ADAPTIVE FINITE-ELEMENT BALLOONING ANALYSIS OF BIPOLAR IONIZED FIELDS

This paper presents an adaptive finite-element iterative method for th e analysis of the ionized field around bipolar high-voltage direct-cur rent (HVDC) transmission line conductors without resort to Deutsch's a ssumption. A new iterative finite-element ballooning technique is used to solve Poisson's equation wherein the commonly used artificial boun dary around the transmission line conductors is simulated at infinity. Unlike all attempts reported in the literature for the solution of io nized field, the constancy of the conductors' surface field at the cor ona onset value is directly implemented in the finite-element formulat ion. In order to investigate the effectiveness of the proposed method, a laboratory model was built. It has been found that the calculated V -I characteristics and the ground-plane current density agreed well wi th those measured experimentally, The simplicity in computer programmi ng in addition to the low number of iterations required to achieve con vergence characterize this method of analysis.