TLE9879 active braking a BLDC Motor

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User18173
Level 1
Level 1
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
0 Likes
6 Replies
Elettrograffiti
Employee
Employee
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.
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User18173
Level 1
Level 1
Hello Elettrograffiti,

thank you for your answer.
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User20268
Level 1
Level 1
First like received
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
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User17952
Level 3
Level 3
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.
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ansede
Level 2
Level 2
First like given 10 replies posted First like received

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?

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

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