Research On Interleaved Boost PFC Converter With Coupled Inductors

With the rapid development of Power Electronics, the problem of harmonic pollution has received more and more attention. As an important component of Power Electronics technology, Power Factor Correction (PFC) is an effective way to restrain harmonic pollution produced by Power Electronics devices and has been used in more and more application field.With the increase of the power rating, the traditional Boost PFC circuit is restricted gradually. By using the interleaved converters technique, voltage and current stress of switches can be decreased. Interleaved boost converters can also reduce input current ripple and the switching losses, so it's very suitable for high-power applications. In order to further reduce the losses, three soft switching topologies for interleaved Boost PFC are analyzed in this paper. On this basis, an interleaved boost converter with coupled inductors is used as the main circuit topology, which has the advantages of operating in both continuous current mode (CCM) and discontinuous current mode (DCM). By using this topology, zero reverse-recovery loss of boost diodes and zero current turn-on of switches can be achieved, and also current sharing between the two cells of the converter can be achieved automatically even in the presence of duty cycle mismatch, resulting in higher efficiency and lower costs.In this paper, the control scheme uses average current control method and through frequency dividing circuit to achieve interleaving control. After design the parameters in detail, establishing the overall simulation platform by using Pspice software and then building a prototype based on the control chip UC3854A. The simulated and experimental results has verified the correctness of the system.In the field of PFC control, analog control is the selection of industries, while the digital control is the future direction of development. Therefore, the system simulation of digital control is given in the last chapter of this article. The simplified small-signal model of the system has been built based on average current control. The duty cycle feedforward loop has been added into the normal current loop to eliminate crossover distortion, and a digital notch filter has been added into the voltage loop to filter the the second harmonic of feedback voltage. The simulation model of the digital control system has been established by using Matlab/simulink. An ideal effect has been obtained through simulating and proves that the theory is feasible.