TMS320F28034: Some code questions about the tidm_dc_dec_buck example

liujun

Intellectual 310 points

Part Number: TMS320F28034
Other Parts Discussed in Thread: SFRA, C2000WARE

Tool/software:

Why are Dcl and SFRA used in the example?

void BUCK_setupDcl(void)
{
BUCK_DCL_RESET(&BUCK_ctrl);
BUCK_ctrl.sps = &BUCK_ctrlSps;
BUCK_ctrl.css = &BUCK_ctrlCss;

BUCK_ctrl.css->T = (float32_t)1.0f / BUCK_DRV_EPWM_SWITCHING_FREQUENCY;

BUCK_ctrl.sps->b0 = BUCK_ctrlRef.ctrlCoeff.B0;
BUCK_ctrl.sps->b1 = BUCK_ctrlRef.ctrlCoeff.B1;
BUCK_ctrl.sps->b2 = BUCK_ctrlRef.ctrlCoeff.B2;
BUCK_ctrl.sps->a1 = BUCK_ctrlRef.ctrlCoeff.A1;
BUCK_ctrl.sps->a2 = BUCK_ctrlRef.ctrlCoeff.A2;

DCL_REQUEST_UPDATE(&BUCK_ctrl);
BUCK_DCL_UPDATE(&BUCK_ctrl);
}

What are the criteria for determining the values of the 5 coefficients(BUCK_ctrlRef.ctrlCoeff.B0/B1/B2/A1/A2)?

Do you have any documents related to the calculation of coefficients B0/B1/B2/A0/A1?

Thanks

3 months ago

0 Sumit Patil1 3 months ago

TI__Expert 3810 points

Hello,

DCL stands for C2000 Digital Control Library consist of 167 controller robust software functions for compensators including direct form or PID mode. You can find more about this following link:https://www.ti.com/tool/C2000-DIGITAL-CONTROL-LIBRARY and documentation/simulink models is located in C2000Ware installation location location: C:\ti\c2000\C2000Ware_5_05_00_00\libraries\control\DCL\c28\docs

You can convert from 2 pole 2 zero frequency to these coefficient using following formula:

SFRA library is used to obtain plant and open loop bode plot using SFRA GUI so that you can import the data in Compensation Designer GUI to obtain these coefficient using plots and entering pole and zero frequency. SFRA docs and GUI are located in C2000DPSDK installation directory: C:\ti\c2000\C2000Ware_DigitalPower_SDK_5_04_00_00\libraries\sfra

You can find the detail of how to use these GUI and libraries in TIDM-DC-DC-BUCK user guide. Let us know if any issue finding any info you are looking for these libraries.

Regards,

Sumit

0 liujun 3 months ago in reply to Sumit Patil1

Intellectual 310 points

Thanks

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TMS320F28034: Some code questions about the tidm_dc_dec_buck example