Hi, I'm using LaunchXL-F28069 (Piccolo Series) TI dsp board to develop a inverter. Though it is an inverter my primary application is to used it in rectification mode. To do the synchronization with AC grid I'm trying to use a Phase-lock loop. The tentative control structure is based as follows.
I read Va, Vb, Vc voltages from grid.
Convert them into alpha-beta using Clark transformation.
Transformation was developed using fundamentals. The transformation block in SolidThinking Embed contains only two inputs and it doesn't work in my desing due to imbalance voltage.)
Alpha-beta convert to DQ0 quantities.
To do this I used fundamental equations and I manually developed a PLL as shown in the attached file.
To operate in the rectification mode I need to add an additional phase angle to output theta before generate PWM.
However when I powered the inverter there is a phase fault occurs. (High current flow from input (AC) and no current in output (DC) ). I think the problem is with PLL. I'm looking for a good reference of PLL development. Therefore I would like to seek any help from anyone who developed this kind of setup.