6 v/f control (vfcplus + encoder), V/f control (vfcplus + encoder), 5motor control (mctrl) – Lenze 8400 TopLine User Manual
Page 186
5
Motor control (MCTRL)
5.6
V/f control (VFCplus + encoder)
186
Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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5.6
V/f control (VFCplus + encoder)
The V/f characteristic control (VFCplus) described above can be operated with a speed feedback.
This has the following advantages:
• Steady-state accuracy of the speed
• Less parameterisation effort compared to the sensorless vector control (SLVC)
• Improved dynamics compared to V/f characteristic control without feedback or to sensorless
vector control (SLVC).
• Suitability for group drives
Stop!
The V/f control requires a speed feedback!
• The speed sensor used has to be set in
. This setting is not made automatically
with the selection of the motor from the »Engineer« motor catalogue!
• If no speed sensor is set in
and the controller is enabled, an impermissibly
high motor current occurs which may destroy the motor thermally!
•
From version 14.00.00
takes place if in case of controller enable it is detected that a motor control type with
feedback is set in
but no speed encoder is set in
.
Stop!
V/f emergency operation
From version 15.00.00
, it is internally switched to the encoderless V/f characteristic
control in case of an encoder open circuit in order to avoid impermissible motor
movements.
• In order that this "V/f emergency operation" works properly, the parameters relevant
for the V/f characteristic control (base frequency, Vmin boost, slip compensation, etc.)
have to be set correctly. As an alternative, a motor parameter identification can be
executed as well.
• The change-over to "V/f emergency operation" is reported via bit 4 in
and via
the bWirebreakUfLinearActive status signal at the SB
• The change-over to "V/f emergency operation" can be suppressed by setting bit 8 to
"1" in
.
Note!
As the slip is calculated in the feedback V/f operation and injected through the slip
regulator, the slip compensation (
) is deactivated with V/f control.
The descriptions in chapter "
V/f characteristic control (VFCplus)
" also apply to the V/f
Detailed information on the speed feedback can be found in the chapter
"
".