2.8 Control Structures
2.8.1 Control Principle
Illustration 2.3: Control structures.
The frequency converter is a high performance unit for demanding applications. It can handle various kinds of motor control principles such as U/f special
motor mode and VVC plus and can handle normal squirrel cage asynchronous motors.
Short circuit behavior on this FC depends on the 3 current transducers in the motor phases.
In
par. 1-00 Configuration Mode
it can be selected if open or closed loop
is to be used
2.8.2 Control Structure Open Loop
Illustration 2.4: Open Loop structure.
In the configuration shown in the illustration above,
par. 1-00 Configuration Mode
is set to Open loop [0]. The resulting reference from the reference
handling system or the local reference is received and fed through the ramp limitation and speed limitation before being sent to the motor control.
The output from the motor control is then limited by the maximum frequency limit.
2.8.3 Local (Hand On) and Remote (Auto On) Control
The frequency converter can be operated manually via the local control panel (LCP) or remotely via analog/digital inputs or serial bus.
VLT
®
AQUA Drive Design Guide
2 Introduction to VLT AQUA Drive
MG.20.N5.02 - VLT
®
is a registered Danfoss trademark
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