UNIFREM v.3.41x
10 May 2017
Page 135 from 180
V/f curve modes on the drive with a high moment of inertia.
8.3.5 Slip compensation
Slip is the side effect of asynchronous motors operation, which means lagging / overtaking the
rotor against the stator due to load. Slip as the difference of stator and rotor frequency is
dependent on many factors. UNIFREM converters evaluate motor slip (slip compensation function
is activated) and slip is added to the stator frequency setpoint.
Parameter ID: 349
SETTINGS
–
> CONTROL AND REGULATION
–
> V/f CONTROL -> SLIP COMPENSATION ->
Slip compensation = turned on
Motor slip compensation effect: Rotor speed will maintain the
value near to the setpoint value at load changes. Moreover, it
greatly increases the torque capability of the motor at low speeds.
The main parameter to tune the rate of slip compensation is the gain in the parameter.
Parameter ID: 350
SETTINGS
–
> CONTROL AND REGULATION
–
> V/f CONTROL -> SLIP COMPENSATION ->
Slip comp. Gain
t [s]
U [V]
START
V
MAX
=V
END
F
NOM
PAR. ID = 4
█
- MT voltage
█
- basic V/f curve
█
- MT frequency
█
- MT current
F [Hz]
STOP
Frequency
STC
PAR. ID = 28
t [s]
Current MT
[A]
generator
motor
