Insulation characteristics of indoor use 3.3 kV-33 kV epoxy resin insulators subjected to contamination and moisture

摘要

An artificial contamination test was undertaken of the indoor 3.3 kV-33 kV epoxy post insulators to study the deterioration and flashover voltage (FOV). The following conclusions were reached: (1) the components of indoor contaminants are mainly ion chloride and ion sulfate. Deposits of these contaminants on insulators of indoor use panels over 2-3 years is less than 0.01 mg/cm/sup 2/; (2) indoor insulators are subject to moisture absorptionand dew condensation due to changes in temperature and humidity; (3) when the insulators are contaminated, FOV decreases considerably when an AC voltage is applied but is uneffected by electrode configuration; (4) FOV can be expressed as a function of surface leakage length (L) and equipment salt deposit density (ESDD), which are related to insulator design and panel contamination measurement, respectively.