114
Installation and user guide
Rev: 4.0
NTT 240/460
Operation mode
6. if, with procedure described into instruction point 5, it’s not easy to stabilize correctly the speed reference
to the desired value set into instruction point 4, then reset the
Covariance current
parameter at default value
(6) and increase
Covariance phase
parameter
;
it’s recommended to increase with steps of 0.01 units, untill
the speed reference is correctly stabilized to the desired value set into instruction point 4.
When target is
reached, please do not exceed beyond with the parameter setting.
7. increase speed reference: for example 700-1000RPM.
8. to further reduce the measured speed noise and current reference noise, increase or decrease
Covariance
current
parameter; it’s recommended to increase or decrease with steps of 2-5 units. In most cases:
•
for motor with a PHASE resistor lower than 0.8Ω and a PHASE inductance lower than 0.8mH, parameter
should be increased.
When target is reached, please do not exceed beyond with the parameter setting.
•
for motor with a PHASE resistor higher than 0.8Ω and a PHASE inductance higher than 0.8mH, parameter
should be decreased.
When target is reached, please do not exceed beyond with the parameter setting.
9. if necessary, to reduce the measured current noise and consequently the measured speed noise, increase
or decrease
Current noise
parameter; it’s recommended to increase or decrease with steps of 2-5 units. In
most cases:
•
for motor with a PHASE resistor lower than 0.8Ω and a PHASE inductance lower than 0.8mH, parameter
should be increased.
When target is reached, please do not exceed beyond with the parameter setting.
•
for motor with a PHASE resistor higher than 0.8Ω and a PHASE inductance higher than 0.8mH, parameter
should be decreased.
When target is reached, please do not exceed beyond with the parameter setting.
10. if necessary, it’s possible to act further on
Covariance phase
parameter to reduce the no load current of the
drive; however, in this way the measured speed noise increases. This solution could be usefull with low
power/current motors.
11. now perform again all instruction points 8-9-10, increasing the speed reference with steps of 200-500RPM
untill the desired application speed is reached. Note that the tuning performed at 500RPM could NOT be
excellent for 2000RPM and vice versa. It’s recommended to iterate the procedure with steps untill the desired
speed is reached and then perform an excellent sensorless tuning. The picture below shows that setting is
not excellent at 500RPM, but it’s excellent for speed higher than 1000RPM.
12. to further reduce the measured current noise and measured speed noise at 500RPM (see previous image), it’s
possible to decrease
Covariance current
parameter again: but this solution does NOT guarantee that tuning
will be excellent at 2000RPM. For this reason, the tuning procedure requires an iteration with increasing
steps for speed reference, in order to avoid abnormal behaviours that may occur if the speed reference
changes from 500RPM to 3000RPM without an excellent tuning in the range.
Содержание NTT 240
Страница 129: ......
