TIDM-1000: VIENNA_readCurrVolADCSignals()

Jeongsoo Yoo

Part Number: TIDM-1000

Hello,

I have a question on the Design Guide TIDM-1000 of Vienna Rectifier-Based, Three-Phase Power Factor Correction (PFC) Reference Design Using C2000 MCU.

Specifically it is on the firmware of pfc3phvienna_F2837x.

With respect to the function of VIENNA_readCurrVolADCSignals() in the file of vienna.h, the variable of VIENNA_iL1Meas_pu is calculated as follows:

VIENNA_iL1Meas_pu = (((float32_t)(VIENNA_IL1_FB_1 + VIENNA_IL1_FB_2 +VIENNA_IL1_FB_3 + VIENNA_IL1_FB_4)) *VIENNA_ADC_PU_SCALE_FACTOR * 0.25f - VIENNA_iL1MeasOffset_pu ) * 2.0f;

I cannot figure out why 2.0 is multiplied at the end.

It is the same story for the other measured current and voltage variables such as VIENNA_iL2Meas_pu, VIENNA_iL3Meas_pu, VIENNA_v1Meas_pu, VIENNA_v2Meas_pu, and VIENNA_v3Meas_pu.

Thank you for your advice.

With regards,

JS Yoo

over 3 years ago

0 Chen Jiang ti over 3 years ago

TI__Genius 15935 points

Hi JS Yoo,

When reading AC values, if you subtract 0.5 from a reading that is 0-1, then you get -0.5 to 0.5 range, the multiplier below brings that back to -1 to 1 pu value

Regards,

Chen

+1 Jeongsoo Yoo over 3 years ago in reply to Chen Jiang ti

Expert 1025 points

Hi Chen,

Thank you for your review.

What do you mean by "subtracting 0.5"?

Do you mean that the value of VIENNA_iL1MeasOffset_pu is around 0.5?

Thank you for your advice.

With regards,

JS Yoo

0 Jeongsoo Yoo over 3 years ago in reply to Jeongsoo Yoo

Expert 1025 points

Hi Chen,

I understood that the value of VIENNA_iL1MeasOffset_pu should be around 0.5.

Please let me close this case.

Thank you for your advice.

With regards,

JS Yoo

C2000™︎ microcontrollers

C2000 microcontrollers forum

TIDM-1000: VIENNA_readCurrVolADCSignals()