Rockwell Automation 6000 PowerFlex Medium Voltage Variable Frequency Drive Commissioning Manual - Manual (Page 92)

92 Rockwell Automation Publication 6000-IN007A-EN-P - October 2014
Appendix C Special Function Parameter Settings
Speed Reference Functions V/F Curve Setting
Relevant parameters: P451, P452, P453
Description: calculates the drive’s output voltage according to set frequency.
There are four available V/F curves: linear, curve, straight-curve and parabolic-
curve. Set the compensation voltage to improve the lower frequency start torque.
Instruction: P451 is low speed voltage compensation (%), P452 is low speed
voltage compensation frequency threshold. If the output frequency is lower than
P452, the output voltage will be improved per P451 (Low Speed Voltage
Compensation).
Set Maximum Modulation Index and Limit Output Voltage Amplitude
Relevant parameters: P455, P456
Description: this function sets the maximum modulation index and limit the
output voltage amplitude, so the drive can run above rated frequency.
Instruction: change the output voltage without changing the output frequency by
adjusting P455. Adjust this value according to the field conditions to ensure the
output voltage/frequency is consistent with standard V/F curve.
P456 is the output voltage amplitude limit; the amplitude of output voltage
cannot exceed this value.
Set Flux Time
Relevant parameters: P454
Description: this function is designed to build a steady rotating magnetic field
before the rotor operates.
Instruction: P454 is the time to build the rotating magnetic field. This value will
not generally be changed.