Rockwell Automation 1395 Digital DC Drive FRN 5-10.10/9.30 - Manual (Page 103)

Chapter 5
Functional Description
5-17
In addition, the parameters listed below are used by the velocity loop
function during test and tune. These parameters must be set up properly for
the tuning function to work properly.
Parameter No. Description
698
Auto Tune I Lim
699 Auto Tune Speed
702 Velocity Loop Damping Factor
Velocity Loop Motor Test
The motor test calculates the motor inertia (Parameter 613) by running the
drive through a defined velocity profile. When the profile is complete,
torques and acceleration/deceleration times are used to calculate motor
inertia. The armature current used during the test is set by Parameter 698.
The default is 25% of rated Motor Current (Parameter 611).
If acceleration time is excessive during Velocity Loop Autotune, Parameter
698 may have to be increased.
The maximum velocity that the motor will run at, is determined by
Parameter 699. The test is most accurate when Parameter 699 is set to base
speed. However, acceptable results can be achieved at lower speeds. In all
cases the motor must be disconnected from the load (system, process or
machine) for this test to yield accurate results.
Velocity Loop System Test
The system test calculates the inertia of the system that is connected to the
motor by running the drive/system through a defined velocity profile.
When the profile is complete, torques and acceleration/deceleration times
are used to calculate System Inertia (Parameter 703).
As with the motor test, the maximum velocity that the motor and system
will run at is determined by Parameter 699. In order to obtain accurate
results the motor must be connected to the load (system, process or
machine).
Velocity Loop Tune
This function calibrates the velocity loop gains (Parameters 659 and 660),
based on the results of the motor and system tests. These tests should be
run prior to attempting to tune the velocity loop to assure that the drive has
the latest information.