arc-flash analysis of utility power systems - Michigan Technological ...

the test system. When the voltage is at 900 volts, the l g I a is equal to 3.55 kA when
using equation (3.1) and 3.76 kA when using equation (3.2). When the voltage is at
1.1 kV, the l g I a is equal to 3.92 kA when using equation (3.1) and 3.68 kA when using
equation (3.2). If the voltage was to be applied in the equation (3.1), there would be a
multiplying factor anywhere from 1.1 to 15 times and the incident energy would
continue to increase.
Figure 4.5: Incident energy based on given bus voltage
As shown in the simulation, the incident energy of both buses in the 15.1 kV
system increased to levels well above the level found in the 14.9 kV system. For bus 2
the incident energy increased from 5.5 to 130.16 cal/cm 2 and bus 3 increased from 1.0
to 25.01 cal/cm 2 . Figure 4.6 is a plot of the bus 3 incident energy against the bus 3
voltage using the derived equations only based off of lab testing. We see that as the
voltage increases the incident energy increases linearly.
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