Description of B-Fast
Run B-FAST Now
B-FAST is a quick magnetic field calculator designed by ENERTECH
for use on the Internet World Wide Web. The software calculates lateral profiles of the
magnetic field for a system of user-defined conductors. The program is based on Ampere's
Law and assumes straight conductors parallel to a flat earth. The permeability of earth is
assumed to be the same as air and the influence of image conductors in the earth is
neglected. Conductor size and other properties are not required for this commonly used
mathematical model. Any energized or un-energized conductor (such as shield wires or
neutral) may be included by specifying a current (in amperes) and a phase angle (the
electrical time angle between a system of currents).
The
conductor system coordinates can be described in either feet or meters as horizontal and
vertical distances with respect to a reference point (0,0) usually located on the earth at
the center of the conductor system. The calculated magnetic field values (in units of mG
or µT, where 0.1 µT = 1 mG) are presented as the semi-major axis of the magnetic field
ellipse (the maximum field value in time) and as the resultant field (the square root of
the sum of the squares of the orthogonal components). The lateral profile calculation
results are magnetic fields values at a series of points that are perpendicular to the
conductor system. The profiles specified by the user includes starting and stopping points
(beginning and end) and the increment for which calculations are to be made. The
start/stop points can use negative values, for example, start at -100 ft , stop at 100 ft
, increment = 5 ft , would calculate the Magnetic fields every 5 ft along a lateral
profile extending from 100 ft on one side of the coordinate system center (i.e. the
right-of-way center) to 100 ft on the opposite side. The height above the earth for these
calculations can be user defined (the default height of 1 meter or 3.28 ft is the IEEE
standard measurement height: IEEE Std 644-1994).
The program does not calculate induced current on shield wires, but
values for any current/phase angle can be input by the user. (The EPRI software ENVIRO can
calculate induced currents on grounded overhead shield wires). More sophisticated software
exists for modeling magnetic fields, such as the EPRI programs RESICALC and SUBCALC, for
modeling transmission and distribution lines and substations. This software is included as
part of EPRI's state-of-the-art EMF Workstation.
B-FAST was developed using the JAVA programming
language pioneered by Sun Microsystems. Your browser must support JAVA in order to run
this application.
Run B-FAST Now
(This program may take several minutes to download)
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