Part Number: TMS320F28379D
from my understanding, ADCPPBOFFREF should be a fixed value. But I didn't understand whats the purpose of the "for loop" is for in the below code. Is it for the calibration? If it for the calibration
I have the following questions:
1. How the K1,K2 values are determined
2. How the following equation is been derived:
offset_lemV = K1*offset_lemV + K2*(IFB_LEMV)*ADC_PU_SCALE_FACTOR;
*******************************************************************************************************************************************************************
#define IFB_LEMV AdcaResultRegs.ADCRESULT1
#define IFB_LEMW AdcbResultRegs.ADCRESULT1
#define ADC_PU_SCALE_FACTOR 0.000244140625 //1/2^12
_iq K1 = _IQ(0.998), // Offset filter coefficient K1: 0.05/(T+0.05);
K2 = _IQ(0.001999); // Offset filter coefficient K2: T/(T+0.05);
offset_lemW = 0;
offset_lemV = 0;
for (OffsetCalCounter=0; OffsetCalCounter<20000; )
{
if(EPwm11Regs.ETFLG.bit.INT==1)
{
if(OffsetCalCounter>1000)
{
offset_lemV = K1*offset_lemV + K2*(IFB_LEMV)*ADC_PU_SCALE_FACTOR;
offset_lemW = K1*offset_lemW + K2*(IFB_LEMW)*ADC_PU_SCALE_FACTOR;
}
EPwm11Regs.ETCLR.bit.INT=1;
OffsetCalCounter++;
}
}
AdcaRegs.ADCPPB2OFFREF = (offset_lemV*4096.0); // setting LEM Iv offset
AdcbRegs.ADCPPB2OFFREF = (offset_lemW*4096.0); // setting LEM Iw offset
******************************************************************************************************************************************************************
I took the above code from IDDK_PM_SERVO_F2839x-v2 example file.
