TMS320F28069: Is it possible change ADC paring mode to work at ADCINA0 & ADCINB1

Hi,

An expert should reply shortly.

Regards,
sal

Hi, tlee

We use the TMS320F28069 in the PMSM motor contrl, now we have problem on the ADC sampling. We know that three phase current in the PMSM stator windings are sinusoidal. We wish to sample ABC currents according their magnitude. From your experience, how to sample the ABC current will have good current control precision? Is it sample the fixed two phase currents when motor rotor in six sectors? Or can we sample the AB , BC and AC currents in order according the motor rotor in which sector in the TMS320F28069 DSP?

user4079194,

I have notified the motor control experts about your question. Is this related to the original question posed by Daniel?

-Tommy

tlee,
Thanks for your reply. Yes, they are related.

You could sample the three phase currents in the same time in most cases if the h/w board has three-phase current sampling feedback signal. The delay between these three currents could be neglected since the converter speed of ADC module is fast enough for most motor drives and there is an RC filter on the current sampling signal.
Or you could sample the A&B, B&C, and A&C currents in order according the sector of SVPWM as you mentioned if you need to achieve much higher response performance on motor drive, but you need to use more ADC channels to implement it, like phase A to ADCA0 and ADCB1, phase B to ADCB0 and ADCA2, phase C to ADCA1 and ADCB2, and then you can sample phase A and B simultaneously by ADCA0 and ADCB0, sample phase B and C by ADCA2 and ADCB2.

Yanming Luo:

Can I change the SOC0/SOC1  from simultaneous sampling mode to single sampling mode after finishing the last conversion of SOC0/SOC1 before the next trigger?

Thanks your time!

 

Yanming Luo:

I use TMS320F28069 for motor control.There is a strange question when using IQmath for calculate. I wrote a very simple function as _IQdiv(50,4250), but the result was 581117743. I verified the IQmathlib for many times. Can you give me some advices? The lib's configuration is in the previous reply.

Yanming Luo:

I use TMS320F28069 for motor control.There is a strange question when using IQmath for calculate. I wrote a very simple function as _IQdiv(50,4250), but the result was 581117743. I verified the IQmathlib for many times. Can you give me some advices? The lib's configuration as follows.