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Improving the Operation Performance
îš‹ 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.
îš„Related Pameters
îš„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
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:
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.
Parameter
No.
Name
Factory
Setting
Change
during
Opera-
tion
Control Methods
V/f
V/f with
PG
Open
Loop
Vector
Closed
Loop
Vector
C3-01 Slip compensation gain
0.0
* 1
* 1. The factory setting will change when the control method is changed. (The V/f control factory settings are given.).
Yes A N o A N o
C3-02 Slip compensation delay time
200 ms
*1
No A No A No
C3-03 Slip compensation limit 200% No A No A No
C3-04 Slip compensation during regeneration 0 No A No A No
C3-05 Output voltage limit operation selection 0 No No No A A
Motor rated slip (Hz) Motor rated frequency (Hz)
Rated motor speed (rpm) Number of motor poles×
120
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