Earth-return path impedances of underground cables. I. Numerical integration of infinite integrals

Although it is generally acknowledged that there is a need to closely formulate the earth-return path impedances of underground cables, research published so far has mainly concentrated on developing approximate formulations, especially for the infinite integrals which arise. Instead of seeking approximations, the paper develops a rigorous method based on direct numerical integration to evaluate the infinite integrals of underground cable earth-return path impedances. The method has immediate practical use in underground cable parameter calculations. It also provides a benchmark by which the accuracy of any proposed approximate method can be assessed. Further, the method can be used to provide training data by means of which infinite integrals can be evaluated using an array of neural networks