Commutation Search

You can use the Auto-MSET method or the Commutation Search method to initialize the motor commutation for AC brushless motors that do not have Hall-effect switches. To use the Commutation Search method, set the Initialization Method of the CommutationInitializationSetup Parameter to Commutation Search. Much less axis movement occurs than with the Automatic Motor Set (Auto-MSET) method. But this might not occur correctly in all project settings.

The Commutation Search Method:

  1. The process starts when you enable the axis. You can enable axes in the Axis Dashboard Module or use the Enable() function.
  2. The drive tries to identify the motor angle by outputting current at different electrical angles. It starts with a known electrical angle. For each angle, the drive outputs the quantity of current that is specified by the CommutationSearchCurrent Parameter for the quantity of time that is specified by the CommutationSearchTime Parameter.
  3. The drive initializes motor commutation based on the acceleration of the motor during the search period. The quantity of current that the drive outputs must be high enough so that loading, friction, and other opposing forces have a minimum effect on the axis. This makes sure that the search is successful.
  4. Motor commutation continues normally. The drive uses the feedback device specified by the FeedbackInput1 Parameter.

Related Topics 

Automatic Motor Set (Auto-MSET)