PowerWorld Transmission Line Parameter Calculator - TransLineCalcHelp1

PowerWorld Transmission Line Parameter Calculator - TransLineCalcHelp1.pdf

http://www.powerworld.com/files/TransLineCalcHelp1.pdf[25-03-2013 11:25:20]

Thumbnails Document Outline



No Outline AvailableFind:

Previous

Next

Highlight all Match caseToggle Slider

Find

Previous

Next

Page: of 13

Presentation Mode Open Print Download Current View

Zoom Out

Zoom In



Automatic Zoom

PowerWorld Transmission Line Parameter CalculatorIntroductionThe PowerWorld Transmission Line Parameter Calculator is a tool designed tocompute characteristic line parametersgiven the type of the conductor and thetower configuration of a three-phase overhead transmission line.The parameters computed are the resistance R, reactance X, susceptance B,and conductance G. These values arecomputed as distributed (per unit ofdistance), lumped or total (for a specific line distance), and in per-unit.CalculationsThe following controls are part ofthe calculations section:Parameters CalculationThis section is to enter the necessarydata to compute thecharacteristic lineparameters thatare shown in the Results panel.Input DataConductor Type:This is the combo boxthat lists all the conductor typesavailable in the Conductors table. To add, remove oredit a specific conductor and its characteristics, seeConductor Type section below.Tower Configuration:This combo boxlists all the tower configurationsavailable in the Tower Configurations table. To add,remove or edit a specifictower configuration,pleasego to the Tower Configuration section below.Line Length:



This is the value ofthe distance of the transmissionline. The units are miles when using English system,or kilometers when using the Metric (SI) system.Line Length Units:The line length units specify the measurement systemto use when entering the linelength. The options areEnglish system or Metric (SI) system. The final andintermediate results will also be shown in the systemspecified here.Page 1 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0Power Base:The system voltampere base in MVA.Voltage Base:The line-line voltage base in KV.Impedance Base:The impedance base in Ohms. This value isautomatically computed when the power base and thevoltage base are entered or modified.Admittance Base:The admittance base in Siemens. It is alsoautomatically computed as the inverse of theimpedance base.Final ResultsWhen all the input data is entered, the results automatically will bedisplayed.The valuesfor R, X, Band G are shown inthree different sections, each sectioncorresponding to Distributed, Lumped or Total, and Per Unit values, respectively.The Power Surge Impedance Loading is calculated only for the lumped section.Intermediate ResultsThe intermediate values calculat



ed to compute the R, X, B,and G values aredisplayed here. The computed geometric mean radius and geometric meandistance are shown in theDistributed values section. The characteristicimpedance and propagation factor are displayed in the Lumped values section.Note:To see the specific calculations usedin this program, see the Calculationssection, at the end of this document.Ampere to MVA Limit ConversionThis section converts thelimits of the transmission line from Amperes to MVAs,given the voltage base, and vice versa.Page 2 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0ConductorTypeThis section is used to add, remove, rename, and edit the information related tothe conductor types. This can be done in two ways: using the form for anindividual conductor type, or using the table for all the conductor types available.Edit ByFormConductorsare identified by a unique code word. All the available conductorsare listed in the Conductor Code Word combo box. By selecting one conductor,all its properties are displayed in the form.There, the user is able to modify anyof those values. After modification of any value,the user has to save thechanges byclicking on the buttonSavebefore changing tabs, otherwise thechanges will be lost.By clicking onNew, a message prompting for a namefor a new conductor will beshown. By clicking onRename



, a new name for the current conductor type isrequired. In order to save the currentconductor type with a different name isnecessary to click onSave As. Finally, to remove the current conductor the usercan do so by clicking on theDeletebutton.Edit ByTableIn this tab, all the conductor types areshown as records in a table, where everyfield is a characteristic ofthe conductor. In order to edit the records in this table,use the Database button described in theDatabase section. While editing thetable, the user can not change of tab until changes are posted or discarded.ConductorPropertiesThe available properties of the conductors are the following:Code Word:Code name for the typeof conductor. The names ofbird species are typically used. Code Word has to beunique.Area:The area of aluminum conductor in circular mils. Acircular mil is the cross-sectional area of a circularconductor having a diameter of1 mil. One mil is onethousandth of an inch (0.001).Aluminum strands:Numberof aluminum strands.Steel layers:Number of steel strands.Page 3 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0Aluminum layers:Numberof aluminum layers.External diameter:Outside diameter of the conductor in inches.GMR:Geometric Mean Radius in feet.DC Resistance:DC resistance of the conductor at 20C per 1 mile inOhms.AC Resistance 25:AC resistance of the conductor at 60 Hz and 25C per1 mile in Ohms.AC Resistance 50:AC resistance of the conductor at 60 Hz and 50C per1 mile in Ohms.AC Resistance 75:AC resistanc



e of the conductor at 60 Hz and 75C per1 mile in Ohms.Inductive Reactance:Inductive reactance per conductor at 1foot spacing at60 Hz in Ohms/mile.Capacitive Reactance:Capacitive reactance per conductor at 1 foot spacingat 60 Hz in MegaOhms/mile.Page 4 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0Tower ConfigurationThis part is used to add, remove, rename,and edit the information related to thetower configurations. This can bedone in two ways: using the form for anindividual tower configuration,or using the table for all the tower configurationsavailable.Edit ByFormTower configurations areidentified by a unique name. All the available towerconfigurations are listed in the TowerConfiguration Name combo box. Byselecting one specific tower configuration,all its characteristics are displayed inthe form. There, the usercan modify any of thosecharacteristics. Aftermodification of any value, the user hasto save the changes by clicking on thebutton



Savebefore changing tabs, otherwise the changes will be lost.By clicking onNew, a message prompting fora name for a new towerconfiguration will be shown. By clicking onRename, a new name for the currenttower configuration is required. In orderto save the currenttower configurationwith a different name is necessary to click onSave As. Finally, to remove thecurrent tower configuration the user can do so by clicking on theDeletebutton.Edit ByTableIn this tab, all the tower configurationsare shown as records in a table, whereevery field is a value of the tower configuration. In order toedit the records inthis table, use the Database button described in the Database section. Whileediting the table, the user can notchange of tab until changes are posted ordiscarded.Tower Configuration ValuesThe valuesof the tower configuration are the following:Name:Name for the tower configuration. Name has to beunique.Phase spacing:x and y coordinatesof phases A, B and C positions.Values are in feet for English system and meters forMetric (SI) system. When these values are modified,the phase spacing gr

PowerWorld Transmission Line Parameter Calculator v.1.0Conductorsper bundle:This section specifies the number of conductors(either single conductor or a bundle of conductors)per phase. The maximum number of conductors perbundle allowed is 4.Use regular spacing:When usinga bundle of conductors, checking theUseRegular Spacing ofcheck box will use the specifiedvalue as a regular spacingamong the conductors. IftheUse Regular Spacing ofcheck box is notchecked, then the custom conductors spacing sectionhas to be used.Conductorsspacing:x and y coordinatesof the conductors in the bundle.



aph isautomatically updated.Drawaxishas to be checked for x and y axis to bedrawn in the graph.Page 5 of 13

Values are in feet for English system and meters forMetric (SI) system. When these values are modified,the bundle spacing graph isautomatically updated.Drawaxishas to be checked for x and y axis to bedrawn in the graph.Temperature: Assumedtemperature in Fahrenheit degreesforEnglish system and Celsius degrees for Metric (SI)system.Frequency:Frequency of the system in Hertz.System of units:The system of unitsused to specify the values of thetower configuration. The options are English systemor Metric (SI) system. The units specified here notnecessarilyhave to math the units specified in theInput Datasection.Page 6 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0DatabaseThe conductor type and tower configurations tables are readby default from thefileconductors.mbd, which is a MS Access database. This database can beread from another *.mdb file by clicking on theSelect Conductors andConfigurations Databasebutton.Note: The conductors.mdb file can alsobe viewed and edited in MS Access.In order to edit a record in the database tables, the user can use the toolbardesigned to do that. Following there is a figureshowing this toolbar:The



First,Prior,Next, andLastbuttons are used to moveamong records. TheInsert,DeleteandEditbuttons are used to insert, delete or edit the currentrecord, respectively. While editing a record, the user can not change of tab untilmodifications are posted through thePost editbutton or canceled with theCancel editbutton. TheRefresh databutton just refreshed the data of theentire table.Page 7 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0CalculationsDistributedParametersResistance()NtRRRRt



+=255025502525

0t50()NtRRRRt

+=50

PowerWorld Transmission Line Parameter Calculator v.1.0Thegeometric mean radiusbetween conductors of one phase isdefined as:GMRDSL

=For 1 stranded conductorreDSL4/



7550755050

50tWhere:RtAC resistance at temperaturetper phase per 1 mile in OhmstAssumed temperature in Celsius degreesR25AC resistance of the conductor at 60 Hz and 25C per 1 mile in OhmsR50AC resistance of the conductor at 60 Hz and 50C per 1 mile in OhmsR75AC resistance of the conductor at 60 Hz and 75C per 1 mile in OhmsNNumber of conductors per phaseInductive ReactanceSLeqL

DDfXln1047

=Where:XLInductive reactance in Ohms/meterfFrequency of the system in Hertzeq

DGeometric mean distance between phases in metersSL

1

=For 1 solid cylindrical conductor2111NNkNmkmSL

dD

===

For more then 1 conductor bundleWhere:SL

DGeometric mean radius in metersrExternal radius of conductor in metersGMRGeometric mean radius given intables for one stranded conductorkm

dDistance between conductorskandmin meters.Note: Ifk =m, thenfor one stranded or solid cylindricalconductor.km

d =SL

DSusceptance

PowerWorld Transmission Line Parameter Calculator v.1.0Where:SC

DGeometric mean radius in metersrExternal radius of conductor in meterskm

dDistance between conductorskand



DGeometric mean radius between conductors of one phase in metersThegeometric mean distancebetween phases is defined as:3cabcabeq

dddD=Where:ab

d,,Distancesbetweenphasesa-b, b-c, c-a, respectively in metersbc

dca

dPage 8 of 13

=SCeq

DDfBln22Where:BSusceptance in Siemens/meterfFrequency of the system in HertzConstant permittivity = 8.8541810-12eq

DGeometric mean distance between phases, defined as aboveSC

DGeometric mean radius between conductors of one phase usingexternal radius in metersThe geometric mean radius between conductors of one phase using externalradius is defined as:r

min meters.Note: Ifk =m, then=r.km

dConductanceAssumedG = 0Where:GConductance in Siemens/meterLumped (Total) ParametersResistance, InductiveReactance, Conductance and Susceptance, using theequivalentcircuit (long line)lsinhc

ZXjRZ=+=2tanh2lc

ZBj

PowerWorld Transmission Line Parameter Calculator v.1.0zy=Where:zDistributed series impedance in Ohms/metery



DSC

=For1conductor2111NNkNmkmSC

dD

===

For more then 1 conductor bundlePage 9 of 13

GY=+=Where:ZTotal series impedance of line in OhmsYTotal series admittance of line in SiemensRTotal series resistance of line in OhmsXTotal series inductive reactance of line in OhmsGTotal series conductance of line in SiemensBTotal series susceptance of line in SiemensZcCharacteristic impedance in OhmsPropagation constant in meters-1lLine length in metersThecharacteristic impedanceandpropagation constantare defined as:yzZc

=Page 10 of 13

Distributed series admittance in Siemens/meterThedistributed series impedanceanddistributed series admittancearedefined as:jBGyjXRz+=+=Where:RDistributed series resistance in Ohms/meterXDistributed series inductive reactance in Ohms/meterGDistributed series conductance in Siemens/meterBDistributed series susceptance in Siemens/meterSurge Impedance LoadingThe surge impedance loading is defined asthe power delivered by a lossless lineto a load resistance equal to the surge (or characteristic) impedanceZc, and isgiven by:CNSIL

ZVP2

=Where:PSILTotal surge impedance loading in a three-phase line in VAVNLine-line nominal voltage in VoltsPage 11 of 13

PowerWorld Transmission Line Parameter Calculator v.1.0Base ValuesImpedance Base



32

)(BllBB

SVZ=Where:B

ZImpedance base in Ohms3B

SPower base in VAllB

VLine-line voltage base in VoltsAdmittance BaseBB

ZY1=Where:B

YAdmittance base in SiemensB

ZImpedance base in OhmsPer Unit (PU) ParametersResistance, InductiveReactance, Conductance, SusceptanceBPUBPUBPUBPU

YBBYGGZXXZR

PowerWorld Transmission Line Parameter Calculator v.1.0



R====Where:RPUPer unit resistanceRTotal series resistance in OhmsXPUPer unit Inductive reactancePage 12 of 13

XTotal series inductive reactance in OhmsXPUPer unit conductanceGTotal series conductance in SiemensBPUPer unit susceptanceBTotal series susceptance in SiemensZBImpedance base in OhmsYBAdmittance base in SiemensMVA To Ampere and Ampere To MVA Limits ConversionMVA to Ampere Limit ConversionNMVAAmp

VLimLim3106

=Where:LimAmpLimit in AmperesLimMVALimit in MVAsVNNominal voltage in VoltsAmpere to MVA Limit Conversion6

103NAmpMVA

VLimLim=Where:LimAmpLimit in AmperesLimMVALimit in MVAsVN

More Information Less Information

Close



Nominal voltage in VoltsReferences[1]J. D. Glover and M. S. Sarma,Power Systems analysis and design,Brooks/Cole, 3rdedition, 2002.[2]A. R. Bergen and V. Vittal,Power SystemAnalysis, Prentice Hall, 2ndedition, 2000.Page 13 of 13

powerworld.comPowerWorld Transmission Line Parameter Calculator - TransLineCalcHelp1.pdf

Fuc0xpbmVDYWxjSGVscDEucGRmAA==: button1: button3: input3: button1_(1): button5: input7: input11: button1_(1)_(2): button5_(1): button1_(1)_(2)_(3): button5_(1)_(2): input11_(1): 1button3_(1): button5_(1)_(2)_(3): button7: button9: button1_(1)_(2)_(3)_(4): button5_(1)_(2)_(3)_(4): select1: autobutton3_(1)_(2): button5_(1)_(2)_(3)_(4)_(5): button1_(1)_(2)_(3)_(4)_(5): textarea7:

Documents

PowerWorld Transmission Line Parameter Calculator - TransLineCalcHelp1