Insulator Designs for ⩾1200 KV Lines

The limitations on design data are shown by analyzing laboratory and field test results. For efficiency of leakage distance, either leakage distance/ flashover voltage × V/3 or flashover voltage/leakage distance can be used. A careful analysis shows rather simple design rules for optimum pollution performance of insulators. The point of sorting out systematic and relevant results out of many already available is emphasized with respect to UHV. The composite insulators, which belong to the longrod type and offer many advantages deserve special interests for application in the UHV range. It is beyond the scope of this paper to deal with the extensive subject.