Hello,
Although I could collect the grid-side voltage during the grid-connected experiment, I have always had a doubt. During the grid-connected experiment, the grid-side relay is connected to the three-phase voltage of the grid, and the N-phase relay is not connected, and the N-phase relay remains disconnected during the experiment. When collecting the grid-side phase voltage, N is still used as the negative side of the voltage. Why can I still collect voltage when collecting voltage? I checked some information. The three-phase four-wire topology uses a three-phase three-wire connection on the grid side. When the N-phase is not connected, when collecting voltage, the line voltage is usually collected, and then Line-to-phase conversion results in a line grid. I hope your company's engineers can help me explain why it is possible to directly collect phase voltages without connecting the N phases.
Sorry for replying to your message so late. What is shown in the picture is how I have the actual hardware connected, in your reply it is N connected to a common point similar to a three phase load, but in my type of connection the grid is three phase A, B, C. Would a virtual neutral point be constructed in this case?