| In recent years,with the development of the automotive industry,the number of cars owned is increasing,and the automotive maintenance industry is also keeping pace with the times,gradually developing in the direction of intelligence,efficiency,and green.Traditional body component repair techniques have gradually been replaced by new dent repair techniques due to their low efficiency and easy to cause additional damage to body components.New repair technologies often use thermal correction to repair vehicle body components,and the selection of heating methods directly affects the efficiency and quality of repair.Due to its advantages of high efficiency,intelligence,and green,induction heating technology has gradually become an important heating method in the field of vehicle body component repair.Based on the development project of the electromagnetic induction heating system for vehicle body parts,this paper studies the control methods and load characteristics of the high-frequency electromagnetic induction heating system for vehicle body parts during vehicle body repair.A series resonant induction heating power supply design scheme for vehicle body parts auxiliary heating is proposed,and the entire system is divided into two parts: the main working circuit and the control circuit.According to the requirements of induction heating power supply for vehicle body component heating,corresponding functional modules are designed and system hardware parameters are designed.The effectiveness of the control method is verified by establishing an electromagnetic induction heating experimental platform.The main research contents of this article are as follows:(1)Firstly,the basic principle and characteristics of electromagnetic induction heating technology were analyzed.An equivalent circuit model was established based on the structure of the load inductor,and the equivalent resistance and inductance of the system load at different frequencies were measured through experiments.Then,the input and output characteristics of two types of half bridge series resonant inverters were obtained through theoretical analysis and simulation analysis.By comparative analysis,the Class II half bridge series resonant inverter circuit was selected as the main circuit of the electromagnetic induction heating device developed in this paper.(2)According to the system performance requirements,parameter designs were carried out for the power circuit and control circuit,and the work of selecting components were finished.The power module includes power filter circuit,rectifier filter circuit,half bridge series resonant inverter circuit and the load inductor.The control circuit includes system control circuit,sampling and protection circuit,IGBT drive signal transmission control circuit and LCD display circuit.(3)The output power of the electromagnetic induction heating system was control by pulse density modulation and pulse frequency modulation.In response to the disadvantage of poor power regulation ability in the low power range of the pulse frequency modulation,the two regulation methods were combined to jointly control the output power of the system.This not only improved the power regulation ability of the system,but also improved the efficiency of the system.Finally,simulation was conducted in MATLAB/Simulink simulation model to verify the rationality of the power regulation method.(4)Finally,an experimental platform for electromagnetic induction heating was built and various functional modules were tested.The LCD display,overcurrent protection,over temperature protection,and IGBT drive signal transmission control functions met the design expectations.Then,by comparing the simulation waveform and experimental test waveform of the load current and the voltage across the lower tube,it was verified that the simulation analysis results of the induction heating device were consistent with the experimental analysis results.The correctness of pulse density modulation and pulse frequency modulation were verified on the electromagnetic induction heating experimental platform.By measuring the temperature changes of vehicle body components before and after heating,it was shown that the electromagnetic induction heating device developed in this paper can complete the task of auxiliary heating of vehicle body components. |
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