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Low Inductance BLDC Motor Current Signal

VinsmokeSanji
Associate III

Hello There,

I am currently work on 6 - Step (Trapezoidal) Control and have developed my software with Nucleo - F302R8. I have a low inductance(23uH) bldc motor. When I've tested this motor with my software, current signal doesn't look right. Also, we have tested bldc motor with another motor driver and signal is same.

What can be the reason of this signal?

Yellow -> Dc_Bus - Phase

Purple -> Phase Current

PWM at 50% duty cycle0693W00000NsgAcQAJ.png 

PWM at 100% duty cycle

0693W00000NsbHZQAZ.png

1 ACCEPTED SOLUTION

Accepted Solutions
VinsmokeSanji
Associate III

Hello @Cristiana SCARAMEL​ ,

The problem was about a motor's itself. We have tested the motor with another driver and signals looked same.

Are you using a custom board and/or custom firmware?

We are using custom board and custom firmware with STM32G431.

Is the 6-step control sensored or sensorless?

It is sensored 6-step control.

Have you checked the waveforms of current and voltages of each motor phase?

Yes, we have checked all motor phases voltage and current signals. And, all signals are same.

Thank you for your answer.

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2 REPLIES 2
Cristiana SCARAMEL
ST Employee

Hello @Yasin Türk​,

from the waveforms there seems to be a problem of loss of motor synchronism.

Could you share more details on your application?

Are you using a custom board and/or custom firmware?

Is the 6-step control sensored or sensorless?

Have you checked the waveforms of current and voltages of each motor phase?

VinsmokeSanji
Associate III

Hello @Cristiana SCARAMEL​ ,

The problem was about a motor's itself. We have tested the motor with another driver and signals looked same.

Are you using a custom board and/or custom firmware?

We are using custom board and custom firmware with STM32G431.

Is the 6-step control sensored or sensorless?

It is sensored 6-step control.

Have you checked the waveforms of current and voltages of each motor phase?

Yes, we have checked all motor phases voltage and current signals. And, all signals are same.

Thank you for your answer.