With its advantages of cleanliness, safety and abundant resources, solar power generation technology is gradually playing an increasingly important role in energy transformation, and will become one of the main forms of power supply in my country in the future.

The photovoltaic industry has become one of the few industries in my country that can simultaneously participate in international competition and gain a leading edge in industrialization. my country's photovoltaic industry chain ranks first in the world in terms of production capacity and output, and its installed capacity ranks first in the world for seven consecutive years. The solar bracket is a supporting device designed for placing, installing and fixing photovoltaic modules in the photovoltaic system.

Scope of application
T/CPIA0013-2019 "Photovoltaic Support" specifies the relevant terms and definitions of photovoltaic supports, product classification, product marking, raw material requirements (aluminum alloy, steel and hardware, composite), product requirements (appearance, dimensional deviation, allowable length and slenderness) ratio, structural or component deformation requirements, anti-corrosion, composite support environmental durability and fire protection requirements), test methods, inspection rules and marking, packaging, transportation and storage, etc.
This standard applies to ground-mounted solar mounts, including fixed solar mounts and fixed tilt-adjustable mounts. The ground-mounted photovoltaic supports in this standard refer to photovoltaic supports installed directly on the surface of plains, mountains, tidal flats, lakes, etc., excluding photovoltaic supports installed on buildings, but photovoltaic supports installed on flat roofs can be implemented by reference.
Among them, the fixed bracket refers to the photovoltaic bracket whose inclination angle is fixed and the inclination angle at which the photovoltaic module obtains the largest amount of solar radiation is usually used as the installation inclination angle in one year. Fixed inclination adjustable bracket refers to a photovoltaic bracket whose inclination can be manually adjusted for a limited number of times according to the maximum solar radiation obtained by photovoltaic modules in different time periods.
In addition, according to the material, the standard is applicable to steel brackets, aluminum alloy brackets and composite brackets.

Standard point analysis
Size deviation
Whether it is a steel bracket, an aluminum alloy bracket or a composite material bracket, the wall thickness of the solar bracket rod is the basis for ensuring the structural strength of the bracket, so it is stipulated that the wall thickness of the bracket rod should not have a negative tolerance.
In order to make full use of solar energy, the assembled structure of the photovoltaic support should be as close to the design value as possible to ensure that the photovoltaic modules are at the best inclination angle and the structure is stable and beautiful.
The dimensional deviation in this standard refers to the deviation of the bracket from the design value after the bracket is pre-assembled before leaving the factory. For the fixed bracket, four key indicators are selected: installation inclination, bracket beam elevation, bracket column surface, and rod centerline; for the inclination adjustable bracket The bracket additionally specifies the deviation of the adjustment angle from the set value (adjustment accuracy).

allowable slenderness ratio of components
If the slenderness ratio of the component is too large, it will cause eccentricity due to deformation due to its own weight. It is easy to bend during transportation and installation, and it will vibrate greatly under the action of dynamic load. Therefore, the slenderness ratio of the component needs to be limited. The adverse effects of compression members due to insufficient stiffness are far more serious than those of tension members, so the allowable value of slenderness ratio of compression members is generally smaller than that of tension members (the smaller the allowable value of slenderness ratio, the higher the resistance to deformation). The allowable slenderness ratio of steel bracket members in this standard is determined according to 6.8.9 of GB50797-2012 "Code for Design of Photovoltaic Power Stations"; the allowable slenderness ratio of aluminum alloy bracket members is determined according to 4.5.4 of GB50429-2007 "Code for Design of Aluminum Alloy Structures" Determined with 4.5.5; composite support members are determined based on experience, with reference to the minimum allowable slenderness ratio of steel support and aluminum alloy support members.

Structural stability (deformation requirements)
The structural stability of photovoltaic supports was evaluated by static load deformation tests. According to the different load directions applied to the component plane, it can be divided into two types: vertical horizontal plane static load deformation test and vertical component plane static load deformation test, the former is the main one. During the static load deformation test on the vertical horizontal plane, the surface load is uniformly applied on the component plane as shown in Figure 1, and the direction is downward along the normal line of the horizontal plane. The surface load value is the standard value of the snow load, the unit is kN/m2, and the duration is 1h.
Observe and record the reading of the displacement measuring instrument and the deformation of the specimen. During the static load deformation test of the vertical component surface, the bracket is installed on a fixed inclined table with an inclination angle of α, α is the installation inclination angle of the bracket component, and the surface load is uniformly applied on the component plane as shown in Figure 2, and the direction is along the component plane method. When the line is upward, the surface load value is the standard value of wind load, the unit is kN/m2, and the duration is 1h. Observe and record the reading of the displacement measuring instrument and the deformation of the specimen.
For fixed brackets, the column top displacement should not be greater than 1/60 of the column height; for fixed inclination adjustable brackets, the column top displacement should not be greater than 1/80 of the column height.

The deflection of the bending member is the key to ensure the overall structural stability of the solar support. According to the provisions of GB50797-20126.8.8 and GB50429-20074.4.1, the allowable deflection of the main beam of the steel bracket and the aluminum alloy support is l/250, and the allowable deflection of the secondary beam is l/250 (installation of frameless photovoltaic modules). ), l/200 (install other forms of components). The allowable value of deflection of flexural members in this standard is determined with reference to the above-mentioned design specifications and combined with actual project experience.

anti-corrosion
The designed service life of the solar photovoltaic system is generally 25 years, and the solar mount system is placed outdoors for a long time to withstand wind, sun and rain. At present, the materials used for photovoltaic supports mainly include three categories: steel, aluminum alloy, and composite materials.
As the most widely used type at present, steel brackets are also the most prone to rust, so they must be treated with anti-corrosion. For carbon structural steel, low-alloy high-strength structural steel, alloy structural steel and other steel supports, hot-dip galvanizing is usually used for anti-corrosion.
This standard guarantees the corrosion resistance of steel brackets through galvanized coating thickness and salt spray corrosion resistance test. The minimum thickness of the galvanized layer is given according to different application scenarios, and the time and protection rating requirements of copper accelerated acetic acid salt spray corrosion test are specified for weak corrosive environment, medium corrosive environment and strong corrosive environment respectively.

The surface anti-corrosion treatment technology of aluminum alloy profiles mainly adopts anodizing method for surface treatment. The standard specifies the minimum thickness of the surface treatment layer of aluminum alloy profiles and the time and protection rating requirements of the copper accelerated acetic acid salt spray corrosion test for the application environments of three different corrosion grades: weak corrosion, moderate corrosion and strong corrosion to ensure the long-term corrosion resistance of aluminum alloy brackets.
Composite stents are generally made of fiber-reinforced composite materials, such as polyester fiberglass, epoxy fiberglass, phenolic fiberglass, etc., which naturally have excellent corrosion resistance. However, polymer-based composites are prone to aging. Therefore, for composite stents, according to the existing GB/T31539-2015 "Fiber Reinforced Composite Pultruded Profiles for Structural Use", water resistance performance tests, alkali resistance performance tests, and ultraviolet durability performance tests are proposed. , Freeze-thaw cycle durability test requirements to ensure the long-term environmental durability of composite scaffolds.
Fire protection requirements for composite supports
When the photovoltaic power generation system is running, arcs may be generated and there is a fire hazard. Therefore, the polymer matrix composite support is required to have a certain flame retardancy. The standard selects two indicators of combustion performance and glow wire finished product test to ensure the flame retardancy of composite materials.
The combustion performance should meet the HB level requirements specified in 8.4 of GB/T2408-2008 "Determination of the combustion performance of plastics horizontal method and vertical method".
Glow wire finished product test should comply with GB/T5169.11-2017 "Fire Hazard Test for Electrical and Electronic Products Part 11: Glow Wire/Basic Test Method for Glow Wire Flammability Test Method for Finished Products (GWEPT)", the test temperature is 750°C. According to the actual test situation, the composite support that meets the two indicators of combustion performance and glow wire finished product test has excellent flame retardancy, which can meet the fire protection requirements of photovoltaic system applications, and can reduce the rapid spread of fire.

Significance of Standard Implementation and Future Prospects
The formulation of T/CPIA0013-2019 is based on ensuring the safe and reliable operation of photovoltaic systems, based on the principles of science, rationality and operability, and based on the technical level of domestic photovoltaic support design and production. It is the first group standard for support products in my country's photovoltaic industry.
The formulation of this standard is to reduce the assembly error of photovoltaic support, ensure the overall bearing capacity of the support, improve the anti-corrosion ability (or environmental durability) of the support, and provide a technical basis for ensuring the quality level of photovoltaic support products.
In 2019, the benchmarking and user-end promotion catalogue work was carried out for three photovoltaic material products, such as photovoltaic tin-coated solder tape, ethylene-vinyl acetate copolymer (EVA) film, and copolymerized olefin (PO) film. Significant results have been achieved in standard implementation, product quality improvement, and brand building.
In the next step, based on T/CPIA0013-2019, we will carry out the catalogue of solar mounting standards and standards, comprehensively promote the quality improvement of photovoltaic mounting products, build a bridge of quality assurance for the upstream and downstream of the industrial chain, reduce product selection costs, and provide photovoltaic support The low-cost and high-quality development of the industry is guaranteed.