Name: Danfoss VLT5000 SyncPos
Brand: Danfoss
Rating: 5 (1 reviews)

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Programmable SyncPos motion controller

MG.10.J8.02 – VLT is a registered Danfoss trade mark

Acceleration Feed-forward FFACC (37)

The

Acceleration feedAcceleration feed

Acceleration feed

forward factor forward factor

forward factor is multiplied

with the 2nd derivative of the setpoint position (the

acceleration of the setpoint) and the result is

added to the control signal. This feature should be

used to compensate for the torque used to accele-

rate/decelerate the system inertia.

NB!

Scaling of the FFACC factor is depending on

the setting of the

Shortest ramp time Shortest ramp time

Shortest ramp time (31).

You should therefore increase the FFACC accor-

dingly when decreasing SyncPos parameter

Shortest ramp time Shortest ramp time

Shortest ramp time (31) and vice versa.

Sampling time for the entire control algorithm

TIMER (14)

For particularly slow systems you can slow down

the entire control system by entering multiples of

1 ms as the sampling time. However, it is important

to remember that such a change influences all the

control parameters!

Therefore, normally you should not deviate from

the value of 1 ms.

BANDWIDTH

Bandwidth Bandwidth

Bandwidth of 1000 means that the set value is

being executed 100%, thus

DerivativeDerivative

Derivative,

ProportioProportio

Proportio

nal nal

nal and

Integral factorsIntegral factors

Integral factors are effective as defined.

But if you are operating a system which could be

jeopardized by vibrations, for example, a crane

with a heavy load then you can limit the bandwidth

in which the PID controller should function.

BANDWIDTH (35) of 300 makes a limitation of 30%

possible. The build-up of a vibration is thus pre-

vented since the control is only moved to with 30%

of the calculated set value.

However, then it is necessary also to use the feed-

forward part of the controller in order to achieve

the corresponding control.

■■

■ Optimizing your controller settings

step-by-step

For best results use the functions in the

testruntestrun

testrun

menu for this purpose;

these help you to evaluate

and optimize the PID controller on the basis of

graphs of the set and actual curves.

However, we recommend only changing one value

at a time and subsequently determining the im-

provement with a testrun

Click on "CONTROLLER" → "PARAMETER" →

"AXIS" and select the VLT, of which you are

currently adjusting the settings.

Setting controller behavior

Before you adjust the controller parameters it is

important to determine which controller behavior

should be achieved.

NB!

The drive elements must never be operated

outside of the technical specifications. Thus

the maximum acceleration is determined by the

“weakest” drive element.

• “Stiff” axis: the fastest reaction possible is

mainly influenced by the

Proportional factorProportional factor

Proportional factor.

You can judge the results on the basis of the

velocity graph.

• Damping of vibrations are mainly influenced

by the

Derivative factorDerivative factor

Derivative factor. The results can best

be assessed in the velocity graph.

• Temporary (static) deviations in position are

mainly reduced by the

Integral factorIntegral factor

Integral factor and

can best be judged on the basis of the posi-

tioning graph.

Optimizing the PID controller

Brand	Danfoss
Model	VLT5000 SyncPos
Category	Controller
Language	English

Danfoss VLT5000 SyncPos User Manual

Table of Contents

Questions and Answers:

Danfoss VLT5000 SyncPos Specifications

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