The application of solar (PV ) power generation is becoming more and more widespread and rapidly developing. In addition to the major equipment such as solar modules, inverters,and step up transformers, the capacity of the connected solar cable materials for the overall profitability of solar stations in the construction of solar power plants, The safety of the operation, whether it is efficient, plays a crucial role as well. The following is a detailed introduction to the use and environment of common cables and materials in solar power plants . According to the system of the solar power station, the cable can be divided into DC cable and AC cable, which are classified according to different uses and environments:
1.DC cable (1 ).Serial cables between components and components . (2 ) Parallel cables between the strings and their strings of the DC distribution box (combiner box ) . (3 ) . DC powers distribution box of the cable between the inverter . The above cables are DC cables , outdoor laying more , to be moisture-proof , anti-sun exposure , cold , heat , UV , in some special circumstances also need anti-acid and other chemical substances .
2.AC cable (1 ).Inverter to step-up transformer connection cable . (2 ) Connect the step-up transformer to the power distribution unit . (3 ) Connection cables from the power distribution unit to the power grid or users . This part of the cable for the AC loads cable , laying more indoor environment , according to the selection of general power cable selection requirements .
3.solar cable.A large number of solar power plants in the outdoor cable laying , poor environmental conditions , the cable materials should be based on anti-UV , ozone , severe temperature changes , and chemical erosion may be .Long-term use of common material cables in such environments will result in fragile cable sheath and may even break down the cable insulation . These conditions can directly damage the cable system , but also increases the risk of short-circuiting the cable in the medium and long term , the possibility of fire or personal injury are also higher , greatly affects the life of the system . Therefore , the use of solar power plants with PV power cables and components is very necessary . With the continuous development of the solar industry, solar components market gradually formed, in terms of cables, has developed a variety of specifications of the solar cable products. Recently developed electron beam cross-link cable , the rated temperature of 120 ℃ , can withstand the harsh climate and withstand mechanical shocks . Another example is the RADOX cable developed according to international standards IEC216 a solar cable , outdoor environment , the service life of rubber cables is 8 times , are 32 times the PVC cable .solar cables and components not only provide the best weather , UV and ozone resistance but also withstand a wider range of temperature changes (eg,from - 40 to 125 °C）
4.Cable conductor material.In most cases , the DC cables used in solar power plants are long-term outdoor work , which is limited by the construction conditions and the connectors are mostly used for cable connections . Cable conductor material can be divided into copper and aluminum core . Copper cable has better oxidation resistance than aluminum , long life , good stability , small pressure drop and low power consumption characteristics ; in the construction of the copper core flexible , allowing a small radius of curvature , so easy to bend , wear tube Easy ; and copper anti-fatigue , repeated bending is not easy to break , so convenient wiring ; the same time , high mechanical strength copper core , can withstand greater mechanical tension , laying a great convenience to construction , but also for the mechanized construction to create the conditions . On the contrary aluminum cable , due to the chemical properties of aluminum , the installation of joints prone to oxidation, especially prone to creep , easily lead to failure . Therefore , the use of copper cables in solar power plants , especially in the laying of buried cable power supply area , with outstanding advantages . Can reduce the accident rate is low , improve the reliability of power supplies /, construction and operation and maintenance features such as convenience . This is the reason why copper cables are mainly used in underground power supplies in China at present .
5.Cable insulation jacket material . During the installation , operation , and maintenance of the PV power plant , the cables may be routed below the ground , in weeds , rough edges of the roof structure and exposed to the air . The cables may be subjected to various external forces . If the cable jacket is not strong enough , the cable insulation will be damaged , affecting the lives of the entire cable or causing problems such as short circuits , fire , and personal injury . Cable research and technical staff found that cross-linked by radiation materials , radiation treatment before the higher mechanical strength . The cross-linking process alters the chemical structure of the polymer of the cable insulation jacket material , the conversion to the fusible thermoplastic material to a non-fusible elastomer material , and the cross-linking radiation significantly to improve the thermal , mechanical , and chemical properties of the cable insulation characteristic . DC loops in operation is often subject to a variety of unfavorable factors resulting from grounding , making the system cannot be normal operation . Such as extrusion , poor cable manufacturing , insulation materials failed , low insulation , DC system insulation aging , or there are some damage defects can cause ground or become a grounding hazard .
Hence, outdoor environment animals invade or bite can also cause DC ground fault . Therefore , in this case , the armored cable with the rodenticide function sheath is generally used .