Jorge Cortés
Professor
Cymer Corporation Endowed Chair
Online event-triggered switching for frequency
control in power grids with variable inertia
J. Feng, W. Cui, J. Cortés, Y. Shi
IEEE Transactions on Power Systems, submitted
Abstract
The increasing integration of renewable energy
resources into power grids has led to time-varying
system inertia and consequent degradation in
frequency dynamics. A promising solution to
alleviate performance degradation is through the use
of power electronics interfaced energy resources
such as renewable generators and battery energy
storage for primary frequency control, by adjusting
their power output set-points in response to
frequency deviations. However, designing a frequency
controller under time-varying inertia is still
challenging. In this paper, we model the frequency
dynamics under time-varying inertia as a nonlinear
switching system, where the frequency dynamics under
each mode are described by the nonlinear swing
equations and different modes represent different
inertia levels. We identify a key controller
structure, named Neural Proportional-Integral
(Neural-PI) controller, that guarantees exponential
input-to-state stability for each mode. To further
improve the controller performance, we present an
online event-triggered switching algorithm to
dynamically select the most suitable controller from
a set of Neural-PI controllers, where each
controller in the candidate pool is optimized for a
specific inertia level. Simulation results obtained
from the IEEE 39-bus system validate the
effectiveness of the proposed online switching
control method with stability guarantees and
optimized performance for frequency control under
time-varying inertia.
pdf
Mechanical and Aerospace Engineering,
University of California, San Diego
9500 Gilman Dr,
La Jolla, California, 92093-0411
Ph: 1-858-822-7930
Fax: 1-858-822-3107
cortes at ucsd.edu
Skype id:
jorgilliyo