Research On Control Strategy Of Bridgeless Boost PFC Converter

With the accelerating process of industrial intelligence,power electronic equipment is widely used in various fields of social production,which provides many conveniences for our lives.However,a series of problems such as harmonic pollution and power quality degradation cannot be underestimated.The emergence of bridgeless topology makes the more efficient PFC possible,and the digital controller is widely used for its precise control and easy algorithm update.This paper focuses on the research of bridgeless PFC digital control algoritlhm and does the following work.The bridgeless PFC is derived from the Boost topology.Firstly,the evolution and working principle of the bridgeless PFC are introduced.Then the complete small signal model is derived.According to the small signal model,the CCM mode average current control algorithm is given.Complete derivation process.At the same time,in order to make the system have a larger working range,a predictive current control algorithm with smaller computational complexity and working in both CCM and DCM modes is studied.The derivation process of the two mode control algorithms is detailed.Discussed and finally implemented on a bridgeless PFC.The trwo control algorithms are built into the circuit simulation model in MATLAB/simulink.The simulation shows that the predictive current algorithm shows better control effect than the average current algorithm in the start-up phase and the light-load phase.And design a 400W prototype,the two algorithms are implemented by DSP28335 respectively,the design process of the whole circuit is introduced in detail,the prototype shows that the prediction current algorithm is better than the average current algorithm in the control effect,the experimental results and simulation basic Consistent.