Radio noise fields of corona on power lines
Thesis DisciplineElectrical Engineering
Degree GrantorUniversity of Canterbury
Degree NameMaster of Engineering
This study is concerned primarily with the theoretical analysis of radio interference from high voltage transmission lines. In particular it examines the relation between the far and near fields of radio noise emanating from power lines under corona. A method is proposed for predicting far fields of radio noise from measurements and analysis of near fields. The near field of radio noise from a power line is nearly quasi-stationary and affects ordinary communication receivers. The far field is predominantly a radiation field which may be of sufficient magnitude to interfere with receivers with sensitive directional antennas. This far field has been virtually ignored in previous radio interference studies, as has, consequently, the problem of relating it to the near field. The prediction of far fields from near-field measurements, besides being theoretically interesting, is useful for purposes of determining distant fields of corona radio noise which are difficult to measure but perceptible on antennas of radio receiving stations. The first part of this thesis contains a systematic development of the basic theory in radio interference analysis. The rest of the thesis deals with the particular problem of near and far field relations. Most of the work described here is theoretical in nature and should be regarded as laying the groundwork for more extensive analyses supported by a liberal amount of experimental data. Some experimental results, representing a partial support of the theory, are described. Suggested methods of further experimental confirmation are outlined. The substance of this study is contained in a paper recently read at the Anzaas Conference in Christchurch.