Defect Detection for Composite Insulators Based on Electromagnetic Wave Spectrum and Field Application

Defect detection is an effective precaution against the brittle fracture fault of operating composite insulators. Based on the principle of electromagnetic wave radiation to the surrounding caused by an inner discharge defect of composite insulators, it is proposed that the ultra-high frequency (UHF) components of electromagnetic wave spectrum are measured, to realize the detection and location of an inner discharge defect in composite insulators. This paper investigates the characteristic spectrums of inner discharge before core rod brittle fracture of composite insulators by experiments on different defects. In addition, this method is applied to substation and transmission line, which is validated to be effective. Research results provide an effective way for remotely detecting the defect of operating composite insulators.