Research on Technical Parameters of Safe Operation and Maintenance on 110kV Shared Towers

The rapid development of mobile communication technology has given birth to the shared tower mode of installing base station equipment on transmission towers, but the radio frequency(RF) radiation faced by the shared tower operators is not clear and the safe gap distances for live working need to be redetermined. Two aspects of research were taken to solve the two problems existing in operation and maintenance on 110kV shared towers. First, the method of field measurement was used to measure the RF electromagnetic field intensity around the tower. The RF electromagnetic field distribution characteristics were obtained. The field division rules were formulated in line with a related national standard, and the radiation protection measures that the operators need to take in different fields were clarified. Second, the switching impulse discharge tests were conducted on a simulated shared tower, and the safe gap distances for live working on shared towers were determined. The results show that the electromagnetic radiation level in the horizontal direction of the ground and that on the inner side of the main material of the tower are relatively weak, while that outside the main material of the tower is strong, up to 154.6V/m; the minimum working distance between the equipotential worker and the side tower frame and that between the worker and the lower cross arm are 1.3m and 1.4m, respectively; the minimum combined gaps that should be met with the side tower frame and the lower cross arm when the worker enters or exits the equipotential are both 1.5m. The research results can provide basis and guidance for safe operation and maintenance on 110kV shared towers.