Investigation of corona phenomenon for a reduced-scale model of hybrid AC and DC lines

A reduced-scale model of a single-phase ac (50 Hz) and a unipolar dc was developed with a suitable scaling factor where the applied voltages were varied up to 80 kV. Many factors were examined to show their effects on the I-V characteristics and on the corona current oscillograms. Also, a two-dimensional field computation program based on the charge simulation method (CSM) was used to model both the hybrid analog and an ac 132 kV double-circuit transmission lines in order to compute the ground-level electric field, number of streamers (for a constant time duration) and corona inception voltage for different arrangements and energization types and levels.