MESSAGES none, at the moment.

    P r o g r a m   E l p l e k  (version 0.9893)
    by Ilkka Leikkonen, Kokkola, Finland

    Also other programs can be downloaded:
    induction motor data, k0-calculator, differential protection calculator,
    spreadsheet for equivalencies (courtesy Jorge Cardenas).
    See the links or bottom of page for more information. Additionally, the program elplek
    contains calculators for summing transmission lines, for parameters of shunt capacitors,
    and for parameters in the per-unit notation 

    Power system analysis software Elplek  ( short circuit and load flow, freeware )
    Calculates all currents in a network in the case of different faults
    (three phase fault, line to line fault, line to earth fault, line to line to earth fault).
    The initial short circuit currents Ik" can be calculated either using the
    superposition method, or according to the IEC 60909 standard ( IEC with some
    minor limitations. The steady state current Ik is not calculated, for example.)
    The prefault state for the superposition method can be taken from a load flow
    calculation, or from a straightforward solution of the network.

    If the initial state is calculated with the superposition method, then the
    currents are calculated as a function of time after the occurrence of the
    fault. In addition, the activation of protection relays is displayed.

    For
    - Easy to use (my subjective view ! )
    - Initial short circuit current with the superposition method,
        or according to IEC 60909
    - Calculates currents as a function of time (not in IEC-calc.)
    - Shows the activation of overcurrent protection relays
      and distance relays (not in IEC-calc.)
    - different protection relays available: definite time, inverse time,
      combined phase,ground, sequence (PGQ), electromechanical,
      user defined, distance l
    - Several tens of overcurrent relay curves programmed in (IEC, ANSI,
      (ABB, Westinghouse, English Electric, etc)
    - Phasor display of currents and voltages
    - Contains a simple relay coordination graphics page
    - When using the superposition method, the prefault state can be taken
        from a load flow calculation
    - Can produce the input file (*.dat file) for the Microtran (EMTP)
      transient simulation program (tested only with the student version)
    - Can produce the input file (*.atp file) for the ATP transient
      simulation program
    - Handles both radial and meshed networks

    The graphical user interface of the program


    (click to enlarge)

     Against
    -     May be slow in the case of "large" networks
       ( "large" = clearly bigger than the screen! )
    - A "stand alone" application
    - Some minor limitations in the  IEC 60909 - calculation.
       ( See the "Help" of the program for more details).
    - Does not calculate the peak current Ip when using the
      superposition method (that is, does not calculate the DC component)
    - Needs several (difficult) parameters for some components (not the IEC-calc.)
      ( Xd, Xd', Xd", Xq, Xq", Td" etc. for the synchronous machines,
        for example)

    Download and Installation instructions
    Download the compressed ("zipped") program file     elplek.zip (2,81 Mb), version 0.9893
    updated April 28  2012.  Changes are described on the     version page
    An older version can be downloaded     here (1,87Mb), just in case.

    Note: *.sld files generated with the new version cannot be read with older versions! )

    Unzip the file and put the program file elplek.exe, the help file
    elplek.hlp and the contents file elplek.cnt and the sample file for relay curves
    TestCurves.csv in the same directory (of your choice).
    Put the example files *.sld (single line diagram files) in a directory
    of your choice. It can be the same as or different from the directory,
    where the program file is.
    The programs k0 calculator and the differential protection calculator
    (see bottom of page) can be started from Elplek, if they are in the
    same directory as Elplek.
    The help-file alone can be downloaded as     elplek.pdf (1.7 Mb), for easier reading.
    (right-click and select "save as")

    Error reports and suggestions
    Please report errors and suggestions to      Ilkka Leikkonen
     In the case of errors,  include also the single line diagram file
    (the *.sld file), if possible. Explain in detail the actions that led to
    the error,  please.

    You can also give feedback by using the feedback form

    Requirements
    The program has been tested under Win98, Win Me, Win 2000, and Win XP .
    It runs also under Windows Vista and Win7, but the help file may not work. Some help
    to this problem may be found at     http://support.microsoft.com/kb/917607/en-us
    The program has not recently been tested under the older versions of windows,
    but I suppose that it will still run under these operating systems because no essential
    changes have been made (Report any problems, please.)

    The program has been reported to work also under Linux OS with Wine installed. 

    The program can be run in a PC with 100 MHz Pentium and
    a 800 * 600 display (or even a 640 * 480), but a faster PC and
    especially a larger display are better.

    What does "elplek" mean?
    It is not actually an acronym, but comes from     ELectrical calculations with comPLEX variables.
    That would give "elplex", but that name was already reserved, so I changed the "x" to a "k".
    Sounds exotic, finnish, doesn't it?

    Known issues

    The displayed winding currents of some transformers may be in wrong order (Feb. 7. 2011)

    O t h e r    p r o g r a m s
    - A program to calculate the equivalent circuit parameters of an induction from the "name-plate data

    - Complex calculator. It is designed to calculate the k0-factor for distance relays.
      The k0 factor is defined as  k    0 = ( ZL0  - ZL1) / ( 3* ZL1), where ZL0 and ZL1 are the
      zero and positive sequence impedances of the transmission line to be protected
      The basic mathematical calculations with complex numbers can also be carried out.

    - A Differential protection calculator.
    A fault in a protection zone (a part of a network) can be detected by comparing the currents at both ends of the zone. If the currents are different, there is a fault in the zone. The comparison is not straightforward, however, if there is a transformer in the zone, because the magnitudes and often also the phases of the primary and secondary currents of a transformer are different. The measured value of either the primary or secondary current must be corrected, or compensated for the differences due to the transformer before the comparison.

    This Differential Protection Calculator (also called a matrix calculator) is designed to calculate the necessary corrections. The phase difference is corrected by multiplying the measured or calculated three phase current vector by a matrix, and the magnitude is corrected by multiplying  by a constant.  

    Spreadsheet for equivalencies: For the calculation of the wye-delta or delta-wye conversion, and for
    studying the risk for an Out Of Phase-fault (OOP) for a transmission line, i.e.the need for Power Swing
    Blocking (PSB    ) (courtesy Jorge Cardenas).

    last updated April 28,  2012