Improvement And Research On Single-Phase Power Factor Correction System

With the sustainable development of power electronics technology, rectification device has been popular applicated, making a large number of non-linear element being accessed to the grid, thus the harmonic pollution problem of public grid is particularly prominent. While traditional passive compensation technology has a certain effect in increasing power factor and reducing input harmonic, but it is a passive and less effective compensation, the power quality can no longer meet the high requirements of modern power system. Active Power Factor Correction (APFC) technology and its technical improvement which has been studied in this paper is an active and effective method in essentially solving the above problems.The structure topology of traditional Single-phase Boost PFC has been deeply analyzed, and the design principle of inductor and capacitor is proposed. The mathematical model in inductor Continous Current Mode (CCM) and Discontinous Current Mode (DCM) is established by the state-space averaging method. For double loop average current control in CCM and single loop voltage control in DCM, the control parameters are setted from the view point of crossing frequency and phase margin based on automatic control principle. The theory is verified by simulation experiment under the environment of Matlab/Simulink.The topology of parallel interleaved Boost PFC has been studied. The improvement principle of interleaved strcture in the aspect of reducing inductor current ripple and improving the power grade of converter has been comprehensively analyzed. The mathematical model is established by the state-space averaging method, and the corresponding control strategy is verified by simulation. The differences and characteristics between interleaved Boost PFC and conventional Boost PFC are analyzed by comparison in terms of inductor design, capacitor RMS current, and critical state into the DCM. The simulation verification seems that the parallel interleaved structure can be uesd well in high power applications.The structure of bridgeless Boost PFC which ellipsis the rectifier bridge has been investigated. The whole power loss of converter is evaluated quantitatively by analysising the loss process of semiconductor device. The bridgeless intreleaved Boost PFC is proposed combined advantages of bridgeless Boost PFC and interleaved Boost PFC. Comprehensively comparison is analyzed in terms of converter loss, total harmonic distortion (THD) and power factor (PF), the result shows that the bridgeless intreleaved Boost PFC has advantages in efficiency improvement and harmonic decrease. The above provides an improvement direction for single-phase power factor correction.