This paper describes Bonneville Power Administration's basic philosophy for predicting audible noise from ac and dc high voltage transmission lines. General formulas for predicting the A-weighted audible noise during rain for ac lines and during fair weather for dc lines which were developed from data from full-scale lines are presented. From this basic calculation, audible noise cumulative distributions, frequency spectrums, and lateral profiles can be estimated

Formulas for Predicting Audible Noise from Overhead High Voltage AC and DC Lines

In the paper is presented a smmary of cage measurements of the radio interference, the audible noise, and the corona losses for a large number of conductors and conductor bundles. The analysis of the test results obtained also leads to the establisment of a theoretical method of predicting the corona performance of conductor bundles, based on experimental data obtained with single conductors and taking into account the actual distribution of the field strength at the surface of individual sub-conductors in the bundle. Some cases of practical interest are discussed with reference to the effect of conductor aging and the asymmetry of the bundle configuration. Application of the theoretical method to the prediction of the corona performance of long three-phase lines, taking the actual field distributions at the center and outer phase conductors into account, is also discussed.

A method of predicting the corona performance of conductor bundles based on cage test results

This paper describes the transmission lines that have been built throughout the world to operate above 700 kV. The paper provides information on the system planning, the electrical design, the mechanical and tower design, and the operation and maintenance experience of lines built in the U.S., Canada, South Africa, Brazil, Venezuela, Russia, Korea, India and Japan. Also briefly discussed is the research conducted around the world to develop systems to operate above 700 kV including the research conducted by EPRI at their high-voltage research facility in Lenox, Massachusetts

Overview of transmission lines above 700 kV

Audible noise produced by corona during foul weather is an important consideration in the design of high-voltage transmission lines. The measurement, analysis and prediction of audible noise and the assessment of noise reduction techniques have constituted a primary area of research at Project UHV. Results of earlier short-term testing utilizing single-phase test facilities have, since 1975, been greatly augmented by longer-term field data obtained on a three-phase test line. This paper presents the results of a portion of this work The effect of the weathering or aging of conductors on noise levels is examined and the effectiveness of the concept of asymmetric conductor bundling for noise reduction is assessed.

Audible Noise Performance of Regular and Asymmetric Bundles and effect of Conductor Aging on Project UHV's Three-Phase Test Line

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.

Audible noise and visual corona from HV and EHV transmission lines and substation conductors

This paper presents the results of a statistical anaylsis of conductor corona generated audible hoise as measured at the Apple Grove 750 kV Test Project, a joint field investigation sponsored by the American Electric Power Service Corporation and the Westinghouse Electric Corporation. A comparison of simultaneous audible noise data is made on three sizes of four conductor bundles [diameter of 1.382 in. (35.1 mm), 1.196 in. (30.4 mm), 1.0 in. (25.4 mm)]. Also a correlation is given of simultaneous readings of audible noise, radio noise and corona loss.

R. L. Zagier

Papers

The Apple Grove 750 kV Project Statistical Analysis of Audible Noise Performance of Conductors at 775 kv