0x2305 - Commutation

When using Permanent magnet synchronous motors (BLAC or BLDC), is necessary to know the position of the rotor in order to apply a correct excitation. This object allows selecting which sensor is used to compute the rotor position.

If the selected sensor is an incremental sensor or it is not aligned with the rotor it will not be able to give the correct value without an initial rotor determination method. This object also provides some methods to localize the position of the rotor. 

The initial angle determination process is automatically executed on entering in Operation enable state. If it success the Initial angle determination process finished bit of the statusword will be set.

This object is used only on BLAC or BLDC motors.

SubIndex description:

• 0x01 (Commutation sensor): The commutation sensor is used to measure the electrical angle of the actuator during operation. The object value has the following meaning:

  Value	Description
  0x00	Quadrature digital incremental encoder
  0x01	Digital halls
  0x02	Analog halls (Linear halls)
  0x03	Reserved
  0x04	Analog signal
  0x05	SSI encoder (single-turn readings)
  0x06	SinCos encoder
  0x07	PWM signal
  0x08	Resolver
  0x09	None

• 0x02 (Initial angle determination method): The object value has the following meaning:

  Value	Description
  0x00	Forced alignment method –This method forces to rotor to align in a known position used as reference.
  0x01	Non incremental sensor used – This method directly use the information coming from the used feedback.
  0x02	Initial rotor position known – This method uses the content of Initial rotor angle object as initial rotor position.
  0x03	Reserved

  

  If initial angle determination method wants to be skipped the Initial rotor position known sensor method must be selected.

• 0x03 (Actual system angle): When using "initial rotor position known" alignment method, this object helps to determine the rotor angle of the starting position as it returns the actual rotor position of the system. Therefore, the system must be positioned in the starting position and the value read must be written in the 'Initial rotor angle' object. This object it is only update in Operation enable status.

• 0x04 (Reference sensor): The reference  sensor is used when the "Non incremental sensor used" Initial angle determination method is selected. It is used to give an absolute reference of the electrical angle to the commutation sensor to avoid undesired initial movements after power up. The object value has the following meaning:

  Value	Description
  0x00	Reserved
  0x01	Digital halls
  0x02	Analog halls (120º)
  0x03	Reserved
  0x04	Analog signal
  0x05	SSI encoder (single-turn readings)
  0x06	SinCos encoder (Analog halls 90º)
  0x07	PWM signal
  0x08	Resolver
  0x09	None

  

  This reference sensor might require an initial calibration to align the reference sensor with the actuator phases the first time is configured. This calibration is done:

  - Set the commutation sensor with the same feedback than reference sensor.

  - Select Forced alignment method as Initial angle determination method

  - Entering in operation enable state (recommended to use the open loop vector mode of operation with a target voltage of 0)

  - Wait for the phasing process.

  - Stop the movement and store all the parameters into the NVM.

  After this process, the offset between the actuator phases and the reference angle is automatically written in the register 0x2308 - Non-incremental alignment.

  - Select Non incremental sensor used as Initial angle determination method

  - Select the commutation sensor as the desired commutation sensor for the final application

• 0x05 (Commutation angle offset): This register indicates the offset between the commutation sensor and the reference sensor. It is used for configuration verification.