Temperature Control System Of Medium Frequency Induction Heating Based On Data Drive

The medium frequency induction heating power supply is an important equipment in the heating process of large workpiece,and the quality of the temperature control algorithm in the induction heating process will directly affect the quality of the post-welding stabilization heat treatment of the workpiece.Due to the different shapes and materials of different types of workpieces,the power required for heating and the generated temperature curves are different,so it is difficult to establish an accurate mathematical model.Moreover,the heat treatment process of the workpiece has the characteristics of non-linearity and large lag,and the temperature control effect of the traditional PID method is poor.Therefore,in order to ensure the stability of the temperature control process,an accurate control method must be adopted.In order to solve the problem that the traditional PID can not accurately control the output of the system.Taking the large-diameter thick-walled TP347 pipeline with ?508mm outside diameter and 50.01 mm wall thickness in petrochemical industry as the research object,a PID control method with constant temperature rise is proposed for the temperature control of the pipeline in the process of induction heating and heat treatment.According to the desired process curve,the temperature control process is divided into three stages: two stages are controlled by constant rate of temperature rise,and one is controlled by constant rate of temperature drop.Matlab simulation results show that the system output temperature can track the given curve well by using the PID control method of constant velocity temperature rise,but this method can not solve the system lag problem well,and the overshoot of the system can not meet the technical requirements.Considering the disadvantage of PID Control method to solve the system lag is poor,we proposed a model-free Adaptive Control(MFAC)temperature Control method based on the data-driven concept,which only uses the input and output data of the controlled system to design the controller and generate the temperature change curve.This algorithm can adjust the power of the induction heating power supply according to the temperature change curve,so as to control the temperature change in the process of pipeline heat treatment.The simulation results show that the scheme has good temperature control accuracy and robustness,and the control effect reaches the temperature control system performance index,and it is more suitable for the temperature control system of medium frequency induction heating pipe heat treatment.In addition,in order to verify the rationality of the model-free adaptive control method,a two-dimensional finite element model of the electromagnetic and thermal coupling of the pipeline induction heating was established based on ANSYS software simulation to study the stabilization and heat treatment process of the pipeline under the condition of induction heating.Thermal analysis experiments were carried out for TP347 pipeline materials,and the temperature changes of the pipeline at different times were obtained,which can provide a good reference for subsequent experiments and reduce the actual experiment time.Finally,the temperature control system of medium frequency induction heating using model-free adaptive control method is applied to the production site of pipeline heat treatment.The field experiment results show that this method can improve the temperature control precision,enhance the uniformity of temperature distribution,make the heat treatment meet the requirements of the production process,and the temperature control effect is good.