Research On The AC-AC Converter Based On The Switched-capacitor

Switched-Capacitor converters mainly composed of switches andcapacitors, would achieve voltage conversion and energy conversion. It is atypical non-inductive converter, with advantage of small size, light weight,high power density, etc. The application prospects of Switched-CapacitorAC-AC converter will be very broad with the miniaturization of electronicdevices development.This paper proposes a novel AC-AC converter based on the principle ofSwitched-Capacitor, which can achieve the AC voltage conversions with aratio of1/4or4. The circuit topology is designed and a detailed analysis ofthe working principle is given. To study the efficiency of the converter, thispaper simplifies the Switched-Capacitor circuit topology into basic units, anddeduced equivalent resistance expression with the use of first-order circuitfull response principles. And also the calculation formula of other majorcircuit parameters, including equivalent capacitance, loss of power switch,the converter efficiency. According to its efficiency expressions, this paperdiscusses several ways to improve the efficiency of the converter, andprovides a theoretical basis to choose the main circuit parameters. Based onthe theoretical analysis, a simulation model of the circuit topology isdesigned, and respectively Buck and Boost simulation analysis. The resultsdemonstrate the effectiveness of the topology.Finally, based on the theoretical analysis and the simulation results, a500W220V/55V switching frequency of50kHz prototype is designed. In aBuck experiments, the input voltage is220V, the no-load output voltage ofthe converter is55.5V, and the output voltage can be kept stable when theload are the resistive, capacitive load. Its efficiency up to88.63%; In theBoost experiments, the input voltage is55V, the no-load output voltage of theconverter is219.3V. The maximum efficiency is90.69%. The experimentalresults verify the good performance of the converter.