Design And Implementation Of Super Audio Frequency Induction Heating Power Supply

With the development of green economy,people's awareness of environmental protection is becoming stronger and stronger.In the metal heat treatment industry,induction heating has gradually replaced traditional heating methods with the characteristics of environmental protection,energy saving and high efficiency,and has been fully applied to quenching,annealing,welding and other processes.Huge demand and strict technological process have put forward higher requirements for the performance of induction heating power supply.This thesis proposes design indicators according to practical application and development trend,and designs a dual ARM-based super audio frequency induction heating power supply.Topology structure is the basis of the design scheme of induction heating power supply.The main circuit design of three-phase uncontrollable rectifier filter circuit and series resonance inverter circuit is determined by studying and comparing the main circuit of induction heating power supply.Then the circuit parameters are calculated according to the design criteria to obtain the selection parameters of power devices.Control strategy is the core of the design scheme of induction heating power supply.The power regulation methods of induction heating power supply are studied and compared.Pulse phase shift power regulation is selected in combination with the main circuit structure,and its power regulation status is analyzed in detail.The scheme is verified by Simulink simulation.In order to solve the problem of load circuit parameter change during heating process,a scheme of resonance frequency tracking is designed by using zero-crossing synchronization technology,which achieves the dynamic tracking of resonance frequency.To solve the problem of frequent start-up and shutdown of induction heating power supply,a fast start scheme is designed by using the automatic identification algorithm of resonance frequency,which greatly reduces the start-up time.To solve the output control problem in complex environment,three output control modes,constant current,constant power and constant temperature,are designed using optimized PI algorithm,which achieves accurate,fast and flexible output control.The main control circuit is the key point in the design scheme of induction heating power supply.According to the design index,the control chip is selected and the design scheme of dual ARM main control circuit is determined.On the hardware side,the circuit design of the main ARM and the auxiliary ARM is completed,and the PCB is drawn.On the software side,pulse phase shifting power regulation is implemented according to the PWM generation principle of HRTIM,and the control program is developed and designed on the basis of Free RTOS according to the design scheme of control strategy.In order to achieve smart human-computer interaction,the configuration touch screen is used to complete the design of the human-computer interaction screen.Finally,the prototype of induction heating power supply is assembled according to the design scheme,and an experimental platform is built by connecting the load.On this experimental platform,experiments such as PWM output,fast start,output adjustment are carried out.The experimental results verify the reliability and accuracy of the design scheme in this thesis.