| Résumé | An investigation is in progress on the corona loss and radio interference characteristics of standard transmission line conductors energized with high voltage direct current. Corona loss has been measured on a single "Drake" ACSR conductor (1.108 in. dia.) and on a two-conductor Drake bundle with 18-inch spacing between conductors. These conductor arrangements were installed, in turn, on a 370-foot outdoor line. A special shielding circuit permits conductor corona losses to be metered separately from both insulator leakage losses and the corona losses from connecting cable and grading ring assemblies. One type of test on this installation is conducted by recording corona loss currents while varying the voltage applied to the conductor in increments during periods of constand weather. A second type of test is conducted by recording loss currents while holding constant voltage on the test line for long periods under variable weather conditions. From results obtained to date, it appears that in dry weather single-conductor losses and two-conductor losses ar eequal, but negative losses are higher than positive losses by a factor of 2 to 3. In wet weather, losses from the two-conductor bundle, and negative losses from the single conductor, are all equal. (Corona loss data in wet weather for the single conductor at positive voltage is not yet available.) At present, test station facilities are being extended by the erection of a second line to enable simultaneous comparative measurements on conductors to be made; more comprehensive corona loss measurements are under way, and an investigation of radio interference is in progress. |
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