Function Applications
-481-
Figure 4-38 Overcurrent stall action
Table 4–29 Related parameters
Para.
No.
Function
Default
Value Range Description
F3-18
V/f overcurrent stall
action current
150% 50% to 200%
When the motor current reaches this value, the AC drive starts the
overcurrent stall function. The default value is 150%, corresponding
to 1.5 times the rated current of the AC drive.
F3-19
V/f overcurrent stall
selection
1
0: Disabled
1: Enabled
Used to enable/disable the V/f overcurrent stall function.
F3-20
V/f overcurrent stall
suppression gain
20 0 to 100
When the current exceeds the overcurrent stall action current, the
overcurrent stall function is enabled and the output frequency
decreases. After the current falls below the overcurrent stall action
current, the output frequency increases to the target frequency,
which prolongs the actual acceleration automatically. A greater
value of this parameter means better suppression effect.
F3-21
Compensation
coefficient of V/f speed
multiplying overcurrent
stall action current
50% 50% to 200%
This parameter is used to reduce the overcurrent stall action current
during high-speed operation. It is invalid when set to 50%. The
recommended value for F3-18 in the field-weakening range is 100%.
When the frequency is high, motor drive current is small, and overcurrent stall action current can result
in greater motor speed dip compared with situations when the frequency is below the rated level. To
improve motor running performance, lower the overcurrent stall action current for situations when the
frequency is above the rated level. This helps to improve acceleration performance and prevent motor
stall in high-frequency applications with large load inertia multiple field weakening requirements, such
as centrifuges.
When the frequency is above the rated level, overcurrent stall action current = (fn/fs) x k x LimitCur
In the formula, fs is the running frequency, fn is the rated motor frequency, k is the value of F3-21
(compensation coefficient of speed multiplying overcurrent stall action current), and LimitCur is the
value of F3-18 (overcurrent stall action current).
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