User guide

Table Of Contents

5 Motor control (MCTRL)

5.2 Selecting the control mode

Lenze · 8400 BaseLine C · Reference manual · DMS 1.6 EN · 01/2014 · TD05

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V/f characteristic control (VFCplus)

The V/f characteristic control (VFCplus) is a motor control mode for standard frequency inverter ap-

plications based on a simple and robust control process which is suitable for the operation of ma-

chines with linear or square-law load torque characteristic (e.g. fans). Furthermore, this motor

control mode is also suitable for group drives and special motors. Due to the low parameterisation

effort, commissioning of such applications is fast and easy.

The V

min

boost (C016) and slip compensation (C021) required for optimising the drive behaviour are

dimensioned for machines with power adaptations to the inverter in the Lenze setting.

V/f characteristic control (VFCplus) ( 78)

Sensorless vector control (SLVC)

Sensorless (field-oriented) vector control is based on a decoupled, separate control for the torque-

producing and the field-producing current component. In addition, the actual speed is reconstruc-

ted by means of a motor model so that a speed sensor is not required.

Sensorless vector control (SLVC)

( 87)

In comparison to the V/f characteristic control without feedback, the following can be achieved by

means of sensorless vector control SLVC:

• A higher maximum torque throughout the entire speed range

• A higher speed accuracy

• A higher concentricity factor

• A higher level of efficiency

• The implementation of torque-actuated operation with speed limitation

• The limitation of the maximum torque in motor and generator mode for speed-actuated opera-

tion

 Tip!

If a high torque without feedback is to be provided at small speeds, we recommend the

"Sensorless vector control" motor control mode.

V/f characteristic control (VFCplus) Sensorless vector control (SLVC)

9300vec092 9300vec095

 Operation in motor mode (CW rotation)  Operation in generator mode (CCW rotation)

 Operation in motor mode (CCW rotation)  Operation in generator mode (CW rotation)

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