This paper mainly introduces the cable selection and design methods in photovoltaic systems, including the factors that should be taken into consideration when selecting cables in photovoltaic systems, how to select suitable cables in different environments, and the principles that cable size specifications should follow.
First, the choice of cables in the photovoltaic system mainly considers the following factors:
1, the insulation performance of the cable;
2, the heat-resistant flame-retardant cable performance;
3, cable moisture, light protection;
4, the laying of the cable;
5, the type of cable core (copper core, aluminum core);
6, the size of the cable specifications.
Second, the connection between different components in the photovoltaic system, due to 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) 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.
3) 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.
4) Indoor wiring (ambient drying)
Shorter DC connections can be used.
Third, the 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) The connection between the inside of the square matrix and the square matrix, the selected cable rated current is 1.56 times the maximum continuous current in the calculated cable.
3) AC load connection. The rated current of the selected cable is 1.25 times the maximum continuous current in the calculated cable.
4) Connection of the inverter, the rated current of the selected cable is 1.25 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 appropriate cable diameter selection is based on two factors, current strength and circuit voltage loss. The formula is:
Line loss = current × circuit bus length × cable voltage factor (available from the cable manufacturer).
Spring Washer,wave spring washer,disc spring washer,helical spring washer
Jiangsu Minglu Stainless steel Co.,ltd , https://www.jsminglubolt.com