Research And Design Of 3kW Vehicle High-Frequency Inverter Power Supply

With the popularization of automobiles and the development of technology,cars nowadays are not just a means of transportation,but their functions and configurations are showing a trend of diversification.More and more electrical equipment is configured on cars,such as car refrigerators,car televisions,induction cookers,electric kettles,etc.These devices all require 220V/50 Hz AC power supply,but currently cars can only provide 12 V DC power through on-board batteries.Therefore,it is necessary to design a reliable,safe and efficient on-vehicle inverter power supply.This article focuses on the common problems of low power,low efficiency,and insufficient anti-interference ability of existing vehicle mounted inverters.A 3k W vehicle mounted high-frequency inverter power supply is studied and designed.The main research content of this article includes:(1)Research and design the topology of a 3kW vehicle highfrequency inverter power supply system.Firstly,based on the development trend of on-board inverter power supply,a two-stage topology is selected as the overall solution of the system,which includes the DC-DC boost link and the DC-AC inverter link.Then,according to the design requirements,the topology structures of the boost and inverter links are selected separately.Finally,the push pull circuit was chosen as the topology structure of the boost circuit,and in order to reduce the current borne by a single switch and reduce circuit operating losses,the front stage of the boost circuit used two push pull circuits in parallel,and the boost rectifier part used a half bridge circuit for synchronous rectification;To meet the requirements of efficient operation and high-power transmission,a full bridge circuit is selected as the topology structure of the inverter link.Finally,the principles of the push-pull circuit and the full bridge circuit were analyzed separately,laying the foundation for the next step of hardware design and device selection.(2)Design and select the hardware of the inverter power supply system.The hardware of the inverter power supply system is divided into the main circuit and the control circuit,with the main circuit responsible for energy transfer and the control circuit responsible for monitoring and controlling the entire system.Based on the topology structure and design indicators of the system,design and select the main components in the main circuit,including high-frequency transformers in the push-pull circuit,power transistors in various circuit topologies,and output filtering devices.Finally,according to the needs of the main circuit,the control circuit is designed,which mainly includes signal acquisition circuit,power transistor drive circuit,and auxiliary power supply circuit.(3)In response to the poor robustness and dynamic characteristics of traditional inverter power supply systems,a control scheme for the system was studied and designed.In order to stabilize the output voltage,a voltage closed-loop PI control is adopted in the DC-DC boost stage,and for the problem of poor dynamic performance of traditional control of inverter circuit,Sliding mode control is used in the inverter link to improve the robustness and dynamic characteristics of inverter power supply system.Afterwards,a model was built on the MATLAB/Simulink simulation platform,and the simulation results showed the effectiveness of the control strategy.Finally,design the system software based on the control strategy.(4)To verify the design scheme of this article,a prototype was built using STM32F407ZGT6 as the main control chip for experimental research.The experimental results indicate that the 3k W vehicle highfrequency inverter power designed in this article meets the design requirements.