单相AC-DC变换电路设计

The Design of a Single-Phase AC-DC Converter Circuit

针对当前基于变压器的ACDC开关电源很难进一步提高电源转换效率的问题,设计了一个新型的变换电路.本次设计的单相AC-DC变换电路结合了功率因素测量和补偿电路,通过单片机控制系统实现AC-DC的高效转换.理想二极管桥控制器LT4320与高效开关稳压控制器LTC3789实现24V的交流输入到36V的直流输出,通过Atmega128单片机控制系统结合基于比较器LM393的功率因素测量电路,完成电源功率因数的测量与补偿;另外,以导通电阻为15mΩ的N型MOSFET作为功率器件,最大限度地提高了电源的转换效率.本设计方案优于传统的基于变压器的AC-DC变换,具有转换效率高、应用性强和设计方案完善等特点.

Taking into consideration the fact that it is difficult to further improve the power conversion effi‐ciency with the current AC‐DC switching power supply based on the transformer ,a new type of AC‐DC conversion circuit is designed in the present study .A single‐phase AC‐DC conversion circuit designed by us combines the power factor measurement with compensation circuit and realizes highly efficient AC ‐DC con‐version through the MCU (Microcontroller Unit)control system .The ideal diode bridge controller LT 4320 and the efficient switching regulator controller LTC 3789 realize the conversion of 36V AC input to 24 DC output .Through the Atmega128 MCU control system combined with the measurement circuit of power factor which is based on the comparator LM393 ,the measurement and compensation of the power factor are accomplished .In addition ,by using the N M OSFET with 15 m Ω's resistance as the power device ,the efficiency of the switching power supply is improved .This design has advantages over the traditional trans‐former‐based AC‐DC conversion circuit by its high conversion efficiency ,strong applicability and good de‐sign plan .