In addition to the design of the battery capacity and the size of the solar module, photovoltaic system design also considers how to choose the right system equipment, that is, how to select solar system components, batteries, and inverters (systems with AC loads) that meet the needs of the system. , controllers, cables, wiring boxes, component brackets, diesel/gasoline (photovoltaic hybrid systems), wind turbines (wind-solar hybrid systems), for large-scale solar photovoltaic power stations, transmission and distribution engineering components such as transformers, Lightning arrestors, load switches, air circuit breakers, AC-DC power distribution cabinets, and system infrastructure, control room construction, transmission and distribution and other issues. The selection of the above-mentioned various equipments needs to comprehensively consider the actual conditions of the location of the system, the scale of the system, the requirements of the customer and other factors. Solar cell modules, component supports, batteries, inverters, and controllers are described in detail in other sections of this book and are not described here. Cable selection The selection of cables in the system mainly considers the following factors: ü Cable insulation performance; ü Heat and flame resistance of the cable; ü cable moisture, light protection; ü Cable laying method; ü type of cable core (copper core, aluminum core); u size specifications of the cable. The connection between the different components in the PV system, because of the different environments and requirements, the cable is not the same. The following lists the technical requirements for different connection sections: 1) Connection between components and components Must carry out UL test, heat-resistant 90 °C, anti-acid, anti-chemical substances, moisture-proof, anti-exposure. 2) Connection between square matrix and square matrix Can be open or buried in the ground, requiring protection against moisture and exposure. It is recommended to wear the tube and the conduit must be heat resistant at 90°C. 3) Wiring between battery and inverter You can use multiple strands that pass the UL test, or use an electric welder cable that passes the UL test. 4) Indoor wiring (ambient drying) Shorter DC connections can be used. Cable size design, must follow the following principles: 1) Short-distance DC connection of storage battery to indoor equipment. The rated current of the selected cable is 1.25 times of the continuous current of the cable. 2) AC load connection. The rated current of the selected cable is 1.25 times the maximum continuous current in the calculated cable. 3) Connection of the inverter. The rated current of the selected cable is 1.25 times the maximum continuous current in the calculated cable. 4) The connection between the inside of the square matrix and the square array, the selected cable rated current is 1.56 times the maximum continuous current in the calculated cable. 5) Consider the effect of temperature on the performance of the cable. 6) Consider that the voltage drop should not exceed 2%. 7) The proper cable diameter selection is based on two factors, current strength and circuit voltage loss. The complete calculation formula is: Line loss = current × circuit bus length × cable voltage factor The cable voltage factor in the equation can be obtained by the cable manufacturer. 4 20Ma Electrical Actuator,Electric Actuator,Switch Type Electric Actuator,Oem Service Electric Actuator ZHEJIANG KINKO FLUID EQUIPMENT CO.,LTD , https://www.kinkoflow.com