4-224
Parameter 20-33 is used when 20-07 is set to 0 and frequency command source is set to analog input. A noisy
analog input signal might cause a problem where the inverter determines that the operation does not reach its
constant speed. Adjust parameter 20-33 according to avoid this situation from occurring.
The following diagram is an overview of the automatic speed regulator (ASR) block.
SLV control mode:
The ASR function adjusts the output frequency to control the motor speed to minimize the difference between the
frequency reference and actual motor speed.
The ASR controller in SLV mode uses a speed estimator to estimate the motor speed. In order to reduce speed
feedback signal interference, a low-pass filter and speed feedback compensator can be enabled.
The ASR integrator output can be disabled or limited (03-00 to 03-05= 43). The ASR output is passed through a
low-pass filter.
20-00
20-02
20-01
20-03
20-08
Frequency
Reference
20-13
20-14
20-17
20-18
Speed
Observer
20-09
20-11
20-10
20-12
Motor Voltage
Motor Current
P
P
I
I
I Limit
Speed
Observer
Feedback
Speed
Feedback
Compensator
L/P Filter
Observer
Error
20-07 = 1 (During accel/decel)
20-07 = 0
Speed Control Integral Reset
03-00 to 03-07 = 43
ASR
Delay time
Torque
Limit
Torque
Reference
+
+
+
+
+
-
20-35
L/P Filter
20-34
P
Figure 4.3.108 ASR speed control diagram (SLV mode)