ABB ACS880 Series Firmware Manual page 62

62 Program features
The autophasing routine is performed with permanent magnet synchronous motors
and synchronous reluctance motors in the following cases:
1. One-time measurement of the rotor and encoder position difference when an
absolute encoder, a resolver, or an encoder with commutation signals is used
2. At every power-up when an incremental encoder is used
3. With open-loop motor control, repetitive measurement of the rotor position at
every start
4. When the position of the zero pulse must be measured before the first start after
power-up.
Note: In closed-loop control, autophasing is performed automatically after the motor
identification run (ID run). Autophasing is also performed automatically before starting
when necessary.
In open-loop control, the zero angle of the rotor is determined before starting. In
closed-loop control, the actual angle of the rotor is determined with autophasing when
the sensor indicates zero angle. The offset of the angle must be determined because
the actual zero angles of the sensor and the rotor do not usually match. The
autophasing mode determines how this operation is done both in open-loop and
closed-loop control.
The rotor position offset used in motor control can also be given by the user – see
parameter 98.15 Position offset
result into this parameter. The results are updated even if user settings are not
enabled by 98.01 User motor model
Note: In open-loop control, the motor always turns when it is started as the shaft is
turned towards the remanence flux.
Autophasing modes
Several autophasing modes are available (see parameter
The turning mode (Turning) is recommended especially with case 1 (see the list
above) as it is the most robust and accurate method. In turning mode, the motor shaft
is turned back and forward (±360/polepairs)° in order to determine the rotor position.
In case 3 (open-loop control), the shaft is turned only in one direction and the angle is
smaller.
Another turning mode,
normal turning mode, for example, because of significant friction. With this mode, the
rotor is turned slowly until a zero pulse is detected from the encoder. When the zero
pulse is detected for the first time, its position is stored into parameter
offset user, which can be edited for fine-tuning. Note that it is not mandatory to use
this mode with a zero pulse encoder. In open-loop control, the two turning modes are
identical.
user. Note that the autophasing routine also writes its
mode.
Turning with Z-pulse, can be used if there is difficulty using the
21.13 Autophasing
98.15 Position
mode).