ABB ACS850-04 series, Firmware Manual

Page: 58 / 296

58 Program features
Application macros
See chapter Application macros (page 81 ).
Automatic fault resets
The drive can automatically reset itself after overcurrent, overvoltage, undervoltage,
external and “analog input below minimum” faults. By default, automatic resets are off
and must be separately activated by the user.
Settings
Parameter group 32 Automatic reset (page 182 ).
Autophasing
Autophasing is an automatic measurement routine to determine the angular position
of the magnetic flux of a permanent magnet synchronous motor. The motor control
requires the absolute position of the rotor flux in order to control motor torque
accurately.
Autophasing is applicable to permanent magnet synchronous motors in these cases:
• One-time measurement of the rotor and encoder position difference when an
absolute encoder or resolver (one pole pair) is used
• Measurement at first start after each power-up when an incremental encoder is
used
• With open-loop motor control, repetitive measurement of the rotor position at
every start.
Several autophasing modes are available (see parameter 11.07 Autophasing mode ).
The turning mode is recommended especially with case 1 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.
The standstill modes can be used if the motor cannot be turned (for example, when
the load is connected). As the characteristics of motors and loads differ, testing must
be done to find out the most suitable standstill mode.
A rotor position offset used in motor control can also be given by the user. See
parameter
97.20 PM angle offset .