TMS320F28075: TMS320F28075 pwm module svgendq

serhii chekanov

Intellectual 640 points

Part Number: TMS320F28075

Good day, TI!

Could you halp me with generating svgendq_calc without 3rd harmonic?

May be someone complite this task, And have sinosoidal phase voltage

over 6 years ago

0 Ramesh Ramamoorthy over 6 years ago

TI__Mastermind 27240 points

If you don't need third harmonic and need only fundamental sinusoid, then use classical inverse Clarke transform that converts two phase alpha-beta to three phase a,b,c. You can review the equations in text books. Math style will be similar to inverse park though not exact.

0 serhii chekanov over 6 years ago in reply to Ramesh Ramamoorthy

Intellectual 640 points

But i have simple inverse Clarke without 3rd harmonic in my SVGEN_calc. That is strange, how can i have 3rd harmonic in standat inverse Clarc.

// Inverse clarke transformation
Va = v->Ubeta;
Vb = _IQmpy(_IQ(-0.5),v->Ubeta) + _IQmpy(_IQ(0.8660254),v->Ualpha); // 0.8660254 = sqrt(3)/2
Vc = _IQmpy(_IQ(-0.5),v->Ubeta) - _IQmpy(_IQ(0.8660254),v->Ualpha); // 0.8660254 = sqrt(3)/2

0 Ramesh Ramamoorthy over 6 years ago in reply to serhii chekanov

TI__Mastermind 27240 points

This is not inverse Clarke. What you showed are intermediate variables used in SVGEN.

0 serhii chekanov over 6 years ago in reply to Ramesh Ramamoorthy

Intellectual 640 points

Could you please say, i can see 3rd harmonic in grafick alpha betta and DQ?

Because I checked all steps before svgen calc and didn't see 3rd harmonic in park Clark transformation. Only after svgen.

0 Ramesh Ramamoorthy over 6 years ago in reply to serhii chekanov

TI__Mastermind 27240 points

That is what I am also saying, 3rd harmonic is introduced if you use SVGEN. If you did not want 3rd harmonic, use inverse CLARKE instead. It will convert 2 phase sinusoid into 3 phase sinusoid without 3rd harmonic.

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TMS320F28075: TMS320F28075 pwm module svgendq