Pollution flashover accidents in H.V. insulators had a great assessment in power outage of transmission lines. Two new techniques using artificial neural networks are presented in this book to monitor the discharging level on the insulator surface. The techniques can be programmed to a monitor that produces an alarm signal when the discharging level reaches dangerous range and hence it can be used to predict the flashover accidents before its occurrence.The new techniques using instantaneous leakage current patterns and the meteorological effects are used to classify the discharging activity...