DRV10970: Question about sensorless BLDC

Eric Li

Part Number: DRV10970
Other Parts Discussed in Thread: MCF8329A, MCF8315C

Tool/software:

Hi,

I have a question about sensorless BLDC.

In addition to BEMF, it seems that magnetic linkage can also be used to estimate the rotor position, and do we have products that use the magnetic linkage method? Why we mainly use BEMF for our products?

Magnetic linkage seems mainly be used in FOC control. As the formula show, Ψsα and Ψsβ are the magnetic linkage of stator, Ψfα and Ψfβ are the magnetic linkage of rotor. This method can estimate the rotor position by calculating Ψfα and Ψfβ. Have you ever heard it before? I know it by accident and want to know the application of it.

Regard,

Eric Li

1 month ago

0 Venkatadri Shantaram84961 1 month ago

TI__Expert 7470 points

Hi Eric,

Yes, this method is FOC based. MCF8316C, MCF8315C, MCF8329A are the devices with FOC based control and they are sensor less solutions.

Phase current is measured, BEMF , rotor orientation is extracted and 90 degree field is generated.

Thanks and Best Regards

Venkatadri S

0 Eric Li 1 month ago in reply to Venkatadri Shantaram84961

TI__Prodigy 100 points

Hi Venkatadri

I know the BEMF method as you say "Phase current is measured, BEMF, rotor orientation is extracted and 90 degree field is generated. In fact, I want to describe another method. Anyway, it seems that the BEMF method is the only one we used in sensorless, right? So there is no need for me to pay attention to other methods.

Thank you for your help and I am looking forward to your reply.

Regard,

Eric Li

+1 Venkatadri Shantaram84961 1 month ago in reply to Eric Li

TI__Expert 7470 points

Hi Eric,

Yes, motor speed and position is estimated by measuring the BEMF.

Thanks and Best Regards

Venkatadri S

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DRV10970: Question about sensorless BLDC