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Electric Motor Drive Equipment 179
Positive DC
bus
Y
DC output
AC input
to inverter
from utility
section
∆
Three
winding ∆
transformer Negative DC
bus
200
∆-Phase input current
0.0
−200
200
Y-Phase input current
0.0
−200
200 Line-Phase input current
0.0
.023333 .03 .036667 .043333
−200 Seconds
Figure 12.6 Series connected bridges 12-pulse converter for ASD. Secondary currents for
wye and delta bridges. Transformer primary line current [12.6].
[© 1996, IEEE, reprinted with permission]
resultant rectifier input currents are shown in Figure 12.6 [12.6]. Each
rectifier input current is typical for a six-pulse rectifier. The resultant
12-pulse rectifier line current has the 11th and 13th as the lowest-order
harmonics (see Chapter 5).
