Computation of Electric Fields: Recent Developments and Practical Applications

This paper describes a library of computer field programs available for design investigations during the development of high-voltage switchgear equipment. The emphasis is on recent developments to a general-purpose multidielectric field program suitable for solving practical field problems in two dimensions or in three dimensions with one axis of symmetry. These developments include an improved presentation of printout data, automatic drawings of computed equipotentials, and accurate calculation of gradient values for practical systems. A quadratic fit method and finite-difference techniques to compute gradient values are discussed together with associated accuracies. Finally, examples are given of the application of this numerical technique to high-voltage switchgear design.