Defect Identification of Composite Insulator Based on Infrared Image

Area of Science:

• Electrical Engineering
• Materials Science
• Power Systems

Background:

• Composite insulator mandrel deterioration poses a significant risk to power grid stability.
• Infrared imaging is effective for defect detection, but sheath aging can obscure mandrel issues.
• Differentiating between these two defects is critical for timely maintenance and preventing failures.

Purpose of the Study:

• To develop a method for distinguishing between mandrel deterioration and sheath aging in composite insulators.
• To analyze the thermal characteristics associated with different types of composite insulator defects.
• To validate a simulation model for accurate defect identification.

Main Methods:

• Experimental testing of two in-service composite insulators with varying heating characteristics.
• Building and utilizing a simulation model to analyze temperature-rise patterns.
• Comparing experimental temperature data with simulation results.

Main Results:

• Composite insulators with oxidative decomposition of epoxy resin exhibit significant temperature rises, often extending from high-voltage hardware to multiple umbrella skirts.
• Composite insulators with fibers fully encapsulated by epoxy resin show smaller temperature rises, primarily localized between the hardware and the first umbrella skirt.
• The simulation model accurately reflects experimental findings, confirming its reliability.

Conclusions:

• The developed simulation model effectively distinguishes between mandrel deterioration and sheath aging defects in composite insulators.
• This model provides valuable guidance for improving the detection rate of mandrel-deteriorated composite insulators.
• Accurate defect identification is essential for ensuring the safe and stable operation of power grids.