5.E.S.'COLL'EGE OF,ENGINEERING , NAVALNAGAR-Proudly Presents

INTERNA TIONAL CONFERENCE., ON

SCIENC;-ENGINEERING & SPIRITUALITY. ~ " :" _.... .:.:...:;:: ',.:1'_.1 ". '. \. It nd

~_, April1 & 2 ,2010

., . QG~Jf~]j1](t~lr~Of...'err .. ., Mr. / .Mrs. f.l;1.s./::IY. .!l(gje Sh :M....7IiJliuude has participated / _.

". ',- Li~" -,/ _/.. ._.Lor ~L . --presen authored paper tiiled: ~//?/Q/..."P.igcet:l7P'~", 07PQCIJ.Qr. .

..1Qr.p.p.H!f'dil.~..r.eh?b.

OPTIMAL PLACEMENT OF CAPACITOR FOR POWER lOSSREDUCTION USING ETAPSOFTWARE

Prof.R.M.Holm ukhe,Department of Electrical Engineering,College of Engineering.Bharati Vidyapeeth University, Pune,Maharashtra.Mobile:90 II064868Mail: rajeshmholmukhe@hotmail.com

Prof.P.V.ChopadeDepartment of Electrical Engineering,College of Engineering,Bharati Vidyapeeth University, Pune.Maharashtra.

INTRODUCTION:The total power (Apparent Power) inkilovolt-amperes (kVA) delivered by adistribution line to a load consists of twoparts, Real Power (kW) and ReactivePower (kVAR). Power factor is amathematical representotion of theamount of reactive power relative tothe amount of real power or apparentpower.Reactive energy is required becauseconnected loads (motors, transformers,and other inductive type loads) andassociated conductors demand thistype of energy along with real energy todo work. As a result. in the absence ofany other source, reactive energy hasto be supplied by the generator at thepower plant. be transformed andtransmitted along the transmission grid,and finally be transformed again on thedistribution system for delivery to thereactive load that requires it.When the distribution system's reactiveload can be canceled by a capacitorplaced at the reactive load center, theentire power delivery system will berelieved of this Kvar burden originallysupplied from the power supplier'sgenerator; thereby making its fullcapacity available to serve real powerloads. If a capacitor is connected to thedistribution system either too far aheadof or too far beyond the system's

inductive load center, the capacitor stillprovides reactive loading relief, but thesystem will not gain the full advantagesof voltage and loss improvement whichwould be afforded by proper capacitorplacement.

Prornod JalamkarMtech Electrical StudentDepartment of Electrical EngineeringBharati Vidyapeeth University,Pune,Maharashtra.

ADAVANTAGES OFINSTALLATION OF CAPACITOR:IMPROVES POWER FACTOR:Asa rural power distribution system loadgrows, the system power factor usuallydeclines. Load growth and a decreasein power factor leads to

Voltage regulation problems; Increased system losses; Power factor penalties Reduced system capacity.Capacitors offer a means of

improving system power factor andhelping to correct the above conditionsby reducing the reactive kilovar loadcorried b the utilit s stem

IMPROVES FEEDERVOLTAGE PROFILEOne of the greatest advantagesgained by the proper sizing endlocation of distribution capacitors isvoltage improvement. By placing

leading volt-amperes reactive (VAR)loads {copacitors} near logging VARload centers (motors for' example), thelogging VARs on a system basis arecancelled with on associated increasein voltage.In addition to improving the systemPower Factor, capacitors also providesome voltage drop correction. Becauseof a copccitors leading current thisflows through the system's logginginductance, capacitors couse avoltage riseon the system.REDUCES POWER AND ENERGY LOSSESDistribution capacitors can reducesystem line losses, as long as the systempower factor is not forced into a leadingmode. Line losses at 80 percent leadingpower factor are just as detrimental asline losses at 80 percent logging powerfactor.INCREASES SYSTEM CAPACITY. As will be seen, capacitors will provideimprovement on the bulk facilities as aby-product of the improvements theybring about on the distribution feeder.

_'~-...ne- __ ,,__ CIooy-"'~'-~--"~""IQO-Go

f~" 1:1:JJ~c o,3ee k\-.A ~ifd,"" c..h.A_k

CAPACITOR SIZING:LIGHT LOAD CONDITIONS

Selecting capacitorlocations for the lightest load requiresdetermining the expected minimumload from the lowest peak month'shistorical load data.Capacitor or kVAR needs may also bedetermined by tracking minimum-maximum load readings from a feeder'sbus-by-bus metering records or fromSCADA (Supervisory Control and DataAcquisition) loading data.PEAK LOAD CONDITIONS

Automatic controls can trackvarious parameters and switch thecapacitor bonks as needed to optimizethe system power factor. The additionalcapacitors should be switched either asan entire bank or in steps in order tokeep the power factor from becomingsignificantly leading at any time. Inaddition, proper switching prevents overvoltage, undesirable voltage flicker andhelps the capacitors perform the taskthey were installed to do. Voltage spikesor surges occur when switchingcapacitors because the switch usuallycloseswhen the system voltage is not ata zero voltage crossing point. Non-zerocurrent switching causes a capacitor toabruptly charge to the system voltageand generally creates wide rangingoverswings. This transient will tokeseveral cycles to decoy end can affectindustrial loads with

u).)n.u.'.,aQt;;c:

CAPACITOR LOCATION:Maximum benefits are obtained bylocating the capacitors os near theinductive reactance kVAR loads ospossible and by matching themagnitude of the inductive reactancekVAR requirement. Practicalconsiderations of economics andavailability of a limited number ofstandard kVAR sizes necessitate thatcapacitors be clustered near loadcenters. Computer modeling or rigorousevaluation of considerable loadmetering data are absalutely necessaryto make the proper capacitorplacement decision and keep line lossesos low as possible

Forindustrial loads, it is best to correct thepower factor at the load.

Optimum benefits (To?btain maximum benefits in voltageImprovement and reduction of loss onsuch a line)are derived by locatingcapacitors at industrial loads and at afeeder's consumer load density centerfor residential load. The residential loadcenter is normally 1/2 to 2/3 thedistance from the substation to the endof the line for uniformly loaded feeders.Thus, the following method isrecommended for locating capacitors:Usea computer model of your electricsystem and allow the computerprogram to place the capacitors on thesystem in blocks of the largest size thatcan be used to limit the voltagechanges to 3 volts per switched bank.There are several suppliers of goodengineering analysis software and manyengineering consultants offer computerservice.

?: :! ~;_ . .., .--.- '-~~ ; ~ ~ ~ ~ ~ ~ ~ ; ~.~ ~ :~; ~ ~ ~ j; ~ :;~ g ~ ~ ~. ~ ~ ~ ~ ~ ? ~ ~ : ~ ~ ~ ~ ~:~ ~ :~~~~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~ ~ ,.. .er- ;., ;.. OM _ ;: - - - - ~ ~ - - - e- ~ ~f1 .e , - :- "' ~ .. -. 41 !: ~ ~ :; :: : :. :: ~ ~-:.~ =

r~~~n;~HBil!iHi!~. ..: _ ... .,..t. _ :'> ;cABOUT ETAP:

ETAP PowerStation is a fully graphicalpower systems analysis program thatruns on Microsoft Windows 98, NT 4.0,2000, Me, and XP environments. TheWindows 2000 and XP Professionalplatforms provide the highestperformance level for demandingapplications, such as large networkanalysis requiring intensive computationand online monitaring and controlapplications.Windows 2000 and XP Professional alsoprovide the highest levels of reliability,protection, and security of criticalapplications, especially for largePowerStation projects (approximately500 busesand larger).P

OPTIMAL CAPACITOR PLACEMENTMost power systems that operate at alogging power factor due to loads anddelivery apparatus (lines andransformers) are inductive in nature.Therefore. power systems requireadditional var flow. This results inreduced system capacity, increasedlosses and decreased voltage.To place shunt capacitors in powersystems. you must perform the followingtasks:

Determine the bank size in kvorDetermine the connection

locationDetermine a control methodDetermine a connection type

(wye or delta)You can determine the capacitor sizeand the proper location for voltagesupport and power factor correction indifferent ways. One common method isbased on applying "rules of thumb"techniques. followed by running multipleload flow studies for fine-tuning the sizeand location. Thismethod may not yieldthe optimal solution. It can also be verytime consuming and impractical forlarge systems.Minimizing the cost while determiningthe capacitor size and locationmathematically is an optimizationproblem. Therefore. you should employan optimization approach. The ETAPOptimal Capacitor Placement (OCP)module is an extremely powerfulsimulation tool that is specificallydesigned for this application. The OCPmodule helps you place capacitors forvoltage support and power factorcorrection while minimizing total cost.The advanced graphical interface givesyou the flexibility to control thecapacitor placement process andallows you to view the resultsgraphically. The precise calcu!ationapproach automatically determines the

best location and bonk sizes. Inaddition, it reports the branch capacityrelease and the savings during t eplanning period due to vor lossreduction.

ocp USING ETAP:ETAPcurrently utilizes the geneticalgorithm for optimal capacitorplacement. Thegenetic algorithm isonoptimization technique based on thetheory of natural selection. A geneticalgorithm stortswith a generation ofsolutions with wide diversity to representchoracteristics of the whole searchspace. By mutation and crossover,good characteristics ore selected andcorried to the next generation. Theoptimal solution can be reachedthrough generations.OCPuses the present worth method toperform alternative comparisons. Itconsiders initial installation andoperating casts.which includemaintenance. depreciation, and lossreduction savings. It also providesinterest rate and inflation consideration.Objective Function of OCP:The objective of optimal capacitor.placement is to minimize the cost of thesystem.The cost includes four parts:

fixed capacitor installation costcapacitor purchase costcapacitor bonk operating cast(maintenance and depreciation)cost of real power losses

RESULT:The optimal capacitor placementcalculation results are reported on theone-line diagram and in the CrystalReports format. The graphical one-linediagram displays the resuits ofcalculations such os bus voltages,branch flows and voltage drops, andload power consumption for maximum,minimum, or overage load.

Use the Display Options editor to specifythe content you want to display. Theone-line diagram flags abnormaloperating conditions in different colors.These inctoce .overloaded cables andover- or under-voltage buses. The one-line diagram also displays newcapacitor information, which includesthe total number of banks, rated kV,rated kvor. operating kvor. and amps.The Crystal Reports format provides youwith reports containing detailedinformation about capacitor installationand load flow analysis. You can use theOCP Report Manager to view theoutput report.

CONCLUSION:Capacitors can thus be used effectivelyfor reactive power compensation whichhelps in improvin.g the power factor,reducing system losses, improvingvoltage, increasing the capacity offeeders etc.Maximum benefits ore obtained byselecting the optimum size of thecapacitor and by locating thecapacitors as neor the inductivereactance kVAR loads as possible andby matching the magnitude of theinductive reactance kVAR requirement.Practical considerations of economicsand availability of a limited number ofstandard kVAR sizes necessitate thatcapacitors be clustered near load

centers. Computer modeling or rigorousevaluation of considerable loadmetering data ore 6bsolutely necessary;0 make the proper capacitorplacement decision and keep line lossesos low as possible. The loss reductionbenefits possible with capacitor use canbe significant enough to economicallyjustify feeder metering or a large shoreof SCADA systemcosts.According to the results obtained ,placement of capacitor at sub 3b givesoptimum benefits.

Acknowledgement:Bharoti Vidyapeeth University forproviding all the facilities andpurchasing ETAPsoftware.

BIBLIOGRAPHY:1. S.I.Wamoto & Y.Tamura (1981),IEEE trans. Onpower apparotus & systems2. D.Rajicic &Y.Tamura( 1988) IEEEtrans. on powersystems volume3. Aoki k.tchimod T, Kanezoshi M. (1985). "Normalstate optimallood allocation in distributionsystems". IEEETrans Power Deliv. Volume 3 (issue I),pp.147155.4. Aoki K, Kuwabara H. Satoh t. Konezoshi M (1988)."An efficient algorithm for load balancing oftransformers and feeders". IEEETrans Power Deliv,Volume 3 (issue 4), pp.1865-1872.D.M.Tagore Reactive power management Mc-Graw Hill 20005. Rani and Vijaya, "Distribution system lossreduction by capacilors",Proc. of NotionalConference on Emerging Trends inEngineering(2000). Husur

ONE-LINE DIAGRAM

RESULT:RESULTWITHOUT CAPACITOR

PLACEMENT

,.

C M~ !Wei

-, ...~:-t

-C"-- - _ .: ~~: Ii MS,

'\

as c.,tt

RESULT WITH CAPACITOR AT SUB2B

. --{'-\,../-

S

'" ,

L-=~'-=- Ja

.-c-

--!. J~.-"::--.",-.~";t,. ~~ .

.,.~."'i;"t.~~;;":~.-;~.'t~

if

RESULTWITH CAPACITOR AT SUB 38

---=:--~:-- --..~:-:.:-:- .

.-:n

m'''- .,-

.:ii;;!:"~~""""

_.-->"", Jpi