Study On The Application Of Active Floating Charge Landing In Single Phase Active Power Factor Correction Converter

With the rapid development of computer and internet's technology, the information dealt by CPU becomes more and more, and the current working for CPU also becomes larger and larger. At the same time, in order to reduce the energy loss, the input voltage should be lower and lower. The CPU's current will be larger than 100A, but the voltage will be lower than 1V in the future. Low voltage but large current output is the necessary development trend. It needs multilevel converters to transform the 400V which outputted by Boost APFC to 1V which needed by CPU. In this way, not only the circuit will become very complex, but the efficiency also won't be ensured. So it is very necessary to reduce the output voltage of Boost APFC.This paper researched the application of AFCL in single phase Boost APFC. It can reduce the output voltage from traditional 400V to 200V, this will be benefit to the design of the follow DC-DC converter. Double frequency converter technology can improve the performance of the system, at the same time, it also can improve the efficiency. This paper constructed a double frequency AFCL, and applied it in Boost APFC, which can slove the efficiency problem caused by the AFCL.First of all, this paper introduced the development of APFC and double frequency converter and expatiated the purpose and significance of the research of Boost APFC with AFCL, and analyzed the reason why the output voltage of traditional Boost APFC usually controlled at 400V. This paper also explained the switch loss and output voltage ripple of Boost APFC. Then this paper analyzed different topologies of Boost APFC with AFCL, putted forward two topologies'small-signal ac model and output voltage ripple's expression, and then controlled the topology whose output grounded with leading-edge modulation one-cycle control and charge control. This paper constructed the double frequency AFCL, and applied it in Boost APFC, analyzed the working principle of the Boost APFC with double frequency AFCL, and researched its control method. On the other hand, this paper also researched the double frequency Boost APFC with single frequency AFCL and double frequency Boost APFC with double frequency AFCL topologies. At last, this paper designed the parameters of main circuit of the Boost APFC with single and double frequency AFCL, then the simulation of the two converters were carried out in Saber, the proposed theory and circuit were verified by simulation results.