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Use of Computerized Web-Based Information System For Determining Losses in 15-6.6 KV Feeders in Traditional Electrical Network Managemment: Case Study Goma Distribution Electrical Network

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Use of Computerized Web-Based Information System For Determining Losses in 15-6.6 KV Feeders in Traditional Electrical Network Managemment: Case Study Goma Distribution Electrical Network Powered By Docstoc
					                                               (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                         Vol. 8, No. 9, 2010

Use of Computerized Web-Based Information System
  For Determining Losses in 15-6.6 KV Feeders in
Traditional Electrical Network Managemment: Case
    Study Goma Distribution Electrical Network

               Ezekiel U. Okike                                             Bakunzi G. Joseph
         Department of Computer Science                               School of Computer Studies,
              University of Ibadan                                   Kampala International University
                Ibadan, Nigeria                                            Kampala, Uganda
              euokike@gmail.com


Abstract— Electrical energy plays very vital role
in modern global economy. The aim of this study                              I. INTRODUCTION
is to develop a framework for a Web-Based                 Modern global economy has rapidly increased by
Information System (WIS) tool for computing               means of the electrical energy. Electrical energy has
losses from 15 – 6.6 KV Feeders in Traditional            also penetrated each area of human activities in
Electrical Network Management (TENM). The                 such way that it has become a second virtual life.
study was conducted in Goma District in the               Furthermore, the availability of electrical energy
Democratic Republic of Congo. Data were                   and the quality of services (QoS) to consumers
collected from 26 key staff of Goma Distribution          shapes and aids national development efforts.
Electrical Network who responded to the                   Goma electrical network is located in North Kivu
questionnaires      and from metered reading              Province East of Democratic Republic of Congo.
documents used in the study. The study                    With the volcanic stones covering the whole Goma
implemented a Computerized Web-Based                      town, laying underground electrical cables is very
Information System (CWIS) to compute                      difficult. Hence the whole electrical network is
different losses in Goma electrical distribution          made up with overhead aluminum cables. The
network. The CWIS computed technical losses in            electrical energy supplied to Goma town is from
five 15-6.6KV feeders of Goma electrical                  Ruzizi hydraulic generation power station located in
distribution network. The study revealed that             the neighboring town of Bukavu in South-Kivu
among the five feeders, feeder 1 (Sud feeder)             province.
consumes 1,469,172.6 KWH representing 66.3%               In Democratic Republic of Congo (DRC), the
of the total annual energy loss while others              company in charge of generation, management,
presented lower annual losses. This is an                 transmission, and distribution of electrical energy is
indication that Feeder 1 is overloaded and                the “Societe Nationale d’Electricite” (SNEL). The
needed to be resized or on the alternative, the           head office of SNEL is located in the DR. Congo
installation of another overhead cable that will          capital town of Kinshasa which is 2000 kilometers
take the half of the load in charge.                      away. Therefore the use of a Computerized Web-
                                                          based information System (CWIS) can allow
Keywords- Electrical energy; energy distribution;         managers to use the information resources from
  feeder loss; computerized information system            Goma electrical distribution network through a
                                                          communication medium.




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                                                                                    ISSN 1947-5500
                                                  (IJCSIS) International Journal of Computer Science and Information Security,
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 Since SNEL still uses manual reading of energy                          Goma distribution                 electrical        network
metering and manual information system, a CWIS                           management?
becomes inevitable. Goma electrical network has
only one Transmission Substation being coded as 2x                     •      What is the level (in percentage) of
10MW-70/15 KV, five primary feeders (1 feeder of                       maximum losses in 15kV and 6.6kV feeders
6.6kv and 4 feeders of 15kv), and fifty five                           of Goma distribution electrical network?
Distribution Substations with code 15/0.4kv-
6.6/0.4kv.                                                                        II.    RESEARCH METHOD
This research is aimed at implementing a
Computerized Web-Based Information System that                A.    The Traditional Approach to Electric Power
can compute losses based on data entry from                   For roughly a century, the developed world has
manual reading of the metering system, as well as             delivered electric power using the same basic four-
compute technical losses (TL) in the 15kv and 6.6kv           step approach: 1) generate power in large,
feeders.                                                      centralized plants; 2) step up the power to high
                                                              voltages and transmit it to regional utilities; 3) step
A. Statement of the Problem                                   down the power to medium voltages to distribute it
                                                              locally; 4) step down the power a final time to
The use of manual information system does not                 deliver it to customer premises. (Figure 2.1.)
show the losses incurred at all the stages of the
generation, transmission and distribution of the
electrical energy in Goma electrical network
system. In addition to this major problem, the
manual information system management includes
poor data storage, slow and difficult retrieval,
inconsistency in data, data redundancy, and the high
probability of losing information stored in files on
shelves due to damage or theft. Hence the need for a
computerized information system which overcomes
these problems cannot be over emphasized.
 B. Objectives of the study
The specific objectives of this study are as follows:
    • To implement a Computerized Web-Based
        Information System (CWIS) for four 15-                Figure 2.1. Traditional Electric Power Approach
        6.6KV feeder losses computation

   •   To demonstrate the current state of electrical
       power supply equipment by showing the                  Figure 2.1: The “traditional “ electric power value
       electrical power losses in the four 15-6.6KV           chain encompassed centralized generation, high
       feeder as a result of power assigned to Goma           voltage transmission, medium-voltage distribution,
       electrical network consumers by the use of             and end use by industrial, commercial and
       the manual information management system.              residential customers (source: Global Environment
                                                              Fund, 2008)
C. Research Questions
The questions to be answered in this study are:
                                                              B.    Goma Electrical Distribution Network Losses
   • To which level (in percentage) can a
                                                                 Computation procedure and framwork
        Computerized Web-based Information
        System (CWIS) be effectively useful for               The electrical framework for energy losses in a
        15-6.6KV feeder losses computation in                 distribution system is presented in the figure 2.2 .



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                                                                                             ISSN 1947-5500
                                                                     (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                               Vol. 8, No. 9, 2010
The steps followed to compute losses at different                                    LLF = 0.8 (LF)2 + 0.2 (LF)                                  (5)
levels in the framework (figure 2.2) of the electrical                               • Peak- power loss (PPL)
distribution network are given below. The primary
feeders are five feeders that have a total length of 46                               Peak- power loss (PPL) in 11kv
kilometers.                                                                          line = 3 I2 R (UF)2 KW                                      (6)
                                                                                     • Annual energy loss
                                                                                     Annual energy loss
                                       Consumer           Consumer
                                                                                           = PPL 8760 LLF KWH                                    (7)
                                                                                     • Average power fed

                                                                                      Average power fed =       V I (existing pf) (UF)
           Distribution
           Substation
                              Service Mains       Service Mains
                                                                                     (LF) KW with pf as power factor (cosines phi)
                                                                                     and KW as kilowatt.                       (8)
                                                                                     The losses in 15kv lines are calculated as shown
                               Distributor (LT lines)                                below:
                                                                                     • Percentage 15/6.6 kv line losses
                    Primary feeder
                                                                                     Percentage 15kv line losses
        Transmission                                                                   =                   100                                   (9)
         Substation



                                                                                            III.     SOFTWARE IMMPLEMENTATION
   Figure 2.2 Electrical Distribution Network framework
                                                                               A.    General architecture of the System
    •     Utilization Factor (UF) at the existing power                           The general architecture of the system is
                                                                               described by figure 3.1 below:
          factor is given as

    UF =                                                      (1)
                                                                                          Presentation                                     GUI
  •       Load Factor (LF) and Loss Load Factor
          (LLF) are given as                                                           15.6 kv         Transformer losses      LT losses
                                                                                      Cable losses
    Peak-Load =       Vw (          )        (2)                                         Losses Computation Software
    Average Load = Vav (                )    (3)                                     System losses       Other Network      User Login
    where n is the number of feeders, Vw is                                                              Information
    working voltage, Vav is average voltage, Ipn is
    the peak current and        is average current in
                                                                                         Persistence             DB files
     th
    n    feeder. The working voltage Vw and the                                     Figure 3.1 General Architecture of the System
    peak current Ipn are collected from the metering
    system.
                                                                               The Graphic User Interfaces (GUI) were
    Hence ,                                                                    implemented for entering data in the database using
                                                                               PhP 5 with Macromedia dreamweaver 8
    LF =                                                      (4)              programming approaches as proposed by Luke and
                                                                               Laura (2003).



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                                                                                                                ISSN 1947-5500
                                                 (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                           Vol. 8, No. 9, 2010
The GUI was designed as form fields for input and                                        TABLE 4.1 B
display of appropriate data as required by the               Feeder     Peak       Avg          Peak         Avg          Load
database for use by the various computational                Name     current    current        load         load         factor
processes. The computational processes were                   Sake     98.000     64.000      1974.087     1211.604       0.613
implemented using appropriate international                   Sous    191.000    140.500      1693.807     1170.528       0.691
standard empirical formulae (see section 2.2).                Nord    100.000     55.000      2014.375     1041.222       0.516
                                                             Centre    70.000     45.000      1410.062     851.909        0.604
Forms for reporting errors from the system are                Sud     200.000    165.000      4028.750     3123.667       0.775
generated automatically by the application software.
The database was implemented using MYSql. In                                        TABLE 4.1C
order to access information in the system,
                                                             Feeder    Loss       Capacity                Peak          Annual
appropriate user authentication and authorization            Name     Load           Of        Utility    Power         Energy
checks were implemented through the system login                      factor    transformer    factor      loss          loss
prompt. The web based capability of the system was                                 centres
                                                              Sake    0.424      5280.000      0.373      18.147       67421.7
implemented using PhP5 with Macromedia                                0.520      5725.000      0.295     112.223      511465.2
                                                              Sous
dreammweaver8. In all, the entire system                     Nord     0.317      2960.000      0.680      53.874      149664.4
requirement are Mysql, PhP5, macromedia dream                Centre   0.412      6510.000      0.216      5.341        19319.0
weaver, Apacher server, and Visio Modeler.                    Sud     0.635      5350.000      0.753     263.702      1469172.5

   IV.     SYSTEM RESULT: ELECTRICAL                                                TABLE 4.1 D
          NETWORK DATA PRESENTATION                          Feeder     Total       Total      Cosine        Avrage
              AND INTERPRETATION                             Name      Energy      Energy       phi          Power
                                                                      received     demded                     fed
 A. Feeder Losses Presentation and Interpretation             Sake    529.864      345.500      0.837       232.891
 The losses and loads in feeders as results of the            Sous    529.864      345.500      0.837       200.472
 system are presented and interpreted in this                Nord     529.864      345.500      0.837       306.804
 section. The resistor (Ω), peak load, average load,         Centre   529.864      345.500      0.837        93.383
 load factor, loss load factor, capacity transformer          Sud     529.864      345.500      0.837       1527.712
 power, utilization factor, peak power loss, annual
 energy loss, cosines phi, and average power fed
 for each feeder have been computed by the CWIS              From table 4.1 (a-d) the cumulative sum was done
 and presented in table 4.1. The peak power losses           by the system to provide the results in table 4.2 (a-
 (ppl) (kw), the average power (kw), and the 15kv-           b). From table 4.2a, the total length of the 15/6.6 kv
 6.6kv line annual energy loss (kwh) bar charts              cable is shown in the first column and last row as
 below show the repartition of loads and losses in           46.557 kilometers. The next column and last row
 the five feeders in order to highlight and guide            shows the total peak load computed as 11.121kva
 managers on what decisions for corrective and
 preventive maintenance may be necessary in                  (the metered value was 11kva). Other computed
 order to balance or to reduce losses.                       values can be seen from the table with the last row
                                                             of each column accounting for total for total values
                                                             as follows: average load, utility factor, was equal to
          TABLES 4.1(A-D). FEEDER LINE                       7398.9 kw, utility factor is 2.31991, and total
                                                             capacity of transformer center is 25.825 kva.
                    TABLE 4.1 A                              Howerver the total power of the Substation which is
Feeder   Cable   Length(M)    Ohm     Working   Avg
                                                             20 kva that shows there is extra power of 5.825
Name     code                  (R)      volt    volt         kva. The system computed the peak power loss in
 Sake     Alu    8761.500    4.505     11.630   10.9         all the feeders as 453.29 kw, and the annual energy
 Sous     Alu    16270.000   11.714    5.120     4.8         loss as 2,217043.14kwh for the year (2008). The
 Nord     Alu    5385.600    3.877     11.630   10.9         average power fed is computed as 2361.26 kw. The
Centre    Alu    10758.000   7.745     11.630   10.9         loss load factor and utilization factor have been
 Sud      Alu    5382.300    3.875     11.630   10.9
                                                             calculated in order to use their average values



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                                                                                       ISSN 1947-5500
                                                                      (IJCSIS) International Journal of Computer Science and Information Security,
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(2.310337divided by 5 and 2.31991divided by 5) in
the electrical network losses calculation. It is noted
that the average power factor of 0.84 is less than
the standard minimum value of 0.90 as stated by
Pabla (2005). From these results the study shows
that the CWIS can provide information that can be
used in preventive and corrective maintenance of
the Goma electrical network distribution.


 TABLES 4.2(A-B). SUMMING NUMERICAL VALUES
       FROM FEEDER READABLE TABLE


                            TABLE 4.2 A
 Feeder      Length(M)         Peak          Avrage       Utility
                                                          Factor
 Name                          Load           Load
 Centre          8761.5
                              1974.08        1211.60     0.37
                                                                                      Fig 4.1 Sake   Sous Nord         Centre       Sud
  Sake           25031.5
                              3667.89        2382.13     0.66
                                                                                   The figure 4.1 reveals that the feeder named “Sud”
 Nord            30417.1                                                           is most overloaded, and has the highest peak power
                              5682.26        3423.35     1.35
                                                                                   loss (ppl). At the other hand the feeder named
  Sous           41175.1                                                           “Center” has the lower load. From this observation
                              7092.33        4275.26     1.56
                                                                                   the managers can well decide which steps can be
  Sud            46557.4                                                           taken in order to reduce the power loss in feeder
                              11121.08       7398.93     2.31                      Sud, and how to balance loads on other feeders
                                                                                   which are lightly loaded.
                   TABLE 4.2 B                                                                KW
Feeder     Loss       Capacity            Peak         Annual       Avrage
           Load      Transformer         Power         Energy       power
Name
          Factor        Power             loss          Loss         Fed
Centre
          0.42       5280            18.14         67421.72         232.89

Sake
          0.94       11005           130.37        578886.99        433.36

Nord
          1.26       15965           184.24        728551.48        740.16
 Sous
          1.67       20475           189.58        747870.56        833.55

 Sud
          2.31       25825           453.29        2217043.14       2361.26




 B. Descriptive Statistics of the System Results
Descriptive statistics of the system results are
shown in the bar charts presented in figure 4.1, 4.2,
and figure 4.3. The interpretation of results is given
                                                                                    Fig 4.2   Sake Sous      Nord Centre Sud
below each bar chart.



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                                                                                                           ISSN 1947-5500
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                                                             According to the formular LLF = 0.8 (LF)2 + 0.2
                                                             the Loss Load Factor (LLF) is highly proportional
The figure 4.2 shows that the same feeder named
                                                             to LF powered by 2. That means that at lower load
“Sud” was demanding the highest power compared
                                                             LLF is small. But at high load LLF is near to one
to others. It reveals that there is a relationship
                                                             so that the I2 (the current) is the one highly
between peak power loss and average power fed.
                                                             influencing the annual energy losses. The peak
Once again the managers have the precise
                                                             ampere recorded from the metering system being of
knowledge of the average power to be cut off from
                                                             200 A, it is visible that the annual energy losses in
feeder named “Sud”, or the size of the transformer
                                                             the feeder named “Sud” must be higher than they
that can supply that average power.
                                                             are in the other feeders where the peak current range
Normally the electrical distribution network
                                                             from 70 A to 100 A. The feeder named “Centre”
manager is interested in how to reduce losses in
                                                             still the one having the lower value of annual losses.
order to increase profit. The Computerized Web-
                                                             The bar charts in figure 5.10 are revealing that there
Based Information System has the capability to
                                                             is a correlation between the average power, the peak
compute annual losses to highlight managers about
                                                             power loss, and annual energy losses. Managers
the magnitude of them. The figure 4.3 shows the
                                                             cannot take decision on how and on which resource
annual energy losses magnitude for each feeder.
                                                             to be engaged to reduce losses if they do not know
        KWH
                                                             their magnitude. Once again the Computerized
                                                             Web-Based Information System has shown it
                                                             capability to compute technical losses (power losses
                                                             and annual energy loss) for each feeder and has
                                                             shown how it is a powerful tool to be used in
                                                             making decisions for preventive and corrective
                                                             maintenance.

                                                                  V.   DISCUSSION, CONCLUSION AND
                                                                         RECOMMENDATIONS
                                                             C.    Discussion of Findings
                                                             Technical losses do occur in electrical feeder
                                                             distribution networks. Pabla (2005) stated that the
                                                             typical maximum losses (in percentage) in 15KV
                                                             and 6.6KV Feeders, should be 4.0%. However,
Fig 4.3     Sake Sous Nord Centre Sud
                                                             technical losses in the Goma electrical distribution
                                                             network appear to be far above this range.
                                                             Out of the total annual energy loss (see table 4.2 -
The bar charts in figure 4.3 reveal that the same            2217043.14 kwh) the feeder called “Sud” takes
feeder Sud presents the higher annual losses. Out of         1,469,172.6 kwh (see table 4.1) which represents
the total annual energy loss (see table 4.2 -                66.3% of the total annual energy loss. Because the
2217043.14 kwh) the feeder Sud takes itself                  peak current (of 200 ampere) demanded was very
1,469,172.6 kwh (see table 4.1) which represents             high therefore annual energy losses were also
66.3% of the total annual energy loss. Because the           increased.
peak current (of 200 ampere) demanded was very               D.    Conclusion
high therefore annual energy losses were also                The losses in 15-6.6 KV feeders (particularly in
increased according to the relation:                         “Sud feeder”) is very high. The implication of those
 Annual Energy losses = 3 I2(UF)2 x 8760 x LLF =             losses is that they reduce the Company profit, life of
K I2(UF)2LLF with K equal to 3 x 8760.



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                                                                                      ISSN 1947-5500
                                                     (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                               Vol. 8, No. 9, 2010
cables and transformers, and the number of                          Economy: New opportunities from the
                                                                    transformation of the Electric Power Sector”,
customers to be supplied with electricity. This has                 Global Smart energy, 2008.
been hidden due the operational manual system in
place. However, with a Computerized Web-Based                    [3]W, Luke and T. Laura, PhP and MySQL Web
                                                                     Development, 2nd, Samms Publishing,
Information System for computing losses, managers                    Indianapolis .
will have insight as to actual losses and be guided              [4] A.S Pabla, Electric power distribution, 4th ed,
towards appropriate corrective and preventive                        McGraw-Hill , USA 2005.
maintenance       necessary to minimize Goma
distribution network losses.                                     [5] Y,Wilis and D, David, “A General guide to
                                                                     writing research proposals and report, A hand
                                                                     book for beginning researchers, 2nd ed,
E.      Recommendation                                               Makerere University, Kampala, 2008.
     From this study, the following recommendations
     becomes necessary for Goma electrical network               AUTHORS PROFILE
                        distribution:
                                                                 Ezekiel U. Okike received the BSc degree in
       • Implementation of the Computerized Web-
                                                                 computer science from the University of Ibadan
          Based Information System in order to
                                                                 Nigeria in 1992, the Master of Information Science
          monitor losses over time for corrective and
                                                                 (MInfSc) in 1995 and PhD in computer science in
          preventive maintenance of the electrical
                                                                 2007 all from the same University. He has been a
          distribution network
                                                                 lecturer in the Department of Computer Science,
       •   Immediate resizing of the overloaded “Sud             University of Ibadan since 1999 to date. Since
           feeder” or installation of another overhead           September, 2008 to date, he has been on leave as a
           cable that will take the half of the load in          senior lecturer and Dean of the School of Computer
           charge.    Whenever       the    distribution         Studies, Kampala International University, Uganda.
           transformers are overloaded and additional            His current research interests are in the areas of
           loads are anticipated, then the existing              software engineering, software metrics, compilers
           transformers should be replaced by higher             and programming languages. He is a member of
           capacity transformers, or new transformers            IEEE Computer and Communication societies.
           may be provided to cater for the loads.
                                                                 Bakunzi G. Joseph is an Electrical Engineer from
                                                                 Institut Supérieur des Techniques Appliquées de
                      REFERENCES
                                                                 Kinshasa and postgraduate student in the School of
                                                                 Computer      Studies,   Kampala      International
                                                                 University . He holds the B.Eng. in Electrical
[1] B, G. Joseph, “ Use of commputerized wed-
    based informmation system for determining                    Engineering and recently graduated with the degree
    losses in traditional electrical network                     of Master      of Science in Systems Software
    management: case study of Goma electrical
    distribution network”. MSc thesis, School of                 Engineering , MSc(SSE).
    computer Studies, Kampala International
    University, xv+ 120 pp, April 2010
[2]Global research Fund. “The Electricity




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