Design And Implementation Of LLC Resonant Charging Module Based On STM32

In recent years,the economies of various countries have developed rapidly,and the global automobile ownership has shown a rapid upward trend.The environmental pollution caused by traditional fuel vehicles and the excessive consumption of non-renewable energy are also becoming more and more serious.As people’s environmental protection calls become stronger,new energy vehicles are born.As one of the important components of electric vehicles,the charging module directly affects the use and popularity of electric vehicles.Therefore,developing a high-performance electric vehicle charging device is of great significance to promote the development of electric vehicles.The LLC resonant circuit can achieve high efficiency density of soft switching,and its small size and low electromagnetic interference are very suitable as the main power module for electric vehicle charging.Therefore,the design of the main power module of this paper uses a half-bridge LLC resonant circuit.Firstly,the working principle of the half-bridge LLC resonant circuit is analyzed.The LLC circuit model is established by the fundamental analysis method(FHA),and its characteristics are analyzed in depth.Combined with the actual requirements of this subject,the parameters of the LLC resonant converter are determined by calculation,and the device selection is completed based on the parameter design.At the same time,using the magnetic integration idea,the magnetic integrated transformer is designed,which greatly reduces the volume and weight of the converter and ensures that it can achieve high power density transmission.The feasibility of the parameters was verified by.PSIM simulation software.Secondly,the extended resonance function method is used to model the small-signal resonant circuit of the LLC resonant circuit.Based on the small-signal model,the dynamic characteristics and Bode plots of the small-signal model are analyzed,and the compensator of the LLC resonant converter is designed.With the digital development trend of power electronic equipment,digital control scheme is adopted in the control strategy.In view of the lack of single-loop design of LLC charging module,this paper adopts PI double closed-loop control to realize stable closed-loop control of resonant circuit.The closed-loop system of half-bridge LLC resonant converter is built by using PSIM software.By simulating the steady-state performance,dynamic performance and charging performance of the converter,the converter designed in this paper has improved stability and anti-interference.The correctness and effectiveness of the control loop design was verified.Finally,this paper designs and produces a 550W prototype,and gives the experimental results and waveform through the experimental platform.It verifies the feasibility and correctness of theoretical analysis and simulation.