APF100 three-phase four-wire power supply system and electrical control box have been produced and put on the market, for personal reference and learning only, not for commercial use, including all parts and model selection. Active power quality filter, the radiator has undergone finite element analysis, and the product operates stably.
Currently, most of our country adopts a three-phase four-wire low-voltage power supply system, namely a 380V/220V neutral point directly grounded low-voltage power supply system. This power supply system has three phase wires (live wires) A, B, and C, and a neutral wire. The reason it is called a neutral wire is that it is derived from the neutral point on the secondary side of the transformer, which is directly grounded and connected to the zero potential of the earth, thus called the neutral line. In the three-phase four-wire low-voltage power supply system, it serves as both the working neutral wire and the protective neutral wire, now known as the PEN line, where PE is the protective neutral wire, N is the working neutral wire, combined to form the PEN line, indicating the working neutral wire also serves as the protective neutral wire, commonly known as "zero and ground combined."
