Voltage Reserve; Switching Frequency Reference; Internal Speed Limitation; Encoder Drift Detection - ABB ACS880 Manual

30 Start-up

Voltage reserve

￭
Use parameter 97.04 Voltage reserve to apply a +2% voltage reserve. This is recommended
with permanent magnet motors to prevent instability in the field weakening area.

Switching frequency reference

￭
To enable a custom switching frequency reference setting, set parameter 97.09 Switching
freq mode to Custom. Check the motor data sheet for the recommended switching frequency
and enter it into parameter 97.01 Switching frequency reference. In case no switching
frequency recommendation is indicated by the motor data sheet, set the parameter to at
least 8...10 times the maximum motor frequency.
Note: Observe the maximum switching frequency of the inverter modules in use.
An alternative is to use an adaptive switching frequency in relation to the output frequency.
To enable this, set bit 1 (High speed mode) in parameter 95.15 Special HW settings. Enter
the minimum switching frequency into 97.02 Minimum switching frequency. In service-level
parameter 97.26 High speed sw freq slope, enter a value so that the output frequency
multiplied by this value corresponds to the effective switching frequency.
WARNING! If adaptive switching frequency is used, make sure the current ripple
caused by a lower switching frequency does not heat the motor up excessively.
Consult the motor manufacturer.

Internal speed limitation

￭
By default, the torque control calculates an internal, safe speed limit for the motor. If the
drive is equipped with a brake chopper, you can disable the internal speed limitation in
service-level parameter 30.32 Speed limit internal. The brake chopper will ensure safe
operation if the drive trips on a fault when the motor is operating in the field weakening area
above the internal speed limit.

Encoder drift detection

￭
Drift (ie. slip) detection of the motor encoder is active by default, and can cause nuisance
faults in high-speed applications (for example, a false 7301/A7B0 event with auxiliary code
0004). Disable the detection in service-level parameter 90.47 Enable motor encoder drift
detection.

Overcurrent fault limit

￭
To protect the motor from demagnetization in case of inverter derating and an overcurrent
fault, a custom overcurrent fault limit can be set using parameter 31.42 Overcurrent fault
limit. The parameter defines the maximum peak current of one phase. If the parameter is
set to 0.00 A, an automatic, internal limit is in use.

Motor temperature protection

￭
Rotor temperature measurement is highly recommended as overheating can permanently
demagnetize the rotor magnets. Some motors are equipped with infrared sensors measuring
the rotor temperature. Stator temperature measurement will not reliably indicate rotor
temperature.

Motor ambient temperature

￭
Set parameter 35.50 Motor ambient temperature before the ID run.