with the first fuse F1, it constitutes redundancy to increase system reliability.

[0044] Figure 4 , Figure 5 The working principle is as follows: during soft start, the first switch branch is controlled to be turned on and the second switch branch is turned off, that is, the first switch S1 in the first switch branch is controlled to be turned on and the second switch S2 in the second switch branch is controlled to be turned off, and the system is soft started through the first switch branch, that is, the first switch S1 and the first resistor R1, wherein the resistor R1 in the first switch branch has a current limiting function; when the system enters a steady-state operation, the first switch branch is turned off and the second switch branch is turned on, that is, the first switch S1 in the first switch branch is controlled to be turned off and the second switch S2 in the second switch branch is controlled to be turned on, and the electric energy of the solar cell BAT is transmitted to the DC / DC converter Con through the second switch branch, wherein the first diode D1 has a function of preventing current backflow to prevent electric energy from flowing from the right side to the left side.

Claims

1. A photovoltaic system DC side wiring scheme, including solar cells and DC / DC converters, characterized in that: It also includes a DC side switch component, wherein the DC side switch component is electrically connected between the solar cell and the DC / DC converter; The DC side switch assembly comprises a first DC side switch assembly, wherein the first DC side switch assembly is electrically connected between the positive electrode of the solar cell and the positive input terminal of the DC / DC converter; The first DC side switch component includes a first switch branch and a second switch branch, the first switch branch and the second switch branch are connected in parallel to form a first common end and a second common end, the first common end and the second common end are electrically connected to the positive electrode of the solar cell and the positive input end of the DC / DC converter, respectively, the first switch branch includes a cascaded first switch and a first resistor, the second switch branch includes a cascaded second switch and a first diode, the cathode of the first diode is electrically connected to the second common end, and the anode of the first diode is electrically connected to the first common end.

2. A photovoltaic system DC side wiring solution according to claim 1, characterized in that: The DC / DC converter is a boost converter.

3. A photovoltaic system DC side wiring solution according to claim 1, characterized in that: The DC side switch component further includes a second DC side switch component, and the second DC side switch component is electrically connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

4. A photovoltaic system DC side wiring solution according to claim 3, characterized in that: The second DC side switch component includes a third switch branch, and the third switch branch includes a second diode, and the cathode and anode of the second diode are respectively connected to the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

5. A photovoltaic system DC side wiring solution according to claim 4, characterized in that: The third switch branch further includes a third switch, which is cascaded with the second diode and electrically connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

6. A photovoltaic system DC side wiring solution according to claim 5, characterized in that: The second DC side switch component also includes a fourth switch branch, which includes a cascaded fourth switch and a second resistor. The third switch branch and the fourth switch branch are connected in parallel and connected between the negative electrode of the solar cell and the negative input terminal of the DC / DC converter.

7. A photovoltaic system DC side wiring solution according to claim 6, characterized in that: The resistance value of the first resistor is greater than the resistance value of the second resistor.

8. A photovoltaic system DC side wiring solution according to claim 6, characterized in that: The DC side switch assembly further includes a third DC side switch assembly, and the third DC side switch assembly includes a first fuse, and the first fuse is located between the positive pole of the solar cell and the first DC side switch assembly.

9. A photovoltaic system DC side wiring solution according to claim 8, characterized in that: The DC side switch assembly further includes a fourth DC side switch assembly, and the fourth DC side switch assembly includes a second fuse, and the second fuse is located between the negative pole of the solar cell and the second DC side switch assembly.