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    CYMCAP for Windows

    May 2004

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    Copyright CYME International T&D Inc.

    All Rights Reserved

    This publication, or parts thereof, may not be reproduced in any form, by anymethod, for any purpose.

    Cyme International T&D makes no warranty, either expressed or implied, includingbut not limited to any implied warranties of merchantability or fitness for aparticular purpose, regarding these materials and makes such materials availablesolely on an "as-is" basis.

    In no event shall Cyme International T&D be liable to anyone for special, collateral,incidental, or consequential damages in connection with or arising out ofpurchase or use of these materials. The sole and exclusive liability to CymeInternational T&D, regardless of the form of action, shall not exceed the purchaseprice of the materials described herein.

    Cyme International T&D reserves the right to revise and improve its products as itsees fit. This publication describes the state of this product at the time of itspublication, and may not reflect the product at all times in the future.

    The software described in this document is furnished under a license agreement.

    Cyme International T&D Inc.3 Burlington Woods, 4th FloorBurlington, MA 01803-02691-800-361-3627 (781) 229-0269FAX: (781) 229-2336

    International and Canada:1485 Roberval, Suite 104St. Bruno QC J3V 3P8Canada(450) 461-3655Fax: (450) 461-0966

    Internet : http://www.cyme.com

    E-mail : [email protected]

    Windows 98 and Windows NT, 2000 & XP are registered trademarks of Microsoft. Autocad is a trademark of

    Autodesk Inc.

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    NOTICE

    The computer programs described in this manual were developed jointly by CYME

    International T&D Inc., Ontario Hydro and McMaster University under the auspices of the

    Canadian Electricity Association (CEA). Neither CYME International T&D, Ontario Hydro,

    McMaster University, CEA, nor any person acting on their behalf: (a) makes any warranty,

    express or implied of any kind with regard to the use of the computer programs, the

    documentation and any information, method or process disclosed therein, or that such

    use may not infringe privately owned rights; or (b) assumes any liabilities with regard tothe use of, or damages resulting from the use of the programs or other information

    contained in this document.

    The software described in this document is furnished under a license agreement.

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    Table of Contents

    Chapter 1 ......................................................................................................................................... 1PROGRAM INSTALLATION........................................................................................................ 1

    1.1 Software and hardware requirements ............................................................................... 11.2 Installing CYMCAP for Windows ....................................................................................... 1

    Chapter 2 ......................................................................................................................................... 3A CYMCAP OVERVIEW ..............................................................................................................3

    2.1 Introduction........................................................................................................................ 32.2 The contents of CYMCAP ................................................................................................. 32.3 The Cable Library............................................................................................................ 42.4 The Duct bank Library..................................................................................................... 42.5 The Heat Source Library................................................................................................. 42.6 The Load Curves Library................................................................................................. 5

    2.7 The Shape Library........................................................................................................... 52.8 The Study-Execution Library........................................................................................... 62.9 How to proceed for a study using CYMCAP ..................................................................... 62.10 The CYMCAP GUI navigator as gateway to the Libraries .............................................. 7

    Chapter 3 ......................................................................................................................................... 9THE CABLE LIBRARY................................................................................................................. 9

    3.1 Introduction........................................................................................................................ 93.2 Cable library management, view, add, modify and delete entries................................... 103.3 Cable components, materials and construction .............................................................. 11

    3.3.1 Conductor material..................................................................................................... 113.3.2 Conductor construction.............................................................................................. 123.3.3 Drying and Impregnation............................................................................................ 12

    3.3.4 Skin and proximity effect loss factors ........................................................................ 133.3.5 Conductor screen....................................................................................................... 133.3.6 Insulation.................................................................................................................... 143.3.7 Dielectric loss factors for insulating materials............................................................ 153.3.8 Insulation screen........................................................................................................ 163.3.9 Sheath........................................................................................................................ 163.3.10 Sheath construction ................................................................................................. 173.3.11 Skid wires (for pipe type cables only) ...................................................................... 173.3.12 Concentric neutral wires .......................................................................................... 173.3.13 Jacket, oversheath and pipe coating material. ........................................................ 173.3.14 Armour ..................................................................................................................... 183.3.15 Armour Bedding-Serving..........................................................................................20

    3.4 General cable description information............................................................................. 203.5 Creating a new cable. An illustrative example................................................................. 213.6 Steps to create a new cable ............................................................................................ 303.7 Useful considerations ...................................................................................................... 313.8 SL-type cables ................................................................................................................. 323.9 Custom materials and thermal capacitances .................................................................. 333.10 Search for a cable with particular characteristics. The library filters............................. 34

    3.10.1 Searching the cable library. The primary filter ........................................................ 343.10.2 Searching the cable library. The secondary filter ................................................... 35

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    Chapter 4 ....................................................................................................................................... 39THE DUCT BANK LIBRARY...................................................................................................... 39

    4.1 Introduction...................................................................................................................... 394.2 Duct bank library management, view, add, modify and delete entries............................ 394.3 Creating a new duct bank. An illustrative example.......................................................... 40

    Chapter 5 ....................................................................................................................................... 45LOAD-CURVES/HEAT-SOURCE-CURVES AND SHAPE LIBRARIES.................................... 45

    5.1 Introduction...................................................................................................................... 455.2 Curves and Shapes .......................................................................................................... 455.3 Shape Library Management ............................................................................................. 46

    5.3.1 Creating a new shape. An Illustrative example.......................................................... 475.3.2 Shifting a shape, an illustrative example. .................................................................. 49

    5.4 Load Curve Library Management .................................................................................... 515.4.1 Create a Load Curve using shapes, an illustrative example .................................... 55

    5.5 Load Curve from field-recorded data............................................................................... 63

    Chapter 6 ....................................................................................................................................... 69STEADY STATE THERMAL ANALYSIS ................................................................................... 69

    6.1 General ............................................................................................................................ 696.2 Methodology and computational standards..................................................................... 696.3 Studies and executions ................................................................................................... 726.4 Library of studies/executions........................................................................................... 72

    6.4.1 Introduction ................................................................................................................ 726.4.2 Managing the library of studies.................................................................................. 736.4.3 Searching for a particular study ................................................................................. 78

    6.5 Labeling studies and executions ..................................................................................... 806.6 Analysis options............................................................................................................... 82

    6.6.1 Generic options......................................................................................................... 826.6.2 Steady state analysis options. .................................................................................. 82

    6.7 General data for the installation....................................................................................... 836.7.1 Ambient temperature and soil resistivity ................................................................... 836.7.2 Non isothermal earth surface modelling. .................................................................. 83

    6.7.3 Moisture migration modelling.................................................................................... 836.7.4 Surrounding medium of the installation .................................................................... 846.7.5 Multiple Cables per phase ........................................................................................ 88

    6.8 Cable Installation Data .................................................................................................... 896.8.1 Geometrical configuration of the installation............................................................. 896.8.2 Additional cable installation salient aspects.............................................................. 896.8.3 Installation types ....................................................................................................... 90

    6.9 Specific cable installation data ........................................................................................ 916.9.1 Bonding..................................................................................................................... 916.9.2 Barring certain bonding options ................................................................................ 936.9.3 Cables touching ........................................................................................................ 936.9.4 Cable transposition ................................................................................................... 946.9.5 Ductbank/duct materials and construction................................................................ 94

    6.9.6 Fraction of return current for single phase cables ..................................................... 956.9.7 Pipe Material And Dimensions.................................................................................. 966.10 Cable Library data and executions ................................................................................ 966.11 Steady state thermal analysis, Example 1: Cables in a ductbank................................. 97

    6.11.1 An illustrative Study Case for cables in a duct bank............................................... 976.11.2 Defining a new study and a new execution ............................................................ 986.11.3 Defining the steady state analysis solution Option ...............................................1006.11.4 Execution Speed bar and associated speed buttons ........................................... 1026.11.5 Defining Regular and/or Irregular ductbanks........................................................ 1046.11.6 Importing a ductbank from the Library .................................................................. 105

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    6.11.7 Defining the General Installation data and setup.................................................. 1066.11.8 Defining the Cable Installation data ...................................................................... 1086.11.9 Rearranging the cables in the proper ducts.......................................................... 110

    6.12 A study case for dissimilar directly buried cables........................................................ 1126.12.1 Case description and illustrations ......................................................................... 1126.12.2 Define a new execution using an existing one as template.................................. 1126.12.3 How to modify the solution option from the CYMCAP menu................................ 113

    6.12.4 Enter a group of cables using absolute coordinates.............................................1156.12.5 Enter a trefoil formation using relative coordinates .............................................. 1166.12.6 Specifying a fixed ampacity circuit ..................................................................... 1186.12.7 Specify a reference circuit for the installation ...................................................... 1196.12.8 Specify a heat source included in the installation................................................. 1196.12.9 Specify the specific installation data ..................................................................... 1216.12.10 Viewing the Graphical ampacity reports for cables in a trefoil formation............ 122

    6.13 Opening more than one executions simultaneously ................................................... 1256.14 Working with more than one executions simultaneously ............................................ 1296.15 Submitting more than one executions simultaneously................................................ 130

    Chapter 7 ..................................................................................................................................... 131TRANSIENT ANALYSIS .......................................................................................................... 131

    7.1 General .......................................................................................................................... 1317.2 Preliminary considerations ............................................................................................ 1317.3 Transient analysis Options ............................................................................................ 1327.4 How to proceed for a transient analysis ........................................................................ 1377.5 Informing CYMCAP that a transient analysis is to be performed.................................. 1387.6 Example and Illustrations ..............................................................................................139

    7.6.1 Case description and illustrations........................................................................... 1397.6.2 Specify the transient analysis option ...................................................................... 1407.6.3 Specify the data for the transient analysis option ................................................... 1417.6.4 Assign Loads to cables ........................................................................................... 1427.6.5 Submit the simulation..............................................................................................1437.6.6 Generate the reports............................................................................................... 1447.6.7 Changing the color of the curves for the transient reports...................................... 147

    7.6.8 Tracing the transients results with the mouse ........................................................ 148

    Chapter 8 ..................................................................................................................................... 149The CYMCAP Menu Options................................................................................................. 149

    8.1 The CYMCAP menu ......................................................................................................1498.2 The CYMCAP menu Files entry .................................................................................. 1508.3 The CYMCAP menu Windows entry........................................................................... 1518.4 The CYMCAP menu for opened executions ................................................................. 152

    8.4.1 The execution menu File activity ..........................................................................1538.4.2 The execution menu Edit activity.......................................................................... 1548.4.3 The execution menu View activity ........................................................................ 1558.4.4 The execution menu Options activity ................................................................... 156

    Chapter 9 ..................................................................................................................................... 159The Sensitivity analysis Option of CYMCAP............................................................................ 159

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    Chapter 10 ................................................................................................................................... 165CYMCAP UTILITIES................................................................................................................ 165

    10.1 Introduction.................................................................................................................. 16510.2 Designate the working directory for CYMCAP ............................................................ 16510.3 Designate the Unit System for the session ................................................................. 16610.4 Designate the AC system frequency for the session .................................................. 16710.5 Designate AC conductor resistance values ................................................................ 168

    10.6 Backup the contents of the Working directory to another directory ............................ 16910.7 Restore from floppy disk to a directory on the hard-disk............................................. 17010.8 Tag specific items from the Libraries........................................................................... 17010.9 Copy selected items to a given data base................................................................... 17210.10 Append a database to another database ..................................................................174

    Chapter 11 ................................................................................................................................... 175THE DUCT BANK OPTIMIZER................................................................................................ 175

    11.1 Introduction.................................................................................................................. 17511.2 An illustrative example of the duct bank optimizer ...................................................... 176

    11.2.1 Invoking the Optimizer .......................................................................................... 17711.2.2 Configuring the Optimizer ..................................................................................... 17711.2.3 Running the optimizer........................................................................................... 18011.2.4 Viewing the results of the optimizer ...................................................................... 182

    Appendix I ........................................................................................................................................ 1DEFAULTS FOR VARIOUS TYPES OF CABLES ...................................................................... 1

    General ..................................................................................................................................... 1A. Concentric neutral cables ................................................................................................. 1B. Extruded dielectric cables................................................................................................. 3C. Low pressure oil filled cables (Type 3) ............................................................................. 5D. High pressure oil (gas) filled cables ................................................................................. 7E. Sheath related defaults..................................................................................................... 8F. Armour related defaults .................................................................................................. 10G. Three core cables .......................................................................................................... 11

    INDEX............................................................................................................................................ 12

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    Chapter 1

    PROGRAM INSTALLATION

    1.1 Software and hardware requirements

    CYMCAP is a 32 bit application, runs on IBM PC or compatible personal computers and can beused with Windows NT and Windows XP operating systems.

    The minimum hardware requirements are:

    A Pentium-based computer;

    32 MB RAM;

    10 MB free memory on the hard disk;

    A Microsoft mouse or equivalent;

    A color monitor with Super VGA and a graphic card supporting 256 colors or more

    Any printer or plotter supported by Windows

    1.2 Installing CYMCAP for Windows

    CYMCAP can be made available through either a CD or be downloaded from our web site atwww.cyme.com/newvwersion.htm. In any case, a password is needed for the application tobe unpacked and installed. Make certain you contact CYME International T&D, to obtainthe proper password.

    Once the application is unpacked and installed the hardware lock, i.e. the protection key isneeded to operate it. The hardware key must be inserted in the line printer port, e.g. LPT1.Furthermore it neds to be configured to recognize the application. For more information, pleaserefer refer to Appendix II: Setting up the protection key.

    The protection key is inactive during normal system operation, i.e. the key does not have to beremoved when CYMCAP is not running. You may connect a printer to the back end of either typeof key (local or network). Neither one should interfere with normal printer operation.

    CHAPTER 1 PROGRAM INSTALLATION 1

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    2 CHAPTER 1 PROGRAM INSTALLATION

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    Chapter 2

    A CYMCAP OVERVIEW

    2.1 Introduction

    Underground and aerial insulated cable installations are intimately linked with ampacity and/ortemperature rise calculations of power cables. The maximum current a cable can sustain withoutdeterioration of any of its electrical and/or mechanical properties, has always been of primeinterest to engineers and constitutes an important design parameter for both system planning andoperations.

    Accurate ampacity studies help maximizing the benefits from the considerable capital investment

    associated with cable installations. Also they help to increase system reliability, the properutilization of the installed equipment and outline of optimum operating strategies under forced orscheduled contingencies.

    CYMCAP is a Windows-based software designed to perform the thermal analysis-relatedcalculations and addresses both steady state and transient thermal analysis. The term thermalanalysis pertains to temperature rise and/or ampacity calculations using the analytical techniquesdescribed by Neher-McGrath and the IEC 287 and IEC 853 International standards.

    No finite-element modeling is included in CYMCAP at this moment.

    2.2 The contents of CYMCAP

    CYMCAP is equipped with calculating engines to accommodate Steady State and Transientanalysis. These simulation programs produce the results and generate tabular and graphicalreports. The results of the steady state analysis are the starting point for any transient calculation.In order to perform any type of transient analysis, it is mandatory to obtain the results insteady state first.

    Data for the steady state and transient simulators is provided through a Graphical User Interface(GUI) supported by the CYMCAP application libraries. These Libraries are the Cable Library, theDuct bank Library, the Shape Library, the Heat Source Library and the Load Curves Library.The Cable library is needed in all computations. The Load Curves Library and the Shape Libraryare essential for transient thermal analysis. Similarly, the Duct bank library and the Heat sourceLibrary are needed for installations featuring duct banks and/or external heat sources usingtransient thermal analysis.

    The CYMCAP libraries need to be populated before the application models of any installation.Although typical entries are provided for all these libraries, it is mandatory to populate them withcomponents reflecting actual system data. Any entries of the application libaries suppliedwith the application should not be interpreted as being typical in any way.

    Finally, CYMCAP keeps a Library of all the simulations that were performed. Unless the userdecides to delete them, all studies along with their data are kept by the application for futurereference. This Library is the Study and Executions library.

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    2.3 The Cable Library

    The Cable Library is a data base containing the detailed construction of various types of powercables. The contents of the Cable Library are used for both steady state and transient analysis.The cable Library, apart from being a data base containing the various cable types, is equippedwith a module that permits the definition of the cables themselves. Fairly detailed data is requiredto describe a cable, because the models used for the thermal representation of the cable relyheavily on the exact cable construction. This data is as essential, as the data describing the cablelayout and the installation operating conditions.

    CYMCAP offers the possibility to provide default cable dimensions based on generic cableconstruction characteristics, once the materials of the various cable components are defined.This facility can be useful for preliminary cable studies but should not be interpreted asaddressing all possible manufacturing practices.. Chapter 3 is dedicated to describing theCable type Library and its various functions.

    2.4 The Duct bank Library

    The Duct bank library is a data base containing the construction details of various duct banks. Aduct bank is a pre-constructed block containing several cable conduits. The purpose of the Ductbank library is to define the geometrical characteristics of these duct banks by specifying the totallength, width, conduit number, duct spacing and specific duct diameter so that the informationcan be used as an integral part of any study for cables installed in duct banks.

    The contents of the Duct bank Library is used for both steady state and transient analysis, sinceduct bank geometrical characteristics are crucial in determining external thermal resistances. TheDuct bank Library, apart from being a data base containing the various duct bank types, isequipped with a module that permits the definition of new duct banks. Chapter 4 is dedicated todescribing the the Duct bank Library and its various functions and facilities.

    2.5 The Heat Source Library

    The Heat source library is a data base containing the transient thermal characteristics of externalheat sources that may be present within a cable installation layout. External Heat sources aredeemed third party bodies that either emit or absorb heat depending on their temperature withreference to the ambient environment temperature. The heat source library contains the heatsource curves that display the temporal variations of the heat source. Typical examples of heatsources are steam pipes and/or water pipes whose temperature can vary as a function of time.

    The Heat source Library is supported by another Library, the Shape Library and is usedexclusively for transient thermal analysis analysis. It is, often, important to include thepresence of heat sources in the simulation, since heat sources alter considerably the temperaturerise of the cables in an installation. The Heat source library, apart from being a data base, isequipped with a module that permits the definition of new heat source characteristics. In Chapter5 we describe the the Heat source Library and its various functions and facilities, by describingthe identical in nature functions and attributes of the Load curves library.

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    2.6 The Load Curves Library

    The Load curves Library is a data base containing the description of the various patterns thecable currents may exhibit as a function of time.

    The Load curves Library is used exclusively for transient analysis and is supported by

    another Library, the Shape Library.The Load curves Library, apart from being a data base, isequipped with a module that permits the construction of the Load curves themselves. Load curvedata is crucial for transient analysis. Load curves are defined in p.u. within the Load curveLibrary. The Load curve description does not contain actual ampere levels information. Theampere base Load curves are interpreted during run time as the steady state value of thecurrents determined for the cables from the steady state thermal analysis. The description of theLoad curves and its various functions are given in Chapter 5.

    2.7 The Shape Library

    The Shape Library is not a stand-alone library. Instead, it is a utilitary library dedicated to

    containing the building blocks for the entries of the Heat Source and the Load Curve libraries.By definition, shapes are defined on a 24-hour basis and represent daily temporal variationalpatterns. Different shapes can be concatenated to produce weekly temporal profile variations.

    Since, however, Heat source shapes can only be invoked from the Heat source libray and Loadcurves shapes can only be invoked from the Load urve Library, there is no danger of confusion.It is essential to enter the required shapes in the Shape Library first and then built the HeatSource curves/Load curves to be used for transient analysis. The Shape Library, apart frombeing a data base, is equipped with a module that permits the construction of new shapes aswell.

    Shapes are expressed in p.u. in order to ascertain flexibility in describing temperature/heat fluxlevels for the heat sources and ampere loading levels for the load curves. The same entry formatis used to describe both Heat source shapes and load curve shapes. Chapter 5 is used todescribing the Load curve Library and its various functions.

    It is emphasized again that all p.u. values entered in shapes and Load Curves/Heat SourceCurves are expressed in p.u of the values these quantities assumed during steady statethermal analysis.

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    2.8 The Study-Execution Library

    This library contains all the studies performed by the application. CYMCAP relies on the conceptsof"studies" and "executions" to categorize study cases. A "study" can be viewed as a standalone scenario for thermal cable analysis, with several simulation alternatives, namedexecutions. A study normally pertains to a given installation exhibiting salient characteristics forthe cable installation or the ambient conditions. Within a "study" one can define many"executions". An "execution" is used to describe a variant of the base case. The followingdiagram illustrates these notions:

    STUDIES

    Study no. 1, Study no. 2, ..............................Study no. xx, ....

    Execution no. 1, ..n ........ Execution no. 1, ..n

    2.9 How to proceed for a study using CYMCAP

    The end result of using CYMCAP is to obtain temperatures and currents for the various cablescontained in a given cable installation, operating under certain conditions. The following is atypical sequence of steps followed when using CYMCAP as an analysis tool.

    1. Make sure that ALL the cables of the installation you are about to study arewell defined construction-wise and dimension-wise. If this is not the case, try toobtain as much information as possible from the cable manufacturer.

    2. Make sure that ALL the cable types that the simulation will use are entered inthe CYMCAP cable Library. If this is not the case, enter them all one by one.

    3. Make sure that the duct bank that the installation employs is entered in the ductbank library. If the installation does not feature a duct bank there is no need topopulate the duct bank library.

    4. Make sure that the geometrical data of the installation you are about to study aswell as the necessary simulation parameters (pipe dimensions, solar radiationintensities, bonding characteristics, ambient temperatures, thermal resistivitiesetc.) are available and well defined. Use the graphical User Interface of CYMCAP todefine the installation in detail.

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    5. Make certain that you clearly specify the type of analysis option you wish toperform. Once you have finished entering the installation data for the particular studycase, save and submit the study case(s).

    6. Make certain that both the system frequency is the one desiredand that the Unitsystem you prefer to work, have been properly set. Ampacities calculated at 50 Hzare not the same as assuming a system frequency of 60 Hz. Furthermore, workingwith the metric or imperial system of units can be convenient depending how theinstallation and/or cable data were initially provided.

    7. Before initiating a transient study make certain that you have specified loads toall the cables in the installation by assigning to every one of them anappropriate load curve from the library of load curves. You cannot assign a loadcurve that has not been first defined in the library. It is therefore necessary to firstdefine the load curves you wish to use and include them in the load curve library. Youdo that by using the Load Curve Library manager

    8. Examine the simulation results by utilizing the extensive tabular and graphicalreports facilities offered by CYMCAP and make the necessary corrections.

    2.10 The CYMCAP GUI navigator as gateway to the Libraries

    Section 2.9 outlined, on a conceptual basis, the sequence for the various steps necessary toperform a study using the CYMCAP application. The same section outlined, also the importanceof the CYMCAP libraries management facilites to enter the data for any particular study scenario.

    Access to all CYMCAP libraries is independent, modular and does not rely on any predeterminedsequence. The CYMCAP libraries and, therefore, all the application activities ranging from datamanagement to actual simulation runs, are accessed through the CYMCAP navigator. TheCYMCAP navigator can be invoked at any time by pressing the button F3.

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    Chapter 3

    THE CABLE LIBRARY

    3.1 Introduction

    This chapter describes how to enter new cables in the library and how to manage an existinglibrary of cables. Keeping the cable library up to date with accurate data is extremely importantbecause the results of the simulations depend heavily on this data. The cable library aspect isone of the major functions of CYMCAP. Access to the cable library allows you not only to add anew cable, but to modify and delete previously entered cables.

    The cable library contains the cable data that comprise the detailed construction of the various

    power cables, material and dimension-wise. Direct access to the cable library permits the user toutilize one or more library cables, within a given execution, for steady state and transient studies.Note that it is also possible to modify the data of a given cable within a particularsimulation scenario (execution) without updating the cable library. This is possiblebecause CYMCAP keeps a copy of the cable from the library within the execution (see alsochapter 6). The information related to cable data within a given execution, is used in thesimulations. The program allows the user to transfer cable data from the cable library to theexecution in question and vice versa. Unless particular reasons prevail, it is always advisableto harmonize the data in the cable library with the actual data used in the various executions.

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    3.2 Cable library management, view, add, modify and delete entries

    The cable library can be accessed by entering the CYMCAP NAVIGATOR. The menu of thenavigator is shown below: Among the principal menu functions we see "Cables". Point there withthe mouse and click the left mouse button. The list of all the cables in the library is shown asfollows:

    Every cable is identified within the cable library by an unique CABLE ID that appears to the left ofthe CABLE TITLE in parenthesis. Its highly recommended also to enter a unique cable TITLE forevery cable.

    It is also seen that a picture showing the cable cross section is displayed for every cable thehighlight bar is positioned upon. Move the Up and Down arrow keyboard keys to browse through

    the library. By virtue of this cable library browser option, CYMCAP allows the user to viewthe salient aspects of the cable constructions without resorting to detailed editing.

    Note also that for every cable a bitmap appears to the left that indicates whether the cable is asingle-core, a three-core, or a pipe-type cable.

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    TO ADD A CABLE to the cable library, position the highlight bar on any cable title and press theNew key located to the right of the navigator list. You can either use that cable as template orcreate a new one from scratch. If you choose the template option, the highlighted cable will beused as a template.

    TO MODIFY A CABLE position the highlight bar on the cable of interest and left-click with themouse on the Edit button located to the right of the navigator list. The same task can beaccomplished by positioning the highlight bar on the cable and double-clicking the left mousebutton.

    TO DELETE A CABLE you position the highlight bar on it and left-click with the mouse on theDelete button located to the right of the navigator list. You can also click and drag any cable formthe library to the disposal bin shown in the upper right corner of the navigator window.

    3.3 Cable components, materials and construction

    When a cable is entered in the library the user has considerable flexibility in specifying both theavailable cable components as well as the materials these components are made of. In theparagraphs that follow, the supported cable components are outlined along with the parameters

    the program will use internally as a function of the component construction. Parameters and/orconstants used by the application, follow the ones in IEC-287-1-1/1994.

    3.3.1 Conductor material

    The conductor material can be copper, aluminum or any other user defined material.Independently of the choice, the program needs the DC conductor material resistivity at 20 C (in

    -m) and the temperature coefficient for the resistance (/K at 20C). When aluminum or copperis selected the program assumes the following values:

    Copper =1.7241e-08, =3.93e-03

    Aluminum =2.8264e-08, =4.03e-03

    When the user selects the conductor material, these values have to be provided.

    Resistance values per IEC 228

    The resistance of the conductors can be calculated or tabulated using IEC 228. The conductormaterial, type and construction are all taken into account during the course of the calculations.The user may choose the option to obtain the resistance of the conductor from the resistancetables tabulated in IEC 228. Depending on conductor cross-sectional area, construction type andmaterial, a different resistance value will be considered. The following restrictions and/orassumptions apply:

    IEC-228 resistance values apply ONLY to copper and aluminum conductors.

    IEC-228 resistance values pertaining to PLAIN conductors are considered. In other

    words, the current version of the program does not support METAL-COATEDconductors.

    For conductor sizes in-between standard tabulated values, linear Interpolation is usedto arrive at the estimated resistance value.

    If the user wishes to consider resistances applicable to class 1 conductors (table I ofIEC 228), the choice "solid" must be used for the conductor construction option in theINPUT program.

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    If the user wishes to consider resistances applicable to class 2 conductors (table II ofIEC 228), the choices "stranded", "compact/compressed", "sector-shaped" and "oval"are pertinent. No other conductor construction option is supported for IEC-228compatible calculations.

    If a conductor cross-section is entered for the cable and not supported by IEC 228,the program will revert to the alternate mode, i.e. the resistance will be calculated.

    For conductor cross-sections, corresponding to blank entries in the tables 1 and 2 ofIEC 228, the program will revert to the alternate mode, i.e. the resistance will becalculated.

    3.3.2 Conductor construction

    The following choices for conductor construction are supported:

    Round Stranded

    Round, compact or compressed

    Segmental (4 segments)

    Hollow core

    Segmental (6 segments)

    Sector shaped

    Oval

    Solid

    Segmental

    Segmental peripheral-strands

    These choices are contingent upon the cable type selected as well as the conductordimensions.The program will indicate which options are valid by highlighting them in the selectionmenu.

    3.3.3 Drying and Impregnation

    This information is used to properly correct for skin and proximity effects when calculating the

    conductor resistance.

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    3.3.4 Skin and proximity effect loss factors

    Skin and proximity effects are used to calculate the ac resistance of the conductor by adjustingthe dc conductor resistance by the factors Ys (skin effect) and Yp (proximity effect) as follows:

    Rac = Rdc (1 + Ys +Yp): Rac, Rdc are AC and DC resistances, respectively.

    In calculating Ys and Yp the constants Ks and Kp are used. The program assumes the followingvalues based on conductor construction. Note that these values have been compiled for copperconductors. Nevertheless, the same values will be assumed for aluminum. The approximation isconsidered to be on the safe side.

    Conductor Construction Ks Kp

    Round stranded dried and impregnated 1.00 0.80

    Round stranded not dried and impregnated 1.00 1.00

    Round compact dried and impregnated 1.00 0.80

    Round compact not dried and impregnated 1.00 1.00

    Round segmental (4 segments) 0.435 0.37

    Hollow, helical stranded, dried, impregnated ** 0.80

    Sector shaped dried and impregnated 1.00 0.80

    Sector shaped not dried and impregnated 1.00 1.00

    Notes:

    - 6 segment conductors are treated as 4-segment conductors

    - Oval conductors are treated as equivalent round conductors

    3.3.5 Conductor screen

    The program does explicitly support "conductor screens", as a cable component The term"shield" is often used as equivalent to the term "screen".

    Notes:

    - Non-metallic screens should be modeled as part of the insulation.

    - If a conductor shield is modelled, the program will assume its material to be the sameas the insulation material.

    - The conductor shield shall be taken into account as part of the insulation when thethermal resistance is computed, but it will not be considered as part of the insulationfor the calculation of the dielectric losses.

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    3.3.6 Insulation

    The insulation materials supported are shown below along with the assumed thermal resistivities.

    The user has the capability of entering a custom material. In this case the thermal resistivity hasto be provided along with the appropriate coefficients for dielectric loss calculations (tan() and ).Thermal resistivity values are shown in C-M/W.

    Material iSolid type/mass impregnated non draining cable 6.0

    LPOF self contained cable 5.0

    HPOF self contained cable 5.0

    HPOF pipe type cable 5.0

    External gas pressure cable 5.5

    Internal gas pressure preimpregnated cable 6.5

    Internal gas pressure mass impregnated cable 6.0

    Butyl rubber 5.0

    EPR 5.0

    PVC 6.0

    Polyethylene 3.5

    Cross linked polyethylene (XLPE) (unfilled) 3.5

    Cross linked polyethylene (XLPE) (filled) 3.5

    Paper-polypropylene-paper-laminate 6.5

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    3.3.7 Dielectric loss factors for insulating materials

    The program assumes the following values for loss-related factors in the dielectric (values takenfrom IEC 287, 1988 revision).

    Paper Impregnated cables Dielectric Loss Factors

    tan()

    Impregnated, pre-impregnated

    or mass-impregnated non-draining. 4.0 0.01

    Self-contained, oil filled, up to 36kV 3.6 0.0035

    Self-contained, oil filled, up to 87kV 3.6 0.0033

    Self-contained, oil filled, up to 160 kV 3.6 0.0030

    Self-contained, oil filled, up to 220 kV 3.6 0.0028

    Oil-pressure pipe-type 3.7 0.0045

    External gas-pressure 3.6 0.004

    Internal gas-pressure 3.4 0.0045

    Butyl rubber 4.0 0.05

    EPR

    up to and including 18/30 (36) kV 3.0 0.020

    above 18/30 (36) kV 3.0 0.005

    PVC 8.0 0.1

    PE (HD and LD) 2.3 0.001

    XLPE

    up to and including 18/30 (36) kV (unfilled) 2.5 0.004

    above 18/30(36) kV (unfilled) 2.5 0.001

    above 18/30(36) kV (filled) 3.0 0.005

    Paper-polypropylene-paper-laminate

    (PPP or PPL) 3.5 0.00095

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    The dielectric loss factors are only taken into account when cables operate at equal or greaterphase to ground voltage than the following:

    Cable Type Voltage level (kV)

    Insulated with impregnated paper

    solid type 38.0

    oil-filled and gas pressure 63.5

    Butyl rubber 18.0

    EPR 63.5

    PE (Hd and LD) 127.0

    XLPE

    unfilled 127.0

    filled 63.5

    PPP or PPL 38.0

    Note:

    - Dielectric losses for voltages lower than indicated are always taken into account for user-defined insulation.

    3.3.8 Insulation screen

    When copper or aluminum insulation screens are specified, the program will perform calculationsaccording to IEC-287/1994 in order to calculate the thermal resistance of the screened insulation.These calculations will apply to three core cables only. For single core cables the insulationscreen is treated as a separate layer. If semiconducting insulation screen is chosen, theinsulation screen will be considered as part of the insulation, for both single core and 3-corecables. The term "shield" is also used for "screen". For 3-phase cables, the program assumesthat the insulation screening applies to the insulation of the individual conductor cores. The sameis true for sector-shaped cables. The term "belted" is utilized by the program to identify 3-phasecables with no screens featuring an additional layer of insulation encompassing all 3 conductors.

    3.3.9 Sheath

    The sheath resistivity (-m at 20C) as well as the thermal coefficient (1/C) are required.Supported materials read as follows:

    Lead =21.4e-08, =4.0e-03

    Aluminum =2.84e-08, =4.03e-03

    Copper =1.72e-08, =3.93e-03

    The user can enter any other material, but in this case the values of and must be provided.For SL-type cables please refer to section 4.6

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    3.3.10 Sheath construction

    The program supports both radial and longitidunal (LC-sheath construction) sheath corrugationfor the case of aluminum and copper only. When default dimensions are set by the program, thecalculation for the sheath thickness followed for the case of aluminum, is applied to copper aswell; see Appendix I.

    3.3.11 Skid wires (for pipe type cables only)

    Skid wires are applicable to pipe type cables only. Despite the fact that skid and concentric wiresshare similar information, skid wires data entry dialog boxes are dedicated to pipe type cables.No cable can have both skid and concentric neutral wires. The program assumes that the skidwires are semicircles. Two skid wires will be assumed present, by default, by the program but thenumber can be changed; see Appendix I. Length of lay considerations applicable to skid wires,are identical to the ones for concentric neutral wires.

    3.3.12 Concentric neutral wires

    Concentric neutral wires are, usually, return wires in distribution cables. The program assumesthat these wires are bare (no insulanting or plastic wrap that they may be equipped with, issupported). Data for the concentric neutral comprise the wire size, the number of wires as well asthe length of lay; see Appendix I for defaults. The concentric wires may be made of copper,brass, zinc, or stainless steel. An alternative form of concentric neutral CYMCAP supports is flat-straps.

    Copper =1.7241e-08, =3.93e-03

    Aluminum =2.8264e-08, =4.03e-03

    Stainless steel =70.000e-08, =0.000000

    Zinc =6.1100e-08, =0.004

    Brass/Bronze =3.5000e-08, =0.003

    If other than the above materials are to be used, the user has to provide resistivity and

    temperature coefficient. is expressed in -m at 20 C and in 1/C.

    Length of lay of a concentric neutral/skid wire is defined as the length required for the wire tomake a complete turn around the cable. It is this length the application requires as data wheneverpertinent for either concentric neutral wires or skid wires.

    3.3.13 Jacket, oversheath and pipe coating material.

    The following materials are supported for cable jacket oversheath and pipe coating (for pipe typecables only).

    Material Thermal resistivity ()Compounded jute and fibrous materials 6.0

    Rubber sandwich 6.0

    Polychropropene 5.5

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    P.V.C up to and 35 kV 5.0

    above 35 kV 6.0

    Butyl Rubber 5.0

    Coal tar wrapping 5.5

    Note:

    - Pipe coating material is entered in the specific installation data and not in cable data.

    3.3.14 Armour

    CYMCAP supports cable armour assemblies in the form of either wires or tapes. For the case ofarmour wires, the program requests as data the number of wires (if not touching), the wire sizeand the length of lay (length of lay is a term applicable not only to armour wires and tapes but toconcentric and skid wires and signifies the cable length needed for the wire to make a completeturn around the cable). For the case of armour tapes, besides the number of tapes and the lengthof lay, the tape width must also be provided. For thermal calculations the armour resistivity aswell as the thermal coefficients are also needed. The following materials are internally supported:

    (A is expressed in -m at 20C and in 1/C)

    Material A Custom non magnetic tape User-defined User-defined

    Custom, magnetic armour wires User-defined User-defined

    Custom magnetic tape User-defined User-defined

    Custom, non magnetic wires User-defined User-defined

    Steel wires touching 13.8 E-08 0.0045

    Steel wires not touching 13.8 E-08 0.0045

    Steel tape reinforcement 13.8 E-08 0.00393

    Copper armour wires 1.721 E-08 0.00393

    Stainless steel armour 70.0 E-08 0.0

    IEC TECK armour 2.84 E-08 0.0043

    If any other material is to be used, the user has to supply the above parameters.

    When magnetic losses are of importance, additional data need to be entered to model the eddycurrents and hysterysis losses of the armour. The parameters needed are the longitudinal and

    transverse permeability (AME and AMT respectively) as well as the angular time delay . Theuser can enter these parameters or have the program select. When the program selects, it willassume AME=400, AMT=10 for steel wires touching or AMT=1 for steel wires not touching andGAMMA=45 degrees. The same values will be assumed for steel tapes. Magnetic propertiesmodelling for the armour is supported only for steel armour assemblies.

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    3.3.15 Armour Bedding-Serving

    CYMCAP defines as armour bedding the layer which is normally encountered below the armourassembly. Armour serving is defined as the layer of protective coverings sometimes found abovethe armour assembly. The following materials are supported for armour bedding.

    Material Thermal Resistivity (C-m/W)

    Compounded jute and fibrous materials =6.00

    Rubber sandwich =6.00

    If any other material is to be used, the user must provide the thermal resistivity.

    3.4 General cable description information

    CABLE RATED VOLTAGE: This is the voltage used to calculate the dielectric losses in thecable. This voltage should be the rated Line to Line voltage for the installation. Even if thecable is used in a single-phase circuit arrangement the hypothetical Line to Line Voltage needs to

    be entered.

    NUMBER OF CONDUCTORS: 1 for single conductor cables and 3 for three conductor cables.No other option is supported.

    CABLE TYPE: CYMCAP supports 5 cable types. These types are conceptual and are onlyused by the application to assign default dimensions to the cable components. The cable type isdefined at the early stages of cable definition (see example below) and read as follows:

    PIPE TYPE cables

    LPOF cables

    CONCENTRIC NEUTRAL cables

    EXTRUDED cables

    OTHER reserved for cables that cannot be directly classified to any of the abovecategories.

    Notes:

    - There is no provision for default dimension assignment to the cable type OTHER

    - There is no components availability restrictions for the cable type OTHER. Note thatsuch restrictions do apply to the remaining types.

    - No pipe type cable can be modeled under the code 5.

    - The component availability restrictions are seen in the data entry dialog boxes as pad-locks not allowing the user to select a particular component construction depending onthe remaining data entered so far. These restrictions are not meant to be rigid and theysimply reflect one philosophy of manufacturing practice from the very many available.

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    CONDUCTOR CROSS SECTIONAL AREA: This is the nominal conductor area and should beentered as such. This area is interpreted by the application to be the "effective" conductor areaand is this value that will be used by the program for resistance calculations. The user hasaccess to standard conductor sizes ordered in increasing order of wire denomination when thecable is defined. Conductor sizes can either be selected from the list or typed explicitly.

    3.5 Creating a new cable. An illustrative example

    A new cable will be created for illustration purposes. The cable will be a typical 250KCMILdistribution cable, rated 35 kV. The cable features Al stranded conductor, XLPE insulation andcopper concentric neutral wires. In what follows a typical sequence of the steps/screens/dialogboxes required to enter a cable is outlined for illustration purposes.

    To create a new cable in the library, position the highlight bar on any cables and click on the Newbutton. If the existing cable is to be used as a template for the new one, answer Yes to theensuing prompt. For this example, no existing cable was used as a template. As the followingscreen indicates, it is required to enter a cable ID and a cable Title.

    The cable ID should be unique because it is used internally as a data base index. It is the cableID and cable title that appears in the library browser. Comments are optional.

    Click OK to accept the entered data and the screen that follows allows the user to begin definingin detail the cable construction, from the point of view of component availability. First specifywhether the new cable will be a single-core or a three-core, by clicking on one of the followingbitmaps:

    Click this bitmap to specify a single-conductor cable

    Click this bitmap to specify a three-conductor cable

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    Then specify the cable type as EXTRUDED (access the scroll list).

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    The program then prompts for the nominal cable voltage (kV).

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    The next piece of data required is the conductor size. Access the standard conductor sizes scrolllist and select 250 KCMIL.

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    Once the conductor size and voltage are entered, the program is ready to accept moreinstructions by displaying the following screen.

    It is seen that no dimensions are entered at all. As the encircled quantities show, it is also seenthat no materials were defined at all. Before proceeding to materials and dimensions, wemust first specify the generic cable components. Among the generic components only thecable insulation has been enabled so far. Let us enable the insulation screen, the concentricneutral and the jacket.

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    Note that the concentric wires were not drawn yet. They will not, until specific data is entered

    later.

    Once all the generic components for the cables are entered, we tell the program that theirdefinition has ended by clicking on the Complete Cable button. The program then shows the firstgeneric component, the conductor, in order to accept further instructions about materials,construction type and dimensions.

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    It is seen that there are several alternatives for the conductor material and construction. Choicesthat are either not permitted or irrelevant with data entered so far are locked, as the appropriatelocker symbol next to them indicates, and are not available for selection. Define the material,construction and dimensions on the same screen and then proceed to the following genericcomponent by selecting the next button at the bottom of the left part of the screen. The similarscreen for the insulation is:

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    The extra information needed to be entered includes the maximum design (steady state) andemergency (transient) operating temperatures the particular cable can withstand. Default values

    are assigned automatically depends on the insulation type material selected by the user. Thesevalues will be used by the program for the corresponding analysis options unless changed by theuser.

    One can proceed in this fashion to fully define the cable in question. Note that until no data ismissing, the cable cannot be saved. Missing data are identified by being encircled in red.

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    The finalized cable is as follows:

    Additional input data like length of lay, internal and external radius of corrugated sheath,

    dimensions of flat-strapped concentric neutrals, etc, can be obtained by pressing on the spacebar.

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    3.6 Steps to create a new cable

    Based on the above-illustrated step by step procedure, the necessary steps to create a newcable and add it in the cable library are summarized below:

    Step 1: Identify the separate layers and cable components and decide how they are to

    be modeled, according to the component availability CYMCAP offers.

    Step 2: Identify the cable components and define the materials they are made of. Incase the program does not support a material for a given component make certainthat the necessary constants are available so that you can enter it as user-defined.

    Step 3: Identify the cable components dimensions and make certain that every layerthickness is well identified. CYMCAP relies on layer thickness to conjectureequivalent layer diameters for both single core and three-core cables of allconstructions. Furthermore, make certain that accurate data concerning length of layfor concentric wires armour and tapes are also available. These data are important tocorrectly estimate loss factors in 2-point bonded systems. It is always useful toascertain that the cable construction dimensions are available from the

    manufacturer. The more the cable construction details are known, the less one hasto rely on the default dimensions provided by the program.

    Step 4: Select the system of Units for the session. Both Imperial and Metric systems aresupported by CYMCAP. The cable dimensions can be entered in either inches(Imperial system) or mm (Metric). Once the cable dimensions are entered in anysystem they can be visualized in the other system by simply switching the Unitsystem.

    Step 5: Enter the cable components and dimensions for the cable (see example below).

    Step 6: SAVE the newly entered cable results.

    Step 7: Obtain a new listing of the library of cables and make sure that the newly entered

    cable appears in the list.

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    3.7 Useful considerations

    a. When cables with oval conductors are to be modeled, the user should enter the

    equivalent round conductor diameter D D Dmajor or = min , where and

    are the corresponding lengths of the major and minor elliptical axis of the oval

    conductor.

    Dmajor

    Dormin

    b. When creating a cable, it is possible that layers not directly identifiable with any of theavailable components are encountered. Closer inspection, often, reveals that one ofthe available layers by the program can be directly used because different names areoften interchangeably used for the same layer. For example, CYMCAP will not accepta cable jacket once armour is defined for a given cable. The cable jacket then canalternatively be modeled as armour serving.

    c. Model metallic conductor screens, as part of the conductor. Similarly, modelsemiconducting conductor screens as part of the insulation, include semiconductiveswellings in the semiconductive screen over the insulation, etc.

    d. If the need for a layer not supported by CYMCAP arises, one can combine two layersin one by calculating an equivalent thermal resistivity for two layers in series. Thiscan be particularly useful for the cases that materials of different thermal resistivity areused for either armour serving or bedding. A conservative approach from a thermalresistance point of view would be to model the two layers as one having as thermalresistivity the one with the higher value.

    e. To model armour wires imbedded in the jacket, one can represent the portion of thelayer below the wires as armour bedding, the wires as armour, and the portion of thelayer above the wires as armour serving.

    f. The sequence of cable components CYMCAP assumes, starts from the conductorand expands outwards with the insulation, insulation shield, sheath, sheathreinforcement, concentric neutral wires, armour bedding, armour, armour serving, and

    finally jacket. It is in this spirit that the terms are used in the program and theirdefinition should be respected.

    g. When a layer is deleted, the user does not have to reflect the change in thedimensions inflicted beyond that layer towards the cable surface. The program willautomatically adjust the dimensions accordingly. The same holds true if a layer isinserted. If a layer is deleted and then reinserted, the layer dimensions areautomatically restored so long as the cable was not saved or the program session hasnot been terminated.

    h. Interjackets and jackets around armour assemblies, should be modeled as armourbedding and serving, because the program does not allow for jacket when armour ispresent.

    i. Metallic parts that are associated with circulating currents should be modeled assheaths, even if they are termed screens. This will assure that the program willcalculate correctly the appropriate loss factors.

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    3.8 SL-type cables

    SL-type cables are 3-conductor cables which are characterized by the fact that every core has itsown sheath or armour wires. The program supports either option but not both simultaneously.

    The SL-type construction is identified during the cable data entry by specifying eitherindividual

    sheath or individual armour construction. Note that the following restrictions apply to theconstruction of SL-type cables:

    SL-type cables are not permitted to have metallic insulation screens.

    No sheath reinforcement is supported for SL-type cables.

    Corrugated sheaths are not supported for SL-type cables.

    SL-type cables will either have individual sheaths or individual concentric neutralwires but not both.

    When SL-type cables are modeled, the bonding arrangement selections available areeither single point bonded or two point bonded.

    Default dimensions for SL-type cables sheaths and armour wires follow the samedefaults as for single-core cables.

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    3.9 Custom materials and thermal capacitances

    CYMCAP gives the user the possibility to enter custom materials for many of the cablecomponents metallic or not. For many non-metallic parts, like insulation, armour bedding, servingetc. the thermal capacitance of the particular component is needed for transient ampacitycalculations. Although the program will consider specific thermal capacitance values for knownand tabulated selected material types, when custom materials are specified typical values areassumed for the thermal capacitances. The Application supports ASCII fileds for any type ofuser-defined components so that their name, as well as their parameters can be clearly identified.The following screen illustrates the concept

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    3.10 Search for a cable with particular characteristics. The library filters

    3.10.1 Searching the cable library. The primary filter

    In order to search for a particular cable in the Library, use the arrow keys Up and Down andnavigate through the cable library. By default all the cables in the library are shown by thenavigator. By clicking the right mouse button, however, a primary filter can be activated thatpermits selective display of the major cable types. In this way the search can narrowed down tosingle-core, three-core or Pipe-type cables. The screen below shows the pop-up filter menuapplied for 3-core cables.

    An additional feature of the primary filter is the ability to sort the displayed cables by either cableID or cable title.

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    3.10.2 Searching the cable library. The secondary filter

    It is not uncommon to desire to locate cables with particular construction characteristics, inaddition to the major generic classification provided by the primary filter. In this case, invoking themore advanced search/filtering facilities of CYMCAP is needed. From the cable library navigatorscreen, invoke the Filter Editor as shown below:

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    Once the filter is invoked the user is presented with the option to specify any particular cablecharacteristics for the search material-wise construction, as seen below. In the particularexample, single core, medium voltage cables (rated higher than 6.00 kV) featuring a conductorcross-section larger than 1250 MCM, copper conductor of stranded construction, with concentricneutral and XLPE insulation are searched for.

    Notes:

    More detailed searches comprising non-metallic components could also be included.

    To bring any cable component attribute to the right, collecting all the desired cablecharacteristics, highlight the desired feature and bring it over by clicking on the rightarrow.

    To remove a selection, highlight the selected attribute to the right and use the left arrow.

    All the specified salient search characteristics are summarized at the bottom of thescreen

    A name could be given to the particular filter search characteristics set and saved forfuture reference.

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    Chapter 4

    THE DUCT BANK LIBRARY

    4.1 Introduction

    Duct banks are pre-arranged assemblies of conduits where cables are placed for undergroundinstallations. This chapter describes how to enter new duct banks in the library and how tomanage an existing library of duct banks. The geometrical disposition of these pre-constructedassemblies is needed to perform the simulations for cables placed in the conduits of the ductbank. Access to the duct bank library allows you not only to add a new duct bank, but to modifyand delete previously entered duct banks.

    4.2 Duct bank library management, view, add, modify and delete entries

    The duct bank library can be accessed by entering the CYMCAP NAVIGATOR. The menu of thenavigator is shown below: Among the principal menu functions we see "Ductbank". Point therewith the mouse and click the left mouse button. The list of the duct banks in the library is shownas follows:

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    Every duct bank is identified within the duct bank library by its TITLE. The duct bank TITLE mustbe unique for every duct bank.

    It is also seen that a picture showing the duct bank cross section is displayed for every entry thehighlight bar is positioned upon. Move the Up and Down arrow keyboard keys to browse throughthe library. CYMCAP allows the user to view the salient aspects of the various duct bankswithout resorting to detailed editing.

    TO ADD A DUCT BANK to the library, highlight any library entry and press the New key locatedto the right of the navigator list. You can either use that duct bank as template or create a newone from scratch. If you choose the template option, the entry the highlight bar is on will be usedas a template.

    TO MODIFY A DUCT BANK highlight the duct bank of interest and left-click with the mouse onthe Edit button located to the right of the navigator list. The same task can be accomplished bypositioning the highlight bar on the entry of interest and double-clicking the left mouse button.

    TO DELETE A DUCT BANK you position the highlight bar on it and left-click with the mouse onthe Delete button located to the right of the navigator list. You can also click and drag any entryfrom the library to the disposal bin shown in the upper right corner of the navigator window.

    4.3 Creating a new duct bank. An illustrative example.

    A new duct bank will be created for illustration purposes. The duct bank will be a sample 3x3 ductbank, i.e. consisting of 3 series of conduits and 3 columns of conduits. In what follows, a typicalsequence of the steps/screens/dialog boxes required to enter a new duct bank is outlined forillustration purposes.

    To create a new duct bank in the library, position the highlight bar on any entry and click on theNew button. If the existing duct bank is to be used as a template for the new one, answer Yes tothe ensuing prompt.

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    For this example, no existing duct bank will be used as a template.

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    As the following screen indicates, it is required to enter a duct bank TITLE.

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    Once the duct bank title is entered, the following screen contains the prompts for the variousgeometrical details outlining the duct bank construction.

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    Once the cursor is positioned into any field for data entry, the needed dimension is outlined on

    the small auxiliary help screen for clarity. The following screen illustrates the completecharacteristics of the new duct bank.

    Click OK to accept the entered data and the screen and save the new duct bank in the library.Examining the new library, we remark that the newly entered duct bank appears as a new entry.

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    Chapter 5

    LOAD-CURVES/HEAT-SOURCE-CURVES AND SHAPE LIBRARIES

    5.1 Introduction

    Load curves are the patterns of current versus time and are used to indicate how the current in agiven cable varies as a function of time over a specific time period. Access to a wide variety ofloading patterns is thus assured for various transient studies. Much like the various types ofcables, the different load curves are kept in a separate library.

    Heat Source curves are the patterns of heat source intensity versus time and are used toindicate how the heat source intensity varies as a function of time over a specific time period.Much like the various types of cables, the different heat source curves are kept in a separatelibrary.

    Shapes are the building blocks used to construct both the Load curves and the Heat Sourcecurves. The shape library is common to both the Load Curve and the Heat source library.

    This chapter describes how to manage these libraries. In what follows, the terms Loadcurve and Heat source curve are treated as conceptually identical, as far as librarymanagement is concerned, despite their physical difference.The term Curve, whereverused, means both. Whatever statements are made, however, for Load curves, applyequally well to Heat Source curves. These curves are used by CYMCAP only forTRANSIENT ANALYSIS.

    5.2 Curves and Shapes

    CYMCAP uses the notion of Shapes in order to assure modularity flexibility and efficiency indescribing the various curve variations versus time.

    A Shape is essentially a curve that spans at most 24 hours. Shapes are used to representdaily variations and feature, typically, hourly resolution. The various shapes can be storedseparately in a Shape Library. This shape library can be accessed when constructing a curve,that spans one or more days. It is useful therefore to conceptualize the shapes not only as stand-alone short term Load variations but as building blocks for the Load curves as well.

    A curve describes the variation of the Loading of a Cable/Heat Source intensity with time andmay be composed of one or more shapes, depending on the duration of the transient to besimulated. Curves can span time intervals ranging from a fraction of a day to one week.

    It is important to realize that CYMCAP forms an association between shapes and Curves. Nocurve can be defined without a Shape. At least one shape is necessary to construct a Curve.When shapes are modified within the shape library, these actions directly affect the Curvesassociated with these shapes. No shape that belongs to an existing curve can be deleted.

    All variations, within the context of the curve definition, are expressed in p.u.The base quantity isthe current/heat source intensity the cable/heat source carries at steady state as resulted/definedfrom the steady state ampacity simulations.

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    Note:

    CYMCAP is also capable of interpreting recorded field measurements and construct Load Curvesthat faithfully reproduce these recordings, with an hourly resolution. These measurements needto be logged in an ASCII file that follows a specific FORMAT. The resulting Load curves aredirectly usable by the program for transient studies (see Section 5.5).

    5.3 Shape Library Management

    The main tool for managing the Shape Library is the CYMCAP Navigator. The shape Library isaccessed by clicking on the entry Shape of the navigator. The list of all available shapes in theshape library appears as the following screen indicates

    It is seen that the shape library is equipped with a browser that is shape-sensitive. Whenever thehighlight bar is positioned on a new shape the screen below shows that very shape. This wayCYMCAP permits rapid visualization of the shapes without resorting to detailed editing.

    TO DELETE A SHAPE position the highlight bar on the shape to be deleted and click on theDelete button to the right. The same can be accomplished by highlighting the shape anddragging into the disposal bin. If that shape is used within a Load curve a warning will follow.

    TO EDIT A SHAPE position the highlight bar on the shape to be edited and click on the Editbutton to the right. You can also edit a shape by double-clicking on it with the left mouse button.

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    TO CREATE A NEW SHAPE position the highlight bar on any shape and click on the Newbutton to the right. If you want to use any given shape as a template for the new one position thehighlight bar on the one to be used as a template.

    TO RENAME A SHAPE you must edit it first.

    5.3.1 Creating a new shape. An Illustrative example.

    Assume that a shape is to be created that spans 24 hours. The first 2 hours will experience aload current of 0.3 p.u. the next 4 hours a load current of 0.6 p.u., the next 5 hours a load currentof 0.85 p.u., the next half hour a load current of 0.34 p.u., the next 4 hours a current of 0.7 p.u.,the next 5 hours a current of 0.5 p.u. and the remaining 3.5 hours a current of 0.92 p.u.

    Enter the CYMCAP navigator and access the shape manager. Position the highlight bar on anyshape and demand a new shape. In the screen that follows, the prompt demands if the currentshape is to be used as a template. We will create a new shape from scratch, thus the answer tothe prompt is NO.

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    We next enter the shape manager work-bench. It is at this point that data particular to thisshape can be entered. At first a title is needed for the shape. This title must be unique anddifferent from the remaining shape titles, if this is to be a valid shape title.

    After entering the title, the time-current data need to be entered. Note that when the table firstappears, all entries of the table are blank and there is no drawing for any segments of the shape.

    As soon as data is entered for the shape, the drawn curve is refreshed appropriately.

    Notes:

    When data for a shape is entered, the current value cannot exceed 1.0 p.u. Scalingfactors can, however, be used when building the Load Curve.

    Every time the cursor is positioned in a given field, the appropriate part of the drawing ishighlighted for better visualization. Furthermore, access to the list of shapes is alsoguaranteed from the shape manager work-bench by virtue of the list of shapesaccessible at the top.

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    The shape manager work-bench features 6 bitmaps on the top of the active window. Three onthe first row and Three on the second row. They are all used for shape management purposes.Position the cursor on any of the bitmaps and a tooltip appears indicating their function. Morespecifically:

    Click on the bitmap showing the diskette to save the shape.

    Click on the bitmap showing the eraser pen to delete the shape.

    Click on the bitmap showing the question mark (?) to inquire what Load curve(s)utilizes that shape.

    Click on the bitmap showing the clipboard to put a shape on the windows clipboard.

    Click on the bitmap with the exclamation mark to revert to the original entries defininga shape, once a modification was effected.

    5.3.2 Shifting a shape, an illustrative example.

    Shapes are normally entered beginning at time 0. It may, however, be desirable to shift a shapeso that any given time can be considered its origin. The application permits this operation to bedone without redefining the shape using the shift button. For instance, assume that the followingshape is to be shifted at the 5

    thhour. Click on shift and define the desired hour

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    The resulting shifted shape is also illustrated below

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    5.4 Load Curve Library Management

    In what follows typical activities relating to Curve library management are illustrated. Thevery same actions can be undertaken for both the Load curves and the Heat Source curves ifnecessary. The example below illustrates Load curves.

    The load curve library is accessed with the CYMCAP navigator by clicking on the entry Loads (toaccess Heat Source curves click on the corresponding navigator data entry). The Load curvesavailable in the library appear in a list. At the same time the Load Curve the cursor is on appearsin the screen below.

    This screen is context-sensitive. If the highlight bar is moved with the Up and Down arrow keys toanother curve, or another curve is selected (click on another curve) the graph showing the Loadcurve changes accordingly.

    To the left of every Load Curve title a bitmap showing a closed drawer is displayed.

    Double click on the Load curve and the bitmap changes (the drawer opens)

    while at the same time the sequence of shapes composing the Load Curve is displayed.

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    This acti