Transcript From power quality recorders-Data acquisition systems NOTE

Overview
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Abstract
Project Description
 Objective
Simulation Model/System Studied
Project Methodology
 Procedure
 Algorithm
Conclusion
Abstract
This project presents an algorithm and approach that is
able to provide the detection and location of the
power quality disturbances. Here, the events like
voltage sag, voltage swell, and transients are analyzed
using S transform and the energy distribution are found
for the power quality disturbances using Parseval’s
Theorem.
The PQD is also been analyzed by both phase
spectrum and amplitude spectrum. The events are
simulated using MATLAB SIMULINK software. The
advantage of the algorithm is it has both timefrequency localization and thus has the visual
observation of power quality disturbance.
Project Description
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OBJECTIVE
 To
detect and analyse the power quality
disturbances that occur in a three phase power
system due to the contribution of the network
impedances and types of customers’ connected
loads.
What is PQD?
Any electrical power problem manifested in
voltage, current, or frequency deviations that results in
failure or mis-operation of customers’ operation.
Need for the study of PQD…
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Variations in the power quality, even for a very
short time, that were not a concern before can be
very costly in terms of process shut-downs and
electrical equipment malfunctions in manufacturing
plants.
Modern day customers demand high power quality
for improved production output as well as for
maintaining an optimal operating cost.
Classification of PQD
The power quality disturbances that we are going to
predict in this project are
 Sag
 Swell
 Transients
SAG
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A voltage sag is a momentary (less than a few
seconds) decrease in voltage outside the normal
tolerance.
The starting of heavy loads, lightning and power
system faults causes voltage sags.
SWELL
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A voltage swell is a momentary increase in voltage
outside the normal tolerance.
Voltage swells are caused by sudden decreases or
the turning off of heavy loads.
Transients
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Sudden, brief increase in current or voltage in a
circuit that can damage sensitive components and
instruments.
These disturbances are shorter than sags or swells,
and are caused by sudden changes in the power
system.
Simulation Model(System studied)
Procedure of proposed approach
PARSEVAL’S
THEOREM
SAG
SWELL
TRANSIENTS
From
power
quality
recordersData
acquisitio
n systems
Applying DSP
techniquesWavelet
Transforms
Feature
Extraction
Technique
Classification
of
PQD
NOTE:
Magnitude Levels: Sag<Swell<Transients
0
1
2
Algorithm of proposed project
N
If Energy
Density(ED) is at
NORMAL
value(EDN)
YES
N
NO
NO
C
If
ED < EDN
YES
N
Algorithm of proposed project
C
If
ED >
EDN
YES
NO
If
ED >
EDSwell
YES
N
NO
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SOFTWARE USED:
MATLAB
APPLICATION:
It can be used at various domains
in the power system.
Simulated Model
Transient Simulink Model
Simulink Output
TRANSIENT Waveforms obtained
from M-File after applying
WAVELET TRANSFORM
Transient waveform-PHASE A
Transient waveform-PHASE B
Transient waveform-PHASE C
Conventional and proposed system
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Automatic prediction of PQD and prediction
accuracy is increased
Solves both data volume and lack of expertise
problems
Damage to the equipments due to breaking down
of insulation can be eradicated.
Conclusion
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In this project, a novel approach to perform data
detection and analysis using s-transform technique is
presented.
This proposed method will be useful to the PQMS
for performing the real-time detection and analysis
of the recorded power quality disturbances.
THANK YOU