Practical design of AC 1000 kV insulator assemblies

The design features of the arc horn applied to the insulator assemblies for AC UHV transmission lines are described. These features have been developed on the basis of detailed studies conducted on the corona characteristics and insulating performance. Since the characteristics of the arc horn for the UHV-class insulator assemblies can not be predicted by the extrapolation of the design practice for those of a 500 kV class, the design features have been validated by full-scale tests. A practical design of the arc horn applicable to AC 1000 kV transmission-line insulator assemblies were obtained by making the most use of such effects as the corona shield effect of the conductor and the effect of the electrode configuration on the switching impulse flashover voltage characteristics