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Controls
In Illustration 14.4, parameter 1-01 Motor Control Principle is
set to [3] Flux w motor feedb and parameter 1-00 Configu-
ration Mode is set to [1] Speed closed loop.
The motor control in this configuration relies on a
feedback signal from an encoder mounted directly on the
motor (set in parameter 1-02 Flux Motor Feedback Source).
To use the resulting reference as an input for the speed
PID control, select [1] Speed closed loop in
parameter 1-00 Configuration Mode. The speed PID control
parameters are located in parameter group 7-0* Speed PID
Ctr.
Select [2] Torque in parameter 1-00 Configuration Mode to
use the resulting reference directly as a torque reference.
Torque control can only be selected in the Flux with motor
feedback (parameter 1-01 Motor Control Principle) configu-
ration. When this mode has been selected, the reference
uses the N·m unit. It requires no torque feedback, since the
actual torque is calculated from the current measurement
of the frequency converter.
To use the process PID control for closed-loop control of
speed or a process variable in the controlled application,
for example, select [3] Process in parameter 1-00 Configu-
ration Mode.
14.6 Internal Current Control in VVC
The frequency converter features an integral current limit
control which is activated when the motor current, and
thus the torque, is higher than the torque limits set in
parameter 4-16 Torque Limit Motor Mode,
parameter 4-17 Torque Limit Generator Mode, and
parameter 4-18 Current Limit.
When the frequency converter is at the current limit during
motor operation or regenerative operation, it tries to get
below the preset torque limits as quickly as possible
without losing control of the motor.
14.7 Local and Remote Control
The frequency converter can be operated manually via the
LCP or remotely via analog and digital inputs and fieldbus.
If allowed in parameter 0-40 [Hand on] Key on LCP,
parameter 0-41 [Off] Key on LCP, parameter 0-42 [Auto on]
Key on LCP, and parameter 0-43 [Reset] Key on LCP, it is
possible to start and stop the frequency converter via the
LCP [Hand On] and [Off]. Press [Reset] to reset the alarms.
After pressing [Hand On], the frequency converter goes
into hand-on mode and follows (as default) the local
reference that can be set using the arrow keys on the LCP.
After pressing [Auto On], the frequency converter goes into
auto-on mode and follows (as default) the remote
reference. In this mode, it is possible to control the
MG37N102
Design Guide
frequency converter via the digital inputs and various serial
interfaces (RS485, USB, or an optional fieldbus). For
information about starting, stopping, changing ramps and
parameter set-ups, see parameter group 5-1* Digital Inputs
or parameter group 8-5* Serial Communication.
Hand
on
Illustration 14.5 LCP Control Keys
Active reference and configuration mode
The active reference can be either the local reference or
the remote reference.
The local reference can be permanently selected by
selecting [2] Local in parameter 3-13 Reference Site.
To permanently select the remote reference, select [1]
Remote. By selecting [0] Linked to Hand/Auto (default), the
reference site depends on whether hand-on mode or auto-
on mode is active.
Remote
reference
+
Auto mode
Hand mode
Local
reference
Illustration 14.6 Active Reference
Danfoss A/S © 6/2016 All rights reserved.
Auto
O
on
Remote
Linked to hand/auto
Local
P 3-13
LCP Hand on,
Reference site
o and auto
on keys
Reset
Reference
14
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133
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