Parker EME
Setting up Compax3
192-120103 N13 C3I20T11 / C3I32T11 December 2010
177
Commutation settings
Another prerequisite for a good control quality is the correct motor commutation.
This comprises several settings.
The commutation angle describes the relation of the feedback position with
respect to the motor pole pair position.
Commutation direction reversal describes the correlation between the position of
the feedback and the commutation position.
Feedback direction reversal describes the direction correlation between the
defined positive direction of the drive and the feedback position.
If the commutation direction does not match the defined direction of rotation, this
will result in a subsequent error with the error message "following error" or "motor
stalled".
A faulty commutation angle value results in increased current and following error.
Therefore the voltage limit is reached faster. If the value of the commutation error
exceeds 90°, the motor will spin due to the positive feedback effect.
These 3 settings can be automatically acquired with the MotorManager.
With the aid of the automatic commutation acquisition, the commutation settings
can be determined and plausibility checks can be made. You will be guided
through the individual wizard pages and the MotorManager will issue a prompt to
define the positive direction of the drive. The wizard pages supporting the user
depend on the feedback system as well as from the motor type (linear or rotary).
This function is activated in the MotorManager:
"Feedback system" wizard under "automatic commutation settings".
The motor should be operated without load (=> no load torque e.g. weight force of
a z-axis).
Additional setting of the commutation for incremental feedback:
This function is activated in the MotorManager:
"Feedback system" wizard under "feedback resolution".
In the event of an incremental feedback (Sine/cosine or RS424 encoder) the
commutation must be defined in addition, in order to find the position reference to
the winding.
Automatic commutation with movement
Commutation with digital hall sensors
I²t - monitoring of the motor
In this chapter you can read about:
Motor continuous usage ................................................................................................ 178
Motor pulse usage ......................................................................................................... 179
Reference point 2: Increased torque thanks to additional cooling ................................... 180
With the I²t - monitoring, the motor is protected against overload or thermal
destruction. For this, knowledge on the load bearing capacity of the motor is
required. This information van be taken from the manufacturer documentation
(motor parameters). Compax3 monitored:
Continuous usage of the motor (motor usage)
Pulse usage of the motor (motor pulse usage)
Hint
