WEG CFW500 V1.8X, Руководство по программированию, Страница: 85 / 172

VVW Vector Control
CFW500 | 10-1
10
10 VVW VECTOR CONTROL
The V VW vector control mode (Voltage Vector WEG) uses a control method with a much higher performance
than the V/f control because of the load torque estimation and of the control of the magnetic flux in the air gap, as
per scheme of
Figure 10.1 on page 10-2 . In this control strategy, losses, efficiency, rated slip and power factor of
the motor are considered in order to improve the control performance.
The main advantage compared to the V/f control is the best speed regulation with greater torque capacity at
low speeds (frequencies below 5 Hz), allowing a relevant improvement in the drive performance in permanent
duty. Besides, the V VW control has a quick and simple setting and it is suitable for most medium-performance
applications in the control of three-phase induction motor.
By just measuring the output current, the V VW control instantly obtains the motor torque and slip. Thus, the
V VW actuates in the output voltage compensation and slip compensation. Therefore, the V VW controller action
replaces the classical V/f functions in P0137 and P0138, but with a calculation model much more sophisticated
and accurate, meeting several load conditions or operation points of the application.
In order to achieve a good speed regulation in permanent duty with a good operation of the V VW control, the
parameter setting in the range P0399 to P0407 and the stator resistance in P0409 are essential. Those parameters
can easily be obtained on the motor nameplate and in the self-tuning routine activated by P0408.