Adaptable speed controller, circuit example for MCTRL-VP-N-ADAPT
Application:
Extruders, where the proportional gain is to be adapted at low speeds
Operation in field setting range
Drives which tend to unstable vector control in the medium speed range
Description:
When the proportional gain of the speed controller is increased the sensorless vector control becomes unstable first in the medium speed range (f = 20 ... 40 Hz). Particularly with a low speed setpoint, a large gain of the speed controller can improve the speed performance.
Adaption of the speed controller
You can adapt the speed controller gain online via the input MCTRL-VP-N-ADAPT. The set gain C0070 is evaluated with the absolute value of the input signal. The reference value for C0070 is an input signal of 100 %.
You can manipulate the gain (C0070) in dependence on the process using a function block (e.g. CURVE) at MCTRL-VP-N-ADAPT.
The adaption is switched off with the input signal FIXED0% (input not connected).
In the Lenze setting the adaption is deactivated with the signal FIXED100%.
Example:
The proportional gain VPN (C0070) is to be adapted using the function block CURVE1 via input MCTRL-VP-N-ADAPT. In the following example, the gain is set to 50 % of C0070 with increasing speed. From experience we know that an increase of the proportional gain is also recommended in the field setting range; the same circuitry can be used by adaption of the characteristic in CURVE1 (e.g. C0960 = 3).
