IEEE Flash Files

IEEE Flash v2.05
================

Copyright (c) 1981-2013, IEEE
All rights reserved.

This program estimates the lightning flashover rates of overhead electric 
power transmission and distribution lines, according to IEEE Standards 
1243 and 1410.  

IEEE Flash is open source software, available from 
www.sourceforge.net/projects/ieeeflash

Members of the IEEE PES Lightning Performance of Overhead Lines Working 
Group: 15.09.08, and its predecessor organizations, have developed this 
program.  URL: http://ewh.ieee.org/soc/pes/lpdl/ 
 

Installation
============

Unzip the archive contents into a directory.  Microsoft Excel 2007 or 
later is required to run the program in Flash2.xlsm.  Also, macros must be 
enabled.

After opening the Flash2.xlsm workbook, a menu "IEEE Flash" will appear on 
the "Add-Ins" tab on Excel's ribbon.  All program functions are accessed 
through this menu.

The worksheet "Flash1.9" estimates flashover performance of transmission 
lines, without line arresters, according to methods published and 
referenced in Standard 1243.  You can edit input parameters right on the 
sheet, and also read/write parameter sets from text files.  

The worksheet "CFO" estimates the total insulation strength of 
distribution line poles with multiple insulation components, according to 
methods described in Standard 1410.  This sheet is still under 
development, but works for the examples published in Standard 1410.  

All other worksheets will support Flash2.0, which will estimate lightning 
flashovers on both transmission and distribution overhead lines, including 
surge arresters.  In order to contribute to this effort, please register 
for a user ID on SourceForge and message the administrator for this 
project on SourceForge.  All code is written and maintained in Microsoft 
Excel Visual Basic for Applications (VBA).
  
Release Notes v2.05
===================

Added a line arrester simulation, with concurrent installation of
OpenEtran.

Release Notes v2.04
===================

1 - Output of critical currents.

2 - Initialize units choice.

Release Notes v2.01
===================

Thanks to Liam Veitch, PB Power.

1 - Fixed bug loading cone tower type from a dat file.

2 - Fixed bug that displayed all Actual Shield Angles as the first one's 
value.  

Change Log Through v1.90
========================

Version 1.9 used a separate program, compiled from C code, to run the 
calculations from a spreadsheet.  It supported only the methods in Std.  
1243 for transmisison lines.  

              F L A S H  1.9
 PRODUCED BY IEEE WORKING GROUP ON ESTIMATING
 LIGHTNING PERFORMANCE OF TRANSMISSION LINES
 ------------------------------------------------
 BASED ON EPRI METHOD BY JOHN ANDERSON
 ORIGINAL FORTRAN METHOD BY NATASHA ROUKOS
 FIRST BASIC VERSION WRITTEN BY JIM WHITEHEAD 9/85
 MODIFIED FOR IBM-PC BY BILL CHISHOLM 1/86 (416)231-4111 X6982
 VERSION 1.4 BY JIM WHITEHEAD  9/87
 VERSION 1.5 BY ROGER CLAYTON AND BILL CHISHOLM 1/89
 VERSION 1.6 BY Ding Yuen and Bill Chisholm 1/90
 VERSION 1.7 FROM WG DEC 1996
 VERSION 1.8 February 2001
 VERSION 1.81 July 2001
    - fixed negative shield angles
    - fixed the Sargent cone surge impedance
    - warning if shielding can't be solved
    - compiled under both Borland C++ Builder 5 and Visual C++ 6
    - note the xls front end doesn't always work with the BCB5 build
 VERSION 1.9 May 2007
    - handles the case where 2 or more phases have equal dominance
      at a given power-frequency phase angle
    - brief output uses English units as appropriate
    - increased MAX_ANGLES to 180

Technical Notes on Versions 1.8 through 1.9
===========================================

v1.90 changes from version 1.81:

1 - Properly handles the backflash distribution to different
    conductors having equal dominance intervals, which often
    occurs on double-circuit lines with symmetry. There is no
    change to the BFR, but the backflash rate per 100 km for
    each conductor is now reported in the detailed results.
    Multi-conductor backflashovers are still not considered.

2 - Provided a sample file, eprired.dat, for the example presented
    in chapter 12 of the EPRI Red Book. The modeling assumptions
    in Flash have evolved over those originally presented in the 
    Red Book. The most important change affecting this example is
    the reduction of critical flashover voltage at 2 microseconds,
    in the case of long spans.  See Figure 7 of IEEE Std 1243-1997
    for an illustration.  Flash calculates a BFR of 1.39 for this
    example, compared to a BFR of 1.1 in the EPRI Red Book.

3 - Flash uses the footing resistances as they are input, without
    any adjustment for current magnitude or frequency.  In IEEE Std
    1243-1997, the second paragraph in section 7 may seem to imply
    that Flash adjusts the footing resistance, but that is not the
    case.  The user should make such adjustments manually, if desired.
    However, the last paragraph in section B.2 of 1243-1997 indicates
    that such adjustments offer no improvement in the Flash program's
    predictive accuracy.

4 - The "brief" output of the command-line program now respects the
    English/Metric unit selection.  This corrects an output problem
    in the Excel front end, in which the flashover numbers were always 
    per 100 km per year, even if the user chose English units and the
    output was labeled per 100 miles per year.

5 - There is no change to the Excel front end, except that the version
    and date label has been updated in cell A29.

v1.81 changes from version 1.8:

1 - Excel front end works on Windows 95/98.

2 - Fixed output of negative actual shield angles.

3 - Fixed calculation of Sargent cone surge impedance.

4 - Warning message if shielding cannot be solved.

v1.80 changes from v1.7 affecting the results:

1 - An array bounds error was fixed around line 3330 of the
    Basic code, affecting the power frequency voltage phase
    angles.  The percentage of flashovers occuring on the
    outside phases of a flat horizontal line will now be
    equal.  The backflash rates of double-circuit lines will
    also generally decrease, often significantly.

2 - The new formulation of beta has been used for the strike
    distance to ground in the electrogeometric model.  The 
    perfect shielding angle will usually increase by a few 
    degrees, and the shielding failure flashover rate will 
    decrease slightly in cases where it was not zero.

3 - The bundled conductor spacing for English units input
    was improperly converted from inches to meters around
    line 1090 of the Basic code.  It is now properly converted
    from inches to mm.