Compared with the northern region, due to the complex geographical and climatic conditions in the south, the design of wind farms in the south and the North also has different differences.
For example, heavy rainfall, severe thunderstorms, freezing disasters and frequent geological disasters in the South will all have a lot of impacts on the design of wind farms, which are rare in the design of wind farms in the north.
Today, let's talk about the differences in line design between the north and south wind farms.
I. On-site reconnaissance as a necessary link in line design, on-site reconnaissance directly affects the accuracy of the design.
Compared with the barren hills in the north, the vegetation is relatively less, and the vegetation in the South is more dense, which has caused great obstacles to the on-site reconnaissance of the line.
Because in mountainous areas with dense vegetation, GPS signals will be affected, directly affecting work efficiency;
At the same time, the topography of the southern mountain area is relatively steep, which also has a direct impact on site reconnaissance;
In addition, the probability of meeting all kinds of aggressive animals in the mountains in the South is greater than that in the north.
The above-mentioned situations undoubtedly increase the difficulty, time and workload of on-site reconnaissance of South wind farm lines.
Second, line electrical 1. Line mode, due to frequent freezing rain disasters in the south, the vegetation in the South is more dense than in the north, resulting in far more cable-based lines in the South than in the north.
The main reason for this situation is that if overhead lines are used, ICE will accumulate on the lines when freezing rain disaster occurs. When the ice accumulates to a certain extent, the line Tower will not be able to load, eventually collapsed.
At the same time, due to the large number of forests in the south, the EIA water conservation department has relatively high requirements for the line, so many lines in the South adopt the cable method.
Due to different climatic conditions in the north, it is difficult to have serious ice accumulation on the line. Therefore, overhead lines are mostly used in the north, and cables are only used partially or completely under special terrain conditions.
2. Lightning protection and grounding the rainfall in the South is larger than that in the north, thunderstorm days are more, and surface water is shallower. Therefore, there is a certain difference in lightning protection and grounding of the line compared with that in the north.
In the insulation design of Southern lines, if overhead lines are adopted, the number of insulators will be larger than that in the north, and the insulation distance requirements will be larger.
In the strong thunderstorm area, the design will take the initiative to reduce the protective angle of the ground wire.
The surface water in the South is relatively shallow, and the soil water content will be relatively high, which has certain influence on the corrosion of metal materials.
When selecting grounding materials, the requirements for corrosion resistance will be higher.
The grounding material in the northern region is generally hot-dip galvanized round steel. In the south, the thickness of the galvanized layer of hot-dip galvanized round steel needs to be thickened, or other materials with better corrosion resistance, such as flexible graphite wire and other materials, are used.
3. Ice melting switch ice melting switch this equipment is almost invisible in the north. In the southern region, the power grid will require some areas with serious ice accumulation to install ice melting switches at the exit of the wind farm transmission line.
Through the ice melting switch, the ice accumulation of wires can be effectively controlled.
Third, the line structure, the line structure part is mainly arranged according to the overhead line mode.
Considering the icing and forest land in the south, the line tower cannot adopt conventional module tower like the northern area.
At this time, it is necessary to reinforce the module tower or adopt a special tower type.
Due to the restriction of forest land, some areas may adopt high-span towers to cross to meet the requirements of relevant crossing specifications.
Whether it is the reinforcement of the modular tower, the use of special tower type or the use of high-span tower crossing, it is undoubtedly a higher requirement for structural design, which is more difficult.
The direct reaction in the project is the increase of engineering quantity, the increase of steel consumption and the increase of Foundation size, which directly leads to the increase of line investment.
Compared with the line design of the same scale in the north, it will be obviously reflected in the amount of the line structure.