High voltage lines usually refer to transmission lines that carry voltages above 10kV. According to GB/T 2900.50-2008, definition 2.1 stipulates that high voltage usually does not include 1000V. The voltage levels of China's domestic high-voltage transmission lines are generally divided into: 35kV, 110kV, 220kV, 330kV, 500kV, 750kV, etc.
1. Range of high voltage lines
1.1 Grades of high voltage lines
Among them, 110kV and 330kV are mostly used in the northern region. Generally speaking, the transmission voltage below 220 kV is called high-voltage transmission, the transmission voltage between 330 and 750 kV is called ultra-high voltage transmission, and the transmission voltage above 1000 kV is called UHV transmission.
1.2 Wiring method of high voltage line
In cities, high-voltage power transmission generally uses cables with insulating layers for underground transmission, and in the wild, overhead lines carried by iron towers are often used for transmission.
2. Safe distance for high voltage lines
2.1 Line and ground of high voltage line
The minimum distance between the line and the ground, under the condition of maximum calculated sag, should not be less than the following values:
The low-voltage line (380V) shall not be less than 6 meters through the residential area, and the low-voltage line (380V) shall not be less than 5 meters through the non-residential area;
Medium-voltage lines (6-10kV) passing through residential areas shall not be less than 6.5 meters, and medium-voltage lines (6-10kV) passing non-residential areas shall not be less than 5.5 meters;
35-110kV lines pass through residential areas no less than 7 meters, 35-110kV lines pass through non-residential areas no less than 6 meters, 35-110kV lines pass through areas with difficult traffic no less than 5 meters;
154-220kV lines pass through residential areas no less than 7.5 meters, 154-220kV lines pass through non-residential areas no less than 6.5 meters, 154-220kV lines pass through areas with difficult traffic no less than 5.5 meters;
330kV lines pass through residential areas not less than 8.5 meters, 330kV lines pass through non-residential areas not less than 7.5 meters, 330kV lines pass through areas with difficult traffic not less than 6.5 meters.
2.2 The distance between high voltage lines and residential areas
If we consider it from the perspective of electric power safety, and consider the wind deflection of high voltage lines caused by strong winds, according to Article 5 of the "Regulations for the Implementation of the Regulations on the Protection of Electric Power Facilities": "The overhead power line protection area is to ensure the safe operation and protection of the built overhead power lines. The safety area that must be set up for the normal power supply of people's lives. In densely populated areas such as factories, mines, towns, market towns, and villages, the protection area of overhead power lines is the horizontal distance of the wire sideline after the maximum calculated wind deviation and the level of the building after the wind deviation The area within the two parallel lines formed by the sum of the safety distance. The horizontal safety distance from the building to the building is as follows under the condition of calculating the maximum wind deflection of the wire sidelines at all levels of voltage:
Below 1kV: 1.0m;
1kV-10kV: 1.5 meters;
35kV: 3.0 meters;
66kV-110kV: 4.0 meters;
154kV-220kV: 5.0 meters;
330kV: 6.0 meters;
500kV: 8.5 meters.