A novel on-line inspection system for transmission lines using optical ground wires

In order to obtain the desired visible images, the infrared images and the meteorological data for the inspection, a novel on-line inspection system for transmission lines is designed and proposed in this paper. The system consists of tower terminal units, Ethernet passive optical networks and master stations. Due to the huge monitoring data sampled by the tower terminal units at each tower, Ethernet passive optical networks are used to transmit the monitoring data in real-time. The fibers in the optical fiber composite overhead ground wires are used as the trunk fibers in the communication systems. They extend from the optical line terminal to the passive optical splitters located in the splice trays at each tower. Then the optical drop fibers are used to connect the tower terminal units and the splitters. A single-trunk-fiber network scheme, multiple-trunk-fiber network scheme and cascaded-OLT network scheme are proposed for the communication systems. The effectiveness and practicability of the proposed inspection system were verified by simulation results and the field data.