Modeling, analysis and testing of autonomous operation of an inverter-based microgrid
File(s)
Supporting information
Author(s)
Pogaku, N
Prodanovic, M
Green, TC
Type
Journal Article
Abstract
The analysis of the small-signal stability of conventional
power systems is well established, but for inverter based
microgrids there is a need to establish how circuit and control
features give rise to particular oscillatory modes and which of
these have poor damping. This paper develops the modeling and
analysis of autonomous operation of inverter-based microgrids.
Each sub-module is modeled in state-space form and all are
combined together on a common reference frame. The model
captures the detail of the control loops of the inverter but not the
switching action. Some inverter modes are found at relatively high
frequency and so a full dynamic model of the network (rather
than an algebraic impedance model) is used. The complete model
is linearized around an operating point and the resulting system
matrix is used to derive the eigenvalues. The eigenvalues (termed
“modes”) indicate the frequency and damping of oscillatory
components in the transient response. A sensitivity analysis is also
presented which helps identifying the origin of each of the modes
and identify possible feedback signals for design of controllers
to improve the system stability. With experience it is possible to
simplify the model (reduce the order) if particular modes are
not of interest as is the case with synchronous machine models.
Experimental results from a microgrid of three 10-kW inverters
are used to verify the results obtained from the model.
power systems is well established, but for inverter based
microgrids there is a need to establish how circuit and control
features give rise to particular oscillatory modes and which of
these have poor damping. This paper develops the modeling and
analysis of autonomous operation of inverter-based microgrids.
Each sub-module is modeled in state-space form and all are
combined together on a common reference frame. The model
captures the detail of the control loops of the inverter but not the
switching action. Some inverter modes are found at relatively high
frequency and so a full dynamic model of the network (rather
than an algebraic impedance model) is used. The complete model
is linearized around an operating point and the resulting system
matrix is used to derive the eigenvalues. The eigenvalues (termed
“modes”) indicate the frequency and damping of oscillatory
components in the transient response. A sensitivity analysis is also
presented which helps identifying the origin of each of the modes
and identify possible feedback signals for design of controllers
to improve the system stability. With experience it is possible to
simplify the model (reduce the order) if particular modes are
not of interest as is the case with synchronous machine models.
Experimental results from a microgrid of three 10-kW inverters
are used to verify the results obtained from the model.
Version
Published version
Date Issued
2007-03-01
Date Acceptance
2006-05-25
Citation
IEEE Transactions on Power Electronics, 2007, 22 (2), pp.613-625
ISSN
1941-0107
Publisher
IEEE
Start Page
613
End Page
625
Journal / Book Title
IEEE Transactions on Power Electronics
Volume
22
Issue
2
Copyright Statement
© 2007 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.
Subjects
Science & Technology
Technology
Engineering, Electrical & Electronic
Engineering
ENGINEERING, ELECTRICAL & ELECTRONIC
inverter
inverter model
microgrid
power control
small-signal stability
DISTRIBUTED GENERATION SYSTEMS
PARALLEL INVERTERS
CONTROLLER
STABILITY
Publication Status
Published