Laying and connection of cables in photovoltaic power generation systems

In recent years, photovoltaic power generation systems have developed rapidly, and the construction of cost-effective and profitable photovoltaic farms reflects the most important goals and core competitiveness
of solar equipment manufacturers.
In fact, the economic benefits not only depend on the efficiency of the solar modules themselves, but also closely related to the supporting system components, and high-quality supporting components can ensure the efficient, stable and long-term operation
of the solar photovoltaic power generation system.
In the solar photovoltaic power generation system, the amount and cost of cables are the basis of supporting electrical equipment, and the amount of electricity exceeds that of the general power generation system, and it is also one of the important factors affecting the efficiency of the
entire system.

The construction cost of cable engineering in photovoltaic power generation projects is generally relatively large, and the choice of laying method directly affects the construction cost, so reasonable planning and correct selection of cable laying method is an important part of
cable design work.

First, the laying of cables

The cable laying method is comprehensively considered according to the engineering situation, environmental conditions, cable specifications, models, quantities and other factors, and is selected
according to the principle of meeting the requirements of reliable operation, easy maintenance and technical and economic reasonableness.
The laying of DC cables of photovoltaic power generation projects mainly includes direct burial sand laying pads, pipe laying, trough laying, cable trench laying, tunnel laying, etc.
, and the laying of AC cables is not much different from the general power system laying method
.

DC cable is mostly used between photovoltaic modules, between strings to DC combiner boxes, between combiner boxes and inverters, its cross-sectional area is small, the number is large, usually the cable is tied along the component bracket or buried directly through the pipe for laying, in the laying generally to consider:

(1) The connecting cable between components and the connecting cable between the string and the combiner box, as far as possible, the use of the component bracket as the channel support and fixation of the cable laying, can reduce the influence of
environmental factors to a certain extent.

(2) The force of cable laying should be uniform and appropriate, not too tight, photovoltaic places generally have a large temperature difference between day and night, and should avoid cable breakage caused by thermal expansion and contraction
.

(3) The photovoltaic material cable leads on the surface of the building should consider the overall beauty of the building, and the laying position should avoid laying cables at the sharp edge of the wall and bracket, so as not to cut and grind the insulation layer and cause short circuit, or cut off the wire by shear force and cause a broken circuit
.
At the same time, it is necessary to consider problems such as
direct lightning strikes on cable lines.

(4) Reasonably plan the cable laying path, reduce crossing, and combine the laying as much as possible to reduce the amount of earthwork excavation and cable consumption in the construction process of the project
.

Second, the connection of the cable

The DC cables in the photovoltaic power generation system are mostly laid outdoors, and the connection method is mainly plugged into the joint, which can be protected through the pipe, and the component bracket is used as the channel and fixed for cable laying to reduce the impact of
environmental factors.
Other cable connections are connected in much the same way
as in general power systems.