Control Structure In Vvc Plus - Danfoss VLT FC 360 Design Manual

Product Overview
2.3.3 Control Structure in VVC
P 1-00
Con g. mode
Ref.
+
Process
S
_
P 7-20 Process feedback
1 source
P 7-22 Process feedback
2 source
Illustration 2.2 Control Structure in VVC
In the configuration shown in Illustration 2.2, 1-01 Motor Control Principle is set to [1] VVC
set to [0] Speed open loop. The resulting reference from the reference handling system is received and fed through the ramp
limitation and speed limitation before being sent to the motor control. The output of the motor control is then limited by
the maximum frequency limit.
If 1-00 Configuration Mode is set to [1] Speed closed loop the resulting reference will be passed from the ramp limitation and
speed limitation into a speed PID control. The Speed PID control parameters are located in the parameter group 7-0* Speed
PID Ctrl. The resulting reference from the Speed PID control is sent to the motor control limited by the frequency limit.
Select [3] Process in 1-00 Configuration Mode to use the process PID control for closed loop control of e.g. speed or pressure
in the controlled application. The Process PID parameters are located in parameter group 7-2* Process Ctrl. Feedb and 7-3*
Process PID Ctrl.
®
VLT AutomationDrive FC 360 Design Guide
plus
P 1-00
P 4-14
Con g. mode
Motor speed
high limit (Hz)
P 3-**
High
Ramp
Low
P 4-12
Motor speed
low limit (Hz)
plus
Open Loop and Closed Loop Configurations
®
MG06B202 - VLT is a registered Danfoss trademark
P 4-19
Max. output freq.
+f max.
Motor
controller
-f max.
P 7-0*
Speed Motor
+
S
PID controller
_
P 7-00 Speed PID
feedback source
plus
and 1-00 Configuration Mode is
2
P 4-19
Max. output freq.
+f max.
-f max.
15
2