1. Relevant standards and specifications for the selection of special cables in solar photovoltaic power generation systems
1. DL/T5044-2004 People's Republic of China Electric Power Industry Standard
2. GB50217 Power Engineering Cable Design Code
2. Main technical requirements for special cables in solar photovoltaic power generation systems
1. Two-core cables should be used for the DC power supply circuit, and single-core cables can be used when needed.
2. Polyvinyl chloride insulated cables are not suitable for high temperature above 100℃ or low temperature below -20℃.
3. When laying cables directly, steel tape armored cables should be used when the cables are under heavy pressure or are in danger of mechanical damage.
4. The temperature of the cable core under the action of the operating current shall not exceed the allowable value determined according to the service life of the cable.
5. Determine the ambient temperature for the continuous allowable current carrying capacity of the cable. If the cable is laid in the air or in the cable trench, the average value of the high temperature should be taken.
3. The selection of special cable path in solar photovoltaic power generation system should meet the following requirements
1. Avoid the cables suffering from mechanical external force, overheating, corrosion and other hazards.
2. Make the cable shorter when meeting safety requirements.
3. Easy to install and maintain.
4. Avoid the place to be excavated. The cable shall meet the requirements of the allowable bending radius of the cable in any way of laying and all path conditions of the cable.
4. Types, characteristics and laying methods of special cables in solar photovoltaic power generation systems
1. Special photovoltaic cables
The cables from the string to the combiner box generally use photovoltaic special cables PV1-F1*4mm2. The photovoltaic cable has a simple structure, and the polyolefin insulation material it uses has excellent heat resistance, cold resistance, oil resistance, and ultraviolet resistance. It can be used under harsh environmental conditions and has a certain mechanical strength.
2, power cable
1) Steel tape armored flame-retardant cross-linked cable ZRC-YJV22
Widely used: connecting cable from combiner box to DC cabinet, DC cabinet to inverter, inverter to transformer, transformer to power distribution device, and power distribution device to power grid.
2) Power cable NH-VV
NH-VV copper core PVC insulated PVC sheathed fire-resistant power cable.
3, control cable
ZRC-KVVP copper core PVC insulated PVC sheathed braided shielded control cable. It is suitable for control and monitoring circuits and protection circuits of AC rated voltage 450/750V and below.
4, communication cable
1) DJYVRP2-22 polyethylene insulated PVC sheathed copper wire braided shielded armored computer special soft cable, suitable for the rated voltage of 500V and below, for electronic computers and automation connection cables with high requirements for interference prevention.
2) RVVP copper core PVC insulated PVC sheathed insulated flexible shielded flexible cable RVVP, also known as electrical connection anti-interference flexible cable, is suitable for alarm, security and other communication cables that need to prevent interference and safe data transmission.
5. RF cable
Solid core polyethylene insulated PVC sheathed radio frequency coaxial cable SYV.
