Equivalent Salt Deposit Density Optical Fiber Sensor for Transmission Lines in Power Grid

The evaluation of the accumulated contamination on insulators is an important problem for the timely cleaning up of insulators in recent years. For the absence of an effective contamination sensor, the flashover problem has not been effectively resolved yet. In this paper, a new equivalent salt deposit density (ESDD) optical fiber sensor for transmission lines is designed and deployed, which consists of micro-controller unit, A/D converter, quartz fiber, photodiode, laser module, data flash memory, solar panel, sensors of temperature and humidity, communication module, and so forth. To obtain the relationship between the optical energy attenuation and the contamination, plenty of experiments are carried out, based on which the back-propagation (BP) neural network model was trained. The results of artificial experiments indicate that the error of sensors could be less than 10%, and the BP neural network model achieves relatively higher accuracy. The type tests are also carried out, in which the errors of both ESDD and non-soluble deposit density are less than 10%. Finally, the ESDD online monitoring system for transmission lines is deployed and provides an accurate measurement of the insulator contamination.