Mathematical modeling is a fundamental instrument in the development of theoretical validation for experimental results and in their interpretation. The gist of this article is the application of a special multivalued function, called Lambert W function, to several aspects of electrical engineering. This multivalued function serves the purpose of inverting a vast gamut of expressions involving exponential functions and can be used in many models concerning electrical insulation issues, yielding lower computational times as opposed to other methods to solve nonlinear problems. In particular, this article presents the analytical calculation of parameters for capacitor field and equipotential lines, Paschen's law inversion, a model for electric field distribution in power cables, the inversion of Schottky and Dissado, Montanari, and Mazzanti model for cable life estimation.