The rapid development of photovoltaic power generation systems in recent years, the construction of economic and efficient profitable photovoltaic farms, reflects the most important goal and core competitiveness of solar cable manufacturer. In fact, economic benefits not only depend on the efficiency of solar modules themselves, but also closely related to supporting system components. High-quality supporting components can ensure the efficient, stable and long-term operation of solar photovoltaic power generation system. In the solar photovoltaic power generation system, the amount and cost of cable is the basis of supporting electrical equipment, which exceeds the general power generation system, and is also one of the important factors affecting the efficiency of the whole system.
The construction cost of cable engineering in photovoltaic power generation project is generally large, and the choice of laying mode directly affects the construction cost. Therefore, reasonable planning and correct selection of cable laying mode are important links in cable design.
I. Cable laying
The cable laying mode is selected according to the engineering situation, environmental conditions, cable specifications, models, quantity and other factors, and in accordance with the requirements of reliable operation, easy maintenance and reasonable technical and economic principles. The laying of DC cables in photovoltaic power generation projects mainly includes directly buried sand cushion brick laying, pipe laying, trough laying, cable trench laying, tunnel laying, etc. There is little difference between AC cable laying and general power system laying.
Dc cables are mostly used between photovoltaic modules, between the cluster and the DC bus box, and between the bus box and the inverter. The cross-sectional area is small and the quantity is large. Usually, cables are tied along the module support or buried directly through the pipe for laying.
(1) The connection cable between components and the connection cable between the cluster and the bus box, as far as possible to use the component bracket as the cable laying channel support and fixation, can reduce the impact of environmental factors to a certain extent.
(2) The stress of cable laying should be uniform and appropriate, and should not be too tight. Generally, the temperature difference between day and night in photovoltaic sites is large, and cable breakage should be avoided due to thermal expansion and cold contraction.
(3) The photovoltaic material cable lead on the surface of the building should consider the overall appearance of the building, and the laying position should avoid laying the cable at the sharp edge of the wall and the support, so as to avoid cutting and grinding damage to the insulation layer and causing short circuit, or cutting the wire caused by shear force. At the same time to consider, the cable line is hit by direct lightning and other problems.
(4) Rationally plan cable laying path, reduce crossing, and merge laying as far as possible to reduce earthwork excavation and cable consumption in the construction process of the project.
Two, cable connection
Dc cables in the photovoltaic power generation system are mostly laid outdoors, and the connection mode is mainly connector insertion, which can be protected through the pipe. The module support is used as the channel and fixation of cable laying to reduce the influence of environmental factors. Other cable connections are roughly the same as those in the general power system.