VFD Siemens Micromaster 440

[ason]

Hey, i have a prob. with to identical VFD setup with
Siemens Micromaster 440,
they uses for 2 roller that feeds a metal belt
they have encoder feedback.
setup the micromaster for vector control with sensor (parameter 1300)

when we give order to drive in 5hz
and we take a look in siemens STARTER
we can see that that setspeed is 5hz but actual speed is 4.85 on one VFD and 5.2 on the other one.

Shouldn't the encoder see that one is driving to slow and then speed up little and the other way for the other one, any ides to solve this?
Thanks,

Micromaster Manual

 

[Nick B]

How are you making the speed setpoint? Analog, Multispeed, Profibus, USS or Keypad etc?

It may just be analog error? When you put the drive in V/Hz or FCC do you still get this error?

Nick

 

[ason]

Hi Nick, we use profibus, thanks for the tip!
Im on the way to work now
i will trying that out

 

[JERA]

Hi

The drives has to be set up as “Vector control with speed encoder (VC)”. Look in this manual:
http://support.automation.siemens.com/WW/view/en/24294529
( Page 247 - 3.23.2.2 )

If the 2 motors are feeding the same metal belt, you have to have one as "master" and the other as "slave".
The setpoint is only send to the "master" and the feedback from the drive is used as setpoint to the slave. In this way you will have a better feed of the belt.
If you are giving the 2 drives setpoint from Profibus they will run as individuals and not as a “team”.

 

[ason]

Jera, We need a slack between the roller and adjusting the hight with a ultrasonic sensor,
one roller sets speed and the other one control the hight on the belt.

here i have a problem
From parameter list, page 153:
http://support.automation.siemens.c...lib.csinfo&lang=en&objid=23708204&caller=view

and from Siemens STARTER when i setup the VFD for
V/f with linear characteristic

How do i adjust that so it´s equal?

 

[ason]

When i activate Vector control with speed encoder
and setpoint to 5 hz,
R0061 is oscillate between 4.85 to 5.2
can i get it better with a VFD
or do need a servodrive?

 

[Nick B]

Have you done a Vector Tune?


Nick

 

[ason]

Is this vector tune?
If so i have done that..

 

[randomx]

Hi all,

i have another question regarding MM440 and encoder module:

Is it possible to use MM440+encoder module+encoder for speed setpoint and not only for loopback reference?
Here is my application problem:
There is existing conveyor belt run by motor which is controlled independently.

I would like to have secondary conveyor belt and its speed should be synchronized with existing conveyor. This conveyor belt is to be controlled with MM440+encode module.
Is it possible to mount encoder on EXISTING conveyor belt in order to provide speed(frequency )reference for secondary conveyor belt?