Remote Optical Thermography Detection Method and System for Silicone Polymer Insulating Materials Used in Power Industry

Live detection of composite insulating materials in electrical equipment is highly demanded for the reliability and safety of the power system. This article proposes a remote optical thermography detection method and system for detecting defects in silicone polymer materials with the advantages of quick and simple operation, safety, visual results, and automatic remote measurement. First, the remote optical thermography detection system was established. Then, silicone polymer insulating materials with typical defects were tested by the proposed system at a long distance of 5 m. Images sequence processing techniques, including fast Fourier transform, principal component analysis, independent component analysis, and partial least-squares regression, were used to enhance defect contrast and reduce background noises. The experiment results have shown that defects with the size of 2 mm in silicone polymer insulating materials can be accurately detected at a long distance of 5 m by the proposed system. Finally, the performance of these adopted processing techniques in remote detection was quantitatively evaluated by two metrics, contrast and signal-to-noise ratio, to provide a reference for industrial applications of thermography detection at a long distance.