Rockwell Automation Publication 7000-UM202D-EN-P - May 2018 15
Chapter 1
PowerFlex 7000 Drive Overview
The PowerFlex™ 7000 drive is a general-purpose, standalone, medium voltage
drive that controls speed, torque, direction, starting, and stopping of standard
asynchronous or synchronous AC motors. This drive works on numerous
standard and specialty applications such as fans, pumps, compressors, mixers,
conveyors, kilns, fan-pumps, and test stands in industries such as
petrochemical, cement, mining and metals, forest products, power generation,
and water/waste water.
The PowerFlex 7000 drive meets most common standards from these
organizations:
• National Electrical Code (NEC)
• International Electrotechnical Commission (IEC)
• National Electrical Manufacturers Association (NEMA)
• Underwriters Laboratories (UL)
• Canadian Standards Association (CSA).
The drive is available with the world’s most common supply voltages at
medium voltage, from 2400…6600V. The design focuses on high reliability,
ease of use, and lower total cost of ownership.
Topology
The PowerFlex 7000 drive uses a pulse width modulated (PWM) – current
source inverter (CSI) topology. This topology applies to a wide voltage and
power range. The power semiconductor switches used are easy-to-series for any
medium voltage level. Semiconductor fuses are not required for the power
structure due to the current limiting DC link inductor.
With 6500V PIV rated power semiconductor devices, the number of inverter
components is minimal. For example, only six inverter switching devices are
required at 2400V, 12 at 3300…4160V, and 18 at 6600V.
The PowerFlex 7000 drive also provides inherent regenerative braking for
applications where the load is overhauling the motor, or where high inertia
loads are quickly slowed down. The drive uses the following:
• Symmetrical gate commutated thyristors (SGCTs) for machine
converter switches
• SGCTs for active front-end (AFE) rectifier configurations for the line
converter switches
• Silicon-controlled rectifiers (SCRs) for 18-pulse rectifier configurations
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