Recital investigation of a fibre reinforced plastic rod in a 11 kV composite insulator using signal processing techniques

The composite insulators are being utilized extensively in the transmission and distribution system because of their better mechanical and electrical properties. They suffer from internal damage/fracture of the Fiber Reinforced Plastic (FRP) rod resulting in degradation of the insulator due to the partial discharges and corona activity. However, degradation of the Fiber Reinforced Plastic (FRP) rod due to electrical and environmental stresses is a critical reliability concern. Hence this research offers an empirical and theoretical exploration of leakage current (LC) signals acquired from FRP rods under accelerated aging conditions through the Rotating Wheel Dip Test (RWDT).To handle this issue, a multi-domain analysis structure has been developed to process LC signals in the time, frequency, and time-frequency domains. The scope of this work is to analysis degradation in the time domain analysis using several statistical parameters such as peak current, RMS, mean, variance, skewness, kurtosis, and crest factor. The harmonic components are related to surface degradation using FFT and PSD methods in the frequency domain. CWT has been adopted to analyze the time-frequency behavior of LC signals.Degradation progression is measured by means of energy and entropy indicators as well as harmonic analysis. Comparative analysis of samples of FRP rods shows unique degradation trends, allowing detection of the critical state of insulation. The results demonstrate that the proposed approach provides improved diagnostic capability for early detection and condition monitoring of insulator degradation.This work establishes an efficient framework for LC-based condition assessment, contributing to improved reliability and preventive maintenance of composite insulators.