PROJECT TITLE :

Effect of grading ring on ice characteristics and flashover performance of 220 kVcomposite insulators with different shed configurations

ABSTRACT:

The energized icing tests for five sorts of 220 kV composite insulators with and without the grading ring (GR) at the high voltage (HV) finish are performed in the artificial climate chamber. Combining with the numerical simulations of electric field (E-field), the variations between the influence of GR and shed configuration on the ice characteristics and flashover performance of composite insulators are compared and analyzed. Results indicate that GR can improve each the ice growths and E-field distributions close to the HV end. The enhancements of GR on the icing flashover voltages underneath light-weight icing degree is comparatively obvious, while with the rise of icing degree, these effects gradually subsided apparent. For different insulators, the consequences of icing degree on icing flashover voltages under the presence of GRs are all higher than that beneath the absence of GRs. Moreover, the influence law of icing degree among completely different insulators remains unchanged beneath the presence and absence of GRs. In general, the development of optimized shed configuration for the icing flashover performance is more obvious than that of GR, which can be thought of together main measure to enhance insulation performance of composite insulators in ice regions.