UNIFREM v.3.41x
10 May 2017
Page 60 from 180
Name [ID]
Description
Def.
can adjust the rate of current regulation or dampen oscillations of the current at start-up.
STC adapt. gain
[1589]
P term of STC adaptation gain.
2,00
0,10 ÷ 20,00
Recommended setting is 2.0.
Vq
correction
[1591]
Configuration of the damping correction to Vq based on cos(phi) derivation. By
setting to 0.00 this feature is turned off.
0,00
-
100,00 ÷ 100,00
Recommended value of the correction is 2.0.
SLIP COMPENSATION
Group of parameters number [348]
Turning on and gain of the slip compensation. Slip compensation is required if greater accuracy of rotor
speed is desired, regardless of load. It also contributes to an increase in torque overload power at low
speeds. The value of slip can be controlled in Slip freq. [938] (page 15).
MENU \ SETTINGS \ CONTROL AND REGULATION \ V/F CONTROL \ SLIP COMPENSATION
Name [ID]
Description
Def.
Slip
compensation
[349]
Turning on the slip compensation in the scalar motor control.
Slip compensation, using the motor mathematical model, corrects the frequency by
a calculated slip so that rotor actual speed is near the speed setpoint value. The
accuracy of the calculated slip is affected by the parameters Stator resistance
[345] (page 45), Magnetizing current [355] (page 45), Nom. power [357] (page
44), Nom. revolutions [356] (page 44).
Turned
off
Turned off
Slip compensation is turned off.
Turned on
Slip compensation is turned on.
Slip restriction
[193]
Turning on / off the slip restriction . Slip restriction operates similarly to torque limit
or overload protection. This feature reduces the possibility of operation in the
unstable part of the torque-speed curve of the motor.
If the slip compensation is turned on, the desired frequency will be generated so it
will not differ from the rotor frequency Freq. RT [937] (page 15) by more than the
configured maximal slip Max. slip [177] (page 60).
Turned
off
Turned off
Slip restriction is turned off.
Turned on
Slip restriction is turned on.
Slip comp. Gain
[350]
Setting the gain of the slip compensation.
1,00
0,01 ÷ 10,00
If the slip correction is obviously not sufficient or too big because of inaccurate parameters,
this parameter allows to tune the slip compensation gain to correct these inaccuracies.
Max. slip [177]
Maximal slip frequency. It is used to limit the slip for the slip compensation function
and the slip restriction function.
5,00
Hz
0,00
÷
Slip filter [995]
Time constant of the slip filter on the slip model output.
100 ms
1 ms ÷ 10000 ms
It helps to adjust the slip compensation dynamics and the slip restriction. In case of slow
reactions, it is necessary to increase the filter time constant and vice versa, when
frequency oscillations occur, decrease the filter time constant.
MAX. CURRENT CONTROLLER (MCC)
Group of parameters number [351]
Maximum current controller parameters (MCC), also called the Current limit.
MENU \ SETTINGS \ CONTROL AND REGULATION \ V/F CONTROL \ MAX. CURRENT CONTROLLER (MCC)
Name [ID]
Description
Def.
Max.
current
controller [352]
Turns on Maximum Current Controller (MCC), which restricts the output current to
Max. mot. current [5] (page 71) or Max. regen. current [549] (page 71) by the
correction of output frequency. It is possible to turn on MCC operation for motoric,
regenerative or both modes of operation. Current limit is used to start large inertial
loads or load proportional to the motor speed (pumps, fans, mixers, mills). It can
Motoric
