Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Vector control correct setting

Status
Not open for further replies.

HanyHamed

Electrical
Jul 20, 2005
27
0
0
AE
How can i know that the vector drive is correctly setted and tuned? suppose i don't trust the auto-tuning and automatic parameters identification?
 
Replies continue below

Recommended for you

Drivemaster,

Well, if your drive product came with trending software, you can trend various values to determine response times, etc. It all depends on how accurate you want the vector drive to be and when it runs within your personal specifications, then i am sure it is tuned well enough.
There really ain't any fast and set rules here.
If you don't trsut the auto tiuning of the drive, then you will have to obtain from the motor manufacturer the exact motor parameters for your motor and manually program those values into the drive.
These values are for the motor only and do not take into account cable lengths, resistance, reactors, dv/dT filters etc and some performance might be lost and still manual tuning might be required.
 
Maybe you can indicate to us all why you are thinking that your specific installation is not functioning correctly and why you do not believe that the vector auto tuning is not functioning. Maybe it is something totally different than what you think. Please provide us with more details and I am sure we might be able to help you out.
 
Autotuning is almost always quite conservative to avoid hunting and oscillation problems.

If you want to optimize your loop performance, you might try manually tuning it.

Drive speed loop tuning usually tunes manually quite easily. One caution--be sure the accel/decel settings are outside the PID loop. If inside, you need to set them both to zero to avoid having them override the loop response.
 
thank you all for your answers, i suspect that orientation is not correctly achieved because after loading the motor the current producing flux component Id changes. also Iq componet is changed with load non-linearly. is it right?
 
Both shall change with load in a vector drive. It is only in a scalar drive that Id is (relatively) constant with load. It is not usual that the autotuning goes wrong. Not with reputable manufacturer's drives.

Read all parameters (the L:s and R:s) and compare with what is found when you autotune again. Make sure that the motor shaft doesn't move when taking the motor parameters. But remember that it shall be free to move (with load) when speed controller gain and integration time is tuned.

Compare what you get. If both sets are reasonably close (+/-10 percent), then you are all set.

If very unequal, try to use the newly acquired set of parameters.

But, as I said, Id and Iq changing with load is not a fault in a vector drive.

Gunnar Englund
 
thank you for yur answer but please verify what you said about the flux component, i think it should not change because its reference is constant....
kindly waiting for your comment
 
Status
Not open for further replies.
Back
Top