Research On Industrial Induction Heating Power Supply And Its Power Regulation Algorithm

Electromagnetic induction heating is an important manufacturing process,which has the advantages of high efficiency,accurate output power control and high performance.It has been widely used in automobile,aviation,home or renewable energy industry.At present,one of the main challenges is that when the induction heating target has complex geometry exposed to magnetic field,the heating is often not uniform enough.Therefore,in order to optimize the heating process,dual frequency induction heating system is usually used as a solution.The dual frequency induction heating mode can heat the target metal workpiece at the same time through two kinds of current with different penetration depth,i.e.medium frequency and high frequency,so that the metal workpiece with irregular structure can be heated evenly.The main research object of this paper is the dual industrial induction heating system.The modular structure of induction heating and the working principle of each component are explained.The different circuit types,three different power regulation models and the dual frequency induction heating modes contained in each module are compared and analyzed.The single inverter synchronous dual frequency induction heating junction based on the rectifier side power regulation is established Construct and optimize the overall module construction scheme.The power regulation based on the power regulation model of rectifier side is mainly realized by three-phase PWM rectifier.In view of the outstanding problems in the application of traditional rectifier control structure,such as poor anti-interference ability and low fault tolerance,combined with the robust control principle,an improved H_?controller is designed.In order to verify the results,the PI controller and the H_?controller are simulated under two starting conditions respectively.The simulation waveforms prove the superiority of the H ?power controller of the rectifier side power regulation model.The inverter module is responsible for the power regulation of industrial induction heating system.In this paper,the basic structure and different working states of the dual frequency induction heating inverter are studied,and the two frequencies in the dual frequency composite resonance circuit,the parameters of the inductance and capacitance elements and the feedback frequency control module are designed.Then,based on thetheoretical analysis and parameter design,an ideal model of single inverter dual frequency resonant inverter structure is established in the MATLAB simulation software.The double frequency current waveform with high frequency is successfully simulated,and the heating of irregular heating plate is further simulated by the finite element method.The result is ideal.Based on the above analysis and simulation,combined with the existing conditions,a small disk coil plate heating element induction heating principle verification device is constructed,and the feasibility of the scheme is verified by the better heating effect.A high-power induction heating test-bed with meter level induction heating coil is designed and manufactured,including the main circuit,digital control board,working power transformer,DC working power module,resonance circuit and heating coil in induction heating load.Finally,the theoretical analysis,simulation research and experimental verification of this subject are summarized,and the corresponding improvement suggestions are put forward for the problems existing in the prototype production.