Antioxidant new energy photovoltaic string inverter current busbar

Abstract

This utility model relates to the field of new energy photovoltaic equipment technology, and discloses an anti-oxidation copper busbar for a new energy photovoltaic string inverter. It includes a copper busbar body with two mounting holes spaced apart along its length inside the body, penetrating the upper and lower end faces. A copper busbar itself is embedded and fixed inside the body. The outer surface of the body is sequentially provided with a first anti-oxidation layer, a transition layer, and a second anti-oxidation layer, forming an anti-oxidation mechanism. A sealing mechanism is provided on the inner wall of the mounting holes to improve the sealing and conductivity of the mounting area. In this utility model, the first anti-oxidation layer, made of nickel-phosphorus alloy, is chemically plated to block air and moisture; the transition layer, made of metallic chromium, is vacuum-plated to strengthen interlayer bonding; and the second anti-oxidation layer, made of polytetrafluoroethylene, is sprayed to prevent corrosion and provide insulation, ensuring power transmission and extending the lifespan of the copper busbar.

Description

Technical Field

[0001] This utility model relates to the field of new energy photovoltaic equipment technology, and in particular to the current-carrying copper busbar of an antioxidant new energy photovoltaic string inverter. Background Technology

[0002] Photovoltaic string inverters are the core power conversion equipment in new energy photovoltaic power station systems. They are mainly used to convert the direct current generated by photovoltaic module strings (composed of several photovoltaic panels connected in series to increase the output voltage) into alternating current that conforms to the grid frequency and voltage standards through internal power electronic conversion circuits (such as inverter topologies containing power devices such as IGBTs). They also have maximum power point tracking (MPPT) function, which can track the optimal operating state of the photovoltaic module strings in real time to maximize the solar power generation efficiency. In addition, they also integrate overvoltage, overcurrent, overtemperature, and leakage protection functions, as well as data acquisition and communication functions. They can monitor power generation data and upload it to the back-end system, which facilitates power station operation and maintenance management. They are widely used in small and medium-sized photovoltaic power stations, distributed photovoltaic systems, and other scenarios. They are the key link connecting photovoltaic modules and the grid, directly affecting the power generation efficiency, operational stability, and safety of photovoltaic power stations.

[0003] During long-term use, the copper busbars in current photovoltaic string inverters are prone to oxidation upon contact with air and moisture, forming an oxide layer. This oxide layer increases the contact resistance of the copper busbars, causing excessive heat to be generated during current flow. This not only reduces power transmission efficiency but may also lead to safety hazards due to overheating, affecting the overall operational stability and lifespan of the photovoltaic string inverter.

[0004] In existing technologies, although some copper busbars are treated with simple plating, the plating adhesion is poor and the anti-oxidation duration is short, making it difficult to meet the requirements of long-term outdoor or complex environments. Therefore, an anti-oxidation new energy photovoltaic string inverter current-carrying copper busbar is proposed to solve the above problems. Utility Model Content

[0005] To overcome the above deficiencies, this utility model provides an antioxidant new energy photovoltaic string inverter current-carrying copper busbar, which aims to improve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An antioxidant new energy photovoltaic string inverter current-carrying copper busbar includes a copper busbar body. Two mounting holes are spaced apart along the length of the copper busbar body, penetrating the upper and lower end faces of the copper busbar body. A copper busbar body is embedded and fixed inside the copper busbar body. A first antioxidant layer, a transition layer, and a second antioxidant layer are sequentially formed on the outer surface of the copper busbar body from the inside out, creating an antioxidant structure. A sealing mechanism is provided on the inner wall of the mounting holes to improve the sealing and conductivity of the mounting location. As a further description of the above technical solution: The first anti-oxidation layer is made of nickel-phosphorus alloy and has a thickness of 5-10 μm. The first anti-oxidation layer is tightly attached to the outer surface of the copper busbar body by chemical plating. The second anti-oxidation layer is made of polytetrafluoroethylene and has a thickness of 3-5 μm. The second anti-oxidation layer is covered on the outer surface of the transition layer by spray curing. As a further description of the above technical solution: The transition layer is made of metallic chromium and has a thickness of 2-3 μm. The transition layer is formed between the first antioxidant layer and the second antioxidant layer by a vacuum coating process. As a further description of the above technical solution: The sealing mechanism includes a conductive coating, an annular protrusion, and a sealing layer. The outer wall of the conductive coating is fixedly connected to the inner wall of the mounting hole by a coating and curing process, and the thickness is 1-2 μm. There are two annular protrusions, which are integrally formed on the port edges at the upper and lower ends of the mounting hole, and the height of the annular protrusions is 2-3 mm. As a further description of the above technical solution: The sealing layer is located on the outside of the annular protrusion. The sealing layer is made of highly thermally conductive insulating silicone gel. The thickness of the silicone gel sealing layer in the uncompressed state is 1.5 to 2 mm. When the bolt is tightened, it is compressed to form an annular sealing ring. As a further description of the above technical solution: The conductive coating is made of silver-based conductive paste. The conductive coating covers the entire inner wall surface of the mounting hole and extends to the inner sidewall of the annular protrusion. As a further description of the above technical solution: The copper busbar body is made of T2 copper, and the cross-sectional area of ​​the copper busbar body accounts for 75% to 85% of the cross-sectional area of ​​the main body of the copper busbar.

[0007] This utility model has the following beneficial effects: 1. In this utility model, the nickel-phosphorus alloy first anti-oxidation layer is tightly adhered by chemical plating, directly blocking the contact between air and moisture and the copper busbar body, thus delaying the oxidation reaction; the metallic chromium transition layer enhances the interlayer bonding strength through vacuum coating process, preventing the protective layer from peeling off and failing; the polytetrafluoroethylene second anti-oxidation layer is covered by spraying and curing, further isolating corrosive media such as dust and acidic gases, and also has insulation properties to prevent leakage, ensuring efficient power transmission and significantly extending the anti-oxidation life of the copper busbar under the complex operating conditions of photovoltaic string inverters, avoiding the decline in conductivity due to oxidation.

[0008] 2. In this utility model, the conductive coating of silver-based conductive paste covers the inner wall of the mounting hole and the inner sidewall of the annular protrusion, which greatly reduces the contact resistance between the copper busbar and the bolt and reduces local overheating. The annular protrusion is integrally formed at the port of the mounting hole, which concentrates the friction force during assembly to avoid scratching the coating. During long-term use, it limits the fretting wear caused by thermal expansion and contraction and prevents the conductive coating from being damaged by the metal substrate. The silicone gel sealing layer is squeezed to form a sealing ring after the bolt is tightened to block moisture and oxygen. Its excellent thermal conductivity can also help conduct local heat, thereby effectively preventing corrosion of the connection part and increased contact resistance, and ensuring the long-term reliability of the connection between the copper busbar and external components. Attached Figure Description

[0009] Figure 1 This is a three-dimensional view of the current-carrying copper busbar of the antioxidant new energy photovoltaic string inverter proposed in this utility model; Figure 2 This is a schematic diagram of the mounting holes of the current-carrying copper busbar in the antioxidant new energy photovoltaic string inverter proposed in this utility model; Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0010] Legend: 1. Copper busbar body; 2. Mounting hole; 3. Copper busbar body; 4. First anti-oxidation layer; 5. Transition layer; 6. Second anti-oxidation layer; 7. Annular protrusion; 8. Sealing layer; 9. Conductive coating. Detailed Implementation

[0011] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0012] Reference Figure 1 , Figure 2 and Figure 3This utility model provides an embodiment of an antioxidant new energy photovoltaic string inverter current-carrying copper busbar, including a copper busbar body 1, which is an overall support frame for the current-carrying copper busbar. Two mounting holes 2 are spaced apart along the length of the copper busbar body 1, penetrating the upper and lower end faces of the copper busbar body 1. Their core function is to provide an assembly channel for bolted connections between the copper busbar and external components, ensuring precise positioning and installation of the copper busbar inside the photovoltaic string inverter. A copper busbar body 3 is embedded and fixed inside the copper busbar body 1. The material of the copper busbar body 3 is... The copper busbar body 3 is made of T2 copper, and its cross-sectional area accounts for 75% to 85% of the cross-sectional area of ​​the main body 1. T2 copper has extremely high purity and excellent conductivity. From the inside to the outside, the outer surface of the main body 1 is sequentially provided with a first anti-oxidation layer 4, a transition layer 5, and a second anti-oxidation layer 6, forming an anti-oxidation structure. The first anti-oxidation layer 4 is made of nickel-phosphorus alloy and has a thickness of 5-10 μm. The first anti-oxidation layer 4 is tightly adhered to the outer surface of the main body 1 through a chemical plating process. Nickel-phosphorus alloy itself has good oxidation resistance and... The first layer of anti-corrosion coating directly forms a protective barrier on the surface of the copper busbar body 1, blocking contact between corrosive media such as air and moisture and the copper busbar body 1, thus delaying the oxidation reaction. The second anti-oxidation layer 6 is made of polytetrafluoroethylene (PTFE) with a thickness of 3-5 μm. The second anti-oxidation layer 6 is applied to the outer surface of the transition layer 5 through a spray curing process. PTFE has excellent weather resistance, chemical corrosion resistance, and insulation. As the outermost protective layer, it can further isolate external dust, acidic gases, and other corrosive media, enhancing the anti-oxidation effect. Simultaneously, its insulation... The insulation properties can avoid the risk of leakage between the copper busbar and surrounding components, providing a safety guarantee for the operation of the copper busbar. It works in conjunction with the inner protective layer to extend the anti-oxidation life of the copper busbar. The transition layer 5 is made of metallic chromium and has a thickness of 2-3μm. The transition layer 5 is set between the first anti-oxidation layer 4 and the second anti-oxidation layer 6 through a vacuum coating process. Metallic chromium has high adhesion properties, which can effectively improve the interfacial bonding strength between the nickel-phosphorus alloy of the first anti-oxidation layer 4 and the polytetrafluoroethylene of the second anti-oxidation layer 6, avoiding the problem of interlayer peeling caused by the large difference in the material properties of the two layers. The inner wall of the mounting hole 2 is equipped with a sealing mechanism to improve the sealing and conductivity of the mounting area. The sealing mechanism includes a conductive coating 9, an annular protrusion 7, and a sealing layer 8. The outer wall of the conductive coating 9 is fixedly connected to the inner wall of the mounting hole 2 through a coating and curing process, with a thickness of 1-2 μm. The conductive coating 9 is made of silver-based conductive paste. The coating area of ​​the conductive coating 9 covers the entire inner wall surface of the mounting hole 2 and extends to the inner sidewall of the annular protrusion 7. The high proportion of silver powder in the silver-based conductive paste can significantly reduce the contact resistance between the copper busbar body 1 and the connecting bolts, reducing local overheating during current transmission. There are two annular protrusions 7, which are integrally formed on the upper and lower ends of the mounting hole 2. The height of the annular protrusions 7 is 2-3 mm. During the assembly stage, they can concentrate the friction force of the bolt head and the lower surface of the nut on themselves, avoiding direct friction with the outer surface coating of the copper busbar body 1 and preventing the coating from being scratched and worn. During long-term use, the structural strength limits the micron-level displacement of the bolt contact surface caused by the thermal expansion and contraction of the copper busbar, reducing fretting wear. The sealing layer 8 is located on the outside of the annular protrusion 7. The material of the sealing layer 8 is a high thermal conductivity insulating silicone gel. The thickness of the silicone gel sealing layer 8 in the uncompressed state is 1.5 to 2 mm. When the bolt is tightened, it is compressed to form an annular sealing ring, filling the gap between the annular protrusion 7 and the gasket, blocking moisture and oxygen from entering the installation gap, and preventing corrosion of the connection between the bolt and the mounting hole. At the same time, its thermal conductivity of not less than 1.2 W / (m·K) can conduct local heat from the connection to the copper busbar body 1, assisting in heat dissipation.

[0013] Working principle: A first anti-oxidation layer 4, a transition layer 5, and a second anti-oxidation layer 6 are sequentially arranged from the inside to the outside on the outer surface of the copper busbar body 1, forming a synergistic protection: The first anti-oxidation layer 4 is a 5-10 μm thick nickel-phosphorus alloy layer, which is tightly adhered to the surface of the copper busbar body 1 through a chemical plating process. The nickel-phosphorus alloy itself has good oxidation and corrosion resistance, and can directly block the contact between air and moisture and the copper busbar body 1, delaying the oxidation reaction; the transition layer 5 is a 2-3 μm thick metallic chromium layer, which connects the first anti-oxidation layer 4 and the second anti-oxidation layer 6 through a vacuum plating process. The second antioxidant layer 6, with its high adhesion properties of metallic chromium, enhances the bonding strength between the two coating layers, preventing interlayer peeling during long-term use and avoiding the failure of the protective structure. The outermost second antioxidant layer 6 is a 3-5μm thick polytetrafluoroethylene (PTFE) layer, which is covered by a spray curing process. PTFE has excellent weather resistance, chemical corrosion resistance, and insulation properties, which can further isolate external corrosive media such as dust and acidic gases, and also prevent the risk of leakage between the copper busbar and surrounding components. The three-layer structure works synergistically to significantly extend the antioxidant life of the copper busbar. A 1-2μm thick silver-based conductive paste conductive coating 9 is applied to the inner wall of the mounting hole 2, covering the entire inner wall surface of the mounting hole and the inner sidewall of the annular protrusion 7. This reduces the contact resistance between the copper busbar body 1 and the connecting bolts. During the bolt tightening assembly stage, the annular protrusion 7 concentrates the frictional force between the bolt head and the lower surface of the nut onto the annular protrusion 7 itself, rather than directly contacting the copper busbar body. This avoids scratches and damage to the coating caused by rotational friction and compression during assembly. During the long-term operation of the inverter, when the copper busbar expands and contracts due to load changes and ambient temperature fluctuations, the annular protrusion 7 can limit the micron-level relative displacement of the bolt connection contact surface through its own structural strength, reducing the frequency and amplitude of "fretting wear" and preventing... The conductive coating 9 and the metal substrate are repeatedly rubbed and ground together. The silicone gel sealing layer 8 has a thickness of 1.5-2 mm in the uncompressed state. When the bolt is tightened, the gasket exerts a compressive force on the silicone gel sealing layer 8, causing the silicone gel to deform and fill the gap between the annular protrusion 7 and the gasket, forming a complete annular seal. This effectively blocks external moisture and oxygen from entering the installation gap and prevents corrosion at the connection between the bolt and the mounting hole. In addition, because the silicone gel has a thermal conductivity of not less than 1.2 W / (m·K), it can quickly conduct the local heat generated at the bolt connection to the copper busbar body 1. Combined with the low resistance characteristics of the conductive coating 9, it achieves the triple function of "sealing and corrosion prevention + high-efficiency conductivity + auxiliary heat dissipation".

[0014] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. Anti-oxidation new energy photovoltaic string inverter through-flow copper bar, comprising a copper bar body (1), characterized in that: The copper busbar body (1) has two mounting holes (2) spaced apart along its length. The mounting holes (2) penetrate the upper and lower end faces of the copper busbar body (1). A copper busbar body (3) is embedded and fixed inside the copper busbar body (1). The outer surface of the copper busbar body (1) is provided with a first anti-oxidation layer (4), a transition layer (5), and a second anti-oxidation layer (6) from the inside to the outside, forming an anti-oxidation mechanism. The inner wall of the mounting hole (2) is provided with a sealing mechanism to improve the sealing and conductivity of the mounting part.

2. The anti-oxidation new energy photovoltaic string inverter bus bar according to claim 1, characterized in that: The first antioxidant layer (4) is made of nickel-phosphorus alloy and has a thickness of 5-10 μm. The first antioxidant layer (4) is tightly attached to the outer surface of the copper busbar body (1) by chemical plating process. The second antioxidant layer (6) is made of polytetrafluoroethylene and has a thickness of 3-5 μm. The second antioxidant layer (6) is covered on the outer surface of the transition layer (5) by spray curing process.

3. The anti-oxidation new energy photovoltaic string inverter bus bar according to claim 1, characterized in that: The transition layer (5) is made of metallic chromium and has a thickness of 2-3 μm. The transition layer (5) is set between the first antioxidant layer (4) and the second antioxidant layer (6) by vacuum coating process.

4. The anti-oxidation new energy photovoltaic module string inverter bus bar according to claim 1, characterized in that: The sealing mechanism includes a conductive coating (9), an annular protrusion (7) and a sealing layer (8). The outer wall of the conductive coating (9) is fixedly connected to the inner wall of the mounting hole (2) by a coating curing process, and the thickness is 1-2 μm. There are two annular protrusions (7), which are integrally formed on the port edges at the upper and lower ends of the mounting hole (2). The height of the annular protrusions (7) is 2-3 mm.

5. The anti-oxidation new energy photovoltaic module string inverter bus bar according to claim 4, characterized in that: The sealing layer (8) is located on the outside of the annular protrusion (7). The material of the sealing layer (8) is a high thermal conductivity insulating silicone gel. The thickness of the silicone gel sealing layer (8) in the uncompressed state is 1.5 to 2 mm. When the bolt is tightened, it is compressed to form an annular sealing ring.

6. The anti-oxidation new energy photovoltaic module string inverter bus bar according to claim 4, characterized in that: The conductive coating (9) is made of silver-based conductive paste. The conductive coating (9) covers the entire inner wall of the mounting hole (2) and extends to the inner wall of the annular protrusion (7).

7. The anti-oxidizing new energy photovoltaic module string inverter bus bar according to claim 1, characterized in that: The copper busbar body (3) is made of T2 copper, and the cross-sectional area of ​​the copper busbar body (3) accounts for 75% to 85% of the cross-sectional area of ​​the copper busbar main body (1).

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