V/F Resonance Damping - Siemens SINAMICS G120 Operating Instructions Manual

Functions
8.24 Open-loop and closed-loop control
Figure 8-85
8.24.1.3

V/f resonance damping

Data
Parameter range:
Warnings:
Faults:
Function chart number:
Description
Resonance effects result in an increased noise level and also can damage or destroy the
mechanical system. These resonance effects can occur for:
● Geared motors
● Reluctance motors
● Large motors
The V/f resonance damping function is working between 6 % and 80 % of the rated motor
frequency when enabled.
Contrary to the "skip frequency" function and parameters P1091 ... P1094, where the
resonance frequency is passed through as quickly as possible, for the V/f resonance
damping (P1338), the resonance effects are dampened from a control-related perspective.
The advantage of this function is that by using this active damping, operation is possible in
the resonance range.
The V/f resonance damping is activated and adjusted using parameter P1338. This
parameter represents a gain factor that is a measure for the damping of the resonance
frequency. The following oscillogram indicates the effect of the resonance damping function
using as an example a reluctance motor with gearbox. The phase output currents are
displayed for an output frequency of 45 Hz.
8-166
Slip compensation
(low stator resistance → poor electrical damping)
P1338
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Operating Instructions, 11/2006, A5E00766042B AA
Control Units CU240S