Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control (PanelView 550) - Manual (Page 17)

Overview of Drive 1-5
7000 “A” Frame 7000A-UM151D-EN-P – March 2013
a)
b)
a) Line current
b) Line-to-line voltage at PCC
Figure 1.2 – AFE rectifier and its input current/voltage waveforms
The AFE rectifier can be used in conjunction with a rectifier duty
isolation transformer or with an AC line reactor (as shown in Figure 1.2).
Isolation transformers are available:
1)
Integral to the Drive
2)
Remote indoor dry type, or
3)
Outdoor oil-filled type
This allows for maximum flexibility in dealing with floor space,
installation cost and control room air conditioner loading.
“Direct-to-Drive” Technology Reduce the cost, size and weight of your medium voltage drive
system with the Allen-Bradley PowerFlex 7000 with Direct-to-Drive
technology. This is the first and only technology that allows you to
directly connect a medium voltage drive to utility power without the
requirement of an isolation transformer. Isolation transformers with
multiple secondary windings are required for traditional AC drives to
address line-side harmonic concerns and common mode voltage.
However, typical isolation transformers are large, heavy, costly,
complex and inefficient. Direct-to-Drive technology combines an
Active Front End (AFE) rectifier to dramatically lower line-side
harmonics and a patented DC link inductor to address common mode
voltage at its source. By addressing harmonics and common mode
voltage, the isolation transformer becomes redundant. This reduces
system complexity to maximize uptime and increases system
efficiency to lower operational costs. Exceptional output voltage and
current waveforms, true of our entire product line, make this ideal for
retrofit applications and allow the use of standard motors for new
applications.