Single-Phase, 240 Vrms, 3500 W Transformerless Grid-Connected PV Array

In one of the examples "Single-Phase, 240 Vrms, 3500 W Transformerless Grid-Connected PV Array", single phase ac current waveform is converted into dq transform. What is the method used for the tranformation. I have attached diagram with this question.

Answer 1

[Sabin]

That's a Clarke to Park Angle Transform. The measured current is the alpha-component and the beta-component is obtained by delaying the measurement. Then, the Clarke to Park Angle Transform is performed. For more information about Clarke to Park Angle Transform see https://mathworks.com/help/sps/ref/clarketoparkangletransform.html