ANALYSIS OF CORONA LOSSES ON DC TRANSMISSION LINES .2. BIPOLAR LINES

As in the case of unipolar corona, theoretical calculation of corona losses for bipolar dc transmission line configurations involves the analysis of the nonlinear ionized field in the interelectrode region. However, the complexity of the analysis is increased considerably because of the presence of ions of both polarities in the region. The problem of the bipolar dc ionized field is stated in terms of the defining equations, and the difficulties of obtaining analytical solutions are discussed. A numerical method of solving the equations applicable to any general bipolar conductor configuration is proposed. By making appropriate simplifying assumptions, the essentially two-dimensional field is reduced to its equivalent one-dimensional form, and the complex problem of the ionized field is transformed into one of solving a set of two-point nonlinear boundary value problems along a number of flux lines of the space-charge-free field. The boundary value problems necessitate the solution of two simultaneous nonlinear equations, and numerical iterative methods of solving these equations are described. The proposed analysis is applied to a simple bipolar dc transmission line configuration, and it is shown that the theoretical calculations are in good agreement with experimental results obtained on a full-scale outdoor test line. Copyright © 1969 by The Institute of Electrical and Electronics Engineers, Inc.