PV cable The selection of cross section shall meet the requirements of allowable temperature rise, voltage loss, mechanical strength, etc. The DC system cable shall be
The long-term allowable current carrying capacity shall be selected and verified according to the allowable voltage drop of the cable. The calculation formula is as follows:
According to the long-term allowable current carrying capacity of the cable: Ipc>=Ical
According to the allowable voltage drop of the circuit: Scac=P ・ 2LIca/△ Up
Where: Ipc ---- allowable current carrying capacity of cable, A;
Ica ---- calculated current, A;
Ical ---- Calculated current for long-term operation of the circuit, A;
Scac ---- cable calculation section, mm2;
P - resistance coefficient, copper conductor P=0.0184 Ω• mm2/m, aluminum conductor P=0.0315 Ω• mm2/m;
L ---- cable length, m; △ Up ---- allowable voltage drop of circuit, V.
Note: The current carrying capacity of the photovoltaic cable is greatly affected by the laying method and the surrounding environment, and the voltage drop of the cable is relatively affected by the cable length
Large, so the current carrying capacity can be considered as the value that can never be exceeded during long-term operation of the cable. It is better to select 70%~80% of the current carrying capacity of the cable
Cable selection can effectively ensure the temperature rise and voltage drop of the line.