Hierarchy of management that covers different levels of management
stable operation of the power system
1. ABSTRACT
In thisstudy,tokeepthe secure andstable operationof the powersystem, distributedgeneration(DIG)
and shuntcapacitorare optimallyplacedinaradial distributionsystem.Manyresearchersare working
on optimal DIGand shuntcapacitor placementusingintelligentmethodlike geneticalgorithm, artificial
neural network,fuzzylogicandantcolonyalgorithm.Insuchregard,a particle swarmoptimization
(PSO) basedtechniqueisusedtodeterminethe optimal locationandoptimal sizeof the DIG andshunt
capacitor.The mainpurpose of thisstudyisto increase the economicadvantage of the distribution
systemoperatoraswell asto decrease the active andreactive powerloss.DifferentindexessuchasCost
Index (CI),Active lossreductionindex(ALRI), andReactivelossreductionindex(RLRI) are proposedand
formulatedaccordingly.Differentcasesare consideredandthe obtainedresultsare deeplyanalyzedfor
findingoutthe bestoptionof systemoperator.
Keywords:DistributedGeneration,ShuntCapacitor,Radial DistributionSystem, Particleswarm
optimization,CostIndex,Active lossreductionindex,Reactivelossreductionindex.
1. INTRODUCTION
Distributionsystemsare the mostimportantpartof powersystemthatare utilizedtosupplypowerto
the variouskindsof consumerssuchas commercial,industrial andresidential [1].The electrical poweris
generatedinconventional powerplantsandthe poweristransmittedoveralongdistance bystepping
up the voltage levelusingastepuptransformer.Before distributingthe powertothe distribution
consumers,the powerissteepeddowntoalowervoltage bystepdowntransformer.Distribution
systemmostlyradial instructure andthere isonlyone powersupplyatthe bus 1 of the system.
Moreover, the type of systempossesshighresistance,therefore the resistance/reactance ratiobecomes
veryhigh[2]-[3].Asa result,there have beenamore active powerandreactive powerlossinthe
distributionsystemandaccordingly,the endcustomerswillface voltage dropandthere isa high
possibilitythatthe voltage magnitude onmostbusesmaybe below the minimumvoltage limiti.e.0.95
P.U. Insuch situation,there hasbeenaconstantloadgrowthamong differentcustomersinrecentyears
and thiswill worsenthe voltage magnitudeinthe forthcomingyears,whichwillreduce the power
systemstabilitymargin[4]-[6].Therefore,the active andreactive powersourcesmustbe integratedin
the systemto improve the voltage magnitude sothatthe powerstability margincanbe improved.For
that reason,the systemplanningengineersare focusingnowadaysonthe incorporationof distributed
generation(DIG) andshuntcapacitorso that a secure and stable operationof powersystemcanbe
achieved.
2. DIG isthe local source of electricitythatissituatedata close distance of the customersandgenerates
cleanand greenelectricity[5]-[8].There are differenttypesof DIGsuchas renewable-basedandnon-
renewable based.The renewablebasedDIGare such as solarDIG, windDIG etc. are mostlyusedsince
theyhave a positive impacttowardsthe environment.The incorporationof DIGcan helpto decrease the
active and reactive powerlossandenhance the voltage magnitudeof the system[9].Moreover,the
active powergenerationof DIGhelpstomatch the active powergrowthof the system[10].
On the otherhand,shuntcapacitor isa source of reactive powerthatcan also be incorporatedinradial
distributionsystem[10]-[11].Placementof capacitorinnon-sinusoidal conditionsneedsconsideration
of harmonicdistortionamplificationdue toeitherseriesorparallel resonance.Optimal sizingand
locationof shuntcapacitorsneedstobe done to realize maximumbenefitswithvoltage profileand
Harmonicdistortionasa constraint.Placementandsizingof shuntcapacitorisa mutli-dimensional and
complex problem.Similartothe DIG, integrationof shuntcapacitorcan helptoreduce line lossesand
improve voltage magnitude.Anadequate reactivepowercompensationhelpstoreduce line loading,
line loss,maintainbettervoltage profile,improve reliability,reduce failurerate andmaintenance cost.
The yearlyconstantyearlyreactive powergrowthcanbe handledeasilywiththe properutilizationof
shuntcapacitor [11].
Although DIGand shuntcapacitor are veryuseful forthe distributionsystem, buttomaximizethe
obtainedbenefitfromthe system, placementof these devicesatoptimal locationwithappropriatesize
isverymuch necessarytoget the highestbenefitfromthe devices.Inthisregard,thispaperproposes
the optimal deploymentof DIGandshunt capacitorin a 33-bus radial distributionsystemtoovercome
line lossesandincrease the financial benefitof the distributionsystemowner.Differentindexessuchas
Cost Index (CI),Activelossreductionindex (ALRI),andReactive lossreductionindex (RLRI) are proposed
and formulatedaccordingly.Differentcasesare consideredandthe obtainedresultsare deeplyanalyzed
for findingoutthe bestoptionof systemoperator.
Aftera detail introductioninSection1of the manuscript,Section2presentsthe modelingof DIGand
shuntcapacitor.The objective functionsof thisstudyare discussedinSection3.Section4 representsthe
solutionalgorithm.The resultandanalysispartisgivenin5th Sectionandthe conclusionof thisstudyis
representedin6thSection.