Improving The Operation Performance; Reducing The Motor Speed Fluctuation (Slip Compensation Function) - Omron VARISPEED F7 User Manual

Improving the Operation Performance

Reducing the Motor Speed Fluctuation (Slip Compensation Function)

When the load is large, the motor slip also grows and the motor speed decreases. The slip compensation func-
tion keeps the motor speed constant, regardless of changes in load. When the motor is operating at the rated
load, parameter E2-02 (Motor Rated Slip) × the slip compensation gain value in parameter C3-01 is added to
the output frequency.
Related Pameters
Parameter
No.
C3-01
C3-02
C3-03
C3-04
C3-05
* 1. The factory setting will change when the control method is changed. (The V/f control factory settings are given.).
Adjusting Slip Compensation Gain (C3-01)
The set value of C3-01 depends on the control method. The factory settings are:
V/f control without PG: 0.0
•
Open Loop Vector control: 1.0
•
Closed Loop Vector control: 1.0
•
6
Set C3-01 to 1.0 to compensate the slip depending on the actual torque output status using the rated slip
(E2-02/E4-02) as reference.
Adjust the slip compensation gain using the following procedure.
1. With Open Loop Vector control Set E2-02 (Motor Rated Slip) and E2-03 (Motor No-load Current) cor-
rectly. The motor rated slip can be calculated using the values on the motor nameplate and the following
formula:
Motor rated slip (Hz)
The motor data can be set automatically using the autotuning function.
2. With V/f control set C3-01 to 1.0.
3. Apply a load, and measure the speed to adjust the slip compensation gain. Adjust the slip compensation
gain by 0.1 at a time only. If the speed is less than the target value, increase the slip compensation gain, and
if the speed is higher than the target value, reduce the slip compensation gain.
4. Setting C3-01 to 0.0 disables the slip compensation function.
36
6-
Name
Slip compensation gain
Slip compensation delay time
Slip compensation limit
Slip compensation during regeneration
Output voltage limit operation selection
Motor rated frequency (Hz)
=
Change
Factory during
Setting Opera-
V/f
tion
* 1
Yes A
0.0
200 ms
No A
*1
200% No A
0 No A
0 No No
×
Rated motor speed (rpm) Number of motor poles
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120
Control Methods
Open Closed
V/f with
Loop Loop
PG
Vector Vector
No A No
No A No
No A No
No A No
No A A