Page 48 - Power Quality in Electrical Systems
P. 48
Voltage Distortion 31
Time (µs)
0 20 40 60 80 100 120 140
0
−5
Current (KA) −10 Lightning stroke current
−15
−20
−25
7
Figure 3-8 Impulsive transient [3.1].
[© 1995, IEEE, reprinted with permission]
5
10
20
50 30
60
40
50
5
10 60
20 30
90
60
50
80
40 70
8
Figure 3.9 Number of thunderstorm days per year in the U.S. [3.3].
[© 1995, IEEE, reprinted with permission]
Example 3.3: Voltage impulse due to a lightning strike. In this example,
we’ll calculate the instantaneous voltage drop across the line imped-
ance, assuming the lightning stroke profile of Figure 3.8 and the line
7
From IEEE Std. 1159-1995, p. 13.
8
From IEEE Std. 446-1995, p. 7.
