An efficient recursive scheme for the simulation of overvoltages on multiphase systems under corona

In the present work, an efficient recursive scheme that was previously described and tested in single-phase transmission lines is extended for multiphase power transmission systems. The scheme uses frequency domain modal theory techniques to obtain an independent solution for each multiphase line segment with frequency dependent parameters. The compensation method is then applied for a combined solution of the voltage profile at each section and its associated “corona branch”. The entire multiphase line is treated as a single nonlinear element by the EMTP. Simulations of field tests on an actual line under corona are presented and comparisons are made with the previous implementations