Part Number: TMS320F2800157
Hi, please refer this data, module overcurrent fault is occuring in different test scenarios. could you please help us to analyse and to find root cause to resolve this issue.
Gain≈12.72 as per our circuit
Vmax =3.3v
Vsmax= Vmax/Gain=3.3/12.72 =0.2594339622641509
Imax=Vsmax/Rshunt=0.2594339622641509 / 0.0003
I(full scale current)= 864.77A
overCurrent_A =
(objSets->overCurrent_A > objSets->maxPeakCurrent_A) ?
objSets->maxPeakCurrent_A : objSets->overCurrent_A;
USER_MOTOR1_OVER_CURRENT_A = 500.0 A
USER_M1_ADC_FULL_SCALE_CURRENT_A = 864.888 A
objSets->maxPeakCurrent_A = 864.888 * 0.475 = 410.82 A
0.475 = safety margin factor
overCurrent_A = min(500 , 410.82)
overCurrent_A = 410.82 A
objSets->currentInv_sf = 4096 / USER_M1_ADC_FULL_SCALE_CURRENT_A;
currentInv_sf=4096/864.888=4.735
cmpValue = overCurrent_A * currentInv_sf;
cmpValue=410.82×4.735≈1944
410.82 A → 1944 ADC counts
You are in three-shunt mode:
USER_M1_IS_OFFSET_CMPSS = (2048+2048+2048)/3 = 2048
dacCMPValH = 2048 + 1944 = 3992
dacCMPValL = 2048 - 1944 = 104
CMPSS_setDACValueHigh(..., 3992);
CMPSS_setDACValueLow (..., 104);
CMPSS is set to trip when: ADC < 104 OR ADC > 3992
