TMS320F28379D: The actual bandwidth of the dual-motor experiment cannot reach the expected bandwidth

Hi Yale,

I noticed that the feedback current value doesn't match the reference, which indicates the current controller doesn't function well. Could you try SFRA again after making sure the current regulator works?

Cheers,

Jiaxin

Hi Jiaxin,

Thanks for your reply.

The customer think that in this experiment the motor is working on speed loop, so the current value of speed loop doesn't need to match the reference. Please take a look of this.

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Thanks & Regards,

Yale

Hi Yale,

You are welcome. The reference manual SPRACO3 gives the frequency response analysis of the fast current loop by SFRA. Thus, the current loop should be closed to attain the same results with the manual. 

Thanks,

Jiaxin

Hi Jiaxin,

The customer said he did follow the experimental steps. But the results of the customer's experiment are different from the results of the manual. Please help analyze what causes.

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Thanks & Regards,

Yale

Hi Yale,

Thanks for the extra information. In Section 7.6, Page 44, the manual specifies that the incremental build level 6 studies the frequency response analysis of the current control loop. Therefore, the current loop should be ensured to work well to duplicate the results of the manual, that is, pi_id.fbk can track IdRef, and pi_iq.fbk can track IqRef, respectively. Users can verify this through incremental build level 3. Please be aware: the SFRA in the manual doesn't evaluate the frequency response of the outer speed loop. Let me know if you have any other question.

Thanks,

Jiaxin

Hi Jiaxin,

The customer tried SFRA in level3 current loop. And the bandwidth is similar with level6.

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Thanks & Regards,

Yale