Impedance-based whole-system modeling for a composite grid via embedding of frame dynamics
Author(s)
Gu, Yunjie
Li, Yitong
Zhu, Yue
Green, Tim
Type
Journal Article
Abstract
The paper establishes a methodology to overcome the difficulty of dynamic
frame alignment and system separation in impedance modeling of ac grids, and
thereby enables impedance-based whole-system modeling of generator-converter
composite power systems. The methodology is based on a frame-dynamics-embedding
transformation via an intermediary steady frame between local and global
frames, which yields a locally defined impedance model for each generator or
converter that does not rely on a global frame but retains all frame dynamics.
The individual impedance model can then be readily combined into a whole-system
model even for meshed networks via the proposed closed-loop formulation without
network separation. Compared to start-of-the-art impedance-based models, the
proposed method retains both frame dynamics and scalability, and is generally
applicable to various network topologies (meshed, radial, etc) and combinations
of machines (generators, motors, converters, etc). The methodology is used to
analyze the dynamic interaction between generators and converters in a
composite grid, which yields important findings and potential solutions for
unstable oscillation caused by PLL-swing coupling in low-inertia grids.
frame alignment and system separation in impedance modeling of ac grids, and
thereby enables impedance-based whole-system modeling of generator-converter
composite power systems. The methodology is based on a frame-dynamics-embedding
transformation via an intermediary steady frame between local and global
frames, which yields a locally defined impedance model for each generator or
converter that does not rely on a global frame but retains all frame dynamics.
The individual impedance model can then be readily combined into a whole-system
model even for meshed networks via the proposed closed-loop formulation without
network separation. Compared to start-of-the-art impedance-based models, the
proposed method retains both frame dynamics and scalability, and is generally
applicable to various network topologies (meshed, radial, etc) and combinations
of machines (generators, motors, converters, etc). The methodology is used to
analyze the dynamic interaction between generators and converters in a
composite grid, which yields important findings and potential solutions for
unstable oscillation caused by PLL-swing coupling in low-inertia grids.
Date Issued
2020-06-23
Date Acceptance
2020-06-15
Citation
IEEE Transactions on Power Systems, 2020, 36 (1), pp.336-345
ISSN
0885-8950
Publisher
Institute of Electrical and Electronics Engineers
Start Page
336
End Page
345
Journal / Book Title
IEEE Transactions on Power Systems
Volume
36
Issue
1
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Identifier
http://arxiv.org/abs/1911.01879v2
Subjects
cs.SY
eess.SY
eess.SY
Publication Status
Published
Article Number
20307709
Date Publish Online
2020-06-23