Simoreg DC drive 6RA7031-6DV62-0

Hi to all members and users to this forum. To start with, I have 2 units identical Simoreg DC drives in our plant and both of them have the same problem.

Simoreg DC drive 6RA7031-6DV62-0 is connected to a DC motor rated
20 HP / 15KW /1150 RPM /260V ARM. /64A ARM. /150V FIELD /2.5A FIELD

The load of the motor is a long chain conveyor maybe around 25 meters long. During normal operation, this chain conveyor is loaded with a big pipe approximately around 6 to 7 TONS maximum.

As per production requirement we need to run this conveyor at the constant speed of 10 meters/min in auto and 5 meters/min in manual mode.


My problem is that the speed of the chain conveyor both in auto and manual is erratic, it runs not in constant speed. Even the chain conveyor is with load or without load still the speed is erratic.

The motor is connected with tachco as a feedback to the drive. Tachco specs is 60V/1000Rpm.

I attached a screenshot from drivemonitor regarding the drive parameters for our reference.



My Question:

1. What parameters on the drive do I need to adjust to run the motor at the maximum torque.

I am facing this problem from the start even during commissioning stage but unfortunately this are not highlighted at that time.

If you need some additional information and clarification to help me in solving my problem please let me know.

Thank you in advance and I am waiting for a friends solution..



Best Regards,
Danpreps

When you put a tach on a DC motor and bring the speed back to the drive, you have created a closed loop which requires that you find the speed loop PID controller and set P and I gains. Sometimes the D gain is set also but not often.

If you are not familiar with tuning closed loops, you should probably find someone who will do it for you and teach you how to do it. A closed loop DC drive with factory default tuning parameters will behave just like you describe.

I almost forgot but there is the inner current loop that also needs tuning. Most modern drives have an autotune feature for this. If yours does, be sure to use it first before doing the speed loop tuning.

I noticed that P83=3. This is armature feedback mode, so your tach is doing nothing.
I dont know your system of course, but the (P225) gain looks very low.
I would run the speed tune, P51 to a 26 and issue a start command

Hi to all, I have a little knowledge regarding drives, but i will try my best sharing with you in order to solve my problem.

I attached wiring diagram for you guys to have more idea on the system. To DickDV & JRW thank you for your quick and great reply.

I have a complete manual for the drives and I will try to change P83=1 and adjust the PID gain today. I will informed you guys what will be the results.

Again thank you for the brilliant ideas you have shared.

sorry for a little bit english problem.

Best wishes,

Danpreps

Simoreg DC drive

I have tried many trialrun changing the P & I gain but results are not favorable. I change also from armature feedback to tacho but no improvement on the erratic speed problem.

I am planning to perform Speed controller optimazition or speed tune but I need some expert suggestions on how to do it correctly,

Do I need to put the expected maximum load on the conveyor prior to speed tune? Aside from parameter P051=26 is any other parameter that need to change? what are the DO's and DONT's during speed tune.

thank you and i'm waiting for friends advise.

danpreps