Servo control

3.8 Note about the electronic motor model

3.8Note about the electronic motor model

A model change takes place within the speed range p1752*(100%-p1756) and p1752. With induction motors with encoder, the torque image is more accurate in higher speed ranges; the effect of the rotor resistance and the saturation of the main field inductance are corrected. With synchronous motors with encoder, the commutation angle is monitored. If the kT estimator has been activated, the torque image for synchronous motors is more accurate too.

3.9V/f control for diagnostics

Description

With V/f control, the motor is operated with an open control loop and does require speed control or actual current sensing, for example. Operation is possible with a small amount of motor data.

V/f control can be used to check the following:

Motor Module

Power cable between Motor Module <–> motor

Motor

DRIVE-CLiQ cable between Motor Module <–> motor

Encoder and actual encoder value

The following motors can be operated with V/f control:

Induction motors

Synchronous motors

CAUTION

V/f control must only be used as a diagnostic function (e.g. to check that the motor encoder is functioning correctly).

Note

In V/f mode, the calculated actual speed value is always displayed in r0063. The speed of the encoder (if installed) is displayed in r0061. If an encoder is not installed, r0061 displays "0".

Note

The operation of synchronous motors with V/f control is allowed only at up to 25 % of the rated motor speed.

84

Drive Functions

Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4

Page 84
Image 84
Efficient Networks S120 manual V/f control for diagnostics, Servo control