ACS601 : how to regulate the "resistive torque" by acting on speed ?

Bonjour,
I have an ACS601 on a machine.
On this machine the "resistant torque" varies with speed and with the filter dirt rate.
When the resistive torque increases because of the filter, i want the speed to decrease to keep the resistive torque at its initial value.
How to make ?
For now I've set the settings 40.14 on PROPORTIONAL and 40.18 on SPEED TRIM but i don't know how to give the correction to the speed...

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fradin.machine Rank: 1496

Asked 2 months ago

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Hi,

Without to know in details your settings and mode of operation of the drive, I can recommend to look in 20.04 torque limit.

Or parameters 32. Here you can define the torque limits 32.7...32.10 or current limits 32.5...32.6.
These are fixed settings and when the corresponding limit is achieved, you can use RO1,2,3.

Or torque control macro.

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by fradin.machine Rank: 1496 on 2/18/2021 5:23:08 AM | Like (0) | Report

Thank's for your answer
It deals with the limit parameters.
My question is about the TRIM reference:
"how to give the correction to the speed ?"
-->
is the current consumed or resistive torque informations available on internal variables
or
must they be assigned to analog outputs SA1, SA2 to enter them as analog inputs EA2, EA3 ?

by fradin.machine Rank: 1496 on 2/18/2021 6:10:36 AM | Like (0) | Report

i fink that the solution is in :
Group 2 Actual Signals
but in my case, i don't anderstand how to use these signals for the speed correction

by kstoilov AKS expert

Rank: 5 on 2/18/2021 8:52:35 AM | Like (0) | Report

Hi,
Got your idea but not quite sure how todo that with ACS600. It is quite old model, the newer drives have more flexible configuration tools. Finally why you don't use a torque limiter or simple current limiter? Of course, you can send the torque to the AO but how this will help without external device (regulator or PLC). The drive has already integrated torque regulator

by fradin.machine Rank: 1496 on 2/18/2021 11:06:21 AM | Like (0) | Report

I'm sorry I don't understand your answer because you don't use the same vocabulary as me.
I recall my initial question :
I have an ACS601 on a machine.
On this machine the "resistive torque" varies with speed and with the filter dirt rate.
When the resistive torque increases because of the filter, i want the speed to decrease to keep the resistive torque at its initial value.
How to make ?

by kamil.herman Rank: 17 on 2/24/2021 12:45:06 AM | Like (0) | Report

I agree with kstoilov . Torque limiter , which limits the output of the speed controller in ACS600 , should control as you say "resistive torque".
It is very simple. Resistive torque is a function of speed. Higher speed makes a higher resistive load. Therefore normally a speed controller built in ACS600 must increase a motor torque to reach a balance with your machine's resistive torque in order to keep preset speed.
This is a normal situation when motor torque is a result of speed control .
If I got your point , controlling the speed of your machine is not that important as keeping resistive torque under limit.
So we need to swap priority between speed and torque control.
This can be simply achieved by limiting motor torque. Note that once the motor torque is at limit , the speed controller is no longer able to control the speed . Motor speed will decrease until limited motor speed is equal to the machine resistive torque.
As an example , image the situation once you release a gas pedal of a car to the half , the car Speed starts to decrease until the engine lowered torque match the resistive torque

by fradin.machine Rank: 1496 on 2/24/2021 9:02:49 AM | Like (0) | Report

You understood well.
Following your advice, I will therefore choose the Torque regulation mode ==>
This drive receives a Torque reference from the Pannel.
The speed is corrected to keep the torque constant
99.02 (TORQUE CONTROL) 99.04 (DTC)
10.01 (EL1P2P) 10.02 (EL1P, 2P) 10.03 (Forward)
11.01 (Ref2%) 11.02 (EXT1) 11.03 (Local)
13… .. (range + scale adjustment)
14.01 (Speed Limit1) SR11 activation according to parameters 32.01 and 32.02
15… .. (signals to be connected to the analog outputs)
20… .. (limitations)
32.01 (below) 32.02 (rpm value) supervision
The machine cycle should therefore be:
1- starting with a clean filter, the speed starts from 0, it increases within the limit of the setpoint torque until all the inertias are overcome.
2- the speed stabilizes at the level imposed by the torque setpoint
3- gradually, the filter becomes dirty so the regulation will decrease the speed to maintain the torque at the setpoint level
4- when the speed will reach a preset threshold, the RO1 will give information to the PLC which will generate the automatic filter change cycle
5- we then find ourselves in situation 2, the speed is increased since the torque regulation allows it, we start again with a clean filter

I am on the right track ?

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kstoilov

Rank: 5

Answered 2 months ago

In addition to Kolyo's answer, you can try to use a Droop Rate parameter . This is a simple function that helps to relieve some motor load by decreasing the motor speed on high motor torque.
however Droop function is not an *exact* tool in terms of Torque limit. Its tuning is like a try and error. Try to set 1 ... 5 %.
I have used it on brushing machine of steel strip.

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kamil.herman Rank: 17

Answered 2 months ago

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ACS601 : how to regulate the "resistive torque" by acting on speed ?

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