The numerical Laplace transform: An accurate technique for analyzing electromagnetic transients on power system devices

A detailed description of the numerical Laplace transform (NLT) for electromagnetic transient calculation on power system devices under linear and non-linear conditions is presented in this paper. The development and main advantages of the NLT are reviewed, as compared to the conventional time domain simulation, including current practices for reducing numerical errors derived from data truncation and discretization of the analytical equations. A simple technique based on the superposition principle to include non-linear conditions in the frequency domain is also fully described. Besides, important results obtained recently with the NLT for different power components are presented, including comparisons with widely used time domain methods, such as the method of characteristics, and the professional simulation program EMTDC. Such comparisons reveal a high accuracy of the numerical Laplace transform when applied to the presented studies.