An Efficient Algorithm for Calculating the Earth Return Mutual Impedance of Conductors With Asymptotic Extraction Technology

It is very essential to calculate the mutual impedance between overhead and buried conductors for analyzing electromagnetic compatibility problems related to a transmission line system. An efficient algorithm for calculating the Pollaczek integral, whose integrand oscillates rapidly and decays slowly, is proposed in this paper. With the help of the asymptotic extraction technique, the Pollaczek integral can be decomposed into the sum of two parts, one of which is expressed with an exponential integral and the other is the one that has a rapidly damped integrand. A comparison of the numerical results with published data shows very good agreement. The proposed approach is a good candidate for calculating impedances related to the Pollaczek integral.