open loop sinusoidal control

[Bud]

Hi, i am trying to control bldc motor sinusoidally. I completed with 6 step commutation.

I asked help in stm32 forum recent, but none helped. I have learned something in sinusoidal bldc control.

• FIrstly i implemented spwm using sine LUT (say 256 vales)
• And i spwm give good looking sine wave.
• I also generated 3 sin waves phase shifted 120 each.
• So now i have 6 spwm (3 sine 120 phase shifted & 3 sine complemented)
• Now i run the motor using this spwm (open loop sin control), the motor runs but consume more than 10amp.

I don't know where i am wrong, guys help me to solve this problem.

[Piranha · Accepted solution]

The required current (sine amplitude) should be dependent on the required torque and speed.

https://www.celeramotion.com/applimotion/support/technical-papers/sinusoidal-drive-operation-with-brushless-pm-motors/

[Bud]

THank you for your response . Ok piranha what you are saying is, running bldc motor under open loop sinusoidal configuration is accurate and will consume more current. Now i will try to synchronize the hall sensor data (RPM) with sin table. Can you give some advice for this.

[Laurent Ca...]

Dear @Bud​ 

Did the @Piranha​ 's answer help you to solve yor problem?

Best regards

Laurent Ca...

[Laurent Ca...]

Dear @Bud​ 

I guess it did, therefore I consider this thread closed.

If not, feel free to reopen it by posting an answer.

Best regards

Laurent Ca...