intelligent database systems lab advisor ： dr.hsu graduate ： keng-wei chang author ：...

Intelligent Database Systems Lab

Advisor ： Dr.Hsu

Graduate ： Keng-Wei Chang

Author ： Gianfranco Chicco, Roberto Napoli

Federico Piglione, Petru Postolache Mircea Scutariu, Cornel Toader

國立雲林科技大學National Yunlin University of Science and Technology

Load Pattern-Based Classification of

Electricity Customers

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO.2 ,MAY 2004


Outline

Motivation Objective Introduction Classification Tools and Models Classification Adequacy Assessment Application of The Classification Techniques Performance Comparisons Concluding Remarks

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Motivation consumption patterns for electricity providers

in competitive electricity markets setting up new tariff structures more closely to

the actual cost in different time periods

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Objective accurate knowledge of the customer’s

consumption patterns represents

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Introduction face new challenges in providing satisfactory

service to customers set up new tariff structures survey two classes of tools

Modified Follow-The –Leader Algorithm Self-organizing maps (SOM)

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Classification Tools and Models rescale or resort related definition

Two clustering tools Modified Follow-The-Leader Algorithm SOM Approach

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KkrRtiverepresentaclass

ncomputerpatternloadtiverepresenta

ncontaineachclusterKkLL

MmlLcustomersofsetthe

Hhllcustomereach

k

kk

kk

m

h

,...,1,,

,,

, ,...,1,

,...,1,,

,...,1,,


Modified Follow-The-Leader Algorithm

unsupervised clustering algorithm, not require initialization of the number of clusters and computes the cluster centers automatically

is the variance of the hth feature of all the load patterns in the population

is the average value of the variance for h=1,…,H

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)1(,1

2

2

2

H

h

kih

mh

hki

m qlqld

2h

2 2

h


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SOM Approach unsupervised neural network, projects a H-

dimensional data set into a reduced dimension space

related definition N1 x N2 H-dimensional units ck, a competitive layer ||xi – ck||, activation function not only the winning unit, but also its neighbor

units

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SOM Approach Update the generic unit ck

is the learning rate

is the value of the neighborhood function referred to the generic unit k

w, the identifier of the winning unit

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)2( oldkikw

oldk

newk cxttcc

t tkw


Classification Adequacy Assessment

General Outline and Definition of the Distances

Adequacy Measures

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1) the distance between two load patterns

2) the distance between a representative load curve and subset , as the geometric mean

General Outline and Definition of the Distances

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)3(1

,1

2

H

h

jh

ih

ji llH

lld

)4(,

1,

1

2

kn

m

mkk

kk lrdn

Lrd

kr kL


Separated and compact1) the mean index adequacy (MIA)

2) the clustering dispersion indicator (CDI)

Adequacy MeasuresN.Y.U.S.T.

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)5(,1

1

2

K

k

kk Lrdk

MIA

)6(

,2

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,2

11

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2

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k

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k

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n

knk

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CDI


Application of The Classification Techniques

Customers of the Romanian national electricity distribution company 234 customers Over three-week time intervals Contain industrial, services, and small-business

two application Application of the Modified Follow-The-Leader

Algorithm Application of the SOM

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Application of the Modified Follow-The-Leader Algorithm

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p = 2.266, k = 16


Application of the Modified Follow-The-Leader Algorithm

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Application of the SOM Average distance from each example of the data set to its

winning units

Distortion of the map as the percentage of samples for which the winning unit and the second winning unit are not neighboring map units

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)7(1

1

M

iiw xc

MQ

)8(1,1

121

M

iww ccneighb

MT


Application of the SOMN.Y.U.S.T.

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MnRM / resolution property

NnRN / degree of utilization of the map

M : population

N : N1 X N2



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Performance ComparisonsN.Y.U.S.T.

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Concluding Remarks both can effectively assist the customer

classification Suggest using them in a way depending on the

objectives

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Review Two clustering tools

Modified Follow-The-Leader Algorithm SOM Approach

Classification Adequacy Assessment Application of The Classification Techniques Performance Comparisons

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Personal opinion …

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intelligent database systems lab advisor ： dr.hsu graduate ： keng-wei chang author ：...

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