simoreg 6ra24 drive

[juad]

hi
i need help to finish my start up for simoreg drive 6ra24 1200 amp
we use it for 450 kw motor for cement factory. i face many problems
1-no one of optimization run so i insert it manually.
2- when it is start with zero set point i get output flacuate (-1 to 1 volt) .
3- when the motor is not loaded i can rotate it to max speed but it did not stop when reference is zero(very slow speed) when the motor is loaded it can not rotate even i reache 700 amp take in mind no mechanical problems as motor rotate on other drive.
thanks.

 

[L D[AR2P#0.0]]

What is the armature voltage when you run the motor at full (rated)speed unloaded ? Are you sure you have the field controller set correctly ?

 

[juad]

hi
the arm voltage about 250 volt, the field voltage is 220 volt with 20 amp.

 

[juad]

hi

the arm voltage about 300 volt the field voltage is 220 volt with 20 amp.
thanks

 

[DickDV]

Can you give us the motor nameplate data and the maximum speed you intend to operate at, please.

 

[juad]

thak you
the dc motor is
410 KW
ARM: 400 V 900 AMP
FIELD: 220 V 30 AMP
R.P.M: 1100

 

[DickDV]

Are you planning to run the motor over 1100rpm? If you are, then you will need an active field regulator to do field weakening which complicates things a bit.

 

[L D[AR2P#0.0]]

It appears from the data posted that the field is weakened as the field current is only 20A compared to 30A nameplate. The motor is achieving max speed with only 250-300 volts applied which again points to the field being weak (and hence the torque is reduced).

Also, what is the "other drive" being referred to here ?

 

[DickDV]

LD, I see the data you mention but it may be an indication of where juan's problem lies.

I need to know from him whether he intends to run overspeed or not so I can advise him properly on setting up the motor's field.

juan states that he is short of torque and also states that he is at 20 field amps rather than 30. There just might be a connection!

 

[juad]

thanks to all

what i want to clear is that the motor did not stop even i giveit
zero volt refrence and zero min speed, so when the motor is unloaded it run at very low speed but when i connect the motor to the load also it did not stopped and the current increase slowey
and the out dc voltage not stabel it go up and down ,it is look like high gain ,i think it must arrange the IR COMPENSTATION to acchive stoping motor at zero refrence as i did it in analoge drives if any one can help me which parametrs arrage IR COMPENSAT. also why the current is increased and not stabel,any reasons that optimazion is not run.
I WANT TO RUN THE MOTOR TILL 1000 RPM,FOR FIELD CURRENT I JUST CHECK WITH 20 AMP WITH ZERO REF SO THE MOTOR MUST BE STOPPED AND NO NEED FOR HIGH TORQE IN ZERO REFRECE NEXST DAY I TRY WITH 30 AMP ALSO SAME RESULTS.
THANKS

 

[DickDV]

I would suggest running this motor at a fixed 30 amp field current in view of the fact that you are only going up to 1000 rpm.

It appears from your last post that when you command zero speed on the drive speed input, the drive output voltage does not go to zero and the rotor keeps turning, even with a load on the shaft.

Does this motor have a tachometer for feedback or are you using armature feedback? That would be the case if there is no tach or encoder.

If no tach, the speed loop tuning will not matter. However, the current loop tuning should be done per the drive manual instructions. Check the drive speed input for noise or, better yet, short the speed reference input to its negative reference (control ground). Is there output voltage when this short is in place? Remove the drive run signal from the drive input. Does the output voltage go away or is it still there? If you have drive output voltage with the run signal removed, the drive is defective and DANGEROUS. Take it out of service immediately. Some DC drives have an adjustable output voltage offset available in the software. Be sure this is set to zero. Check to see if the speed reference input has some negative voltage offset set in the software. Or maybe the speed input is bipolar (positive voltage runs forward and negative voltage runs backward). These are very hard to set at exactly zero. If you don't need reversing, change the speed input signal to unipolar which is 0-10vdc typically.

Let us know some answers to the above and we will continue to try to help.

 

[juad]

thanks
1-the motor with tacho
2- i use uni polar ref
3- when i connect ref to zero(no pot) also i get output dc voltage
4- even i give zero volt from pot or direct the drive give output about+1 to -1 volt and the motor rotate at very slow speed
5-if no enabel give to the drive the motor stop
6-when i increase the ref the ouput voltage increase the current is not stabel when i check 8 volt at out of drive the amp about 900 amp
7-the drive is not brandnew .

 

[DickDV]

I understand you to say that the motor has a tach which feeds shaft speed back to the drive. That would make the system a closed-loop speed regulator with P, I, and D gains in the software somewhere.

If easily available in the software, change the drive speed controller to armature feedback. That takes the tach and loop tuning out of the system. Then short the speed reference to zero and check for drive output voltage again.

An output of 1VDC on a 400V armature hardly seems like a problem but, if I understand you correctly, the current rises to 900amps at 8VDC. I'm not sure you can get below 1VDC on leaky old SCR's. You may need to remove the Run signal when you are commanding zero speed.