Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 21)

Overview of Drive 1-5
7000 “A” Frame 7000A-RM001A-EN-P – January 2011
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.
a)
b)