ABB ACS880 Firmware Manual page 46

46 Program features
pulses that change their state six times during one revolution, so it is only known
within which 60° sector of a complete revolution the initial position is.
Rotor
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.
In open-loop mode, the zero angle of the rotor is determined before the start. In
closed-loop mode, 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 modes.
Note: In open-loop mode, the motor always turns when it is started as the shaft is
turned towards the remanence flux.
A rotor position offset used in motor control can also be given by the user – see
parameter 98.15 Position offset
Note: The autophasing routine also writes its result into
Autophasing results are updated even if user settings are not enabled by
motor model mode.
Several autophasing modes are available (see parameter
The turning mode 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
N
S
user.
Absolute encoder/resolver
98.15 Position offset
98.01 User
21.13 Autophasing
user.
mode).