The effect of high direct voltage on the formation and dislodging of water drops hanging from a smooth conductor will be shown and used to explain the resulting corona characteristics, such as pulse amplitude and repetition rate, audible noise, radio influence (RI) and loss current, and corona current waveforms. Phenomena taking place during the conductordrying period are also explained. The relationship between the number and spacing of points on a smooth conductor, on one hand, and RI and loss current, on the other, is demonstrated. Results obtained from water-drop experiments are compared with those from experiments using metal points of various shapes.

Corona Phenomena from Water Drops on Smooth Conductors under High Direct Voltage

A collection of directly comparable radio noise field data from 75 high-and extra-high-voltage lines was presented in earlier papers by a joint CIGRE and IEEE task force. In the present paper a summary of different methods for calculating radio noise levels from transmission lines is presented and a comparison of measured and calculated values is given.

Comparison of Radio Noise Prediction Methods With CIGRE/IEEE Survey Results

This paper summarizes the results of a research effort conducted by Bonneville Power Administration (BPA) to determine the effect of altitude on corona phenomena from high voltage transmission lines. A computer-controlled, reliable, unattended test station was installed at an altitude of 1935 m on a double-circuit 500-kV line near Basin, Montana, to continuously monitor audible noise (AN), radio noise (RI), and television interference (TVI). To obtain comparative data at a lower elevation, another test station was installed on a 500-kV line of similar design near Stayton, Oregon, at an altitude of 277 m. Comparison of the high altitude data with the lower elevation data and with predictions demonstrated that the correction factor of 1 dB/300 m developed in the 1950's and 1960's for radio noise is still valid and is also applicable for AN, TVI and, possibly, corona losses.

Effect of High Altitude on High Voltage AC Transmission Line Corona Phenomena

Voltage Gradients on High-Voltage Transmission Lines [includes discussion]

The results of laboratory studies and preliminary field tests exploring the effects of conductor size and bundling on audible and visual phenomena associated with corona in wet weather are presented. Tubular conductors in five diameters of 1.063 to 2.375 inches were tested. To the authors' knowledge, this is the first paper to systematically develop the information necessary to estimate audible noise and the visual aspects of conductor corona on the variety of conductor sizes used for 345 kV to 765 kV and higher.

S. C. Bartlett

Papers

Radio Influence Tests in Field and Laboratory - 500-Kv Test Project of the American Gas and Electric Company

The Radio-Influence Characteristics of Bundle and Single Conductors - 500-Kv Test Project of the American Gas and Electric Company