Data-driven identification of dissipative linear models for nonlinear systems
arXiv:1907.12640
The paper proposes a method to derive a dissipative linear approximation of an unknown nonlinear system from input‑output data by first identifying a linear model and then adjusting its matrices to enforce dissipativity, with guarantees on how the perturbation affects the original system’s local dissipativity.
Abstract
We consider the problem of identifying a dissipative linear model of an unknown nonlinear system that is known to be dissipative, from time domain input-output data. We first learn an approximate linear model of the nonlinear system using standard system identification techniques and then perturb the system matrices of the linear model to enforce dissipativity, while closely approximating the dynamical behavior of the nonlinear system. Further, we provide an analytical relationship between the size of the perturbation and the radius in which the dissipativity of the linear model guarantees local dissipativity of the unknown nonlinear system. We demonstrate the application of this identification technique to the problem of learning a dissipative model of a microgrid with high penetration of variable renewable energy sources.
6 pages