CurrRefFilter

General

Type	ES
Offline editable	Yes
Devices supporting the parameter	Lexium LXM52 Drive, Lexium LXM52 Linear Drive, Lexium LXM62 Drive, Lexium LXM62 Linear Drive, Lexium ILM62 Drive Module
Traceable	Yes

Functional Description

The parameter is used to enter the time constant of a first order low pass filter in the velocity control loop in ms. The filter acts on the reference current in the velocity controller circuit. Like the VelFilter, this filter is used to suppress high frequency oscillations which for example, may occur due to a two-mass oscillator with a rigid coupling. In general, both filters are set to the same values.

If the filter is set too low, high-frequency resonances of the mechanics may lead to the control loop becoming unstable. If the filter is set too high, the dynamic of the control loop is reduced in the first instance; even higher values may lead to the control loop becoming unstable. The optimal conditions must be determined.

NOTE: In the case of a loose coupling (belts, chains, ...), it is better to set VelFilter and CurrRefFilter to 0 and, if necessary, to reduce the speed controller parameters (Vel_P_Gain and Vel_I_Gain) as well.

NOTE: The parameter value is transferred from the master to the slave via the parameter channel of the Sercos at every access. Typically, this takes about 10 ms. However, times up to 1 s may be realized if large amounts of data are transferred on the parameter channel.

NOTE: This parameter can be determined as of firmware version V01.35.x.0 by using the AutoTune automatic controller optimization.

This parameter has no effect for asynchronous motors in open-loop V / f mode (ControlMode = open-loop control / 1).