A generalized procedure to obtain first integrals for nonconservative dynamics systems: application to power systems

A technique for constructing first integrals for nonconservative dynamical systems based on Noether´s principle is reviewed and presented. The technique, which provides a systematic approach, is applied to power systems with nonnegligible transfer conductances, and a first integral is derived. The result is shown to be identical to that obtained by an ad-hoc procedure that has provided excellent practical results. The techniques also provides an avenue to obtain other infinitesimal transformations, which may lead to a more general first integral. Various results available on the variational behavior of nonconservative systems in nonlinear mechanics are introduced to the engineering community