Motor phasing guide (commutation alignment)
This section describes the minimum steps required by an external master to align the feedback of a system to the attached actuator. This guide contains the registers involved in the procedure.
It is highly recommended to read the commutation section before following this guide.
This section describes the minimum steps required by an external master to align the feedback of a system to the attached actuator. This guide contains the registers involved in the procedure.
Setting up basic motor information
Motor rated current and pair poles are the elements required for the alignment procedure
Set the motor pair poles by writing the register - 0x106
Set the motor rated current by writing the register - 0x100
Current tuning
The motor phasing sequence requires a proper tuning of the current in order to avoid undesired damage to the system. Follow the current tuning guide for further information.
Setting up commutation and reference feedbacks
Next step is to setting up the commutation and reference feedback parameters. Every feedback has its own particularities, but there are usually three main elements present in all the cases:
Resolution. Number of counts per mechanical revolution. For some feedbacks the resolution is automatically set by the drive such as in the resolver case. However other feedbacks like digital and analogue encoders is specified by the user.
Pair poles. For magnetic based feedbacks the pair poles of the feedback requires to be specified by the user. Resolver and halls are examples.
Polarity. The polarity of the feedbacks must be aligned with the polarity of the drive output generation. The next steps help to identify the polarity properly.
Set commutation modulation to Sinusoidal modulation (Brushless AC) - 0x14F
Set the polarity register of the feedback to be configured to 0.
Set commutation & reference feedback as internal generator: 0x151 & 0x153 equal to 3 (internal generator)
Set the feedback to be configured as position feedback: 0x361
Configure internal generator to simulate a commutation feedback:
Set voltage or current (if tuned properly) operation mode - (0x014) - 0 or 2
Enable motor - Control Word register (0x010).
Set a positive target value enough to move the actuator - target voltage Q (0x018) or current Q (0x01A)
Read the position - (0x030). If it increases, then the polarity is correct. On the other hand, if the position decreases, set the polarity to 1 (reversed)
Stop the motor and restore the modified parameters.
Commutation feedback alignment
Note
If the feedback to be aligned is Digital halls, refer to Digital halls alignment section
Configuration of phasing procedure
Set commutation modulation to Sinusoidal modulation (Brushless AC) - 0x14F
Set Max. current on phasing sequence to a value close to the rated current of the motor by writing the following parameter - 0x155
Set Phasing timeout to 500 ms by writing the following parameter - 0x156
Set Phasing accuracy to 3600 electrical millidegrees ( as a rule of thumb, a 1% of an electrical revolution ) by writing the following parameter - 0x157
The Phasing accuracy and the phasing current may be changed depending on the system's characteristics.Set Phasing mode to 1 by writing the following parameter - 0x154
Launch phasing alignment
Finally, the phasing sequence can be executed. This procedure aligns commutation feedback with the actuator. However, the results are copied into the reference feedback registers, so the already aligned feedback might be used later as reference. Follow the next steps:
Example
A system is composed by an absolute BiSS C encoder and an analogue encoder. The BiSS C will be used as reference and position feedback and the analogue encoder as commutation and velocity. Before using the BiSS C as reference, it must be aligned to the actuator and obtain the required parameters and store them into the drive. Then It might be used as reference and align the Sin Cos using non-forced methods.
To align BiSS C, it must be set as commutation feedback, then execute a phasing forced method, and finally set it again as reference feedback.
Set the feedback to be aligned as commutation feedback (0x151)
Select forced method as alignment method (0x154) - 1
Enable motor - Control Word register (0x010)
Wait until phasing bit of status word (0x011) is active
If the aligned feedback is going to be used as reference, follow next steps, otherwise the system is ready to operate normally.
Disable motor - Control Word register (0x010)
Set the aligned feedback as reference feedback (0x153)
Set the desired commutation feedback (0x151)
Select non-forced method as alignment method (0x154) - 0
The system is ready to operate normally.
Note
The alignment procedure is only needed once. In case it were necessary to repeat the procedure, changing the commutation feedback causes the drive to lose the phasing. This can be used to force the driver to perform the phasing again
Digital halls alignment
Non-forced alignment method of digital halls against digital halls is not supported. Do not use this alignment method with this configuration.
Configuration of phasing procedure
Set commutation modulation to Sinusoidal modulation (Brushless AC) - 0x14F
Set Max. current on phasing sequence to a value close to the rated current of the motor by writing the following parameter - 0x155
Set Phasing timeout to 2000 ms by writing the following parameter - 0x156
Set Phasing accuracy to 60000 electrical millidegrees (This value is necessary for aligning digital halls) by writing the following parameter - 0x157
Set Phasing mode to 1 by writing the following parameter - 0x154
Make sure digital halls pole pairs (0x392) are correct. These will generally match the motor pole pairs (0x106)
Launch phasing alignment
Finally, the phasing sequence can be executed. This procedure aligns commutation feedback with the actuator.
Set Digital halls as commutation feedback (0x151)
Select forced method as alignment method (0x154) - 1
Enable motor - Control Word register (0x010)
Wait until phasing bit of status word (0x011) is active
Disable motor - Control Word register (0x010)
Select "no-phasing" as alignment method. (0x154) - 2
If desired, store the configuration
The system is ready to operate normally.
Note
The alignment procedure is only needed once. In case it were necessary to repeat the procedure, changing the commutation feedback causes the drive to lose the phasing. This can be used to force the driver to perform the phasing again