Electronic transformer and three-phase four-wire power system thereof

A three-phase four-wire power system, comprising:

• a power supply configured to provide a first-phase power source, a second-phase power source and a third-phase power source, the power supply having a neutral line;
• a load;
• and
• an electronic transformer coupled between the power supply and the load, the electronic transformer comprising:
• a first forward rectifier coupled between the first-phase power source and a first output terminal;
• a second forward rectifier coupled between the second-phase power source and the first output terminal;
• a third forward rectifier coupled between the third-phase power source and the first output terminal;
• and
• a backward rectifier coupled between the neutral line and a second output terminal, wherein each of the first forward rectifier, the second forward rectifier, the third forward rectifier and the backward rectifier comprises 2 to 5 diodes, and any one of the diodes is directly connected in parallel with each of the other diodes;
• wherein the first forward rectifier, the second forward rectifier and the third forward rectifier are configured to perform half-wave rectification on the first-phase power source, the second-phase power source and the third-phase power source to generate a rectified first-phase power source, a rectified second-phase power source and a rectified third-phase power source, and to superpose the rectified first-phase power source, the rectified second-phase power source and the rectified third-phase power source at the first output terminal as an output voltage of the electronic transformer.