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AN2388

Software design

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4.6.2

The (

α,β)-> (d,q) projection (Park transformation)

In the following code the constant and variables under consideration are implemented in

1.15 format. The quantity Teta_cm represents the rotor flux position calculated by the

current model.

************************************************************************************

**************************Park Transformation

(alfa, beta) ->(d,q)

iSd = iSalfa*Cos_Teta_cm+iSbeta*Sin_Teta_cm.....*

iSq = -iSalfa*Sin_Teta_cm+iSbeta*Cos_Teta_cm

void Park(void)

{

mul_q15_q15_q31(qIalfa,Cos_Teta_cm,&qId_tmp_1);

mul_q15_q15_q31(qIbeta,Sin_Teta_cm,&qId_tmp_2);

qId_1 = (short)(qId_tmp_1>>16);// Q1.31 ->Q1.15 conversion

qId_2 = (short)(qId_tmp_2>>16);// Q1.31 ->Q1.15 conversion

qId = (qId_1+qId_2);//Id component in Q1.15 format

mul_q15_q15_q31(qIalfa,Sin_Teta_cm,&qIq_tmp_1); //Sin_Teta_cm is the tabled

value Sin_Cos_Table[Sin_Index]

mul_q15_q15_q31(qIbeta,Cos_Teta_cm,&qIq_tmp_2);//Cos_Teta_cm is the

tabled value Sin_Cos_Table[Sin_Index+64]

qIq_1 = (short) (qIq_tmp_1>>16);// Q1.31 ->Q1.15 conversion

qIq_2 = (short) (qIq_tmp_2>>16);// Q1.31 ->Q1.15 conversion

qIq = (-qIq_1)+(qIq_2);//Iq component in Q1.15 Format

}

SinTeta_cm and cosTeta_cm indicate respectively the Teta_cm sine and cosine values.

The modalities required to determine these values are explained later in this document.

4.6.3

The Current model implementation (rotor flux estimator)

This chapter represents the core module of the Field Oriented Control (FOC).

This module takes as input id, iq plus the rotor electrical speed. In addition to the essential

equations, the numerical considerations, code is also be shown.

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