continues the previous article.
5. solar cell component
Normally, a solar cell component is composed of a five-layer structure from top to bottom: photovoltaic glass , encapsulating film, battery sheet, encapsulating film, and backplane. The structure diagram is as follows :
(1) Photovoltaic glass
Due to the poor mechanical strength of single solar photovoltaic cells, they are easy to break; the moisture and corrosive gases in the air will gradually oxidize and rust the electrodes, and cannot withstand the harsh conditions of open-air work; at the same time, the work of single photovoltaic cells The voltage is usually small and difficult to meet the needs of general electrical equipment. Therefore, solar cells are usually sealed between an encapsulated panel and a backsheet by EVA film, forming an indivisible photovoltaic module with encapsulation and internal connections that can independently provide direct current output. Several photovoltaic modules, inverter , and other electrical accessories form a photovoltaic power generation system.
After coating, the photovoltaic glass covering the photovoltaic modules can ensure a higher light transmittance , so that the solar cells can generate more electricity; at the same time, the tempered photovoltaic glass has higher strength , which can enable solar cells to withstand greater wind pressure and larger temperature differences between day and night. Therefore, photovoltaic glass is one of the indispensable accessories of photovoltaic modules.
Photovoltaic cells are mainly divided into two categories: crystalline silicon cells and thin film cells. The photovoltaic glass used in crystalline silicon cells mainly uses the calendering method, and the photovoltaic glass used in thin film cells mainly uses the float method.
(2) Encapsulating adhesive film (EVA)
The solar cell encapsulating adhesive film is located in the middle of the solar cell module, wrapping the cells and bonding to the glass and backplane. The main functions of solar cell encapsulation film include: providing structural support for solar cell circuit equipment, providing maximum optical coupling between cells and solar radiation, physically isolating cells and circuits, conducting heat generated by cells, etc. Therefore, encapsulation film products need to have high water vapor barrier rate, high visible light transmittance, high volume resistivity, weather resistance and PID resistance.
Currently, EVA film is the most widely used solar cell encapsulation film material. As of 2018, its market share is about 90%. It has more than 20 years of application history, product performance is balanced and cost-effective. POE film is another widely used photovoltaic packaging film material. As of 2018, its market share is about 9%5. This product is an ethylene -octene copolymer that can be used for solar single glass and double glass. The packaging of glass components is particularly widely used in double-glass components. POE film has excellent characteristics such as high water vapor barrier rate, high visible light transmittance, high volume resistivity, excellent weather resistance and long-term anti-PID performance. In addition, the product's unique high reflective performance can improve the component's resistance to sunlight. The effective utilization rate helps to increase the power of the module and can solve the problem of white glue film overflow after the module is laminated.
(3) Cell chip
Silicon solar cell is a typical two-terminal device. The two terminals are on the light-receiving surface and the backlight surface of the silicon chip.
The principle of photovoltaic power generation: When a photon shines on a metal, its energy can be completely absorbed by an electron in the metal. The energy absorbed by the electron is large enough to overcome the Coulomb force inside the metal atom to do work and escape from the metal surface. , becoming optoelectronics. Silicon atoms have 4 outer shell electrons. If atoms with 5 outer shell electrons, such as phosphorus atoms, are mixed into pure silicon, it becomes an N-type semiconductor. If atoms with 3 outer shell electrons are mixed into pure silicon, such as Boron atoms form a P-type semiconductor. When P-type and N-type are combined together, a potential difference will form at the contact surface, becoming a solar cell. When sunlight hits the P-N junction, current flows from the P-type side to the N-type side, forming an electric current.
According to the different materials used, solar cells can be divided into three categories: The first category is crystalline silicon solar cells , including monocrystalline silicon and polycrystalline silicon . Its research and development and market application are relatively in-depth, and photoelectric conversion It has high efficiency and occupies the main market share of current solar cells; the second category is thin-film solar cells , including silicon-based thin films, compound types and organic types. However, due to the scarcity or toxicity of raw materials, low conversion efficiency, poor stability and other shortcomings, There are few market applications; the third category is new solar cells, including laminated solar cells, etc., which are currently in the research and development stage and the technology is not yet mature. The main raw material of
solar cells is polycrystalline silicon (which can produce monocrystalline silicon rods, polycrystalline silicon ingots, etc.). Its production process mainly includes: cleaning and texturing, diffusion, edge etching, dephosphorized silicon glass, PECVD, silk Screen printing , sintering, testing, etc.
process | description |
Cleaning and texturing | Purpose: removes the mechanical damage layer and surface oil stains on the surface of the silicon wafer to form an uneven texture and increase the absorption of sunlight by the silicon wafer. Principle: ① Monocrystalline silicon wafer: uses alkaline solution to the different crystal faces of monocrystalline silicon at different corrosion rates , forming a pyramid-like suede surface on the surface of the silicon wafer ② Polycrystalline silicon wafer : utilizes the strong oxidation of nitric acid The complexing property of hydrofluoric acid can oxidize and complex the silicon wafer. Combined peeling leads to isotropic non-uniform corrosion on the silicon surface, thus forming a pit-like suede surface. N type, making it PN junction . principle: carries the POCL3 solution into the diffusion furnace tube through gas, causing it to react to generate phosphorus and precipitate on the surface. Phosphorus penetrates into the silicon wafer at high temperatures to form an N region. |
edge etching | Purpose: performs edge insulation treatment on the back and four sides of the chip to remove the PN junctions on the back and four sides to prevent short circuits in the positive and negative electrodes. principle: uses high-frequency glow discharge reaction. The reaction gas is activated into active particles and diffuses to the edge of the silicon wafer, where it reacts with the silicon wafer to generate volatile silicon tetrafluoride and is removed. |
Removal of phosphosilicate glass | Purpose: During the diffusion process of , the deposition of P2O5 produced by the decomposition of POCl3 On the surface of the silicon wafer, P2O5 and Si generate silicon dioxide and phosphorus atoms. This silicon dioxide layer containing phosphorus atoms is called phosphosilicate glass. The existence of the glass layer will affect the metal electrode and The contact of the silicon wafer reduces the conversion efficiency of the battery. At the same time, the glass layer also contains multiple layers of metal ion impurities, which will reduce the minority carrier lifetime, so a cleaning process is introduced. principle: chemical reaction. |
PECVD | Purpose: reduces the reflection loss of light, enhances the intensity of absorbed light, and improves battery efficiency. Principle: uses low-temperature plasma as the energy source. The sample is placed on the cathode of glow discharge under low pressure. The glow discharge (or additional heating element) is used to heat the sample to a predetermined temperature, and then an appropriate amount is introduced. The reaction gas reacts with plasma through a series of chemical reactions to form a solid film on the surface of the sample. |
Silk screen printing | Purpose: makes metal electrodes on both sides of the solar cell. The front side collects electrons, and the back electrode is convenient for welding and component manufacturing. Principle of : uses the basic principle that the graphic part of the screen is permeable to ink, and the non-graphic part is impermeable to ink. |
sintering | Purpose: dry the slurry on the silicon wafer, burn out the organic components of the slurry, and form a good ohmic contact between the slurry and the silicon wafer. Principle: drying, sintering and cooling, etc. |
Here is an extended introduction to the differences and connections between photovoltaic cell panels monocrystalline and polycrystalline
monocrystalline and polycrystalline are two technical routes for crystalline silicon solar energy. If a single crystal is compared to a complete stone, then polycrystalline is a stone made of gravel. Due to different physical properties, the photoelectric conversion efficiency of single crystal is higher than that of polycrystalline, but the cost of polycrystalline is relatively low.
The photoelectric conversion efficiency of monocrystalline silicon solar cell is about 18%, with the highest reaching 24%. This is the highest photoelectric conversion efficiency among all types of solar cells, but the production cost is very high, because monocrystalline silicon generally uses tempered glass. And encapsulated with waterproof resin, it is strong and durable and has a service life of up to 25 years. The manufacturing process of
polycrystalline silicon solar cell is similar to that of monocrystalline silicon solar cell , but the photoelectric conversion efficiency of polycrystalline silicon solar cell is much lower, and its photoelectric conversion efficiency is about 16%. In terms of production cost, it is cheaper than monocrystalline silicon solar cells. The material is easy to manufacture, saves power consumption, and the overall production cost is lower. The specific differences between
are as follows:
project | difference |
constitutes different | single crystal: The particles inside the crystal are arranged regularly and periodically in three-dimensional space, or the whole crystal is composed of the same spatial lattice in the three-dimensional direction. The arrangement of particles in the entire crystal is in space. For long-term order. polycrystalline: is a collection of single crystals with numerous oriented grains. |
has different characteristics than | single crystal: has a certain shape and long-range order. Such as copper single crystal, silicon single crystal, etc. Many single crystal particles with different orientations can be pieced together into polycrystals. Single crystals are anisotropic. polycrystalline: is isotropic. When taking in polycrystalline diffraction patterns or performing diffraction counting, polycrystalline samples also have their own characteristics. |
have different properties | single crystal: The macroscopic properties of each part inside the crystal are the same; different directions in the crystal have different physical properties; the crystal has a periodic structure, and when melting, each part requires the same temperature; in an ideal environment The grown crystals should be convex polygons. polycrystalline: When the grain size of polycrystalline is small, it is difficult for the grains to visually display the crystal planes, crystal prisms, etc. The sample has poor clarity and shows scattered light. |
The connection between single crystal and polycrystalline: The essence of polycrystalline is a defective single crystal.
With the rise of unsubsidized Internet bidding and the increasing scarcity of installable land resources, the global market demand for efficient products is increasing. Investors' attention has also shifted from the previous rush to install to returning to the roots, that is, the power generation performance and long-term reliability of the project itself, which is the key to future power station revenue. At this stage, polycrystalline technology still has advantages in cost, but its efficiency is relatively low.
The sluggish growth of polycrystalline technology is due to many reasons: on the one hand, R&D costs remain high, which results in new process manufacturing costs also being at a high level. On the other hand, the equipment is incredibly expensive. However, even if the power generation efficiency and performance of high-efficiency monocrystalline are beyond the reach of polycrystalline and ordinary monocrystalline, some price-sensitive customers will still be at a loss when choosing.
At present, it seems that high-efficiency single crystal technology has achieved a good balance between performance and cost. Mono crystal sales have dominated the market.
(4) Backsheet
Solar backsheet is a photovoltaic packaging material located on the back of solar cell modules. It is mainly used to protect solar cell modules in outdoor environments and resist the effects of light, humidity, heat and other environmental factors on packaging films, cells, etc. It acts as a weather-resistant insulating protection against the erosion of materials. Since the backsheet is located on the outermost layer on the back of the photovoltaic module and is in direct contact with the external environment, it must have excellent high and low temperature resistance, ultraviolet radiation resistance, environmental aging resistance, water vapor barrier, electrical insulation and other properties to meet the requirements Solar cell modules have a service life of 25 years. As the photovoltaic industry's requirements for power generation efficiency continue to increase, some high-performance solar backsheet products also have high light reflectivity to improve the photoelectric conversion efficiency of solar modules.
According to material classification, backsheets are mainly divided into organic polymers and inorganic materials. Solar backsheets usually refer to organic polymers, and inorganic materials are mainly glass. According to the production process, there are mainly composite type, coating type and co-extrusion type. At present, composite backsheets account for more than 78% of the backsheet market. Due to the increase in the market application of dual-glass components, the market share of glass backsheets exceeds 12%. Coated backsheets and other structural backsheets are approximately 10%. The raw materials of
solar backsheet mainly include PET base film, fluorine material and adhesive . Among them, the PET base film mainly provides insulation and mechanical properties, but has poor weather resistance; fluorine materials are mainly divided into two forms: fluorine film and fluorine-containing resin, which provide insulation, weather resistance and barrier properties; the adhesive is mainly composed of synthetic resin It is composed of chemicals such as , curing agent and functional additives, and is used to bond the PET base film and the fluorine film in the composite backsheet. At present, the backsheets of high-quality solar cell modules basically use fluorine-containing materials to protect the PET base film. The only difference is the form and composition of the fluorine materials used. Fluorine material is compounded on the PET base film in the form of fluorine film through adhesive, which is the composite backsheet ; it is directly coated on the PET base film in the form of fluorine-containing resin through a special process, which is the coated backsheet .
Generally speaking, composite backsheet has superior comprehensive performance due to the integrity of the fluorine film ; coated backsheet has a price advantage due to its lower material cost.
The main types of composite backsheets
Composite solar backsheets can be divided into double-sided fluorine film backsheets, single-sided fluorine film backsheets, and fluorine-free backsheets according to the fluorine content. Due to their respective weather resistance and other characteristics, they are suitable for different applications. Environment, generally speaking, the weather resistance to the environment is double-sided fluorine film backsheet, single-sided fluorine film backsheet, and fluorine-free backsheet, and their prices generally decrease in order. The mainstream backplane types and their product profiles currently on the market are as follows:
Classification standard | Product type | product overview |
Double-sided fluorine film composite backsheet | TPT backsheet (PVF/PET/PVF) | The most common type of double-sided fluorine-containing backsheet on the market, using a composite process, combining the PVF fluorine film and the middle layer PET base film Combined with adhesive. The inner layer of fluorine material protects PET from ultraviolet corrosion and is specially treated to bond better with the encapsulating film. The outer layer of fluorine material protects the back of the component from moisture, heat, and ultraviolet erosion. |
KPK type back plate (PVDF/PET/PVDF) | htm Compared with TPT, l17||
KPF type backsheet (PVDF/PET/fluorine film) | uses composite technology to PV The DF fluorine film is compounded on the PET base film through an adhesive. On the other side, the fluorine-containing resin mixed with titanium dioxide is tightly and evenly coated on the PET base film using a cast film-making process. The coating is cured at high temperature to form a layer with the PET base film. The self-adhesive fluorine-containing film is different from the fluorine coating coating that is easy to peel off. This fluorine film meets the high performance requirements of foreign fluorine film products such as UV resistance and water resistance, and at the same time, the price is significantly reduced. | |
single-sided fluorine film composite backsheet | TPE type backsheet (PVF/ PET/PE) | mainly uses PE (polyolefin film) instead of the inner fluorine film. Since one side contains fluorine, its protective performance is not as good as the TPT structure, and it is difficult to withstand the long-term anti-UV aging test, but the cost is lower than the TPT structure. |
KPE backsheet (PVDF/PET/PE) | mainly uses PE (polyolefin film) instead of the inner fluorine film. Since one side contains fluorine, its protective performance is not as good as the KPK backsheet, and it is difficult to withstand the long-term UV aging test. , but the cost is lower than the FPF structure. | |
Fluorine-free | PPE type backsheet | Usually the outer layer of PET needs to be strengthened for UV resistance and weather resistance, and is bonded with adhesives. Fluorine-free backsheets have relatively poor resistance to damp heat, dry heat, and ultraviolet rays due to their material properties, and are mainly used in photovoltaic modules with relatively low weather resistance requirements. |
Note: (1) The PVF (monofluorinated resin) film is extruded from PVF copolymer. This formation process ensures that the PVF decorative layer is dense and flawless, and there is no PVDF (difluorinated resin) coating during spraying or roller coating. Defects such as pinholes and cracks often occur, so the decorative layer insulation of PVF film is better than that of PVDF coating. PVF coated membrane materials can be used in places with more severe corrosive environments;
(2) During the manufacturing process of the PVF membrane, the extrusion arrangement of the molecular lattice in the longitudinal and transverse directions greatly enhances its physical strength, so the PVF membrane has more Great toughness;
(3) PVF membrane has stronger wear resistance and longer life;
(4) The extruded PVF membrane has a smooth and delicate surface, with no streaks, orange peel or micro-wrinkles on the surface caused by roller coating or spraying. class defects.
Applicable scenarios
Double-sided fluorine film composite backsheet Due to its superior weather resistance, it can withstand harsh environments such as severe cold, high temperature, wind and sand, rain, etc., and is usually widely used in plateaus, deserts, Gobi and other areas; Single-sided fluorine film composite backsheet is a cost-reduced product of double-sided fluorine film composite backsheet. Compared with double-sided fluorine film composite backsheet, its inner layer has poor UV resistance and heat dissipation, Mainly suitable for roofs and areas with mild UV rays.
6. Photovoltaic inverter
In the process of solar photovoltaic power generation , the power generated by the photovoltaic array is DC power, but many loads require AC power energy. The DC power supply system has great limitations. It is not convenient to convert voltage, and the load application range is also limited. Except for special electrical loads, an inverter is required to convert DC power into AC power. The photovoltaic inverter is the heart of the solar photovoltaic power generation system. It converts the DC power generated by the photovoltaic power generation system into the AC power required for life through power electronic conversion technology. It is one of the most important core components of the photovoltaic power station.
photovoltaic inverter is mainly composed of input filter circuit, DC/DC MPPT circuit, DC/AC inverter circuit, output filter circuit, and core control unit circuit.The types of photovoltaic inverters are:
classification standard | types |
according to the number of phases of the output AC voltage | single-phase inverter and three-phase inverter |
are applied in grid-connected power generation system or off-grid power generation system | grid-connected inverter and off-grid inverter |
Types of photovoltaic power generation applied | Centralized photovoltaic power generation inverter and distributed photovoltaic power generation inverter |
Whether energy is stored | Grid-connected inverter and energy storage inverter |
Technical route | Centralized inverters, string inverters, distributed inverters and micro inverters |
The current market is mainly dominated by centralized inverters and string inverters. With the rapid growth of the distributed photovoltaic market and the increasing proportion of string inverters in centralized photovoltaic power plants, string inverters account for approximately 60% of the installed capacity of photovoltaic power plants. The centralized inverter converts the aggregated DC power into AC power, which has a relatively large power; the string inverter converts the DC power generated by the components directly into AC power and then aggregates it, and the power is relatively small. The comparison between centralized inverter and string inverter is as follows:
Inverter type | Advantages | Disadvantages | Application fields | Development trends |
String inverter | is small in size and light in weight, easy to transport and install; has small self-loss at night; small single unit capacity, small loss of power generation in case of failure; photovoltaic modules generate more electricity | has low conversion power; high power density, high operating temperature of components, relatively high failure rate, and relatively high cost. | distributed power stations such as household and industrial and commercial rooftops, agricultural greenhouse photovoltaics, and water surface photovoltaics, as well as concentrated power stations such as hills and large ground The single-machine power of | power stations is becoming larger. development, effectively lowering the cost of a single watt, and the application of ground power stations is gradually increasing; the conversion efficiency continues to improve, and it is developing towards technical fields such as intelligence and security. |
Centralized inverter | has high conversion efficiency; small number of components and low cost ,reliability High | A single unit is large in size, heavy in weight, and difficult to transport and install; it requires separate construction and installation of infrastructure; a single unit has a large capacity, resulting in large power generation losses in the event of a failure | Large centralized power stations such as ground and mine pits | Continuously improve the capacity of a single machine, reduce power station investment and cost of electricity |
After the concept of smart power stations was proposed, the importance of photovoltaic inverters has become more and more prominent. The design and manufacturing of photovoltaic inverters need to be considered from the perspective of the entire system, in addition to conversion efficiency, but also take into account comprehensive protection, stable operation, safety and reliability, and grid friendliness. ; As photovoltaic power station management becomes more and more refined, photovoltaic inverters carry tasks such as data collection, power station monitoring, and energy management. They are uploaded to network servers or local computers through GPRS, Ethernet, Wi-Fi, etc., allowing users to Relevant data can be viewed on the Internet, mobile phones or local computers, making it convenient for power station managers and users to view and manage the operating data of photovoltaic power stations, which can save a lot of manpower and material costs.
(1) photovoltaic grid-connected inverter
photovoltaic grid-connected inverter not only converts direct current into alternating current, but its output alternating current can be synchronized with the frequency and phase of the mains power, so the output alternating current can be returned to the mains power. The application diagram of photovoltaic grid-connected inverter is as follows:
(2) Photovoltaic energy storage inverter
Photovoltaic energy storage inverter integrates the functions of photovoltaic grid-connected power generation and energy storage power station, which can overcome the unstable power generation of photovoltaic modules due to weather changes. Disadvantages: improve the quality of the power grid; by storing electric energy at the trough and outputting electric energy at the peak, the peak power generation of the grid can be greatly reduced, the capacity of the grid can also be greatly increased, and the utilization rate of the grid can be improved. Photovoltaic energy storage inverters can be used in centralized and distributed photovoltaic power stations. The specific working principle of the
photovoltaic energy storage inverter is: the power generated by photovoltaics is given priority to local loads, and excess energy is stored in the battery. If there is still excess power, it can be selectively integrated into the grid. When the photovoltaic power generation is insufficient, the battery discharges to provide electric energy for local loads, thereby reducing dependence on the power grid and traditional energy sources.
Renewable energy has developed rapidly in recent years and has huge potential. However, instability has restricted the rapid development of renewable energy, resulting in a large amount of light and electricity abandonment. Energy storage products can smooth the fluctuations of renewable energy and promote An important means for large-scale consumption and integration of renewable energy. Energy storage is also one of the key technologies in the new energy utilization model of Energy Internet . Energy storage inverters are the interface between the power grid and energy storage devices and can be used in different situations (grid-connected systems, island systems and hybrid systems). Energy storage inverter is a type of inverter suitable for smart grid construction and used in energy storage. It has two-way inversion as its basic feature and has a series of special performances and functions. Energy storage is a necessary condition for the realization of smart grids. The energy storage link in smart grids can effectively regulate power resources, balance the difference in power consumption between day and night and in different seasons, adjust surplus and shortage, and ensure the security of the grid. It is an application of renewable energy. An important prerequisite and an effective means to realize interactive management of power grid. Energy storage inverters are suitable for various applications that require dynamic energy storage. They store electric energy when the electric energy is surplus. When the electric energy is insufficient, they invert the stored electric energy and output it to the grid. They play an emergency independent inverter role in the microgrid. .
7. Photovoltaic brackets
Photovoltaic brackets are special equipment designed and installed in solar photovoltaic power generation systems to support, fix and rotate photovoltaic modules. In order for the photovoltaic power station to achieve the best power generation efficiency, the photovoltaic brackets need to be fixed in a certain orientation, arrangement and spacing according to the topography, climate and solar resource conditions of the construction site. As the "skeleton" of the power station, the performance of the photovoltaic bracket directly affects the power generation efficiency and investment income of the photovoltaic power station.
With the gradual decline of photovoltaic subsidies, it is increasingly difficult to improve the photoelectric conversion efficiency of battery components, and there are fewer flat and low-cost sites. Photovoltaic brackets are playing an increasingly important role in photovoltaic power station investment. regards them as a way to reduce costs and increase efficiency. , important measures to improve the investment efficiency of power stations . In recent years, photovoltaic stents have developed rapidly in terms of technology and market. On the one hand, photovoltaic bracket products are becoming more lightweight and high-strength, innovating in structures, materials, etc., improving product performance, reducing material weight, and reducing manufacturing costs and transportation costs; on the other hand, the degree of integration and intelligence is increasing day by day. Through continuous integration Designed to facilitate on-site construction and later operation and maintenance, while integrating artificial intelligence , Internet of Things, big data and other new generation information technologies, the power generation efficiency has been further improved.
(1) Photovoltaic brackets are divided into fixed brackets and tracking brackets
according to whether they can track the rotation of the sun. The design requirements, power generation efficiency and application instructions in photovoltaic power generation systems are as follows:
. In terms of design requirements,
needs to be based on the item. The destination geological survey report is used to complete the preliminary design of the support foundation; secondly, the pull-out force test of the column is completed according to the stress condition of the support, and the support foundation form and column form are determined; at the same time, wind load, snow load and other climatic conditions are determined according to different national standards, different project locations Confirm the overall bracket design; finally, complete the corresponding bracket arrangement and single bracket design based on the component form, number of modules in series, inverter, combiner box and other photovoltaic components in the photovoltaic system.
photovoltaic power stations using fixed brackets. At the beginning of the design, the components will be fixed at a specific angle based on the local geographical environment, climate and other conditions to ensure that they can receive the maximum solar radiation. Generally, the component positions will not change after they are fixed. No matter how frequent adjustments are, for fixed and adjustable brackets, the component orientation will be manually adjusted every year based on the season and light conditions. Fixed brackets are cheaper, more stable, and have lower initial investment costs, but their utilization rate of solar energy is lower than that of tracking brackets. adopts a photovoltaic system with tracking brackets. The orientation of its components is automatically adjusted according to the lighting conditions, which can reduce the angle between the components and direct sunlight, obtain more solar radiation, and effectively improve power generation efficiency. Power stations that use tracking brackets need to increase a certain initial investment cost, and need to bear certain device operation risks and later operation and maintenance costs. The selection of fixed brackets and tracking brackets in photovoltaic power station systems requires comprehensive consideration of various factors and detailed input-output marginal benefit calculations. In summary, fixed brackets have disadvantages in terms of power generation efficiency, strong wind resistance (fixed windward area), etc., as well as disadvantages in terms of stability, cost, cable investment, operation and maintenance (small workload, easy board cleaning), etc. Advantages; On the contrary, the tracking bracket has comparative advantages in improving power generation efficiency and facilitating the integration of bifacial components and other technologies, but it also has problems such as high cost and stability. Photovoltaic stent requires comprehensive use of structural mechanics system (static load, dynamic load, etc. fluid mechanics ), mechanical drive system, electronic control system and other multi-disciplinary professional knowledge. The design and product structure are relatively complex and have high technical content. Balance the relationship between cost and power generation gain to design the optimal solution. photovoltaic bracket products are mainly used to install, support and fix photovoltaic modules. Topographic factors need to be considered, and the foundation and bracket design should be adjusted according to complex terrain such as flat land, mountains, hills, Gobi, farmland, tidal flats and other complex terrains; at the same time, photovoltaic brackets need to have strong Wind, snow and earthquake resistant , anti-corrosion and other properties to meet the needs of long-term operation in various natural environments such as wind, frost, rain and snow; the tracking bracket needs to combine the bracket system, electronic control system and drive system to improve the power generation of the power station by calculating the optimal control scheme efficiency, while achieving remote control of photovoltaic power stations requires power station automation and intelligent technologies. . In terms of power generation efficiency
(2) Application in photovoltaic power generation system
(3) Characteristics of the stent industry
and technical content