Compiler/TMS320F28075: TMS320F28075

sagar,

I am unclear about the question,

1. What will be the advantage of ABC-DQ (POS & NEG) transformation with spll for phase synchronisation.

In controlSUITE we have two version of SPLL for three phase grid, one is a simple ABC-DQ0 assuming balanced grid. The second one is DDSRF PLL which uses pos and negative decomposition of ABC-DQ0 and exploits the twice omega ripple that you would see ...

Please refer to the UG, or the following application report
www.ti.com/.../sprabt4a.pdf



2. three phase spll takes instantaneous DQ values.. please refer to the UG

Hi,

Thanks for reply.
How you can synchronize phase using ABC-DQ0 technique.for unbalanced grid how to do phase synchronization ?
I am doing following way .

1. what is the difference between ABC-DQ0 and SPLL technique .
2. I have unbalance grid application. So I have to used DDSRF PLL .
3. I have 1.65 V Dc level shifted mains voltage ( Line to Line).
4. I subtract the dc Level ADC count (2047) from ADC result count of mains sense.
5. In software I am using ABC_DQ0_POS_F and ABC_DQ0_NEG_F files for ABC to DQ0 transformation
6. I assign ADC result count to ABC_DQ0 Transformation input.For Ex. vac_abc_dq0_pos.a = VmeasRY;
Similarly done for other 2 count and to negative transformation.
7. Then I called this function ABC_DQ0_POS_F_FUNC(&vac_abc_dq0_pos);
From this I will get the d and q value .
8. This d and q values I assign to spll d and q inputs .I am using SPLL_3ph_DDSRF_F files.

spll.d_p = vac_abc_dq0_pos.d;
spll.q_p = vac_abc_dq0_pos.q;
spll.d_n = vac_abc_dq0_neg.d;
spll.q_n = vac_abc_dq0_neg.q;

spll.cos_2theta=(float)cos((2)*spll.theta[0]);
spll.sin_2theta=(float)sin((2)*spll.theta[0]);

SPLL_3ph_DDSRF_F_FUNC(&spll);
9. after this I get the phase count.

pll_phase = spll.theta[0];

Is this correct way to do phase synchronization.
How to check phase is actually synchronizes with mains.

Regards,
Sagar

Hi,

www.ti.com/.../sprabt4a.pdf

I am using the same document for reference.In this document on page no.24 they have given flowchart the same way I am doing.Iam not understand how to calculate theta in ABC-DQ0 transformation and SPLL.
Regards,
Sagar Yadav