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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hello,

We are developing a gate controller using Infineon Motor Control IC, we have a custom board that uses IM564-X6D and IMC102T-F064. 

The register MotorCurrent is not giving the current in RMS,in our custom board.

When i tested in the eval board it was giving the RMS current.

How can i solve this problem?

 

Attached is the MCEWizard Configuration.

 

Best Regards,

 

Paulo

 

13 Replies
Krupashankar
Moderator
Moderator
Moderator
500 replies posted 50 likes received 25 likes received

Hi @PaulojM,

Thanks for posting your question on this forum.
Experts in this product will check your points and then update you. we kindly expect a delay in response in this term due to the annual shutdown.

Thanks for understanding.

Best Regards,

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alex-d
Level 1
Level 1
10 sign-ins 5 sign-ins First like given

Hello!

I believe I can help, but I could use some clarification.

When you say that the register MotorCurrent was not giving the correct units, were you hoping to view this register in MCEDesigner?

alexd_0-1703877931717.png

If you were hoping to view the register as a live trace in MCEDesigner but the trace is not showing the correct units, you can enable a setting in MCEDesigner that allows you to change the trace unit.

In MCEDesigner, Go to Preferences --> Tuning Value Format --> Data Scaling Unit assignment --> check the "UNLOCK" option.

Now, when you go to set up a trace, you may edit the units within these dropdown boxes:

alexd_1-1703878097027.png

If you were looking to view this register in the Register Structure Definitions section of MCEDesigner, click on the register.

alexd_3-1703878640053.png

alexd_2-1703878558772.png

Here you should be given both the count value (the raw ADC), the scaling for converting the Count value to the real value, and the Real Value itself.

If there is only a count unit and no A rms, then it is likely that MCEDesigner doesn't know to scale the counts to A rms. In this case the question becomes more of how to convert the raw ADC counts for that register back to the voltage going into your current sensor, and back into the actual current of the motor. I'm not sure if there's a way to add your own custom scaling to MCEDesigner or not.

I hope this helps.

 

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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hi @alex-d,

Thanks for your answer.

Sorry for not specifying before, but the problem is not exactly the scalling, and it is not only happening on MCEDesigner.

The issue in question is that the register itself, has a sinusoidal wave like some of the others register that carry current values.

For demostration, in MCEDesigner when i select a trace for Motor Current, with correct scaling, the current i see in the trace is sinusoidal. The same happen when i read the register from UART.

PaulojM_1-1704186198805.png

PaulojM_0-1704185969388.png

In the following screenshots i compared Motor current and IU. The IU value seems to be ok.

PaulojM_4-1704186385098.png

PaulojM_2-1704186255865.png

Since the Motor Current Register gets the value from this calcule:

PaulojM_6-1704186842918.png

I also saw registers IdFilt and IqFilt, and their value, which should also be in RMS, and they are sinusoidal.

PaulojM_7-1704187211292.png

PaulojM_5-1704186652173.png

Since this happens in Id and Iq, it, the cause should be how those registers are obtained. I don't know if its from an internal calculation or external measurement.

 

Best Regards,

Paulo 

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RupakC
Moderator
Moderator
Moderator
100 solutions authored 250 sign-ins 25 likes received

Hi @PaulojM 

Since the issue is not faced on the eval board, therefore we suspect issues with the custom board design. 

Please share the current sensing circuit (schematic) of the custom board.

Regards

RupakC
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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hi @RupakC,

Thank you for answering.

If you could please check out the other answer i would apreciate it.

Since the Iu is giving the correct value and that is whats connected to the external circuit, i am not sure if that is the problem.

PaulojM_8-1704188208584.png

I went and tried to see the value in Ipeak, since that is needed to obtain Iq and Id, and the value was always 0

PaulojM_12-1704188823147.png

PaulojM_11-1704188809675.png

If you still need the schematic of the current sensing circuit, i will send it later.

 

Best Regards,

Paulo

 

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RupakC
Moderator
Moderator
Moderator
100 solutions authored 250 sign-ins 25 likes received

Hello @PaulojM 

Could you kindly explain in detail, the difference in your observations while using the Custom board and the Evaluation board ? we would like to understand what is your observations on the evaluation board and how are the observations different on the custom board. 

Regards

RupakC
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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hello @RupakC,

The project is to control diferent power inductions motors with the same board.

I tested diferent motors and the MotorCurrent register was allways giving RMS current.

Using the evaluating board with a 750W induction motor i was getting results like the following one:

PaulojM_1-1704278841887.png

Now i am testing the custom board, with a 200W induction motor, just to see if its working OK, the results i get are this ones:

PaulojM_2-1704279522530.png

The custom board is mostly a copy from the eval board, and the configuration i did in the MCEWizard is basicaly the same, just changing the parameters that difer between motors.

The motor also seems to be running good, so the only thing that i dont see giving the result i expected is this. The current should be an RMS value, but something is not working correctly.

 

Best Regards,

Paulo

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RupakC
Moderator
Moderator
Moderator
100 solutions authored 250 sign-ins 25 likes received

Hello @PaulojM 

Before moving into the problem, I see that you are trying to drive an induction motor with the imotion products. Can you kindly confirm if you have followed the document in the link below: 

https://www.infineon.com/dgdl/Infineon-Induction_motor_control_by_iMOTION-ApplicationNotes-v01_00-EN...

Regards

RupakC
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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hi @RupakC ,

Yes, i followed that document. The motor runs as expected, both directions.

Best Regards,

Paulo

 

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RupakC
Moderator
Moderator
Moderator
100 solutions authored 250 sign-ins 25 likes received

Hello @PaulojM 

The control for the induction motor is open loop V/F control. For this type of control, you may ignore the current waveforms shown in the designer tool as long as the motor runs properly. Instead, you may check the motor phase currents in DSO and see if they are satisfactory. 

Regards

RupakC
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PaulojM
Level 3
Level 3
25 replies posted 100 sign-ins First like received

Hi @RupakC,

Thank you for the answer.

I don't want to use that register to know if the motor runs properly.

My intentions were to use the MotorCurrent register to create a safety measure in the script.

Since the MotorCurrent should already be in RMS, it would save me the  work from doing something to find the peak current from one of the current register (Iu/Iv/Iw) and calculate the RMS current.

Best Regards,

Paulo

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Hi @RupakC,

After some more testing, i noticed more problems. In the eval board i could use the MotorLim with the 750W induction motor, and it would have an effect on the current, but now nothing happens.

I would use the MotorLim to reduce the current mostly in the aceleration. 

The Iu and Iv are in phase, is that normal?

PaulojM_0-1704819602691.png

And Iu/Iv are 180º delayed from Iw.

PaulojM_1-1704819800160.png

Can it be caused by some parameter in the MCEWizard configuration? Or is caused by the current sensing circuit?

If you think the cause could be the MCEWizard configuration i would apreciate if you could check the MCEWizard configuration file attached.

Best Regards,

Paulo

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RupakC
Moderator
Moderator
Moderator
100 solutions authored 250 sign-ins 25 likes received
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