Rockwell Automation 20G PowerFlex 750-Series AC Drives User Manual
Page 23
Rockwell Automation Publication 750-RM002B-EN-P - September 2013
23
Drive Configuration
Chapter 1
The following is a plot of voltage and current at the reactor. The output of the
drive is sent through a sine wave filter then to the reactor. The shape of the
waveform is determined by the amount of capacitance in the sine wave filter.
If you wanted to know what voltage you can expect at the three phase reactor,
consider an example where the user has four reactors in series. The inductance of
each is 1.2mH, 5mH, 5mH and 3mH. First item to calculate is XL for each
reactor. .
Now total it. XL1 + XL2 + XL3 + XL4 = 5.35 ohm.
For a three phase reactor the current is represented by the
equation,
Isolate the voltage.
The current value can be what the least rating of the reactors are or if the rating
are greater than the drive rating, use the drive rating. In this case the drive is rated
for 14 amps.
XL
2
pi
×
f
×
H
×
=
XL1
2
pi
Ч
60
Ч
1.2 1000
⁄
(
)
Ч
0.45ohm
=
=
XL2
2
pi
Ч
60
Ч
5 1000
⁄
(
)
Ч
1.88ohm
=
=
XL3
2
pi
Ч
60
Ч
5 1000
⁄
(
)
Ч
1.88ohm
=
=
XL4
2
pi
Ч
60
Ч
3 1000
⁄
(
)
Ч
1.13ohm
=
=
I
V
XL
3
×
(
)
⁄
=
V
I
XL
Ч
3
Ч
=