Research On Interleaved Totem-pole Bridgeless PFC Converter Based On SiC Device

As the front stage of the power system,the performance of PFC is related to the entire power converter.There are many topological structures of PFC,and totem-pole bridgeless PFC has become a research focus in recent years.Totem-pole bridgeless PFC uses the least components and has better EMI characteristics.There are only one high-frequency switch and one low-frequency switch in the current flow path during operation,which helps to improve efficiency.The third-generation wide-bandgap semiconductor device SiCMOSFET has excellent performance when used in continuous conduction mode totem-pole bridgeless PFC due to its low on-resistance and good body diode reverse recovery.In order to reduce the input current ripple and achieve power sharing to expand the power level of the entire converter.The CCM mode interleaved totem-pole bridgeless PFC converter based on SiC devices is designed,and the hardware circuit design and software program design are completed,the theoretical efficiency is calculated and the performance difference of inductors made with different magnetic cores is compared.the rationality of the parameter design and the feasibility of the control strategy were verified by PSIM simulation,and a 4.4k W interleaved totem-pole bridgeless PFC test prototype was built.The performance of single-channel totem-pole bridgeless PFC and interleaved totem-pole PFC converters were tested when the switching frequency of SiC-MOSFET is 100 k Hz.And a detailed analysis of the SiC-MOSFET gate oscillation problem in the bridge circuit is carried out.The Quasi-PR Controller can achieve no static difference following the AC given current.Adding feedforward compensation to the control and using the Quasi-PR Controller can enhance the response speed of the system,improve the followability of the inductor current to a given current,and reduce the input current zero-crossing distortion.Based on PLECS,the main circuit and a control simulation with feedforward compensation of interleaved totem-pole bridgeless PFC are constructed to make it work in CCM mode.The inverter mode is expanded for the interleaved parallel totem pole bridgeless PFC circuit,so as to improve the utilization rate of the converter through bidirectional conversion.Through the PLECS software,the AC grid-connected and AC load-powered interleaved totem-pole main circuit and control loop simulation are built.The key simulation waveforms in different modes are given.