Exact Solution of Pollaczek´s Integral for Evaluation of Earth-Return Impedance for Underground Conductors

Calculation of earth-return impedance for underground conductors is based on the efficient evaluation of Pollaczek´s integral. So far, the established practice involved either approximate expressions or numerical integration algorithms. Apart from extensive comments on the latter, this paper presents for the first time three exact solutions in the form of converging series. One of the series guarantees a specific relative accuracy for any parameter range with a specific number of terms and can be regarded as the definite solution that will hopefully settle the issue of computing Pollaczek´s integral both rapidly and accurately. The exact solution provides the means to assess the validity of the impedance formula.