Hello,

Our product speed range is between 3-60 hz. We have problems in low frequencies (under 4hz motor is working intermittently). Our Drive is Siemens Simovert Masterdrive VC. Drive working mode is P100= 4 (Vector control with tachometer (n-speed) with pulse encoder).

Is there a way to solve this problem with changing parameters?

Note: when we increase parameter P235=4, P236=4 to P235=10, P236=10 it is good at low speed, But now motor is working intermittently at HIGH speed!?

 

Dear Suleyman,

Did this problem begin after a certain time or is it going on from the start-up?

For the first case I will recommend you to check the connection of the pulse encoder (shielding, broken wire, mechanical coupling problem, etc).

For the second case there may be a thousand reasons, difficult to say from here.

 

Hello,

If it was a bad encoder the drive would fault out. Sounds to me like a tuning issue. Your drive needs to be tuned properly to your mechanical system. Since I don't know your system I recommend performing P115=2, P115=4, and P115=5, in that order. I would make a backup of the parameter set in the drive first! The P115=4 is an autotune of the speed loop. After the autotune is done, you will probably still get poor performance at low speed, raise the gain by about %25, you might have to play with it a little.

If tuning is not your thing, then you can cheat by changing the effective gain based on the speed setpoint using data sets or free blocks.

Good Luck,

FRD

 

Thanks for your replies,

I have solved the problem with gain adaption
according to the speed.
P235 = 10
P236 = 4
P233 = 0
P234 = 100
P232 = 148 (frequency actual value)