NOTE!
While the default values for the drive’s closed-loop controller will often provide satisfactory performance, the control of the system can
often be optimized by adjusting some of the closed-loop controller’s parameters. It is also possible to autotune the PI constants.
The figure is a block diagram of the drive’s closed-loop controller. The details of the reference handling block and feedback handling block are described
in their respective sections below.
2.8.5 Feedback Handling
A block diagram of how the drive processes the feedback signal is shown below.
Feedback handling can be configured to work with applications requiring advanced control, such as multiple setpoints and multiple feedbacks. Three
types of control are common.
Single Zone, Single Setpoint
Single Zone, Single Setpoint is a basic configuration. Setpoint 1 is added to any other reference (if any, see Reference Handling) and the feedback signal
is selected using par. 20-20.
Multi-zone, Single Setpoint
Multi-zone, Single Setpoint uses two or three feedback sensors, but only one setpoint. The feedbacks can be added, subtracted (only feedback 1 and 2)
or averaged. In addition, the maximum or minimum value may be used. Setpoint 1 is used exclusively in this configuration.
VLT
®
AQUA Drive Design Guide
2 Introduction to the VLT AQUA Drive
MG.20.N5.22 - VLT
®
is a registered Danfoss trademark
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