Rockwell Automation 20P PowerFlex Digital DC Drive - Manual (Page 104)

104 Rockwell Automation Publication 20P-UM001I-EN-P - February 2013
Chapter 2 Drive Start Up
Tune the Speed Regulator
The speed regulator auto tuning test detects the total inertia value of the motor
shaft (in Kg
• m 2 ), the friction value (in N • m) and the calculation of the
proportional (P) and integral (I) gains of the speed regulator.
1. While still in the “Autotune” group, configure the motor shaft rotation
direction via Par 1029 [Speed Tune Dir]; 1 “Forward” = clockwise or 2
“Reverse” = counter-clockwise, with reference to the motor commutator
end.
2. Speed Regulator Autotune assumes full field is applied. Verify that
parameters 280 [Nom Mtr Fld Amps] and 467 [Max Fld Curr Pct] are
set correctly. Tuning with less than full field current will result in
different gains because of the lower motor torque values.
3. Select Par 1027 [Spd Reg Autotune] and enter “1.”
4. Press Enter.
IMPORTANT This test requires the free rotation of the motor shaft combined with the load.
The auto tuning test of the speed loop cannot be carried out on machines with
a limited stroke.
IMPORTANT If the PowerFlex DC drive is wired for two-wire control, with a digital input
programmed for “Run,” the HIM Start/Stop cannot be used for autotune.
Maintain the “Run” input for autotune.
ATTENTION: The motor will rotate during this tuning procedure. Hazard of
personal injury exists due to motor shaft rotation and/or machinery motion.
IMPORTANT The test is carried out by using the torque limit value set in the Par 1048
[Autotune Cur Lim] (recommended value = 20%). The torque reference is
applied via a step reference (without a ramp); therefore there must not be any
“backlash” in the mechanical transmission and it must be compatible with
those operations using the torque limit value set in the Par 1048 [Autotune Cur
Lim]. You can modify the torque limit value via this parameter.
IMPORTANT In applications where the system total inertia value is very high, it is necessary
to increase the value of Par 1048 [Autotune Cur Lim] in order to avoid “Time
out” errors. The speed regulator auto tuning test of the speed loop is not
suitable for drives used in “elevator” and/or lifting system applications.