User Manual Chapter 7 - Parameters Description 97
P.206
n
t
Ramp Profile
Set
P.201
I
t
Figure 7.6.9: Current Limit Control in Ramp
A signalling of the "current limit" condition is available on the digital output as "Current limit".
A signalling of the "overcurrent" condition is available on the digital output as "Alarm state".
Code Name [Code] & Function. Default MIN MAX Unit Variation IPA
P.200 En lim in ramp [0] None 0 0 2 427
[1] PI Limiter
[2] Ramp freeze
P.201 Curr lim in ramp 170 20 170 % I nom 428
P.202 En lim in steady [0] Disable 0 0 1 429
[1] Enable
P.203 Curr lim steady 170 20 170 % of I nom 430
P.204 Curr ctrl P-gain 30.0 0.1 100 % 0.1 431
P.205 Curr ctrl I-gain 10.0 0.1 100 % 0.1 432
P.206 Curr ctr feedfwd 0 0 250 % 433
DC Link Limit
The function when enabled, performs a control on the voltage level of the DC link bus capacitor.
During fast deceleration if the load has a big inertia, the DC link value can suddenly increase close to the alarm
threshold. In this case the ramp is controlled keeping the voltage level within safety values.
Consequently the deceleration ramp time is automatically extended, in order to achieve the deceleration of the load,
trying to avoid an eventual block for "overvoltage" (OV alarm).
As for the current limiter, the DC-Link controller is PI-based, with the addition of a programmable feed forward term.
P.220 En DC link ctrl (Enabling DC link control)
P.220 = 0 Function disabled.
P.220 = 1 Enabling of the DC link control function.
P.220 = 2 DC-Ramp ctrl
During fast deceleration, if the DC link level increase close to the alarm threshold, the ramp stage
will be momentary blocked and the speed kept at the value reached in this moment.
When the DC link level, will decrease again within the internal safety values, the ramp will be
restarted with the profile set. The ramp time is thus lengthened by the execution of this control.
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