Main materials and equipment selection and requirements for distributed photovoltaic power station


1. Photovoltaic support roof support adopts hot-dip galvanized carbon steel support, and components are fixed on aluminum alloy purlins by backplane or pressing block.The fasteners are made of stainless steel.The designed wind resistance capacity of the bracket is 30m/s;Ensure long-term outdoor use requirements.Material and performance requirements: (1) Material requirements.The main material of steel structure is Q235B. The electrode is E43 series electrode.(2) Mechanical properties requirements.Tensile strength, elongation, yield point, cold bending test and other mechanical properties of the selected steel structure should comply with the relevant provisions of carbon Structural Steel (GB/T 700-2007).(3) Chemical composition requirements.The content of carbon, sulfur, phosphorus and other chemical elements of the main material of the steel structure shall conform to the relevant provisions of Carbon Structural Steel (GB/ T700-2007).(1) Steel members shall be treated on the surface, and the method and grade of rust removal shall comply with the relevant provisions of the current national standard “Corrosion grade and Rust Removal Grade of Steel Surface before painting” (GB/ T8923-2011).(2) rust removal method.Steel members can be sandblasted or shot peening derusting method, if the chemical derusting method, should be selected with rust removal, phosphatizing, passivation two or more functions of the treatment liquid, its quality should be in line with the current national standard “multi-functional steel surface treatment liquid general technical conditions” (GB/ T12612-2005).(3) Derusting grade.The derusting grade shall meet the requirements of Sa2 1/2.Anticorrosion requirements: (1) steel members using metal protection layer anticorrosion mode.Steel structure supports are coated with hot-dip galvanized coating. Hot-dip galvanized coating shall meet the relevant requirements of “Technical Requirements and Experimental Methods of Hot-dip Galvanized Coating for Steel And Metal Covered Parts” (GB/T13912 — 2002), and the thickness of galvanized coating shall not be less than 80μm.(2) Galvanized thickness detection.The thickness of galvanized layer shall be tested in accordance with the method provided in Technical Requirements and Experimental Methods for Hot Dip Galvanized Layer of Metal Covering Steel Parts.(3) hot dip galvanized anti-deformation measures.Reasonable anti-deformation galvanizing scheme is adopted to prevent obvious deformation of components after hot dip galvanizing.Aluminum alloy material: 1 material requirements.The material is generally 6061 or 6063.② Mechanical properties requirements.The base material quality, chemical composition and mechanical properties of the selected aluminum profiles must comply with the relevant provisions of GB 5237.1.③ The surface treatment must meet the technical requirements, in line with GB 5237.2 — 2004 “Aluminum alloy building Profiles, Part 2; Anodized, colored profiles”.④ The appearance quality of the profile conforms to the provisions of GB 5237.2 — 2004. The surface of the profile should be neat and smooth, and serious defects such as cracks, peeling, corrosion and bubbles are not allowed.2. Cement foundation Cement foundation using C30/20 label, and a 20-day curing cycle.Add reinforcement or embedded parts according to the design drawings.3. Photovoltaic modules (1) The service life of photovoltaic modules under normal conditions is not less than 25 years, and the module power standard is strictly in accordance with the relevant requirements in TUV IEC61215, IEC61730.The output power shall not be less than 80% of the standard power in the 25-year service life.(2) The single power of the polycrystalline silicon module provided shall not be less than 255W, and the photovoltaic module shall have a high area ratio of power and area ratio not less than 143.5W/m².The power to mass ratio is greater than 12W/kg, and the filling factor FF is greater than 0.70.(3) The components are packaged in class A standard battery pack (NO defects in EL imaging). The color of the upper surface of the battery of the components is uniform, no mechanical damage, and no oxidation spots on the solder joints.(4) Each battery and interconnection strip of the component shall be neatly arranged, and the frame of the component shall be clean and free from corrosion spots.(5) Bubble or delamination is not allowed to form a path at the edge of a battery and the component in the package layer of the component. The geometric size and number of bubble or delamination should comply with the detailed specifications of the corresponding product.(6) The insulation resistance of the component can not be less than 200M ω under normal conditions.(7) The photovoltaic cell surface should have good self-cleaning ability;Surface resistance to corrosion and wear should meet the requirements of the corresponding national standard.(8) EVA, glass and other laminated packaging components, EVA cross-linking degree should be in 75% ~ 85%, EVA and glass peel strength is greater than 50N/cm.The peeling strength of EVA and component backplane is greater than 40N/cm.(9) The contractor shall provide test data of photovoltaic modules, calibration test equipment of standard components calibrated by TUV, and test standard STC (T=25℃, 1000W/m², AM1.5).(1) Photovoltaic cables must be certified by domestic or international certification bodies with TUV certification and UL certification.Certification certificate.(2) The dc side cable should be selected according to the principle of reducing line loss and preventing external interference. The double insulation uv resistant flame retardant copper core cable should be selected. The cable performance meets the requirements of GB/T 18950-2003 performance test;Z-pfg DC cables are recommended.(3) THE AC side needs to be selected according to the form and safety of laying, using multi-strand copper core fire-retardant cable;The recommended model is ZR-YJVR.Photovoltaic grid-connected inverter (hereinafter referred to as inverter) is the core equipment in photovoltaic power generation system, and must use mature products of high quality and good performance.The inverter inverts the direct current (DC) generated by the photovoltaic array into single-phase sinusoidal alternating current (AC), and outputs the electric energy that meets the requirements of the power grid.The inverter should meet the following requirements: (1) The power factor and power quality of grid-connected inverter should meet the requirements of China’s power grid, and all performance indexes should meet the requirements of “Technical Regulations for Photovoltaic Power Station Access to Power Grid” issued by State Grid Corporation in May 2011.(2) The installation of the inverter should be simple and without special requirements.(3) The inverter shall adopt the maximum power tracking technology (MPPT) of solar cell components.(4) All the inverters used have the performance of safe operation for more than 3 years.(5) The inverter is required to be able to run automatically with a high degree of visualization of the running state.The display clearly displays real-time operating data, real-time fault data, historical fault data, total energy yield data, and historical energy yield data (queried by month or year).(6) The inverter is required to have the function of automatic recording and storage of fault data, and the storage time is more than 10 years.(7) The inverter body requires a DC input break switch, emergency stop operation switch.(8) The inverter should have short circuit protection, island effect protection, overtemperature protection, AC and DC overcurrent protection, DC bus overvoltage protection, power grid outage, power grid overvoltage and undervoltage, power grid overfrequency, photovoltaic array and inverter itself grounding detection and protection functions, etc.And the corresponding conditions and working conditions of each protection function are given (i.e. when protection action, protection time, self-recovery time, etc.).(9) The inverter shall be certified by the national approved certification body in accordance with the requirements of CNCA/CTS0004:2009 certification technical specifications.(10) The average fault-free time of inverter is not less than 10 years, and the service life is not less than 25 years.(11) The warranty period of the inverter is not less than 5 years.(12) The inverter shall have low voltage crossing capability.(1) Switch cabinet adopts standard modular design, which is composed of various standard units with module E=25mm. Units of the same specification have good interchangeability.(2) All primary equipment and components shall be able to withstand the dynamic and thermal stable current not lower than that of the bus without damage.All electrical components shall be CCC certified, and the distribution cabinet shall provide full type test/partial type test with sufficient operating performance.(3) The main bus and branch bus are made of copper material with high conductivity.When bolted, there should be no less than two bolts per joint.(4) Wiring.The rated voltage of the secondary terminal block is not less than 1000V, and the rated current is not less than 10 a. the secondary terminal block has a partition board, labeled cable sleeve, and terminal screw.Each terminal block shall be numbered.All the conductors of the control loop should use the insulation voltage not less than 1000V. Except for the leading wire of the secondary plug-in in the power distribution cabinet, the multi-strand copper stranded wire with a cross section of not less than 2.5mm2² should be used for other conductors.Both ends of the guide wire should be numbered.The position of terminal block should consider convenient disassembly and wiring, and reserve 20%.Terminal block should be flame retardant terminal.(5) Selection of main components.Frame circuit breaker, molded case circuit breaker, contactors, thermal relays and other international and domestic high-quality products, with domestic certification products.ABB circuit breaker, Phoenix lightning protector and other high-quality devices are selected.Frame circuit breaker has its own intelligent protection unit configuration;The protection unit has perfect three-stage protection and upper and lower level coordination function.Feeder molded case circuit breaker should adopt electronic release or thermomagnetic electronic release.Switch cabinet control and display components such as;Selection switches, buttons, indicators, relays, current transformers, etc., should choose high-quality products with operating experience.7. Photovoltaic construction auxiliary materials (1) bridge.In the process of construction, the screws used in the hot dip galvanized bridge used by the outdoor bridge are stainless steel series or measures are taken to prevent rust.The thickness of zinc layer shall not be less than 65mm for thin plates less than 5mm, and not less than 86μm for thick plates.(2) Lightning protection grounding flat iron.The flat iron parameters used are 25mm×4mm and 4mm×40mm hot-dip galvanized flat iron for welding.(3) PVC power sheath pipe.It is mainly used for cable laying on optical volt AC side. The fixed bushing adopts 304 stainless steel screws.(4) Screws, nuts, nuts.All the materials are made of 304 stainless steel to achieve fixed strength and anti-rust function.

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