Danfoss VLT AQUA Drive Design Manual page 23

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VLT AQUA Drive Design Guide
Parameter
Feedback 1 Source
Reference/Feedback Unit
PID Normal/Inverse Con-
trol
PID Proportional Gain
PID Integral Time
This table summarizes the parameters that are needed to set up the drive's Closed Loop Controller when a single feedback signal with no conversion is
compared to a single setpoint. This is the most common type of Closed Loop Controller.
2.9.2. Closed Loop Control Relevant Parameters
The drive's Closed Loop Controller is capable of handling more complex applications, such as situations where a conversion function is applied to the
feedback signal or situations where multiple feedback signals and/or setpoint references are used. The below table summarizes the additional parameters
that may be useful in such applications.
Description of function
par. 20-00 Select the source for Feedback 1. This is most commonly an analog input, but other sour-
ces are also available. Use the scaling of this input to provide the appropriate values for
this signal. By default, Analog Input 54 is the default source for Feedback 1.
par 20-12 Select the unit for the setpoint reference and feedback for the drive's Closed Loop Con-
troller. Note: Because a conversion can be applied to the feedback signal before it is used
by the Closed Loop Controller, the Reference/Feedback Unit (par. 20-12) may not be the
same as the Feedback Source Unit (par. 20-02, 20-05 and 20-08).
Normal
par. 20-81 Select [0] if the motor's speed should decrease when the feedback is greater than
the setpoint reference. Select
feedback is greater than the setpoint reference.
par. 20-93 This parameter adjusts the output of the drive's closed loop controlled based on the error
between the feedback and the setpoint reference. Quick controller response is obtained
when this value is large. However, if too large of a value is used, the drive's output fre-
quency may become unstable.
par. 20-94 The integrator adds over time (integrates) the error between the feedback and the set-
point reference. This is required to ensure that the error approaches zero. Quick controller
response is obtained when this value is small. However, if too small of a value is used,
the drive's output frequency may become unstable. A setting of 10000 s disables the
integrator.
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MG.20.N4.02 - VLT is a registered Danfoss trademark
2. Introduction to VLT AQUA Drive
Inverse
[1] if the motor's speed should increase when the
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