Propagation of Wind-Power-Induced Fluctuations in Power Grids

Abstract:

Renewable generators perturb the electric power grid with heavily non-Gaussian and correlated fluctuations. While changes in generated power on time scales of minutes and hours are compensated by load frequency control, the sub-second grid frequency dynamics are well described by models of phase-coupled oscillators. On such small timescales, we observe local frequency fluctuations in the distribution grid which depend on wind power generation. Motivated by such experimental findings, we present analytical expressions to estimate the propagation of fluctuations on fixed timescales in power grids and analyze their decay in the grid as a function of the system parameters, most importantly inertia. We demonstrate how width and shape of frequency increment statistics scale with distance to the volatile feed-in and deduce the subtle role of emerging softmodes in grids with low inertia. Our work contributes (i) to the important problem of power quality in grids with a high share of renewable generation and (ii) to the more general field of perturbation spreading in network dynamical systems.

Hauke Haehne1, Joachim Peinke1,2, Stefan Kettemann3,4, and others

1 Institute of Physics and Forwind, Carl von Ossietzky Universitaet Oldenburg, Kuepkersweg  70, 26129 Oldenburg, Germany
2 Fraunhofer IWES, Kuepkersweg 70, 26129 Oldenburg, Germany
3 Jacobs University, Department of Physics and Earth Sciences, Campus Ring 1, 28759 Bremen, Germany
4 Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang 790-784, South Korea