Paper Info
Title
Global Analysis of Synchronization Performance for Power Systems: Bridging the Theory-Practice Gap
Abstract
The issue of synchronization in the power grid is receiving renewed attention, as new energy sources with different dynamics enter the picture. Global metrics have been proposed to evaluate performance and calculated under highly simplified assumptions. In this article, we extend this approach to more realistic network scenarios and more closely connect it with metrics used in power engineering practice. In particular, our analysis covers networks with generators of heterogeneous ratings and richer dynamic models of machines. Under a suitable proportionality assumption in the parameters, we show that the step response of bus frequencies can be decomposed in two components. The first component is a system-wide frequency that captures the aggregate grid behavior, and the residual component represents the individual bus frequency deviations from the aggregate. Using this decomposition, we define—and compute in closed form—several metrics that capture dynamic behaviors that are of relevance for power engineers. In particular, using the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">system frequency</italic> , we define industry-style metrics (Nadir, RoCoF) that are evaluated through a representative machine. We further use the norm of the residual component to define a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">synchronization cost</italic> that can appropriately quantify interarea oscillations. Finally, we employ robustness analysis tools to evaluate deviations from our proportionality assumption. We show that the system frequency still captures the grid steady-state deviation, and becomes an accurate reduced-order model of the grid as the network connectivity grows. Simulation studies with practically relevant data are included to validate the theory and further illustrate the impact of network structure and parameters on synchronization. Our analysis gives conclusions of practical interest, sometimes challenging the conventional wisdom in the field.
Year
DOI
Venue
2020
10.1109/TAC.2019.2942536
IEEE Transactions on Automatic Control
Keywords
DocType
Volume
Mathematical model,Synchronization,Power system dynamics,Generators,Turbines,Transfer functions
Journal
65
Issue
ISSN
Citations 
7
0018-9286
4
PageRank 
References 
Authors
3.42
1
2
Name
Order
Citations
PageRank
Fernando Paganini15912.18
Enrique Mallada220031.21