PROJECT TITLE :

Influence of glucose as a contaminant on discharge characteristics of HVAC insulator

ABSTRACT:

Contaminant is the most factor affecting the insulation performance. The contaminant composition determines the inception voltage and therefore the intensity of insulation discharge. This paper studies the extraordinary discharge activity at low humidity (77% RH) in AC 500 kV Gangcheng substation where the contaminant contained glucose, and this phenomenon was rarely explained in previous publications. Electrical and chemical performances of glucose as a contaminant on insulation surface were investigated by suggests that of discharge test (below eightyp.c RH), artificial pollution test (100p.c RH), molecular dynamics simulations, and quantum chemistry calculations. The experimental results show that thanks to stronger moisture absorption capability compared to non-glucose contaminant, glucose contamination sample has lower discharge inception voltage and stronger discharge intensity at seventy fivep.c RH as the content of glucose exceeds zero.10 mg/cm2. Quantum chemical calculations reveal that the glucose molecules will decompose to come up with free radicals with the unpaired electrons underneath the robust electrical fields. The surface carbonation enhances the electron transfer rate and strengthens the discharge intensity. Moreover, the competitive adsorption of glucose and water molecules cause the low moisture discharge phenomenon, and it wants to be thought-about for insulation style and maintenance in areas producing sugar.