26
Rockwell Automation Publication 750-AT006D-EN-P - January 2022
Chapter 1 Background
Elements of the torque loop are summarized:
Torque Reference Selection (T
REF
)
– The torque reference can come from various sources. The torque reference source is selected by
position, velocity, and torque mode parameters 10:30…10:33:
•
Velocity Regulator output
•
Minimum of Velocity Regulator Output after conversion to torque 10:2072 [Trq Ref Out] compared to 10:2073 [Trq Commanded] torque
signal - SLAT Min Control
•
Maximum of Velocity Regulator Output after conversion to torque 10:2072 [Trq Ref Out] compared to 10:2073 [Trq Commanded] torque
signal - SLAT Max Control
•
Sum of Velocity Regulator Output after conversion to torque 10:2072 [Trq Ref Out] added to 10:2073 [Trq Commanded] torque signal -
This is also the torque reference configuration used for all position modes.
•
HIM (local or remote)
•
Preset Torque Parameters
•
Analog Input
•
Network Communication
•
Process PID Controller
See the PowerFlex Drives with TotalFORCE Control Programming Manual, publication
, for more information.
Torque Scaler (K
J
)
– The torque scaler is an overall gain in the system that affects tuning and overall position and Velocity mode
performance. See
for more information. Here, T
S
is also defined.
Friction Compensation
– Friction compensation is used in some applications to compensate for known amounts of friction. It is not shown
in the previous figures. See
Friction Compensation on page 100
for more information. However, load observer is often used instead because
it requires no knowledge of these mechanical quantities. See
for more information.
Torque Notch Filters (N)
– The torque notch filters consist of 4 second order filters that each have adjustable width, depth, and gain. See
for more information. The adaptive tuning feature can be configured to automatically adjust these filters. See
for more information. These filters are typically used to remove mid and high frequency motor-side resonances.
for more information.
Torque Low-Pass Filter (LP)
– The torque low-pass filter is a first order filter. See
for more information. The
adaptive tuning Gain Stabilization feature can be configured to automatically adjust this filter. See
for more
information.
Torque Lead-Lag Filter (LL)
– The torque lead-lag filter is a first order filter with adjustable gain. See
for more
information.
Adaptive Tuning
– The adaptive tuning feature can be configured to automatically adjust torque notch and low pass filters. See
for more information.