Rockwell Automation Allen-Bradley PowerFlex 755T Flux Vector Tuning User Manual

Rockwell Automation Publication 750-AT006D-EN-P - January 2022 73
Chapter 4 Auto Tuning
Variables that are relevant to the automatic calculation of calculated control loop gains and load observer gains include those listed in
Table 22.
Load Observer mode affects the automatic calculation of calculated control loop gains and load observer gains. Different methods are
applied based on the load observer mode:
• Load Observer Disabled or Velocity Estimate Only
on page 73
• Load Observer Only, Load Observer with Velocity Estimate, or Acceleration Feedback on page 73
Load Observer Disabled or Velocity Estimate Only
When 10:901 [Load Ratio] > 0 and 10:2020 [LdObs Mode] = Disabled (0) or 10:2020 [LdObs Mode] = Vel Est Only (3), K
VI
is enabled to remove
any velocity steady state error that produces these load observer mode settings. When R > 0, the torque scaler K
J
presents a high gain in the
control loop forward path. As a result, the load observer bandwidth equals the velocity loop bandwidth to maintain stability.
Figure 67 - Autotune Gain Relationships for Load Observer Disabled or Velocity Estimate Only
Load Observer Only, Load Observer with Velocity Estimate, or Acceleration Feedback
When 10:901 [Load Ratio] > 0 and 10:2020 [LdObs Mode] = LdObs Only (1) or 10:2020 [LdObs Mode] = LdObs VelEst (2) or
10:2020 [LdObs Mode] = Accel Fdbk (4), K
VI
is disabled because load observer operates as a good velocity integrator.
Table 22 - Variables for Calculating Control Loop and Load Observer Gains
Bandwidth Abbreviation Parameter No. Parameter Name Description Units
T
BW
— — Torque Loop Bandwidth Hz
Z 10:907 [System Damping] System Damping —
System BW 10:906 [System BW] System Bandwidth Hz
K
PP
10:1754 [c PReg Kp] Position Loop Bandwidth Hz
K
PI
10:1756 [c PReg Ki] Position Integrator Bandwidth Hz
K
VP
10:1955 [c VReg Kp] Velocity Loop Bandwidth Hz
K
VI
10:1957 [c VReg Ki] Velocity Integrator Bandwidth Hz
K
OP
10:2021 [c LdObs Kp] Load Observer Bandwidth Hz
K
OI
10:2023 [c LdObs Ki] Load Observer Integrator Bandwidth Hz
LPF 10:2154 [c Trq LPF BW] Torque Low Pass Filter Bandwidth —
0
K
PI
K
PP
K
VP
K
VI
2
4
1
Z
1
2
4
1
Z
K
OP
K
OI
0
LPF
5
System
BW
1
T
BW
)(
4
1
2
Rigid
Z
)(
)1(4
1
2
Compliant
RZ 
2 Hz
(Open Loop
Virtual Encoder)

Rockwell Automation Allen-Bradley PowerFlex 755T Flux Vector Tuning Specifications

General

Brand	Rockwell Automation
Model	Allen-Bradley PowerFlex 755T Flux Vector Tuning
Category	Industrial Equipment
Language	English