Study On Three-phase Digital PFC Rectifier Circuit With PFM

In the modern manufacturing industry,large-scale equipment needs more and more high-quality and reliable power supply.The traditional switching power and linear power supply have shortcomings so that the system efficiency is poor,low power factor,harmonic distortion,ripple seriously.In the use of such power supply,we usually need to add the capacitive filter in the power rectifier output,and this measure intermittent will lead to short-term current spikes,so that the output current can’t be synchronized with the voltage,which requires high-precision Production equipment,the normal operation of a serious impact,has been unable to meet the needs of practical applications.Especially in high-power applications,such problems become more prominent.In view of this problem,in recent years,there are a lot of research theory and solutions,has become a power electronic technology industry research hot spots.In this paper,based on the analysis and comparison of the topology and control methods of the existing rectifier technology,a pulse frequency modulation rectification technology is proposed,which is a PFC circuit technology which adopts full digital PFM modulation to realize high power factor.Based on the basic principle of voltage-based PFC circuit topology,digital phase-locked loop theory and modulation rectification control theory,this paper expatiates on the hardware and software platform of the system,the principle of functional module,Debugging,the final test of the key parameters of the waveform and record test data.Through the data analysis,the feasibility and reliability of the scheme are verified.This results of test show that the total system power capacity is 15 KW.The output voltage is 750 V,the maximum output current is 20 A,the system efficiency is about 95.7%,the power factor correction is 0.99,total current harmonic is 2.11%,which accords with the expected design target.