Flux speed regulator (induction motors) – Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) Commissioning - ForGe Control User Manual
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Rockwell Automation Publication 7000-IN012B-EN-P - June 2014
Chapter 4 Commissioning the Drive
• L Leakage High - indicates that the measured leakage inductance is greater
than 0.35 pu. Possible causes are:
– The inductance of long motor cables is increasing the apparent leakage
inductance of the motor. In this case, the measured leakage inductance
is probably correct.
– The motor is very small (leakage inductance generally increases with
decreasing motor size).
– Because of the design of the motor, this method of measuring leakage
inductance does not produce a valid result. Obtain the leakage
inductance from the motor data sheet, or if this is not possible, set the L
Total Leakage parameter to its default value of 0.20 pu.
Flux Speed Regulator (Induction Motors)
This method combines the auto-tuning of the Flux and Speed regulator in a
single step. It calculates parameters, Lm Rated (P#131), T Rotor (P#132) in
Motor Model Group and Total Inertia (P#82) in Speed Control group.
During this auto-tune step the motor will run at speed set in Autotune Spd Cmd.
The default setting is 30 Hz. Ensure the motor rotates during this auto-tune.
Verify motor rotation physically or by monitoring FlxFbk VoltModel (P#342).
Stall condition may calculate wrong tuning parameters. If it happens, ensure you
set the tuning parameters Lm Rated, T Rotor, and Total Inertia to default before
re-starting this tuning.
Flux Regulator
Three parameters determine tuning for the flux regulator in an induction motor:
• FlxReg Bandwidth in Flux Control
• Lm Rated in Motor Model
• T Rotor in Motor Model
Set FlxReg Bandwidth to the default value of 10 r/s for almost all applications.
Lm Rated and T Rotor are usually unknown; measure them individually. Both of
these motor parameters change substantially with different operating conditions,
but the variations do not significantly affect the operation of the flux regulator.
IMPORTANT
For synchronous motors, please refer