A New technology of transformer bushing state detection based on transient dielectric response

Abstract Failure of the transformer bushing will cause to be powered down or damaged, affecting safe operation power system. This paper proposes a method using system harmonics as dielectric response excitation source and studies insulation online detection technology based on transient characteristics. The technical scheme structure monitoring characteristics are given. A calculation model short-circuit grounding capacitor switching 35kV substation was established, harmonic frequency content amplitude distribution grid disturbance were analyzed. case measurement is research shows that generate overvoltage in short circuit grounding, switching, etc. range test band (1Hz~1kHz), also large, which can used an source. causes change acts “probe” reflects state bushing. medium high-frequency bands spectrum domain sensitive moisture, diagnose