4-269
SLV mode adjustment
18-00:
Slip compensation gain
a) Slip compensation can be used to control the full rang speed accuracy under load condition.
b) If the speed is lower than 2 Hz and the motor speed decreases, increase the value of 18-00.
c) If the speed is lower than 2 Hz and the motor speed increases, reduce the value of 18-00.
Slip compensation gain uses a single value for the whole speed range. As a result the slip compensation
accuracy at low speed is high but slight inaccuracies might occur at high speeds.
Adjust parameter 18-02 together with the compensation value or continue to adjust 18-00 if the speed accuracy at
higher speed is not acceptable. Please note adjusting these parameters might impact the accuracy at lower
speeds.
The impact of 18-00 on the torque and the speed are shown in figure 4.4.101.
Torque
Speed
Decrease 18-00
Increase 18-00
Figure 4.4.101 18-00 Effect on the torque and speed
18-01:
Slip compensation gain at high speed
It is not required to adjust the Slip compensation gain at high speed if the motor is loaded. After adjusting
parameter 18-00 it is recommended to increase the reference frequency and check the motor speed. In case of a
speed error increase the value of 18-01 to adjust the compensation. Increase the motor rated frequency (01-12
base frequency) and increase the value of 18-01 to reduce the speed error. If the speed accuracy becomes worse
due to an increase in motor temperature it is recommended to use a combination of 18-00 and 18-01 for
adjustment.
Compared to 18-00, 18-01 serves as a variable gain for the full speed range. Parameter 18-01 determines the slip
compensation at the motor rated speed and is calculated follows:
Reference Frequency
Slip Compensation Gain = (Slip Compensation Gain at low speed + Slip Compensation Gain at high speed) x
Motor rated frequency (01-12)
