AC/DC conversion is to convert AC to DC, and its power flow direction can be bidirectional. The power flow from the power supply to the load is called “rectification”, and the power flow is returned to the power supply by the load called “active inverter”. AC/DC converter input is 50/60Hz AC, because it must be rectified and filtered, so the relatively large size of the filter capacitor is essential, and at the same time due to safety standards (such as UL, CCEE, etc.) and EMC directives Restrictions (such as IEC, FCC, CSA), EMC input must be added to the AC input side and components that comply with safety standards are used, which limits the miniaturization of the AC/DC power supply. In addition, due to internal high frequency, high voltage, and high current. The switching action makes it more difficult to solve the EMC electromagnetic compatibility problem, and it also puts high requirements on the internal high-density installation circuit design. For the same reason, the high voltage and high current switch make the power consumption of the power supply increase, which limits the AC. /DC converter modular process, so the power system optimization design method must be used to achieve a certain degree of satisfaction with the work efficiency.
AC/DC conversion can be divided into half-wave circuits and full-wave circuits according to the wiring mode of the circuit. According to the number of power phases, it can be divided into single, three-phase and multi-phase. According to the working quadrant of the circuit, it can be divided into one quadrant, two quadrants, three quadrants and four quadrants.