Maintenance of photovoltaic modules is the most direct guarantee for increasing power generation and reducing power loss. Then the focus of photovoltaic operation and maintenance personnel is to learn the relevant knowledge of photovoltaic modules.
First of all, let me tell you about photovoltaic power generation and why we are vigorously developing photovoltaic power generation. China's current environmental status and development trends, large-scale and uncontrolled development and utilization of fossil fuels, not only accelerate the depletion of these precious resources, but also cause increasingly serious problems. Environmental damage.
China is the world's largest coal producer and consumer, and nearly 76% of its energy is supplied by coal. This over-reliance on fossil fuel energy structure has caused great environmental, economic and social negative impacts. A large amount of coal mining, transportation and burning has caused great damage to our country's environment. Therefore, we vigorously develop the use of renewable energy sources such as solar energy. This is an inevitable choice for our country's energy security and sustainable development.
Photovoltaic power generation system composition
The photovoltaic power generation system mainly consists of a photovoltaic module array, a combiner box, an inverter, a phase change, a switch cabinet, and then a system that remains unchanged, and finally comes to the power grid through lines. So what is the principle of photovoltaic power generation?
Photovoltaic power generation is mainly due to the photoelectric effect of semiconductors. When a photon irradiates a metal, all its energy can be absorbed by an electron in the metal. The energy absorbed by the electron is large enough to overcome the gravitational force inside the metal and do work, leaving the metal surface and escaping to become a Optoelectronics, silicon atoms have 4 outer electrons. If phosphorus atoms, which are atomic phosphorus atoms with 5 outer electrons, are doped into pure silicon, an n-type semiconductor is formed.
If atoms with three outer electrons, such as boron atoms, are mixed into pure silicon to form a p-type semiconductor, when the p-type and n-type are combined together, the contact surface will form a cell gap and become a solar cell.
Photovoltaic modules
The photovoltaic module is the smallest indivisible solar cell combination device with a center and internal connections that can provide DC output alone. It is also called a solar panel. The photovoltaic module is the core part of the entire photovoltaic power generation system. Its function is to use the photoacoustic radiation effect to Solar energy is converted into DC power output. When sunlight shines on the solar cell, the battery absorbs electrical energy to generate photoelectron holes. Under the action of an electric field in the battery, the photogenerated electrons and spins are separated, and an accumulation of charges of different signs appears at both ends of the battery. And generate photo-generated negative pressure, which is what we call the photo-generated photovoltaic effect.
Let me introduce to you the polycrystalline silicon photovoltaic module produced by a certain company. This model has an operating voltage of 30.47 volts and a peak power of 255 watts. By absorbing solar energy, the solar radiation energy is directly or indirectly converted into electrical energy through the photoelectric effect or photochemical effect. Generate electricity.
Compared with monocrystalline silicon components, polycrystalline silicon components are simpler to manufacture, save power consumption, and have lower overall production costs, but the photoelectric conversion efficiency is also relatively low.
Photovoltaic modules can generate electricity under direct sunlight. They are safe and reliable, have no noise and no pollution emissions, and are absolutely clean and pollution-free.
Next, we introduce the structure of the device and dismantle it.
Junction Box
The photovoltaic junction box is a connector between the solar cell array composed of solar cell modules and the solar charging control device. It mainly connects the electric energy generated by the solar cells to external circuits.
Tempered Glass
The use of tempered glass with high light transmittance is mainly to protect the battery cells from damage, which is equivalent to Jian Bai saying that our mobile phone tempered film plays a protective role.
Encapsulation
Because the film is mainly used to bond and fix tempered glass and battery cells, it has high transparency, flexibility, super low temperature resistance and water resistance.
The tin bar is mainly used to connect the positive and negative batteries to form a series circuit, which generates electrical energy and leads it to the junction box.
Aluminum Alloy Frame
The frame of the photovoltaic module is made of rectangular aluminum alloy, which is lightweight and heavy. It is mainly used to protect the crimping layer and play a certain sealing and supporting role, which is the core of the cell.
Polycrystalline Silicon Solar Cells
Polycrystalline silicon solar cells are the main component of the module. Their main function is to perform photoelectric conversion and generate a large amount of electrical energy. Crystalline silicon solar cells have the advantages of low cost and simple assembly.
Backplane
The backsheet is in direct contact with the external environment on the back of the photovoltaic module. The photovoltaic packaging material is mainly used to package the components, protect raw and auxiliary materials, and isolate the solar modules from the reflow belt. This component has good properties such as aging resistance, insulation resistance, water resistance, and gas resistance. Features.
Conclusion
The main frame axis of the photovoltaic module is composed of photovoltaic tempered glass encapsulated micro-film, cells, tin bars, aluminum alloy frames, and backplane junction boxes to form SC plugs and other main components.
Among them, the crystalline silicon cells are coordinated to connect multiple cells forward and reverse to form a series connection, and then are led to the junction box through the bus belt to form a high-voltage output power battery module. When solar light is set on the surface of the module, the board generates current through electrical conversion. , the direction of the current flows from the positive electrode to the negative electrode. There is a layer of one-dimensional film on the upper and lower sides of the cell that acts as an adhesive. The surface is highly transparent and impact-resistant tempered. The back of the glass is a PPT backsheet that has been laminated by heating and vacuuming. Because The PPT and glass are melted into the cell piece and adhered into a whole. An aluminum alloy frame is used to seal the module edge with silicone. There are bus leads on the back of the cell panel. The battery lead box is fixed with high temperature resistance. We have just introduced the photovoltaic module equipment through disassembly. Structure and working principle.
Post time: Jun-05-2024