Jan 29, 2020
11:51 PM
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Jan 29, 2020
11:51 PM
Hello,
I'm trying to brake a BLCD Motor.
I set the 3 Bridge Low Side Drivers to State ON to get a short-circuit between the coil's.
In any combination I tried this, allways any Over-current Status occurred.
How can I fix this Problem!?
Best regards
Eto
I'm trying to brake a BLCD Motor.
I set the 3 Bridge Low Side Drivers to State ON to get a short-circuit between the coil's.
In any combination I tried this, allways any Over-current Status occurred.
How can I fix this Problem!?
Best regards
Eto
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6 Replies
Feb 03, 2020
05:00 AM
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Feb 03, 2020
05:00 AM
Hello Eto,
In general, when a motor brakes it means that the mechanical energy stored in the system, so called inertia, must be dissipated somehow.
When using dynamic braking with Low Side Fets, as you are doing, this inertia is reconverted in electrical energy. This means that currents will flow in the phases of the BLDC motor and as a consequence in the low side mosfets of your 3 bridge.
These currents can be particularly high depending on the speed at which your motor is running before breaking. I would suggest you to read this article for a pretty good understanding of a BLDC (actually PMSM, but the only difference is the shape of the BEMF voltage) motor physics: http://www.mdpi.com/1424-8220/13/3/3831/pdf.
Back to your problem, as the high currents are a consequence of the physics of the system, you cannot avoid them. Also consider that these currents will flow through the motor coils and your mosfets, dissipating as heat.
If you are aware of these effects and still want to proceed with your braking scheme, then I would suggest to change the threshold of the over-current detectors implemented in the BDRV of the TLE9878.
Referring to the User Manual:
https://www.infineon.com/dgdl/Infineon-TLE9879QXA40-UM-v01_04-EN.pdf?fileId=5546d4624e24005f014e52ca...
you can find the section "On-Diagnosis" at page 867. You need to change the value of the VDS threshold in the register CTRL3.DSMONVTH according to the RDSon of the Low side mosfets, as explained in the example.
In general, when a motor brakes it means that the mechanical energy stored in the system, so called inertia, must be dissipated somehow.
When using dynamic braking with Low Side Fets, as you are doing, this inertia is reconverted in electrical energy. This means that currents will flow in the phases of the BLDC motor and as a consequence in the low side mosfets of your 3 bridge.
These currents can be particularly high depending on the speed at which your motor is running before breaking. I would suggest you to read this article for a pretty good understanding of a BLDC (actually PMSM, but the only difference is the shape of the BEMF voltage) motor physics: http://www.mdpi.com/1424-8220/13/3/3831/pdf.
Back to your problem, as the high currents are a consequence of the physics of the system, you cannot avoid them. Also consider that these currents will flow through the motor coils and your mosfets, dissipating as heat.
If you are aware of these effects and still want to proceed with your braking scheme, then I would suggest to change the threshold of the over-current detectors implemented in the BDRV of the TLE9878.
Referring to the User Manual:
https://www.infineon.com/dgdl/Infineon-TLE9879QXA40-UM-v01_04-EN.pdf?fileId=5546d4624e24005f014e52ca...
you can find the section "On-Diagnosis" at page 867. You need to change the value of the VDS threshold in the register CTRL3.DSMONVTH according to the RDSon of the Low side mosfets, as explained in the example.
Feb 03, 2020
09:22 PM
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Feb 03, 2020
09:22 PM
Hello Elettrograffiti,
thank you for your answer.
thank you for your answer.
Oct 01, 2020
03:35 PM
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Oct 01, 2020
03:35 PM
Elettrograffiti wrote:
Hello Eto,
In general, when a motor brakes it means that the mechanical energy stored in the system, so called inertia, must be dissipated somehow.
When using dynamic braking with Low Side Fets, as you are doing, this inertia is reconverted in electrical energy. This means that currents will flow in the phases of the BLDC motor and as a consequence in the low side mosfets of your 3 bridge.
These currents can be particularly high depending on the speed at which your motor is running before breaking. I would suggest you to read this article for a pretty good understanding of a BLDC (actually PMSM, but the only difference is the shape of the BEMF voltage) motor physics: http://www.mdpi.com/1424-8220/13/3/3831/pdf.
Back to your problem, as the high currents are a consequence of the physics of the system, you cannot avoid them. Also consider that these currents will flow through the motor coils and your mosfets, dissipating as heat.
If you are aware of these effects and still want to proceed with your braking scheme, then I would suggest to change the threshold of the over-current detectors implemented in the BDRV of the TLE9878.
Referring to the User Manual:
https://www.infineon.com/dgdl/Infineon-TLE9879QXA40-UM-v01_04-EN.pdf?fileId=5546d4624e24005f014e52ca...
you can find the section "On-Diagnosis" at page 867. You need to change the value of the VDS threshold in the register CTRL3.DSMONVTH according to the RDSon of the Low side mosfets, as explained in the example.
Hello Elettrograffiti,
Im also trying to turn on one low mosfet but there are always overcurrent protections. Is there a function that disables these protections?
Best regards,
John
Nov 22, 2020
05:57 PM
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Nov 22, 2020
05:57 PM
Hi,
First,you shoud set the 3 Bridge Low Side Drivers to State PWM,then set the MCMOUT rigister to active the 3 Bridge Low Side Drivers.This method will avoid overcurrent protection.The operation of MCMOUT register,you can refer to the HALL commutaion table.
First,you shoud set the 3 Bridge Low Side Drivers to State PWM,then set the MCMOUT rigister to active the 3 Bridge Low Side Drivers.This method will avoid overcurrent protection.The operation of MCMOUT register,you can refer to the HALL commutaion table.
Jun 09, 2022
03:23 AM
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Jun 09, 2022
03:23 AM
We are working with TLE9879 Arduino shield to test our application while we are designing the electronic PCB of our product.
We need in our application mantain the BLDC motor energized in an static position, that is keep the motor braked.
I understand that this action is not implemented in Arduino library, it requires program TLE9879 ic.
Do you propose a specific action? Enable the corresponding motor phase by PWM control?
Dec 21, 2022
09:53 PM
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Dec 21, 2022
09:53 PM
Hello @ansede
In the following thread, we have already resolved your issue.
https://community.infineon.com/t5/MOTIX-MCU/TLE9879-static-braking-BLDC-Motor/td-p/356294.
Thank you for posting on Infineon community.
Regards
RupakC