Tool/software:
We have been using TI’s 28379D controller for UPS application, facing issue in 12 pulse SCR controlled rectifier bridge, getting current spike in R-phase positive leg and B–phase negative leg in steady state condition,
DC bus voltage also increased momentarily.
We have used the TI’s PLL code for ZCD detection. If we can get the example code for 12 pulse phase-controlled rectifier that would be very helpful.
GPIO used for SCR firing pulses
for Delta bridge without phase shift
R-Phase Upper Positive Leg ----> GPIO4
R-Phase Lower Negative Leg ----> GPIO5
Y-Phase Upper Positive Leg ----> GPIO6
Y-Phase Lower Negative Leg ----> GPIO7
B-Phase Upper Positive Leg ----> GPIO8
B-Phase Lower Negative Leg ----> GPIO9
for star bridge with phase shift
R-Phase Upper Positive Leg ----> GPIO36
R-Phase Lower Negative Leg ----> GPIO37
Y-Phase Upper Positive Leg ----> GPIO38
Y-Phase Lower Negative Leg ----> GPIO39
B-Phase Upper Positive Leg ----> GPIO40
B-Phase Lower Negative Leg ----> GPIO41
Frequency of 12 pulse SCR controlled rectifier control loop execution is 158 microseconds and its sequence is
- ADC Sampling
- PLL
- Alpha Calculation
- SCR Triggering Logic
