Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 18)

Chapter
1
7000 “B” Frame 7000-UM150I-EN-P – June 2013
Overview of Drive
Introduction
The PowerFlex™ 7000 represents the third generation of medium
voltage drives at Rockwell Automation. The PowerFlex 7000
medium voltage AC drive is part of the PowerFlex family of AC
drive products. The Allen-Bradley PowerFlex™ family of Drives
incorporates leading-edge technology, embedded communications,
and significant commonality across multiple platforms, networks,
operator interface programming and hardware. Designed for end
users, solution providers and OEMs, PowerFlex 7000 air-cooled
drives meet applications ranging from fractional to 5,500 horsepower.
The PowerFlex 7000 is a general purpose stand alone medium
voltage drive that controls speed, torque, direction, starting, and
stopping of standard asynchronous or synchronous AC motors. It is
intended for use on a host of standard and specialty applications such
as fans, pumps, compressors, mixers, conveyors, kilns, fan-pumps,
and test stands. Primary industries for these applications include
petrochemical, cement, mining and metals, forest products, power
generation, and water / waste water.
The PowerFlex 7000 is a global product that adheres to the most
common standards from NEC, IEC, NEMA, UL, and CSA. It is
available with the world’s most common supply voltages at medium
voltage, from 2400-6600 volts.
The design focus is on high reliability, ease of use, and lower total
cost of ownership.
Topology
The PowerFlex 7000 utilizes a Pulse Width Modulated (PWM) –
Current Source Inverter (CSI) for the machine side converter as
shown in Figure 1.1. This topology offers a simple, reliable, cost
effective power structure that is easy to apply to a wide voltage and
power range. The power semiconductor switches used are easy-to-
series for any medium voltage level. Semi-conductor fuses are not
required for the power structure due to the current limiting DC link
inductor.
With 6500 volt PIV rated power semiconductor devices, the number
of inverter components is kept to a minimum. For example, only six
inverter switching devices are required at 2400V, 12 at 3300-4160V,
and 18 at 6600V.