Introduction to the use of cables and materials commonly used in solar photovoltaic power stations
During the construction of a solar photovoltaic power station, in addition to the main equipment, such as photovoltaic modules, inverters, and step-up transformers, the photovoltaic cable materials connected to the photovoltaic power station have the same effect on the overall profitability, operation safety, and high efficiency of the photovoltaic power station. plays a vital role..
According to the system of solar photovoltaic power station, cables can be divided into DC cables and AC cables. According to the different uses and use environments, they are classified as follows:
1. DC cable ( or PV cable)
(1) Serial cables between components.
(2) Parallel cables between the strings and between the strings and the DC distribution box (combiner box).
(3) The cable between the DC distribution box and the inverter.
The above cables are all DC cables, and there are many outdoor layings. They need to be moisture-proof, sun-proof, cold-resistant, heat-resistant, and UV-resistant. In some special environments, they also need to be protected from chemicals such as acid and alkali.
2. AC cable (LV&MV power cable, etc.）
(1) The connecting cable from the inverter to the step-up transformer.
(2) The connecting cable from the step-up transformer to the power distribution device.
(3) The connecting cable from the power distribution device to the power grid or the user.
This part of the cable is an AC load cable, which is laid in the indoor environment and can be selected according to the general power cable selection requirements.
3. Photovoltaic special cable
A large number of DC cables in photovoltaic power plants need to be laid outdoors, and the environmental conditions are harsh. The cable materials should be determined according to the resistance to ultraviolet rays, ozone, severe temperature changes and chemical erosion. The long-term use of ordinary material cables in this environment will cause the cable sheath to be fragile, and even decompose the cable insulation. These conditions will directly damage the cable system, but also increase the risk of short-circuiting the cable. In the medium and long term, the possibility of fire or personal injury is also higher, which greatly affects the service life of the system.
4. Cable conductor material
Most of the DC cables used in photovoltaic power plants work outdoors for a long time. Due to the limitation of construction conditions, connectors are mostly used for cable connection. Cable conductor materials can be divided into copper core and aluminum core.
5. Cable insulation sheath material
During the installation, operation and maintenance of photovoltaic power plants, cables may be routed in the soil below the ground, in overgrown rocks, on the sharp edges of roof structures, or exposed to the air, and the cables may be impacted by various external forces. If the cable jacket is not strong enough, the cable insulation will be damaged, affecting the service life of the entire cable, or causing problems such as short circuits, fire and personal injury hazards.