Enhanced hybrid technique for calculating ground impedances of underground power cables

A recently investigation of the series solution presented by Wedepohl et al., in 1973, yields a new hybrid technique for calculating Z_G of buried cables. An enhanced hybrid technique partly analytic-numeric is used in this paper to assess the behavior of other important techniques for calculating ground-return impedances of underground power cables. The accuracy of the here proposed technique is comparable to the Wedepohl series solution, hypergeometric confluent functions, numerical integration modified method and an image based closed-form approximation.