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LorenzoB
Level 1
Level 1
5 sign-ins First reply posted First question asked

Hi,

I’m using XMC13 to drive a brushless motor using Dave and algorithm “V/F startup to FOC” .

I able to run the motor and also it starts at high start up torque, but the transition to FOC doesn't work when the motor starts with load, motor stopping and screeching after the V/f ram up finished and threshold speed has been reached.

The motor works when it start in no load condition and the load increasing after FOC achieved

Do you have any suggestion in order to improve this issue?

Let me know

 

Best regards

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1 Solution
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

For a motor drive where the torque requirements are high, on load, the parameters are to be fine tuned or some code (example: injecting more id and/or iq whichever aids in generating more torque, or torque control immediately after switching to FOC and then shifting to the desired control on reaching the steady state condition) can be added which will provide the necessary startup current to push the motor. 

Also, it will be better to use the algorithm "V/f Startup with Transition to FOC" to ensure smooth transition to closed loop (FOC) with possible less current/starting current and max torque while keeping the stator flux perpendicular to the rotor flux in a smooth and controlled way.

Best Regards,
Sai

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @LorenzoB,

 Can you please share the file/link to the code you're running on the XMC. We'll go through that and get back to you. 

motor stopping and screeching after the V/f ram up finished and threshold speed has been reached - When is this happening exactly ?
What is the reference speed/torque being given to he motor and also, when is the transition to FOC intended (at what time, what speed and other conditions) ?

The motor works when it start in no load condition and the load increasing after FOC achieved - So V/f to FOC transition is happening without and issue when the motor is on no load ?

Best Regards,
Sai
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LorenzoB
Level 1
Level 1
5 sign-ins First reply posted First question asked

Hello,

I can't share complete code, I share the Dave generated one.

The motor must to give a start up torque at least 3.5Nm and than 4Nm in steady state condition at 450rpm.  Regarding the V/f to FOC parameters I did trials with threshold speed 100-200rpm and 10-20rpm/s of ramp up speed, but in all condition the motor starts and when the threshold speed has been reached the motor stop and the transition to FOC fails.

When I did the trial on no load condition or low starting torque < 1Nm the transition V/F to FOC is performed correctly and steady state condition has been reached. Than If the brake torque being increased to the target 4Nm, the motor work correctly.

All the trials did on a testing braking system    

 

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @LorenzoB ,

  The .zip folder shared doesn't have dave related files, only a few source files. Can you please export these files to archive and share. 

Best Regards,
Sai
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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

For a motor drive where the torque requirements are high, on load, the parameters are to be fine tuned or some code (example: injecting more id and/or iq whichever aids in generating more torque, or torque control immediately after switching to FOC and then shifting to the desired control on reaching the steady state condition) can be added which will provide the necessary startup current to push the motor. 

Also, it will be better to use the algorithm "V/f Startup with Transition to FOC" to ensure smooth transition to closed loop (FOC) with possible less current/starting current and max torque while keeping the stator flux perpendicular to the rotor flux in a smooth and controlled way.

Best Regards,
Sai
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