V/F Control With Fcc - Siemens SINAMICS G120 Operating Instructions Manual

Figure 8-86 Resonance damping
8.24.1.4

V/f control with FCC

Data
Parameter range:
Warnings:
Faults:
Function chart number:
Description
The inverters have a current measurement function. This permits the output current to be
precisely determined referred to the motor voltage. This measurement guarantees that the
output current is sub-divided into a load component and a flux component. Using this sub-
division, the motor flux can be controlled and can be appropriately adapted and optimized in-
line with the prevailing conditions.
FCC operation is only activated after the FCC starting frequency P1333 has been exceeded.
The FCC starting frequency P1333 is entered as a percentage to the rated motor frequency
P0310. For a rated motor frequency of 50 Hz and a factory setting of P1333 = 10 %, this
results in an FCC starting frequency of 5 Hz. The FCC starting frequency may not be
selected too low as this has a negative impact on the control characteristics and can result in
oscillation and system instability.
The "V/f with FCC" control type (P1300 = 1) has proven itself in many applications. It has the
following advantages with respect to the standard V/f control:
● Higher motor efficiency
● Improved stabilizing characteristics
Control Units CU240S
Operating Instructions, 11/2006, A5E00766042B AA
– higher dynamic response
– improved behavior to disturbances/control.
8.24 Open-loop and closed-loop control
P1300, P1333
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Functions
8-167