Computation of transmission line transients including corona effects

An efficient algorithm for computation of transients in parallel multiconductor transmission systems including corona effects is developed using the finite-difference method. A hybrid scheme consisting of both forward and backward differences is used to discretize the telegraphers´ equations. This results in a tridiagonal difference equation and turns out to have a regressive solution with good stability and high-efficiency. Good agreement is shown between computed and measured results for many cases. The model corona proposed by X.-R. Li et al. (IEEE Power Electron. Soc. Summer Meeting, paper no.88 SM 579-5, 1988) is extended to multiphase cases to match the algorithm. The two aspects of the corona effect, power loss and change in capacitance, are combined by simply simulating a nonlinear capacitor having the same charge-voltage characteristics as the line in corona