Why Do Photovoltaic Cables in Solar Energy Use Tinned Copper Core Wires?

The conductors of many wires and cables are of various kinds. Their purpose is to energize. The conductive medium is generally dominated by metals. They can be divided into various qualities, such as copper, aluminum, silver, etc. Why use special tinned copper as a conductor? Let's take a look at the main materials of photovoltaic wire and cable conductors? What are the advantages and disadvantages.

Aluminum conductor

Advantages: First, the price is cheap, the copper rod is 3.5 times the price of the aluminum rod, and the proportion of copper is 3.3 times that of the aluminum, so the aluminum core photovoltaic wire and cable is much cheaper than the copper core photovoltaic wire and cable, and the aluminum core photovoltaic cable is suitable for low-cost projects. or temporary electricity. Second, the cables are light, which reduces shipping costs.

Disadvantages: aluminum wire has low conductivity, large electrical loss, poor tensile strength, low corrosion resistance, and the joint is easy to oxidize. If copper wire is used for connection, due to potential difference, the joint is easy to corrode, and it is easy to cause open circuit failure.

Aluminum alloy conductor

Advantages: Compared with pure aluminum conductor photovoltaic wires and cables, the tensile strength and elongation of aluminum alloy conductors are improved, and the elongation rate is increased to 30%, which is safer and more reliable. Aluminum alloy conductor photovoltaic wire and cable connection is as safe and stable as copper conductor photovoltaic wire and cable connection, with strong self-weight bearing capacity, aluminum alloy has good bending performance, and its unique alloy formula and processing technology greatly improve flexibility; the flexibility of aluminum alloy 30% higher than copper and 40% less elastic than copper.

Disadvantages: The corrosion resistance of aluminum alloy conductors is worse than that of aluminum, the temperature resistance is worse than that of copper, and the thermal expansion coefficient is much higher than that of copper, and some are even higher than ordinary aluminum.

Bare copper wire

Bare copper wire is a very common and widely used conductor material. It is made of pure copper rod and made of copper wire. It has the advantages of simple material, copper metal surface and interior, yellow appearance, good ductility, low resistivity, and low heat generation. It can be used for many wires and cables and various materials with good thermal conductivity, as well as photovoltaic wires. conductor. The disadvantage is that it is easy to oxidize, and the unit price is higher than that of aluminum series.

Tinned copper wire

The tinned copper core wire in photovoltaic wire and cable looks silver because tin is a silver metal. The process of tinned copper wire is a little more complicated than bare copper wire. After the pure copper rod is drawn into a wire, a thin layer of tin is plated on the surface of the copper wire through the hot-dip tinning process. Tin is stable in air at room temperature because a dense oxide film is formed on the surface of tin, preventing further oxidation of tin. Therefore, tin plating on the copper surface does not affect the resistance, and can improve the oxidation resistance of copper to a certain extent.

The performance of the above conductors is determined according to the performance of the low-voltage circuit. The comprehensive performance ranking of these four conductors is summarized as: tinned copper wire > bare copper wire > aluminum alloy conductor > ordinary aluminum conductor.

The operating environment of photovoltaic power plants is generally harsh, and they are often installed in deserts, barren mountains, water surfaces, roofs and other environments. This requires photovoltaic cables to have good resistivity and not easy to oxidize. Therefore, for a long time, tinned copper wire has been selected as the Conductor is a kind of conductor that is most suitable for use environment and has the most stable electrical performance.