|
Discrete
wavelet analysis of power system transients |
|
Wilkinson,
W.A.; Cox, M.D. |
|
Power
Systems, IEEE Transactions on , Volume: 11 Issue: 4 , Nov. 1996 |
|
Wavelet
analysis is a new method for studying power system transients. Through
wavelet |
|
analysis,
transients are decomposed into a series of wavelet components, each of
which |
|
is a
time-domain signal that covers a specific octave frequency band. This
paper presents |
|
the
basic ideas of discrete wavelet analysis. A variety of actual and
simulated transient |
|
signals
are then analyzed using the discrete wavelet transform that help
demonstrate the |
|
power
of wavelet analysis.
|
|
Wavelets
and electromagnetic power system transients |
|
Robertson,
D.C.; Camps, O.I.; Mayer, J.S.; Gish, W.B. |
|
Power
Delivery, IEEE Transactions on , Volume: 11 Issue: 2 , April 1996 |
|
The
wavelet transform is introduced as a method for analyzing electromagnetic
transients |
|
associated
with power system faults and switching. This method, like the Fourier |
|
transform,
provides information related to the frequency composition of a waveform,
but it |
|
is
more appropriate than the familiar Fourier methods for the nonperiodic,
wide-band |
|
signals
associated with electromagnetic transients. It appears that the frequency
domain |
|
data
produced by the wavelet transform may be useful for analyzing the sources
of |
|
transients
through manual or automated feature detection schemes. The basic
principles |
|
of
wavelet analysis are set forth, and examples showing the application of
the wavelet |
|
transform
to actual power system transients are presented.
|
|
Analysis
of electrical transients in power systems via a novel wavelet recursion |
|
Galli,
Anthony Wayne, Gerald T. Heydt. |
|
Purdue
University graduate School |
|
This
work utilizes wavelet analysis, a relatively new mathematical tool, to |
|
develop
a new method of analysis for electrical transients in electric power
systems. |
|
Techniques
which are currently employed fall into two main categories: time domain or |
|
the
integral transform domain. Time domain methods include the mathematical
solution |
|
of
differential equations and companion circuit techniques. The integral
transform |
|
domain
methods include Laplace transform and frequency (e.g., Fourier transform) |
|
analysis.
Both of the aforementioned categories can be stressed when solving systems
of |
|
equations
with a wide eigenspectrum or when a system of equations is subjected to a |
|
nonstationary
forcing function. One of the benefits of wavelet analysis, however, is the |
|
ability
to easily resolve signals of a nonstationary nature. In this thesis, four
wavelet |
|
recursion
formulae -- the Right Formula Backward Difference (RFBD), the Left Formula |
|
Backward
Difference (LFBD), the Right Formula Forward Difference (RFFD), and the |
|
Left
Formula Forward Difference (LFFD) -- are derived for the solution of the |
|
differential
equations that are germane to the analysis of electric power systems. The |
|
convergence
properties of the formulae are discussed and several examples are |
|
Transient
power quality problems analyzed using wavelets |
|
Power
Delivery, IEEE Transactions on , Volume: 12 Issue: 2 , April 1997 |
|
In the
literature, wavelet techniques have been proposed for the identification
of power |
|
system
transient signals (e.g., lightning impulse, and capacitor switching
transients). In this |
|
paper,
the wavelet technique is proposed for the analysis of the propagation of
transients |
|
in
power systems. The advantages and disadvantages of the method are
discussed and |
|
the
way in which these analysis methods complement previously reported
identification |
|
methods
is described. An example based on the discretized solution of a
differential |
|
Wavelet
modelling of transients in power systems |
|
WESCANEX
97: Communications, Power and Computing. Conference Proceedings., |
|
This
paper presents a new scheme to model transients in power systems. Since
transients |
|
are
nonstationary both in time and space, their analysis and characterization
are difficult, |
|
and
the traditional method of Fourier transform and short-time Fourier
transform have |
|
their
limitations in transient analysis. Here, the authors propose the use of a
new |
|
time-frequency
multiresolution wavelet analysis of transients in power systems. The final |
|
objective
is to build an intelligent transient recorder, which is capable of
detecting and |
|
classifying
power system transients by type from the transient waveform signature
based |
|
on an
effective and efficient wavelet modelling and characterization.
|
|
A
new approach to detect transformer inrush current by applying wavelet |
|
Zhang
Chuanli; Huang Yizhuang; Ma Xiaoxu; Lu Wenzhe; Wang GuoXing |
|
Power
System Technology, 1998. Proceedings. POWERCON '98. 1998 International |
|
Conference
on , Volume: 2 , 1998 |
|
Page(s):
1040 -1044 vol.2 |
|
In
this paper, a mother wavelet suitable for processing transient signal in
power system is |
|
constructed
according to the theory of wavelet analisys and the Improve Recursive |
|
Wavelet
Transform (IRWT) is presented in order to meet the real time demands of |
|
analysing
power system signals. At the same time, research work are carried out to |
|
detect
transformer inrush current. IRWT has been used to analyze transformer
inrush |
|
current
generated by PSCAD ans id proved both effective and feasible.
|
|
Investigation
of transformer inrush current using a dyadic wavelet |
|
Energy
Management and Power Delivery, 1998. Proceedings of EMPD '98. 1998 |
|
International
Conference on , Volume: 2 , 1998 |
|
This
paper presents the application of a dyadic wavelet to investigate
transformer inrush |
|
current.
Inrush currents are simulated using the Electromagnetic Transient Program |
|
(EMTP).
Different values of remnant flux and point of voltage switch-on are chosen
to |
|
produce
various inrush current waveforms. The dyadic wavelet is applied to analyze
the |
|
signature
of the simulated inrush waveforms. Preliminary results are presented.
|
|
Power
System Transients Characterization and Classification using Wavelets and |
|
http://citeseer.nj.nec.com/mo98power.html |
|
This
paper presents a framework for transients classification using wavelet
transform and |
|
two
specific artificial neural networks, propabilistic neural networks (PNN)
and resource |
|
allocating
neural networks (RAN). One significant feature of wavelet for transients |
|
characterization
is its time-scale two dimensional but compact representation. One |
|
distinguishing
feature of PNN and RAN is the ability to adjust their architecture |
|
automatically
to adapt to new environment quickly and accurately, which makes them the |
|
promising
candidates for transients classification in power system. Some
experimental |
|
results
have indicated the suitability of this framework for transients
classification.
|
|
Wavelet
Analysis of Power Systems Transients Using Scalograms and |
|
J. LIU
; P. PILLAY; P. RIBEIRO |
|
Electric
Machines and Power Systems, 27:1331–1341, 1999 Copyright c 1999 Taylor
& |
|
The
Wavelet Transform has attracted considerable attention in the field of |
|
power
quality analysis recently. It has proved to be a powerful tool to study
those |
|
transients
that have time-localized information. In this paper, the insight to be |
|
gained
from using multiresolution analysis and scalograms is presented. With |
|
multiresolution
analysis, the original signal is transformed into coeficients in |
|
different
octave levels. From the scalogram of the respective coeficients at each |
|
level,
the special features of the original signals become distinctive.
Advantages |
|
of the
wavelet transform over the Fourier transform are also presented. Typical |
|
power
transients are used to test the method to illustrate its applicability in
the |
|
analysis
of power transients.
|
|
Wavelet
transform solution of multiconductor transmission line transients |
|
Magnetics,
IEEE Transactions on , Volume: 35 Issue: 3 Part: 1 , May 1999 |
|
In
this paper a wavelet transform approach is used to solve multiconductor
transmission |
|
line
equations. By using wavelets on the interval, differential and integral
operators are |
|
represented
by sparse matrices. Then the time domain differential equations of |
|
multiconductor
transmission lines are reduced to algebraic ones. The unknowns of the |
|
algebraic
system are the coefficients of the wavelet basis functions. Therefore a |
|
Fourier-type
approach is obtained for transient analysis of transmission lines. The |
|
procedure
reduces the CPU times with respect to the usual transient analysis
obtained by |
|
time
stepping methods. An initial analysis of the numerical characteristics and |
|
performances
of the method is carried out considering constant RLCG multiconductor |
|
A
wavelet transform based scheme for power transformer inrush identification |
|
Xianguing
Liu; Pei Liu; Shijie Cheng |
|
Power
Engineering Society Winter Meeting, 2000. IEEE , Volume: 3 , 2000 |
|
Page(s):
1862 -1867 vol.3 |
|
A new
scheme for transformer inrush identification is proposed in this paper.
The new |
|
scheme
is based on the wavelet packet transform algorithm. The main advantage of
the |
|
proposed
scheme is that different kinds of inrush of the transformers can be
correctly |
|
identified
from different types of the internal faults of the transformers. Also, the
external |
|
fault
of the transformers can also be identified from the internal fault with
the proposed |
|
scheme.
Test results with the sampled data from a prototype device on a dynamic
power |
|
system
model verify the effectiveness of the proposed scheme. Furthermore,
another |
|
advantage
of thus algorithm is that it can be realized in real time applications.
|
|
An
alternative method for transient analysis via wavelets |
|
Meliopoulos,
A.P.S.; Chien-Hsing Lee |
|
Power
Delivery, IEEE Transactions on , Volume: 15 Issue: 1 , Jan. 2000 |
|
This
paper presents an alternative method for the transient analysis of
dynamical systems. |
|
The
method consists of the traditional frequency domain analysis to capture
the steady |
|
state
operation of the system and a wavelet-based transient analysis which
captures the |
|
disturbance.
The total solution is obtained from the superposition of the steady state
and |
|
disturbance
solutions. This paper focuses on the second part of the solution method.
The |
|
authors
have named this method WBTA (wavelet-based transient analysis). It can be |
|
implemented
using any set of orthogonal wavelets. In this paper, they present an |
|
implementation
with Daubechies wavelets. The results obtained using this method are |
|
compared
and verified with a numerical time-domain analysis method. A concise |
|
description
of the method is presented followed by examples.
|
|
Classification
of power system transients: synchronised switching |
|
Styvaktakis,
E.; Bollen, M.H.J.; Gu, I.Y.H. |
|
Power
Engineering Society Winter Meeting, 2000. IEEE , Volume: 4 , 2000 |
|
Page(s):
2681 -2686 vol.4 |
|
This
paper presents a new method for the identification and classification of
transients |
|
due to
synchronised capacitor switching in three-phase systems. Signal processing |
|
techniques
are introduced to detect the switching actions in the individual phases. |
|
Synchronised
switching methods for capacitor energisation are considered. The proposed |
|
method
enables detection and classification of synchronised capacitor switching
events. |
|
This
in turn will lead to a reduction in the amount of data to be reported from
a power |
|
Electric
power transient disturbance classification using wavelet-based hidden |
|
Jaehak
Chung; Powers, E.J.; Grady, W.M.; Bhatt, S.C. |
|
Acoustics,
Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE |
|
International
Conference on , Volume: 6 , 2000 |
|
Page(s):
3662 -3665 vol.6 |
|
We
utilize wavelet-based hidden Markov models (HMM) to classify electric
power |
|
transient
disturbances associated with degradation of power quality. Since the
wavelet |
|
transform
extracts power transient disturbance characteristics very well, this |
|
wavelet-based
HMM classifier illustrates high classification correctness rates. The
power |
|
transient
disturbance is decomposed into multi-resolution wavelet domains, and the |
|
wavelet
coefficients are modeled by a HMM. Based on this modeling, the maximum |
|
likelihood
classification is applied to classify actual power quality transient
disturbance |
|
data
recorded on a 7200 V distribution line, and the result is tuned by post-processing.
Of |
|
507
power quality events experimentally observed by an electrical utility,
95.5% are |
|
Hybrid
F.E.-wavelet method for nonlinear analysis of nonuniform MTL |
|
Barmada,
S.; Musolino, A.; Raugi, M. |
|
Magnetics,
IEEE Transactions on , Volume: 36 Issue: 4 Part: 1 , July 2000 |
|
This
paper deals with the numerical solution of nonuniform Transmission Lines (TL)
with |
|
nonlinear
loads. The method presented here is based on the combination of wavelet |
|
expansion
and Finite Elements (FE) in space and time domain. By expanding voltages, |
|
currents
and operators by means of wavelet functions, the TL equations are
transformed |
|
into
algebraic equations where the differential operator is represented by a
matrix and the |
|
unknowns
are the coefficients of the wavelet expansion of voltages and currents.
The |
|
numerical
efficiency of the method is tested by analyzing uniform, nonuniform lines
and |
|
nonlinear
loads. The results are compared with results obtained by means of
different |
|
Visualizing
wavelet transformed travelling waves on power transmission line |
|
Advances
in Power System Control, Operation and Management, 2000. APSCOM-00. |
|
2000
International Conference on , Volume: 2 , 2000 |
|
The
paper reports work on analysis travelling waves, with make occur on power |
|
transmission
lines using Bewley Lattice Diagram (BLD) and wavelet transform (WT). It |
|
also
reports the development work on a visualizing system, which implements the
BLD an |
|
WT
methods for visualizing the travelling wavelets using the Java computer
programming |
|
languages.
The paper describes the BLD and WT tecniques for the analysis of the |
|
electromagnetic
transients on power lines. Analysis of electromagnetic transients is |
|
important
in the area of transmission lines protection since the high frequency
components |
|
of the
transients can be utilized for the identification of the location of
disturbances of |
|
line.
The structure of the visualization system is then described. The
usefullness of the |
|
system
is demostrated by applying it to the fault distance identification problem
on a 330 |
|
kV -
transmission line. The java visualization system reporter in this paper
provides and |
|
excellent
tool to dynamically so the complicated formation of travelling waves along
the |
|
lines
initiated by large disturbance. It is usefull to system planning and
protection |
|
engineers.
It is also a valuable tool for the teaching of electromagnetic transients
analysis.
|
|
Wavelet-based
simulation of transients along transmission lines with frequency |
|
Power
Engineering Society Summer Meeting, 2000. IEEE , Volume: 2 , 2000 |
|
This
paper describes a transmission line model which is based on wavelet
transform, and |
|
takes
into account frequency dependence of its parameters. Multiresolution
decomposition |
|
of
time domain signals is used to view the transient at different sub-bands,
solving each |
|
sub-band
using the corresponding values of frequency dependent parameters. Open
line |
|
energization
transients computed using this model are presented as an illustration, of
the |
|
proposed
method of modeling and simulation.
|
|
Accurate
modeling and simulation of transmission line transients using |
|
frequency
dependent modal transformations |
|
Abur,
A.; Ozgun, O.; Magnago, F.H. |
|
Power
Engineering Society Winter Meeting, 2001 IEEE , Volume: 3 , 2001 |
|
Page(s):
1443 -1448 vol.3 |
|
The
frequency dependent line model (also known as the J. Marti model) which is |
|
currently
used in most electromagnetic transient programs, is very efficient and
accurate |
|
for
most simulation cases. However, it makes an approximation in choosing the
modal |
|
transformation
matrix that is used to switch variables between the phase and modal |
|
domains
at each simulation time step. This approximation may not hold true for
certain |
|
tower
configurations and/or conductor types where line parameters vary
drastically with |
|
frequency.
In this paper, a wavelet based alternative solution, which incorporates |
|
frequency
dependence of transformation matrices into the simulation process is |
|
Wavelet
analysis for estimation of mean-curve of impulse waveforms |
|
superimposed
by noise, oscillations and overshoot |
|
Satish,
L.; Gururaj, B.J. |
|
Power
Delivery, IEEE Transactions on , Volume: 16 Issue: 1 , Jan. 2001 |
|
This
paper describes a novel approach to estimate the mean-curve of impulse
voltage |
|
waveforms
that are recorded during impulse tests. These waveforms in practice are |
|
superposed
by noise, oscillations, and overshoot. The approach is based on
multiresolution |
|
signal
decomposition (a kind of wavelet transform) and has many advantages over |
|
existing
methods, since it does not assume any model for estimating the mean-curve,
is |
|
interactive
in nature, suitable for full and chopped impulses, does not introduce
distortions |
|
due to
its application, is easy to implement and does not call for changes to
existing |
|
standards.
Results presented show its applicability. |
|
