Air substation is a set of equipment including transformer, low pressure panel, cut-out fuse, lightning arrester, etc., which is installed in the open air and on the base. Aerial substations are connected to medium pressure feeders and reduce the medium pressure voltage to the consumption voltage.
Medium pressure voltage levels in Iran's power grid are 11, 20 and 33 kV, the extent of the 20 kV network is greater in the country, and the voltage levels of 11 and 33 kV are used in several southern cities of the country. The voltage levels of weak pressure (consumed voltage) in the country's power grid are (380-400) three-phase volts and (220-231) single-phase volts.
If the increase in the installation of air substations leads to the optimal expansion of medium pressure networks, it can bring benefits such as economic reduction of losses, solving the problem of current imbalance in long weak pressure feeders, the possibility of balancing the load of transformers due to the reduction of the number of subscribers covered by each transformer. Significant reduction of costs related to the maintenance of weak pressure feeders, increase in power quality by separating subscribers, solving voltage drop problems in long weak pressure feeders and reducing the propagation of disturbances.
Of course, the proper use of the low pressure network also has advantages such as solving privacy problems in medium pressure networks, increasing the reliability of the network through the possibility of performing maneuvers at the low pressure level, increasing the utilization factor of network transformers through creating effective coverage in the service area. The transformer increases urban beauty by reducing the number of installed transformers and low construction costs compared to medium pressure networks.
Airmail installation location
:Air stations are divided into three categories according to their location as follows
Air posts installed at the end of the air line
Air stations installed in the middle of the air line
Aerial posts installed on land lines
:The installation location of the air post should have the following specifications and conditions
The ground where the air station is to be built should be dry and free of any air obstacles such as tall trees
The location of the air station should be suitable in terms of access roads so that there is no problem during installation and repairs.
The surroundings of the bases of the air post should be free of obstacles with a radius of 1.5 meters
The soil around the foundations of the aerial post should be free of any obstacles for the installation of the foundations and the ground system.
The location of the construction of the air station should be outside the boundaries of Harim.
The range of air post installation
Air stations are usually installed in the boundaries of the border areas, belt highways and main entrances of the city and inside the marginal residential towns and streets with a width of more than 12 meters.
Different departments of airmail
You can see the actual shape and schematic of the air post in the following pictures, which will be introduced and explained in each of its different parts.
