4-226
SLV mode gain tuning (20-00~20-03, 20-09~20-18)
1)
Tune the low-speed ASR P and I gain 20-02 ~ 20-03, make sure the reference frequency is set below the
value of parameter 20-15.
2)
Tune the high-speed ASR PI gain 20-00~20-01, make sure the reference frequency is above the value set in
parameter 20-16 value.
3)
Both low-speed ASR gain and the high-speed gain can be set to the same values and only require to be
adjusted in case of system instability.
4)
reduce the low-pass filter time constant 20-13~20-14 to decrease the bandwidth of the feedback system and
re-tune the ASR gain, in case tuning of the ASR P and I gain 20-00~20-03 does not improve the system
response.
5)
Tune low-speed low-pass filter time constant 20-14, make sure the reference frequency is below parameter
20-15 value.
6)
Tune high-speed low-pass filter time constant 20-13 at frequency reference, make sure the reference
frequency is above parameter 20-16 value.
7)
Increasing the low-pass filter time constant can limit the bandwidth of the speed feedback system and may
reduce the system response. Increasing the low-pass time reduces the speed feedback signal interference
but may results in sluggish system response when the load suddenly changes. Adjust the low-pass filter time
if the load stays fairly constant during normal operation. The low bandwidth of the speed feedback must be
supported by the low gain of ASR to ensure the stable operation.
8)
Decreasing the low-pass filter time constant may increase the bandwidth of the speed feedback and the
system response. Decreasing the low-pass time may increase the speed feedback interference resulting in
system instability when the load suddenly changes. Decrease the low-pass filter time is a quick system
response is required for rapidly changing loads. The high bandwidth of the speed feedback allows for a
relative high ASR gain.
9)
In case tuning 20-00~20-03 and the low-pass filter time constant 20-13~20-14 do not improve the system
response time, tuning the PI gain 20-09~20-12 of the speed estimator may be required.
10) Setting a high gain for the speed estimator (high proportion (P) gain and small integral (I) time) increases the
bandwidth of the speed feedback, but may cause speed feedback interference resulting in system instability.
11) Setting a low gain for the speed estimator (small proportion (P) gain and high integral time) decreases the
bandwidth of the speed feedback, may improve speed feedback interference resulting in a more stable
system.
12) The default values for the ASR can be used in most applications, no adjustment is required. Adjusting the
low-pass filter time and speed estimator gain requires a good understanding of the overall system. If a
high-speed system response in combination with stable operation is required consider using SLV control
mode.
13) Parameter 20-15 sets the gain switch frequency at low-speed and parameter 20-16 sets the gain switch
frequency at high-speed.
14) Operating at a speed below 20-15 will result in an increased excitation current for low-speed operation
accuracy. When the frequency reference rises above 20-16, the inverter will output the rated excitation
current at the no-load voltage (02-19).
15) For general purpose applications parameter 20-15 should be set to a value of 5~50% of the motor base
frequency. If this value is too high, the inverter output may saturate. Parameter 20-16 should be set to a
value of 4Hz or more above the value of 20-08.
16) When experiencing speed jitter at high speed and stable operation during mid-range speed while operating a
heavy load (>100%), it is recommended to reduce the no-load voltage (02-19) or tune the FOC parameters
(18-05 ~ 18-06).
17) Parameter 20-17 and 20-18 are for compensating speed feedback at low speed and high speed.
