TMS320F28069 query

Srijan Ashok said:

He just wanted to understand what will be the percentage of CPU utilization if the motor is run at full 60000rpm

That depends on the control solution, the estimator type, and the rates for current / estimation / and velocity loops.

And some of those rates will be effected by simple control theory based on the maximum speed of the motor.  @ 60 KRPM, assuming this is 2 poles, that is a 1 KHz max speed, which is reasonable.  It means your current controller will need to run at least 8 KHz (faster is better).

If this is a low dynamics application you could use something like InstaSPIN-BLDC....but InstaSPIN-FOC is actually more flexible and much higher capability...and you could still potentially use as little as 20 MIPS for the motor control portion of this application.  If you increase frequency of control / estimation you could use as much as 50 MIPS.

This is a 4 kHz motor....it will be massively difficult to run advanced control algorithms effectively. you simply don't have enough MIPS. This motor will also have essentially no inductance, so current sampling and control techniques will be ineffective. 

You will probably need to run a BLDC type of control scheme, and run it very fast...like 90 KHZ PWM with 45 KHZ commutation update rates. It's possible you could do this on a 90 MHZ F2806x....if there isn't a price concern I'd look at a 200 MHZ processor like F28377. 

It sounds like they have some capability though and just need a faster processor, correct?

Thanks for the revert!! So should i go ahead with F28069 (will it suffice?) or should F28337 be better suited. Cost might be a concern.

Thanks,

Srijan

They can start with F2806x or F28377D (which has some roadmap versions that I believe they would be most interested in using. )