Application And Use Environment of Common Photovoltaic Cables And Their Materials

In recent years, the application of solar power (PV) power generation has become more and more extensive and has developed rapidly. In the process of photovoltaic power station construction, in addition to the main equipment, such as photovoltaic modules, inverters, and step-up transformers, the photovoltaic cable materials that are connected to the photovoltaic power station have a great impact on the overall photovoltaic power station. Profitability, operation safety, and high efficiency also play a crucial role. The following is a detailed introduction to the use and use environment of cables and materials commonly used in photovoltaic power plants.

According to the system of photovoltaic power station, cables can be divided into DC cables and AC cables, which are classified as follows according to different uses and use environments:

1. DC 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

(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.

Therefore, it is very necessary to use photovoltaic special cables and components in photovoltaic power plants. With the continuous development of the photovoltaic industry, the photovoltaic accessories market has gradually formed. As far as cables are concerned, photovoltaic professional cable products of various specifications have been developed. The recently developed electron beam cross-link cable, rated at 120°C, can withstand harsh weather environments and withstand mechanical shocks. Another example is the RADOX cable, which is a special solar energy cable developed according to the international standard IEC216. In the outdoor environment, the service life is 8 times that of the rubber cable and 32 times that of the PVC cable.

Photovoltaic special cables and components not only have the best weather resistance, UV resistance and ozone erosion resistance, but also can withstand a wider range of temperature changes (for example: from -40 to 125 ℃). In Europe, technicians have passed tests, and the temperature value that can be measured on the roof is as high as 100-110 °C.

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. The copper core cable has the characteristics of better oxidation resistance than aluminum, long life, better stability, low voltage drop and low power loss; in construction, due to the good flexibility of the copper core, the allowable bending radius is small, so it is convenient to bend and pass through the tube. It is easy; and the copper core is fatigue-resistant and not easy to break after repeated bending, so the wiring is convenient; at the same time, the copper core has high mechanical strength and can withstand large mechanical tension, which brings great convenience to construction and laying, and also creates conditions for mechanized construction . On the contrary, due to the chemical properties of aluminum, the installation joints are prone to oxidation (electrochemical reaction), especially creep, which can easily lead to failures.

Therefore, copper cables have outstanding advantages in the use of photovoltaic power stations, especially in the field of direct buried cable power supply. It can reduce the accident rate, improve the reliability of power supply, and facilitate construction, operation and maintenance. This is the reason why copper cables are mainly used in underground cable power supply in China.

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. Cable scientific research and technical personnel found that the material cross-linked by radiation has higher mechanical strength than before radiation treatment. The cross-linking process changes the chemical structure of the polymer of the cable insulation jacket material, the fusible thermoplastic material is converted into a non-fusible elastomeric material, and the cross-linking radiation significantly improves the thermal, mechanical and chemical properties of the cable insulation characteristic.

The DC circuit is often affected by a variety of unfavorable factors during operation, resulting in grounding, which makes the system unable to operate normally. Such as extrusion, poor cable manufacturing, substandard insulation materials, low insulation performance, aging DC system insulation, or some damage defects can cause grounding or become a potential grounding hazard. In addition, the invasion or bite of small animals in the outdoor environment will also cause DC ground faults. Therefore, armored cables with rodent repellent functional sheaths are generally used in this case.

In the field of new energy and environmental protection, Xinshengda wire is also constantly advancing with the times. At present, the photovoltaic wire of XSD cable has passed the UL certification, and the product quality is guaranteed. If you are interested, you would like to know more about XSD's photovoltaic wire. And other cable products, you can consult our professionals to serve you.