4-249
17-14=1,
Under VF control mode, no-loading drives particular induction motor with oscillation. And such kinds of
motors mostly are high-speed type.
Note: Because Vector mode measures no-load current of motor by internal current vector structure, so
the particular induction motor can avoid the oscillated problem in the VF control mode.
Group 18: Slip Compensation Parameters
18- 00
Slip Compensation Gain at Low Speed
Range 【0.00~2.50 】
18- 01
Slip Compensation Gain at High Speed
Range
【-1.00~1.00】
18- 02
Slip Compensation Limit
Range
【0~250】%
18- 03
Slip Compensation Filter Time
Range
【0.0~10.0】sec
18- 04
Regenerative Slip Compensation Selection
Range
【0】: Disable
【1】: Enable
18- 05
FOC Delay Time
Range
【1~1000】msec
18- 06
FOC Gain
Range
【0.00~2.00】
Slip compensation automatically adjusts the output frequency based on the motor load to improve the
speed accuracy of the motor mainly in V/F mode.
The slip compensation function compensates for the motor slip to match the actual motor speed to the
reference frequency.
Slip compensation adjustment in V/F mode
18-00: Slip compensation gain at low speed
The adjustment of slip compensation gain at low speed follows the below procedure:
1. Set the rated slip and the motor no-load current (02-00).
2. Set the slip compensation (18-00) to1.0 (factory default setting is 0.0 in V / F control mode)
3. For the operation with a load attached, measure the speed and adjust the slip gain (18-00)
accordingly (increase in steps of 0.1).
- If the motor speed is lower than frequency reference, increase the value of 18-00.
- If the motor speed is higher than frequency reference, decrease the value of 18-00.
When the output current is greater than the no-load current (02-00), the slip compensation is enabled and
the output frequency increases from f1 to f2. Refer to Fig.4.4.90., the slip compensation value is calculated
as follows:
[Output current (12-08) – motor no-load current (02-00)]
Slip compensation value = Motor rated sync induction rotation difference
x
[Motor output rated current (02-01) –motor no-load current (02-00)]