Differences in design of north and south wind farm lines


Technical Information



Compared with the northern region, due to the complex geographical and climatic conditions, the south has a different design in the north and south wind farms. For example, heavy rainfall, strong thunderstorms, freezing disasters, frequent geological disasters in the south, etc., will have a lot of impact on the design of wind farms, which are rare in the design of wind farms in the north.

Today, we will talk about the difference in the design of the north and south wind farms.

First, on-site survey

Site surveying as a necessary part of the line design directly affects the accuracy of the design. Compared with the north, it is mostly barren hills, with relatively few vegetation, and the vegetation in the southern region is more dense, which has greatly hindered the site site survey work. Because in the dense mountainous areas, the GPS signal will be affected, which directly affects the work efficiency. At the same time, the terrain in the southern mountainous area is relatively steep, which has a direct impact on the site survey. In addition, various kinds of offensive animals are encountered in the southern mountain forest. The chance is also greater than the north.

The above-mentioned situations are undoubtedly increasing the difficulty, time and workload of the on-site reconnaissance work of the southern wind farm line.

Second, the line electrical

1, line mode

In the south, due to the frequent occurrence of freezing rains and the relatively dense vegetation in the south, the southern wind farms are much more cable-lined than the north.

The main reason for this situation is that if an overhead line is used, when a freezing rain disaster occurs, ice will accumulate on the line. When the ice accumulates to a certain extent, the line tower cannot be loaded and eventually collapses. At the same time, due to the large number of forests in the south, the environmental assessment department of the EIA has relatively high requirements on the lines. Therefore, many lines in the south use cable methods.

Due to the different climatic conditions in the north, it is difficult to have serious ice accretion in the line. Therefore, the north adopts the overhead line method. Only when the terrain conditions are special, the cable method will be partially or completely used.

2, lightning protection grounding

The rainfall in the south is larger than that in the north. There are more thunderstorms and shallower surface waters. Therefore, there is a certain difference in the lightning protection grounding of the lines compared with the north.

In the insulation design of the southern line, if the overhead line is used, the number of insulators will be more than that of the north, and the requirements for the insulation distance will be larger. In the strong thunderstorm area, the design will actively reduce the protection angle of the ground wire.

The surface water in the south is shallow, the soil water content will be relatively high, and it will have some influence on the corrosion of metal materials. Corrosion resistance requirements are higher when selecting grounding materials. In the north, the grounding material 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, are used.

3, melting ice switch

The ice-melting switch is almost inaccessible in the north. In the south, the power grid will require the installation of a melting ice switch at the exit of the wind farm. The ice-melting switch can effectively control the accumulation of ice on the wire.

Third, the line structure

The circuit structure is mainly organized according to the overhead line. Considering the ice accumulation in the south and the situation of forest land, the line tower cannot use the conventional modular tower like the northern part. At this point, the module tower needs to be reinforced or modified, or a special tower type. Due to forest land restrictions in some areas, high-span towers may be used to cross the relevant requirements.

Whether it is the reinforcement of the modular tower, the use of special towers or the use of high-span tower crossings, it is undoubtedly a higher requirement for structural design and more difficult. The direct response in the project is an increase in the amount of engineering. The increase in the amount of steel used and the increase in the base size directly lead to an increase in line investment. Compared with the same scale circuit design in the north, there will be obvious manifestation in the amount of circuit structure engineering.