Rockwell Automation 20G PowerFlex 750-Series AC Drives - Manual (Page 348)

348 Rockwell Automation Publication 750-RM002B-EN-P - September 2013
Chapter 6 Integrated Motion on the EtherNet/IP Network Applications for PowerFlex 755 AC Drives
2. Click the Power tab and configure the appropriate boxes according to your
application.
Regenerative Power Limit The amount of energy that the drive allows during regeneration. If an
external regenerative power supply or shunt (dynamic brake) resistor is used,
it is recommended that this value be set to -200.0%.
Important: If this value is set too low, the ability of the drive to stop a
motor is limited.
Bus Regulator Action • Disabled - This selection disables the drive’s internal DC bus voltage
regulation feature. Select this option if there is an external regenerative
brake or regenerative line supply connected to the drive DC bus.
• Shunt Regulator - This selection is used when either an external shunt
resistor is connected to the drive or the internal IGBT is controlling the
power dissipation to the resistor (the type of shunt resistor is selected
below).
• Adjustable Frequency - This selection let the drive either change the
torque limits or ramp rate of the velocity to control the DC bus voltage.
This option is not recommended for positioning applications because it
overrides the velocity and the system can overshoot or may not stop.
• Shunt then Adjustable Frequency - This selection lets the Shunt resistor
absorb as much energy as it is designed for, then transitions to adjustable
frequency control if the limit of the resistor has been reached.
• Adjustable Frequency then Shunt - This selection enables adjustable
frequency control of the DC bus. If adjustable frequency control cannot
maintain the DC bus within limits, the shunt resistor is activated.
Shunt Regulator Resistor
Type Select the type of resistor connected to the drive. Internal resistors include
20-750-DB1-D1 or 20-750-DB1-D2 for frames 1 and 2 drives, respectively.
External identifies that a user-selected resistor is used.
External Shunt When using an external shunt resistor select “Custom.”